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Worldwide semiconductor market revenue is on track to achieve a 9.4 percent expansion this year, with broad-based growth across multiple chip segments driving the best industry performance since 2010.

Global revenue in 2014 is expected to total $353.2 billion, up from $322.8 billion in 2013, according to a preliminary estimate from IHS Technology (NYSE: IHS). The nearly double-digit-percentage increase follows respectable growth of 6.4 percent in 2013, a decline of more than 2.0 percent in 2012 and a marginal increase of 1.0 percent in 2011. The performance in 2014 represents the highest rate of annual growth since the 33 percent boom of 2010.

“This is the healthiest the semiconductor business has been in many years, not only in light of the overall growth, but also because of the broad-based nature of the market expansion,” said Dale Ford, vice president and chief analyst at IHS Technology. “While the upswing in 2013 was almost entirely driven by growth in a few specific memory segments, the rise in 2014 is built on a widespread increase in demand for a variety of different types of chips. Because of this, nearly all semiconductor suppliers can enjoy good cheer as they enter the 2014 holiday season.”

More information on this topic can be found in the latest release of the Competitive Landscaping Tool from the Semiconductors & Components service at IHS.

Widespread growth

Of the 28 key sub-segments of the semiconductor market tracked by IHS, 22 are expected to expand in 2014. In contrast, only 12 sub-segments of the semiconductor industry grew in 2013.

Last year, the key drivers of the growth of the semiconductor market were dynamic random access memory (DRAM) and data flash memory. These two memory segments together grew by more than 30 percent while the rest of the market only expanded by 1.5 percent.

This year, the combined revenue for DRAM and data flash memory is projected to rise about 20 percent. However, growth in the rest of the market will swell by 6.7 percent to support the overall market increase of 9.4 percent.

In 2013, only eight semiconductor sub-segments grew by 5 percent or more and only three achieved double-digit growth. In 2014, over half of all the sub-segments—i.e., 15—will grow by more than 5 percent and eight markets will grow by double-digit percentages.

This pervasive growth is delivering general benefits to semiconductor suppliers, with 70 percent of chipmakers expected to enjoy revenue growth this year, up from 53 percent in 2013.

The figure below presents the growth of the DRAM and data flash segments compared to the rest of the semiconductor market in 2013 and 2014.

2014-12-18_Semi_Sectors_Growth

Semiconductor successes

The two market segments enjoying the strongest and most consistent growth in the last two years are DRAM and light-emitting diodes (LEDs). DRAM revenue will climb 33 percent for two years in a row in 2013 and 2014. This follows often strong declines in DRAM revenue in five of the last six years.

The LED market is expected to grow by more than 11 percent in 2014. This continues an unbroken period of growth for LED revenues stretching back at least 13 years.

Major turnarounds are occurring in the analog, discrete and microprocessor markets as they will swing from declines to strong growth in every sub-segment. Most segments will see their growth improve by more than 10 percent, compared to the declines experienced in 2013.

Furthermore, programmable logic device (PLD) and digital signal processor (DSP) application-specific integrated circuits (ASICs) will experience dramatic improvements in growth. PLD revenue in 2014 will grow by 10.2 percent compared to 2.1 percent in 2013, and DSP ASICs will rise by 3.8 percent compared to a 31.9 percent collapse in 2013.

Moving on up

Among the top 20 semiconductor suppliers, MediaTek and Avago Technologies attained the largest revenue growth and rise in the rankings in 2014. Both companies benefited from significant acquisitions.

MediaTek is expected to jump up five places to the 10th rank and become the first semiconductor company headquartered in Taiwan to break into the Top 10. Avago Technologies is projected to jump up eight positions in the rankings to No. 15.

The strongest growth by a semiconductor company based purely on organic revenue increase is expected to be achieved by SK Hynix, with projected growth of nearly 23 percent.

No. 13-ranked Infineon has announced its plan to acquire International Rectifier. If that acquisition is finalized in 2014 the combined companies would jump to No. 10 in the overall rankings and enjoy 16 percent combined growth.

The table below presents the preliminary IHS ranking of the world’s top 20 semiconductor suppliers in 2013 and 2014 based on revenue.

2014-12-18_Semi_Ranking_Final

Troubles for consumer electronics and Japan

Semiconductor revenue in 2014 will grow in five of the six major semiconductor application end markets, i.e. data processing, wired communications, wireless communications, automotive electronics and industrial electronics. The only market segment experiencing a decline will be consumer electronics. Revenue will expand by double-digit percentages in four of the six markets.

Japan continues to struggle, and is the only worldwide region that will see a decline in semiconductor revenues this year. The other three geographies—Asia-Pacific, the Americas and the Europe, Middle East and Africa (EMEA) region—will see healthy growth. The world will be led by led by Asia-Pacific which will post an expected revenue increase of 12.5 percent.

The case is made for delivering liquid precursors from a central delivery system to the epi/dep tool as a vapor of precisely-controlled composition. 

By EGBERT WOELK, Ph.D., Dow Electronic Materials, North Andover, MA, USA and ROGER LOO, Ph.D., imec, Leuven, Belgium 

The epi and deposition processes for silicon-based semiconductor devices have used gaseous and liquid precursors. Gaseous precursors are compounds whose vapor pressure at room temperature is higher than 1500 torr (2000 mbar), which is sufficient to drive a mass flow controller (MFC). Using only one MFC, gaseous precursors can conveniently be metered to the process. Silane and dichlorosilane (DCS) have been used with that method. The industry has also used Trichloro silane (TCS) that boils at around 33°C and can be directly metered to a low pressure epi process using an appropriate MFC. For the epi of SiGe, germane, which is a gas, has been used.

