Category Archives: Metrology

September 19, 2006 – SEMATECH and its manufacturing-oriented subsidiary, the International SEMATECH Manufacturing Initiative (ISMI), have signed an agreement to incorporate ASML Holding NV’s resolution enhancement techniques (RET) in order to qualify imaging performance of advanced logic patterns, metrology structures, and defect designs for the 45nm, 32nm, and 22nm technology nodes.

Under the deal, ASML will supply advanced RET mask patterns for the SEMATECH design structures and deliver a fully qualified set of masks together with a set of validation wafers. ASML will also develop optimized scanner settings for the mask patterns to be exposed on the company’s TWINSCAN XT:1700i scanner, at ASML’s demo lab facility in Veldhoven, The Netherlands, measuring the imaging performance of the exposures through SEM measurements and simulations.

“We are pleased to collaborate with ASML on determining the right lithography solutions for the 45nm, 32nm, and 22nm technology nodes,” stated John Allgair, litho metrology program manager for ISMI. “We are looking forward to reviewing the results from this project and making some key technology selection information available to our member companies.”

September 12, 2006 — /MARKET WIRE/ — MIDDLEFIELD, CT — (Zygo Corporation (NASDAQ: ZIGO), a leading worldwide optical metrology supplier, today announced that it has received a follow-on order from a leading North American semiconductor manufacturer as part of a multi-million-dollar commitment to use ZYGO’s Z3D 7000(tm) metrology tool for high volume manufacturing process control.

The Z3D 7000(tm) optical metrology tool performs high-resolution surface topography measurements on bare and patterned 200mm and 300mm semiconductor wafers. It provides high measurement precision at throughputs that exceed those achievable with existing mechanical profiling techniques, such as atomic force microscopy. The tool has been designed to meet the growing need for in-line etch, deposition, and planarization process metrology 45nm node and beyond. It is equipped with SEMI(r) compliant automation, ISO Class 2 certified clean hardware and meets all ergonomic and safety certifications needed for production line equipment.

Robert Stoner, ZYGO’s Vice President, Metrology, made the following comment, “This commitment is a strong endorsement of our strategic product roadmap by an important customer. It is also a measure of our success in building a world-class team focused on the semiconductor process control market. We believe ZYGO’s technology leadership will allow us to increase our market share of noncontact optical metrology into the semiconductor front end manufacturing process.”

Zygo Corporation (NASDAQ: ZIGO), headquartered in Middlefield, Connecticut, is a worldwide supplier of optical metrology instruments, precision optics, and electro-optical design and manufacturing services, serving customers in the semiconductor capital equipment and industrial markets. See ZYGO’s web site at www.zygo.com for additional information.

All statements other than statements of historical fact included in this news release regarding our financial position, business strategy, plans, anticipated growth rates, and objectives of management of the Company for future operations are forward-looking statements. Forward-looking statements are intended to provide management’s current expectations or plans for the future operating and financial performance of the Company based upon information currently available and assumptions currently believed to be valid. Forward-looking statements can be identified by the use of words such as “anticipate,” “believe,” “estimate,” “expect,” “intend,” “plans,” “strategy,” “project,” and other words of similar meaning in connection with a discussion of future operating or financial performance. Actual results could differ materially from those contemplated by the forward-looking statements as a result of certain factors. Among the important factors that could cause actual events to differ materially from those in the forward-looking statements are fluctuations in capital spending of our customers, fluctuations in net sales to our major customer, manufacturing and supplier risks, dependence on and timing of new product development, rapid technological and market change, risks in international operations, dependence on proprietary technology and key personnel, length of the sales cycle, environmental regulations, and fluctuations in our stock price. Further information on potential factors that could affect Zygo Corporation’s business is described in our reports on file with the Securities and Exchange Commission, including our Form 10-K, as amended, for the fiscal year ended June 30, 2005.

For Further Information Call:
Walter A. Shephard
Vice President Finance, CFO, and Treasurer
Voice: 860-704-3955
[email protected]

SOURCE: Zygo Corporation

Sept. 6, 2006 — FEI Co. of Hillsboro, Ore., announced that Japan’s JFE Steel Corp. has ordered a Titan 80-300 for its research center in Kawasaki. JFE Steel, a leading global supplier of steel products, is the first Japanese customer to order the Titan S/TEM.

JFE Steel’s Titan S/TEM will be utilized primarily for chemical-microstructural characterization of coated layers and advanced metrology and precipitates, and to obtain chemical bonding data from layer interfaces, according to FEI.

In its 2006 fiscal year, JFE Steel produced more than 30 million tons of raw steel and reported more than U.S. $23 billion in revenues.