Tetraethylorthosilicate (TEOS) has long been used for the deposition of SiO2 and has mostly been delivered using direct liquid injection (DLI). DLI meters the flow of the liquid precursor to a flash evaporator and provides good control, but flash evaporation requires high temperatures and care must be taken that the precursor compound does not break up prematurely. This can be a challenge for precursors that work at lower deposition temperatures.

More recently, trisilane (Si3H8) has been used for low temperature Si epi and deposition. The delivery of trisilane to the process uses the carrier-gas-assisted delivery method. In the most common implementation, it employs an on-board evaporation ampoule dedicated to one reactor. The same setup has been used for III-V compound semiconductor and LED epi with good success. Driven by cost pressure, however, the LED epi industry is moving from dedicated onboard ampoules to a central delivery system for high-volume precursors like trimethylgallium (TMGa). One part of the cost reduction simply comes from the economies of scale. Another aspect comes from the elimination of excessive hardware, such as thermal baths and pressure controllers, and their maintenance. Most importantly, a substantial part of the cost reduction comes from yield increases due to improved process control. The same central delivery system can be used for trisilane and other liquid CVD precursors for silicon-based CVD for similar cost reduction.

Carrier-gas-assisted precursor delivery

Liquid compounds with an RT vapor pressure between 1 and 400 mbar require carrier-gas-assisted delivery. Many liquid compounds within that vapor pressure range are excellent precursors for CVD and epi processes. For such compounds, the difference between the vapor pressure and the process pressure is too small to drive an MFC for straight metering. Adding a carrier gas increases the pressure to between approximately 760 and 1500 torr (1000 and 2000 mbar). The selection of a good delivery pressure depends primarily on the desired concentration.

The carrier-gas-assisted delivery method has long been used for trimethylgallium (TMGa) and trimethylaluminium (TMAl) for the growth of GaAs and GaN. For the growth of GaAlN and GaInN for LEDs, the composition ratio of the two group III precursors is extremely critical for the performance of the final product. Therefore, the precision of the evaporation and the metering has always been a concern.

FIGURE 1a shows the setup for a straight gas delivery and FIGURE 1b shows the setup for a carrier-gas-assisted delivery. The design shown in Figure 1b requires no modification of the epi/dep tool in order to accept a normally liquid precursor. From an epi/ dep tool perspective, the design shown in Figure 1b behaves just like the straight gas delivery of Figure 1a. As such, it allows the use of the gas mixture from one delivery system at several points of use, i.e. the output of the delivery system can be subdivided. In Figure 1b the precursor vapor is made on demand. While the output (mol flux of precursor per time) is theoretically unlimited, there are practical limits that restrict the output to approximately 20 standard liters per minute (slm). The main limitation is the dynamic range of the metering valve: the best units have a dynamic range of 1 in 104, which means that they can reliably control a flow between 0.002 and 20 slm. This is important for the mol flux precision at smaller flows, i.e. when only one or two tools draw precursor.

FIGURE 1a. High vapor pressure precursor, straight vapor delivery. S: pressure sensor, V: metering valve. S and V are normally integrated into a pressure regulator. MFC meters neat vapor.

FIGURE 1a. High vapor pressure precursor, straight vapor delivery. S: pressure sensor, V: metering valve. S and V are normally integrated into a pressure regulator. MFC meters neat vapor.

FIGURE 1b. Low vapor pressure precursor, carrier gas assisted delivery in Dow's VAPORSTATIONTM Central Delivery System. S: pressure sensor, V: metering valve. MFC meters diluted precursor vapor. Pressure and temperature control guarantee high precision concentration.

FIGURE 1b. Low vapor pressure precursor, carrier gas assisted delivery in Dow’s VAPORSTATIONTM Central Delivery System. S: pressure sensor, V: metering valve. MFC meters diluted precursor vapor. Pressure and temperature control guarantee high precision concentration.

On-board ampoules and central delivery system

There are several designs of carrier-gas-assisted delivery sources. The traditional design meters carrier gas into the ampoule rather than the mixture into the process chamber. Such a delivery system is dedicated to one reactor because the mass flow is metered upstream of the evaporation vessel and the associated MFC is controlled by the epi/dep tool. The ampoule serves two functions: (1) as the transport vessel and (2) as an evaporation device. For cost reasons, the ampoule should be of simple design. This means that trade-offs for the evaporation performance have to be made. The trade-offs result in line-to-line delivery rate variations and a noticeable change of delivery rate over the life of the ampoule. For some products, such changes require run-to-run recipe adjustments. In some cases the on-board ampoule is connected to a central dispense unit that transfers liquid precursor into the on-board ampoule. The result is a complex system that is still subject to delivery rate shifts requiring recipe adjustments.

A new central delivery system design is shown in Figure 1b. The task-optimized evaporator is fitted with temperature, pressure and level sensors that hold the precursor output variation at less than +/-0.4% by use of special stability algorithms. The evaporator is a permanently-installed part of the central delivery system. It is fed from a supply canister and features two precision thermometers inside the precursor liquid and gas distribution baffles and strainers for entrained droplets. Once calibrated, the system delivers a precisely known rate to a number of epi/dep reactors in the fab.

FIGURE 2 shows the output concentration of two calibrated central delivery units under various loads [1]. The curve that is alternately dotted and solid represents the signal of the binary gas sensor, which was alternately connected to one or the other unit. The other curves represent the output of the two units in standard liters per minute. The results show that proper calibration of the temperature and pressure sensors results in error of the delivery of less than +/- 0.4%. This precision cannot be achieved with ordinary on-board ampoules.