September 6, 2006 – Nova Measuring Instruments, Rehovoth, Israel, is soliciting bids from approximately 100 companies to license six of its patents relating to use of a lithography tool with integrated metrology, and will even accept bids for outright ownership of the technology.

The company says it will use an auction model to set a market price for the licenses (including counterpart Israeli patents, pending US continuations, and European and Japanese applications), which it says covers only a small portion of its portfolio. Among the patents being auctioned: four relating to a lithography track with integrated optical measurement capability, used with overlay registration, critical dimensions, and macrodefect inspection; and two patents from its advanced process control group, related to methods for photolithographic processing involving making a spectrophotometric measurement and using it to influence the processing time, focus or exposure of a processing tool.

“We believe this auction will allow us to capitalize on favorable industry trends and unlock the true value of our intellectual property assets,” stated Gabi Seligsohn, president and CEO of Nova, adding that the auction will help avoid litigation of potential infringements in the future by establishing the value of the assets and monetizing them.

Nova is accepting bids for either a license for a particular model of semiconductor processing equipment (including customer rights to use), or a license to practice the patents at a fabrication facility. The company says it may select one or more offers, or none at all, with successful bidders notified by Feb. 15, 2007. A full list of the companies that have been invited to participate in the auction, including leading-edge IC manufacturers, semiconductor equipment manufacturers, and metrology companies, is available on the Hoffman & Zur Web site.

“By allowing the market rather than the courts to value patents, intellectual property worth many millions of dollars can be monetized in a more efficient, less contentious manner – clearly a benefit to the industry,” stated Eran Zur, partner at law firm Hoffman & Zur retained to handle the process.

September 6, 2006 – Nova Measuring Instruments, Rehovoth, Israel, is soliciting bids from approximately 100 companies to license six of its patents relating to use of a lithography tool with integrated metrology, and will even accept bids for outright ownership of the technology.

The company says it will use an auction model to set a market price for the licenses, which it says covers only a small portion of its portfolio. Among the patents being auctioned: four relating to a lithography track with integrated optical measurement capability, used with overlay registration, critical dimensions, and macrodefect inspection; and two patents from its advanced process control group, related to methods for photolithographic processing involving making a spectrophotometric measurement and using it to influence the processing time, focus or exposure of a processing tool.

“We believe this auction will allow us to capitalize on favorable industry trends and unlock the true value of our intellectual property assets,” stated Gabi Seligsohn, president and CEO of Nova, adding that the auction will help avoid litigation of potential infringements in the future by establishing the value of the assets and monetizing them.

Nova is accepting bids for either a license for a particular model of semiconductor processing equipment (including customer rights to use), or a license to practice the patents at a fabrication facility. The company says it may select one or more offers, or none at all, with successful bidders notified by Feb. 15, 2007. A full list of the companies that have been invited to participate in the auction, including leading-edge IC manufacturers, semiconductor equipment manufacturers, and metrology companies, is available on the Hoffman & Zur Web site.

“By allowing the market rather than the courts to value patents, intellectual property worth many millions of dollars can be monetized in a more efficient, less contentious manner – clearly a benefit to the industry,” stated Eran Zur, partner at law firm Hoffman & Zur retained to handle the process.

Lights-out MEMS Manufacturing


September 1, 2006

BY SHARI FARRENS AND JAMES HERMANOWSKI, SUSS MicroTec, Inc.

It is well-known in semiconductor manufacturing that fast process feedback leads to better process control, which results in higher yield. In-line and in-situ metrology evolved over the past several years and are now available for commercial production as MEMS companies move into foundries. Delays in process feedback due to off-line metrology reduce yields, drive product costs higher, and delay time-to-market. Integrated overlay alignment metrology for wafer-to-wafer bonding provides a pathway for “lights-out” manufacturing with full piece of mind.

Wafer-bonding processes cover a variety of approaches including anodic, direct/fusion/SOI, and thermocompression (glass frit, eutectic, metal, and adhesive), which allow for bonding a variety of material and substrate combinations. The trend in all wafer bonding manufacturing is toward tighter alignment accuracy in all application areas. Industry standard techniques involving viscous flow of interlayer materials, such as glass frit and eutectic metals, are primarily used in applications with alignment specifications >5µm. However, it is possible to extend these techniques to 2µm with proper process development and continuous monitoring. Advanced bonding techniques that eliminate viscous flow and reduce overall thermal budgets result in alignment capabilities below 1 µm. To maintain this performance in production requires accurate and immediate metrology feedback.