FIGURE 2. Output and concentration of two calibrated VAPORSTATIONTM Central Delivery Systems. Concentration remains within +/- 0.4% of set point regardless of load.

FIGURE 2. Output and concentration of two calibrated VAPORSTATIONTM Central Delivery Systems. Concentration remains within +/- 0.4% of set point regardless of load.

Recently, the application of the VAPORSTATION Central Delivery system has been expanded to deliver SnCl4 to a new process for the deposition of GeSn. It was fitted to a gas delivery line that was available on a mainstream silicon epi tool.

GeSn epi using a SnCl4 as new precursor

There has been increasing interest in GeSn and SiGeSn as alternative Group IV semiconductor material for electrical and optical device applications. The continuing expansion of traditional silicon with Sn and Ge offers additional design options for band gap and stress engineering. Over the past years, stress engineering using Ge made a major contribution to the improvement in Si-CMOS device performance. More recently the use of GeSn as a stressor for Ge-CMOS and relaxed GeSn as a virtual substrate, which is used to create tensile strain in a Ge epitaxial film, have been considered. The creation of tensile strain in an epitaxial Ge film is expected to result in germanium with a direct band gap [5] for photonic devices. Epitaxial Ge1-xSnx itself has also been considered as a promising candidate material for lasers and photodetectors. It has been predicted that, for sufficiently high Sn content, relaxed Ge1-xSnx turns into a direct band gap semiconductor [6,7]. Recent work of imec and its partners describe the active functionality based on the heterogeneous integration of strained GeSn/Ge on a Si platform providing photo-detection in the mid-infrared [8].

Due to the poor solubility of Sn in the Ge matrix of less than 1%, the epitaxial growth of (Si)GeSn is very challenging. Low solubility demands out-of- equilibrium growth conditions and, from epitaxial growth point of view, extremely low growth temperatures. Until recently, GeSn was grown by molecular beam epitaxy — a technique that is not suited for mass production. More recently, deuterated stannane, SnD4 has been used as Sn precursor for a CVD process, but the practical application is questionable due to the instability of SnD4.

To eliminate the problems posed by SnD4, imec chose to investigate stannic chloride SnCl4 , a stable, benign, abundant and commercially-available liquid Sn compound. Currently though, most of the CVD reactors for SiGeSn epi are not designed to use liquid precursor sources. In order to facilitate the use of liquid CVD precursors at imec, Dow Electronic Materials provided an R&D version of the central delivery system. It features the output stability and other benefits described above. The use of one of these units enabled imec to use SnCl4 and develop a groundbreaking new CVD process using digermane (Ge2H6) and SnCl4 to grow GeSn epitaxial films in a production-compatible CVD reactor. The films are metastable GeSn alloys with up to 13% substitutional Sn [10,11].

FIGURE 3 shows a typical cross section transmission electron microscope (TEM) picture with associated (224) x-ray diffraction reciprocal space mapping (XRD RSM) of a fully strained GeSn layer, grown on top of a relaxed Ge virtual substrate. The deposition temperature for the GeSn growth was kept low (320°C) in order to allow Sn incorporation in Ge lattice without Sn precipitation or agglomeration.

FIGURE 3. (a) Cross-section TEM of a 40 nm fully strained defect free GeSn layer on 1 lm Ge/Si buffer substrate with 8% Sn grown with AP- CVD using combination of Ge2H6 and SnCl4. (b) RHEED diagram of the Ge0.92Sn0.08 surface after deoxidation in UHV at 420°C. The pattern exhibits a strong (2x1) surface reconstruction along the [110]Ge direction. (c) (224) XRD-RSM of the 40 nm Ge0.92Sn0.08/Ge bilayer showing that GeSn is fully strained on Ge.

FIGURE 3. (a) Cross-section TEM of a 40 nm fully strained defect free GeSn layer on 1 lm Ge/Si buffer substrate with 8% Sn grown with AP- CVD using combination of Ge2H6 and SnCl4. (b) RHEED diagram of the Ge0.92Sn0.08 surface after deoxidation in UHV at 420°C. The pattern exhibits a strong (2×1) surface reconstruction along the [110]Ge direction. (c) (224) XRD-RSM of the 40 nm Ge0.92Sn0.08/Ge bilayer showing that GeSn is fully strained on Ge.

The TEM picture in Fig. 3(a) exhibits a defect-free and high crystalline quality for the 40-nm-thick GeSn layer. Furthermore, the surface quality of the as-grown Ge0.92Sn0.08/Ge/Si heterostructure was investigated by reflection high-energy electron diffraction (RHEED) analysis after ex-situ transfer to a MBE system. An annealing in ultra-high vacuum up to 420°C resulted in an oxide-free GeSn surface showing a strong (2×1) surface reconstruction as seen on RHEED pattern along the [110] azimuth (Fig. 3(b)). Finally, the XRDRSM around the (2 2 4) Bragg reflections (Fig. 3(c)) demonstrates that the grown GeSn layer is fully strained on Ge/Si (001) substrate.

Conclusion

The use of an improved delivery system for liquid CVD precursors allowed the
use of stannic chloride for the growth of GeSn. The new process developed by imec produces metastable GeSn with concentrations of substitutional tin of 13%.
TM Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow.

References

1. Control of vapor feed from liquid precursors to the OMVPE process, E. Woelk, R. DiCarlo, Journal of Crystal Growth, Available online 29 October 2013, In Press, Corrected Proof.
2. p and n-type germanium layers grown using iso-butyl germane in a III-V metal-organic vapor phase epitaxy reactor, R. Jakomin, G. Beaudoin, N. Gogneau, B. Lamare, L. Largeau, O. Mauguin, I. Sagnes, Thin Solid Films, 519, (2011), 4186–4191.
3. Crystalline Properties and Strain Relaxation Mechanism of CVD Grown GeSn, F. Gencarelli, B. Vincent, J. Demeule- meester, A. Vantomme, A. Moussa, A. Franquet, A. Kumar, H. Bender, J. Meersschaut, W. Vandervorst, R. Loo, M. Caymax, K. Temst, M. Heyns, ECS Trans. 50, (2013), 875-883.
4. Antimony surfactant for epitaxial growth of SiGe buffer layers at high deposition temperatures. Storck, P.; Vorder- westner, M.; Kondratyev, A.; Talalaev, R.; Amamchyan, A.; Woelk, E. Thin Solid Films vol. 518 issue 6 January 1, 2010. p. S23-S29.
5. M. V. Fischetti and S. E. Laux, Journal of Applied Physics 80, 2234 (1996).
6. D. W. Jenkins and J. D. Dow, Physical Review B, 36, 7994 (1987).
7. M. R. Bauer, J. Tolle, C. Bungay, A. V. G. Chizmeshya, D. J. Smith, J. Menéndez and J. Kouvetakis, Solid State Communication 127, 355 (2003).
8. A. Gassenq, F. Gencarelli, J. Van Campenhout, Y. Shimura, R. Loo, G. Narcy, B. Vincent, and G. Roelkens, OPTICS EXPRESS 20 (25) , 27297 (2012).
9. R. F. Spohn and C. B. Richenburg, ECS Transactions 50 (9), 921 (2012).
10. B. Vincent, F. Gencarelli, H. Bender, C. Merckling, B. Douhard, D. H. Petersen, O. Hansen, H. H. Henrichsen, J. Meersschaut, W. Vandervorst, M. Heyns, R. Loo, and M. Caymax, Appl. Phys. Lett., 99, 152103 (2011).
11. F. Gencarelli, B. Vincent, J. Demeulemeester, A. Vantomme, A. Moussa, A. Franquet, A. Kumar, H. Bender, J. Meerss- chaut, W. Vandervorst, R. Loo, M. Caymax, K. Temst, and M. Heyns ECS Journal of Solid State Science and Technology 2 (4), 134 (2013).
12. S. Gupta, B. Vincent, B. Yang, D. Lin, F. Gencarelli, J. Lin, R. Chen, O. Richard, H. Bender, B. Magyari-Koepe, M. Caymax, J. Dekoster, Y.; Nishi, and K. Saraswat, K. Extended Abstracts of the 2013 International Electronic Device Meeting (IEDM) (2012) p. 375.

EGBERT WOELK, PH.D., is director of marketing at Dow Electronic Materials, North Andover, MA. ROGER LOO, PH.D., is a principal scientist at imec, Leuven, Belgium.

By DAVE HEMKER, Senior Vice President and Chief Technology Officer, Lam Research Corp.

Given the current buzz around the Internet of Things (IoT), it is easy to lose sight of the challenges
– both economic and technical. On the economic side is the need to cost-effectively manufacture up to a trillion sensors used to gather data, while on the technical side, the challenge involves building out the infrastructure. This includes enabling the transmission, storage, and analysis of volumes of data far exceeding anything we see today. These divergent needs will drive the semiconductor equipment industry to provide very different types of manufacturing solutions to support the IoT.

In order to fulfill the promise of the IoT, sensor technology will need to become nearly ubiquitous in our businesses, homes, electronic products, cars, and even our clothing. Per-unit costs for sensors will need to be kept very low to ensure the technology is economically viable. To support this need, trailing-edge semiconductor manufacturing capabilities provide a viable option since fully depreciated wafer processing equipment can produce chips cost efficiently. For semiconductor equipment suppliers, this translates into additional sales of refurbished and productivity-focused equipment and upgrades that improve yield, throughput, and running costs. In addition to being produced inexpensively, sensors intended for use in the IoT will need to meet several criteria. First, they need to operate on very low amounts of power. In fact, some may even be self-powered via MEMS (microelectromechanical systems)-based oscillators or the collection of environmental radio frequency energy, also known as energy harvesting/scavenging. Second, they will involve specialized functions, for example, the ability to monitor pH or humidity. Third, to enable the transmission of data collected to the supporting infrastructure, good wireless communications capabilities will be important. Finally, sensors will need to be small, easily integrated into other structures – such as a pane of glass, and available in new form factors – like flexible substrates for clothing. Together, these new requirements will drive innovation in chip technology across the semiconductor industry’s ecosystem.

The infrastructure needed to support the IoT, in contrast, will require semiconductor performance to continue its historical advancement of doubling every 18-24 months. Here, the challenges are a result of the need for vast amounts of networking, storage in the Cloud, and big data analysis. Additionally, many uses for the IoT will involve risks far greater than those that exist in today’s internet. With potential medical and transportation applications, for example, the results of data analysis performed in real time can literally be a matter of life or death. Likewise, managing the security and privacy of the data being generated will be paramount. The real-world nature of things also adds an enormous level of complexity in terms of predictive analysis.

Implementing these capabilities and infrastructure on the scale imagined in the IoT will require far more powerful memory and logic devices than are currently available. This need will drive the continued extension of Moore’s Law and demand for advanced semiconductor manufacturing capability, such as atomic-scale wafer processing. Controlling manufacturing process variability will also become increasingly important to ensure that every device in the new, interconnected world operates as expected.

With development of the IoT, semiconductor equipment companies can look forward to opportunities beyond communications and computing, though the timing of its emergence is uncertain. For wafer processing equipment suppliers in particular, new markets for leading-edge systems used in the IoT infrastructure and productivity-focused upgrades for sensor manufacturing are expected to develop.

The use of a semi-aqueous organic film stripper and residue remover that does not contain N-Methyl-2 pyrrolidone (NMP) is compared with current NMP-based chemistry.

By NIK MUSTAPHA and DR. GLENN WESTWOOD, Avantor Performance Materials, Inc. MARKUS TAN, JOACHIM NG, and YANG MING CHIEH, Philips Lumileds Singapore

Philips Lumileds collaborated with Avantor Performance Materials, a global manufacturer of high-performance chemistries, to evaluate one of Avantor’s post-etch residue remover and photoresist stripper products as a replacement for a current chemistry. Avantor’s J.T. Baker ALEGTM-368 organic film stripper and residue remover is an engineered blend of organic solvents and semi-aqueous compo-nents suitable for bulk photoresist removal and post-etch/ash residue and sidewall polymer removal. Designed to provide broad process latitude in terms of processing times and temperatures, ALEGTM-368 organic film stripper and residue remover is completely water soluble, requires no intermediate solvent rinse, and contains no hydroxylamine (HA), NMP, or fluoride elements.

The authors worked together to assess whether a change to Philips Lumileds’ process of record (POR), using this product, could be accomplished without impacting yield or device quality, and with the desired cost savings.

NMP replacement challenges

Pending changes in environmental, health, and safety regulations in key manufacturing locations around the world may prohibit the use of NMP-based post-etch residue and photoresist removal products in LED manufacturing. The shift can already be observed in Europe and in some parts of Asia and the United States, where companies are moving toward NMP-free manufacturing environments. In today’s competitive environment, it is vital for companies to find alternative chemistries that are not only effective and emphasize good performance, but also provide better cost of ownership. Philips Lumileds is taking a significant step to be part of this change.

Initial verification tests of NMP-free product

As part of the process verification, several wafers were used to check etch rate on critical substrates such as III/V Nitride, Al, Ag, and Au. These wafers were also used to verify the effectiveness of the ALEGTM-368 product to remove photoresist. Data were then compared with the current POR (TABLE 1).

TABLE 1. Comparable etch rate data (A/min) shown by baseline and ALEGTM-368 product on critical substrates.

TABLE 1. Comparable etch rate data (A/min) shown by baseline and ALEGTM-368 product on critical substrates.

It was important to confirm the effectiveness of the ALEGTM-368 product in stripping capability of negative photoresist. A wafer with 5μm thickness was used as an experiment. The wafer was dipped in the ALEGTM-368 product at 75°C followed by a water rinse step. To ensure uniformity of chemical performance, five locations were inspected by a scanning electron microscope (SEM) before and after treatment with the NMP-free product (FIGURE 1). Post-treatment images after dipping the wafer in the ALEGTM-368 product indicated that no resist remained on top of the metal surface (FIGURE 2). This supports the effectiveness of the ALEGTM-368 product; it is capable of stripping photoresist completely, without visible damage to the metal surface.

FIGURE 1. Cross-sectioning images showing resist on top of III/V metal surface before ALEGTM-368 process step.

FIGURE 1. Cross-sectioning images showing resist on top of III/V metal surface before ALEGTM-368 process step.

FIGURE 2. Cross-sectioning images showed no resist on top of III/V metal surface after processing in ALEGTM-368.

FIGURE 2. Cross-sectioning images showed no resist on top of III/V metal surface after processing in ALEGTM-368.

Resist stripping and residue remover verification test on pattern wafers

Further tests were conducted on pattern wafers comparing POR and the ALEGTM-368 product at 75 °C, for 30 minutes. Wafers were then cleaved and subjected to SEM inspection.

LEDs Fig 3a LEDs Fig 3b

 

FIGURE 3. Post-treatment for POR material. No photoresist remained under high-magnification confocal microscope inspection. POR material showed good stripping capability on patterned wafers.

LEDs Fig 4a LEDs Fig 4b

 

FIGURE 4. Post-treatment using the ALEGTM-368 product. No resist remained under high-magnification confocal microscope inspection. POR material showed good stripping capability on patterned wafers. 

 

High-magnification images were obtained to verify cleaning performance and stripping capability of the ALEGTM-368 product and POR wafers. For top-view inspection, a high-magnification confocal microscope was used to verify complete removal of photoresist. Results are shown in FIGURES 3 and 4. Both the POR and the ALEGTM-368 product showed equal performance in terms of cleaning polymer residues and stripping photo resist on patterned wafers (FIGURES 5 and 6). The next critical step was to verify electrical performance for both the POR and the ALEGTM-368 product.

LEDs Fig 5a LEDs Fig 5b

 

FIGURE 5. SEM images showing post-treatment for POR. 

LEDs Fig 6a LEDs Fig 6b

 

FIGURE 6. SEM images showing post-treatment for the ALEGTM-368 product. 

Electrical performance for engineering lots

Wafers were sampled from several production lots before being split into two groups, one group using the baseline and the other using the ALEGTM-368 product. Both groups were processed in an automated tool following the recommended process condition at an operating temperature of 75°C and a processing time of 30 minutes. To achieve wafer uniformity, the tool was equipped with a mega-sonic function and recirculation to ensure effective cleaning of post-etch residues and stripping of negative photoresist.

After chemical treatment, the wafers were given an intermediate rinse using an IPA solvent to remove any remaining traces of the ALEGTM-368 product from the surface of the wafer. Without this step, chemical left on the surface of the wafer could cause corrosion, water marks, or other device defects. Wafers were then subjected to a QDR (quick dump rinse) to remove all remaining solvent on the wafers. This step normally takes five to ten minutes, with noticeable CO2 bubbling to serve as extra protection from corrosion of exposed metal. Finally, all wafers were subjected to a nitrogen dry for five minutes, a vital process since any remaining moisture could cause severe corrosion and impact electrical performance and final yield.

Once all process steps were performed, both groups were subjected to electrical tests to ensure the chips on the wafers were functioning well and within specifications. Results, as indicated in FIGURE 7, showed no significant differences in term of electrical performance for both the baseline and the ALEGTM-368 product. All wafers met specification and were subject to final yield probe.

FIGURE 7. Electrical performance comparing ALEGTM-380 and ALEGTM-368 products for real production wafers.

FIGURE 7. Electrical performance comparing ALEGTM-380 and ALEGTM-368 products for real production wafers.

Comparable Performance in Final Yield

The same production wafers which were processed using the ALEGTM-368 product at 75 °C were then subjected to final yield analysis and compared to current POR. There was slight improvement in the standard deviation for the ALEGTM-368 product when compared to baseline chemistry. Overall, both products showed comparable final yield at 98 percent (FIGURE 8).

FIGURE 8. Yield distribution for ALEGTM-380 and ALEGTM-368 products on real production wafers.

FIGURE 8. Yield distribution for ALEGTM-380 and ALEGTM-368 products on real production wafers.

Reduced Cost of Ownership

It is undeniable that operating cost is a major consideration in LED manufacturing. Prior to adopting the current POR chemistry, Philips Lumileds tried both HA-based and NMP-based chemistries. Using the HA-based chemistry, a pre-treatment process was needed to soften the photoresist prior to stripping, followed by a solvent intermediate rinse. A strip process with the ALEGTM-368 product eliminated this step and resulted in significant cost savings and increased throughput due to process simplification (TABLE 2).

TABLE 2. Higher throughput and better cost of ownership due to a reduction in process steps.

TABLE 2. Higher throughput and better cost of ownership due to a reduction in process steps.

Summary

The NMP-free ALEGTM-368 product was comparable to POR when tested in various steps of the LED manufacturing process, including: substrate compatibility on critical layers, electrical performance on actual device, and final yield. In terms of process simplification, use of the ALEGTM-368 product also showed similar technical benefits as POR, in which a significant reduction of the number of steps and chemicals used in the process leads to improved cost of ownership.

This collaboration demonstrates how a manufacturer can translate its commitment to environmental, health, and safety improvements and reduction of cost of ownership into the commercialization of a new cleaning process which can bolster its competitive position in the global LED manufacturing industry.

NIK MUSTAPHA is a Principal Applications Engineer, AvantorTM Performance Materials, Inc. MARKUS TAN is Chief Process Engineer, JOACHIM NG is Senior Manager-Process Engineering, and YANG MING CHIEH is a Process Engineer at Philips Lumileds Singapore. DR. GLENN WESTWOOD, Senior Research Scientist, AvantorTM Performance Materials, Inc.

Pixelligent Technologies, producer of PixClear, nanocrystal dispersions for demanding applications in the Solid State Lighting and Optical Coatings & Films markets, announced today that it closed $5.5 million in new equity funding. The funds will be used to support its accelerating customer growth in Asia, the EU and the U.S., and also to hire application engineers, product managers, manufacturing engineers, and staff scientists.

“During the past 12 months Pixelligent has seen a tremendous increase in demand for its nanocrystal dispersions, predominantly driven by the leading LED package manufacturers and the emerging OLED panel makers. Pixelligent’s high-index and transparent nanocrystals are becoming increasingly important in delivering more lumens per watt while also delivering cost efficiencies. This demand is coming from LED and OLED customers around the globe with the fastest growth being realized in Asia,” commented Craig Bandes, President & CEO, Pixelligent Technologies.

To support the growth coming out of the Asian market, Pixelligent appointed distributors and agents throughout Asia in 2014 and expects to do the same in the EU in 2015. Part of the proceeds from this round are being used to support the global expansion of Pixelligent’s marketing and distribution footprint.

This round included support from both a number of new family offices and existing investors. To date, Pixelligent has raised more than $23.0M in equity funding and has been awarded more than $10.0M in U.S. government grant programs.

Cypress Semiconductor Corp. and Spansion, Inc. this week announced a definitive agreement to merge in an all-stock, tax-free transaction valued at approximately $4 billion. The post-merger company will generate more than $2 billion in revenue annually.

“This merger represents the combination of two smart, profitable, passionately entrepreneurial companies that are No. 1 in their respective memory markets and have successfully diversified into embedded processing,” said Rodgers, Cypress’s founding president and CEO. “Our combined company will be a leading provider of embedded MCUs and specialized memories. We will also have extraordinary opportunities for EPS accretion due to the synergy in virtually every area of our enterprises.”

Under the terms of the agreement, Spansion shareholders will receive 2.457 Cypress shares for each Spansion share they own. The shareholders of each company will own approximately 50 percent of the post-merger company. The company will have an eight-person board of directors consisting of four Cypress directors, including T.J. Rodgers and Eric Benhamou, and four Spansion directors, including John Kispert and Ray Bingham, the Spansion chairman, who will serve as the non-executive chairman of the combined company, which will be headquartered in San Jose, California and called Cypress Semiconductor Corporation.

The merger is expected to achieve more than $135 million in cost synergies on an annualized basis within three years and to be accretive to non-GAAP earnings within the first full year after the transaction closes. The combined company will continue to pay $0.11per share in quarterly dividends to shareholders.

“Bringing together these high-performing organizations creates operating efficiencies and economies of scale, and will deliver maximum value for our shareholders, new opportunities for employees and an improved experience for our customers,” said John Kispert, CEO of Spansion. “With unparalleled expertise, global reach in markets like Japan and market-leading products for automotive, IoT, industrial and communications markets, the new company is well positioned to deliver best-of-breed solutions and execute on our long-term vision of adding value through embedded system-on-chip solutions.”

The closing of the transaction is subject to customary conditions, including approval by Cypress and Spansion stockholders and review by regulators in the U.S., Germany and China. The transaction has been unanimously approved by the boards of directors of both companies. Cypress and Spansion expect the deal to close in the first half of 2015.

Jefferies LLC and Morgan Stanley & Co. LLC served as financial advisors and Fenwick & West and Latham & Watkins acted as legal counsel to Spansion. Qatalyst Partners acted as financial advisor and Wilson Sonsini Goodrich & Rosati acted as legal counsel to Cypress.

Slideshow: IEDM 2014 Preview


November 26, 2014

This year, the IEEE International Electron Devices Meeting (IEDM) celebrates 60 years of reporting technological breakthroughs in the areas of semiconductor and electronic device technology, design, manufacturing, physics, and modeling. The conference scope not only encompasses devices in silicon, compound and organic semiconductors, but also in emerging material systems. In 2014 there is an increased emphasis on circuit and process technology interaction, energy harvesting, bio-snesors and bioMEMS, power devices, magnetics and spintronics, two dimensional electronics and devices for non-Boolean computing.

Solid State Technology will be reporting insights from bloggers and industry partners during the conference, and this slideshow provides an advance look at some of the most newsworthy topics and papers to be presented at the annual meeting, to be held at the Hilton San Francisco Union Square Hotel from December 15-17, 2014.

Click here to launch slideshow. 

Bay Bridge, San Francisco at dusk

 

Related news and blogs: 

Intel and IBM to lay out 14nm FinFET strategies on competing substrates at IEDM 2014

Slideshow: IEDM 2013 Highlights

Soraa announced today that it has introduced a perfectly compatible version of its award-winning MR16 LED lamp. Featuring the company’s signature elements of full-visible-spectrum light, Soraa’s constant current MR16 LED lamp is the ideal lighting solution for restaurants, retail, high-end residential, and office environments where superior light quality and dimming are essential.

Equipped with a standard GU5.3 two-pin base, Soraa’s constant current MR16 LED lamp fits into any MR16 fixture and fully conforms to the ANSI/ IECE compatible form factor. Unlike other MR16 LED lamps, the constant current LED lamp is designed to accept an external driver which supplies the lamp with low voltage DC input current, eliminating the need to fit a transformer in limited space.

Providing enormous dimming and control flexibility, light output can now be programmed to the desired level when using a programmable or remote driver. The lamp also achieves zero flicker when used with a DC driver and is available in 10 degree, 25 degree and 36 degree versions.

“Incompatibility issues between LED lamps, fixtures, dimmers and transformers continue to hinder the advancement and adoption of LED technology,” explained George Stringer, Senior VP of North America Sales at Soraa. “Our new constant current MR16 LED lamp overcomes these hurdles, enabling flexibility and choice without compromising on performance and quality.”

Soraa’s constant current MR16 LED lamp features the company’s Point Source Optics for beautiful, high intensity, and uniform beams; and unique Violet-Emission 3-Phosphor (VP3) LED technology for perfect rendering of colors and whiteness. Utilizing every color in the rainbow, especially deep red emission, Soraa’s VP3 Vivid Color renders warm tones beautifully and accurately, and achieves a color-rendering index (CRI) of 95 and deep red (R9) rendering of 95 at color temperatures ranging from 2700K to 4000K. And unlike blue-based white LEDs without any violet/ ultra-violet emission, the company’s VP3 Natural White is achieved by engineering the violet emission to properly excite fluorescing agents including natural objects like human eyes and teeth, as well as manufactured white materials such as clothing, paper and cosmetics.

Related news: Soraa founder wins Nobel Prize in physics

By Daniel QI, SEMI China

General Lighting is a Key Growth Driver

As a result of cost reduction and performance improvements, LED lighting is becoming more and more competitive in general lighting market. Energy-efficient fluorescent lamps (like CFL) productions have experienced growing and stabilizing stages in recent years; however, energy-efficient fluorescent lamp production is now facing a significant decline in 2014 as LED lighting products represent a faster growing segment of this market. SEMI China believes that the general lighting market will replace the LCD TV backlight market as the largest application market for LEDs in 2014, and general lighting market will continue to drive the LED industry over the next several years.

ChinaLED1

China’s LED Fab Industry Is Consolidating and Recovering

Due to overly optimistic expectations for future market growth and opportunities, coupled with many local governments providing subsidies for MOCVD equipment procurement, China’s LED fab industry entered into a hyper-growth period between 2010 and 2011, resulting in 76 LED fabs being established by the end of 2011. Many of these companies struggled given challenges in ramping up and with over-supply in the market. Fab capacity utilization lagged for many companies.

Following this post hyper growth period, fab utilization eventually recovered and improved throughout 2013, reaching about 90% by first quarter in 2014 (see next figure). Two key reasons are evident for improved capacity utilization. First, as previously mentioned, demand in general lighting application has increased. Second, China’s LED fabs have undergone consolidation since 2012. Consolidation occurred as some of LED fabs went bankrupt or exited the industry entirely, thus mitigating oversupply in the China market. These bankrupted or former LED fabs are not included in the utilization statistics shown in the figure below.

 ChinaLED2

China LED Fab Industry Expansion Plan

There has been very limited news of LED fab expansions over the previous two years, but the situation has changed as a number of China’s LED companies have announced new fab projects and/or expansion plans in 2014. SEMI believes that over the next three to four years upstream LED manufacturers in China will enter robust era of growth. Unlike 2010 and 2011, this expansion round will be dominated by leading manufacturers, not new entrants. Also, the total increase in MOCVD tool quantity in 2014 and 2015 will be from just six companies  and will account 74% of the total quantity of MOCVD tools installed in China. It is expected that the number of new MOCVD tools installed will exceed 1,000 from 2014 to 2018.

ChinaLED3

The New Edition of China LED Fab Industry Report

SEMI China has recently published a new report of China’s LED Fab Industry in October 2014.This report covers: the LED lighting market, global LED fab capacity forecast, China’s LED fab industry utilization statistics, a listing of all of China’s LED fabs, LED fab expansion plans by supplier, China MOCVD tool market analysis and forecast, China GaN epitaxial wafer capacity statistics, and LED forecast by wafer size.

For more information, please contact Daniel QI: [email protected]

Even as the 2014 Nobel Prize in Physics has enshrined light emitting diodes (LEDs) as the single most significant and disruptive energy-efficient lighting solution of today, scientists around the world continue unabated to search for the even-better-bulbs of tomorrow.

Enter carbon electronics.

Electronics based on carbon, especially carbon nanotubes (CNTs), are emerging as successors to silicon for making semiconductor materials. And they may enable a new generation of brighter, low-power, low-cost lighting devices that could challenge the dominance of light-emitting diodes (LEDs) in the future and help meet society’s ever-escalating demand for greener bulbs.

Scientists from Tohoku University in Japan have developed a new type of energy-efficient flat light source based on carbon nanotubes with very low power consumption of around 0.1 Watt for every hour’s operation–about a hundred times lower than that of an LED.

In the journal Review of Scientific Instruments, from AIP publishing, the researchers detail the fabrication and optimization of the device, which is based on a phosphor screen and single-walled carbon nanotubes as electrodes in a diode structure. You can think of it as a field of tungsten filaments shrunk to microscopic proportions.

They assembled the device from a mixture liquid containing highly crystalline single-walled carbon nanotubes dispersed in an organic solvent mixed with a soap-like chemical known as a surfactant. Then, they “painted” the mixture onto the positive electrode or cathode, and scratched the surface with sandpaper to form a light panel capable of producing a large, stable and homogenous emission current with low energy consumption.

“Our simple ‘diode’ panel could obtain high brightness efficiency of 60 Lumen per Watt, which holds excellent potential for a lighting device with low power consumption,” said Norihiro Shimoi, the lead researcher and an associate professor of environmental studies at the Tohoku University.

Brightness efficiency tells people how much light is being produced by a lighting source when consuming a unit amount of electric power, which is an important index to compare the energy-efficiency of different lighting devices, Shimoi said. For instance, LEDs can produce 100s Lumen per Watt and OLEDs (organic LEDs) around 40.

Although the device has a diode-like structure, its light-emitting system is not based on a diode system, which are made from layers of semiconductors, materials that act like a cross between a conductor and an insulator, the electrical properties of which can be controlled with the addition of impurities called dopants.

The new devices have luminescence systems that function more like cathode ray tubes, with carbon nanotubes acting as cathodes, and a phosphor screen in a vacuum cavity acting as the anode. Under a strong electric field, the cathode emits tight, high-speed beams of electrons through its sharp nanotube tips — a phenomenon called field emission. The electrons then fly through the vacuum in the cavity, and hit the phosphor screen into glowing.

“We have found that a cathode with highly crystalline single-walled carbon nanotubes and an anode with the improved phosphor screen in our diode structure obtained no flicker field emission current and good brightness homogeneity,” Shimoi said.

Caption: This image shows a planar light source device from the front. Credit: N.Shimoi/Tohoku University

Caption: This image shows a planar light source device from the front. Credit: N.Shimoi/Tohoku University

Field emission electron sources catch scientists’ attention due to its ability to provide intense electron beams that are about a thousand times denser than conventional thermionic cathode (like filaments in an incandescent light bulb). That means field emission sources require much less power to operate and produce a much more directional and easily controllable stream of electrons.

In recent years, carbon nanotubes have emerged as a promising material of electron field emitters, owing to their nano-scale needle shape and extraordinary properties of chemical stability, thermal conductivity and mechanical strength.

Highly crystalline single-walled carbon nanotubes (HCSWCNT) have nearly zero defects in the carbon network on the surface, Shimoi explained. “The resistance of cathode electrode with highly crystalline single-walled carbon nanotube is very low. Thus, the new flat-panel device has smaller energy loss compared with other current lighting devices, which can be used to make energy-efficient cathodes that with low power consumption.”

“Many researchers have attempted to construct light sources with carbon nanotubes as field emitter,” Shimoi said. “But nobody has developed an equivalent and simpler lighting device.”

Considering the major step for device manufacture–the wet coating process is a low-cost but stable process to fabricate large-area and uniformly thin films, the flat-plane emission device has the potential to provide a new approach to lighting in people’s life style and reduce carbon dioxide emissions on the earth, Shimoi said.