Approaches to Bond Alignment Metrology

Typical wafer-bonding manufacturing processes use off-line alignment metrology systems for process control. Examination of the alignment occurs during back-end-of-line processes when dicing reveals the bond interface. The first step in the metrology flow is wafer alignment, clamping into a bond fixture, and transport to the bonder. Next, temperature, force, and pressure are applied to form the permanent bond. Final alignment results are measured off-line using various in-house metrology tools. They vary according to materials and methods. If the process shifts out of control, the entire lot of wafers is scrapped since detection is delayed for several additional manufacturing steps.


Figure 1. In-line and real time wafer bonding metrology.
Click here to enlarge image

Figure 1 represents an in-situ metrology model, available on cluster equipment, that allows for pre- and post-bond monitoring of alignment accuracy and user-defined algorithms for “go” and “no-go” processing without operator intervention. This system allows for measurement of post-bond results after each processed wafer, or at a user-defined frequency within the lot. Different optics can be used for initial alignment and the post-bond metrology step. For example, the wafer-to-wafer alignment can be done using a backside alignment (BSA) scheme with visible light, while the metrology can be measured using infrared (IR) illumination.

The user establishes process control set points to accept or reject wafer pairs at each step. Marginal wafers (such as those with bad alignment marks) can be excluded from being permanently bonded via pattern recognition software. Rejected product can be re-aligned manually and continued in the process or sent to reject cassettes. Tool alarms will alert the operator whenever user intervention is required. The in-line metrology system also facilitates fast tool installations and maintenance because of immediate data collection and feedback.

In-line metrology does not affect production throughput because a single bond-alignment (BA) module can be configured to conduct initial wafer alignment and measure post-bond overlay in a multi-tasking configuration. In most cases, the aligner is not the bottleneck of the cluster platform and multi-tasking the aligner for metrology is a next obvious step toward improved yield and reduced scrap.

Enabling “Lights-out” Production

Many wafer-bonding processes require slow temperature ramps or long anneal times resulting in cycle times of 20-45 minutes per wafer. Therefore, 25 bonded pairs can take 12 hours to process. An automated cluster tool with in-line metrology allows hands-free production and computerized process control. The machine can stop production if the final process results drift out of specification. This enables the machine to run for long periods of time without human intervention, and is dubbed “lights-out” production. Process control set points established by the engineer can accept or reject wafer pairs during post-bond metrology. The wafers can be flagged or sent to a reject cassette, or the tool can be alarmed and stopped to prevent additional wafers from being introduced into the process.

Overlay Measurement Methods

Alignment schemes that allow the user to visualize the targets and align them include transparent substrate alignment (TSA), BSA, inter-substrate alignment (ISA), and IR. TSA is used when one wafer is transparent and the alignment marks from that substrate can be observed simultaneously with the opaque wafer below – a system much like standard mask alignment. BSA involves an initial image capture of the front-side alignment marks on the first wafer and a subsequent alignment of backside marks on the second wafer to stored images of the upper substrate. IR imaging is used to peer through both wafers simultaneously and is most often used during the inline metrology step (Figure 2). In the ISA method, optics are inserted between the two substrates to be aligned. The objectives image both the upper and lower alignment marks simultaneously and in real-time (Figure 3). Each method has trade-offs in terms of accuracy and compatibility with various substrate types (Table 1).


Figure 2. IR alignment principle. High contrast is achieved by double side polish on the upper wafer and proper design of the alignment marks and materials choices.
Click here to enlarge image

null


Figure 3. ISA alignment uses dual imaging objectives on both the left and right alignment optics. Visualization of the face-to-face alignment marks is possible with this system regardless of substrate transparency.
Click here to enlarge image

null


Table 1. Critical Comparison of Wafer to Wafer Bond Alignment Methods
Click here to enlarge image

null

Baseline Capability of the Metrology System

After bonding, the wafers’ front sides are permanently attached. TSA or BSA methods are used for post-bond metrology in any application using a transparent substrate, such as glass or sapphire, and IR is used exclusively for face-to-face alignment marks buried at the bond interface. To evaluate the reliability of an in-line metrology system, a systematic error analysis was completed for each step in the alignment process flow.


Table 2. Effects of various target shapes and settings on target position repeatability.
Click here to enlarge image

In this case, system repeatability was calculated by training a target and then allowing the system to measure its location over time, obtaining a baseline for tool capability. Different targets were then used to determine if specific targets afforded higher repeatability. Each target style was tested with the IR vs. visible metrology methods. Finally, focus and illumination settings were adjusted to extremes to determine the process window for the contrast settings. Table 2 summarizes 150 measurements for each experiment. In production the system reports and records a fitness parameter that is measured between the actual target and the trained target for success criteria.

Summary

In-line, real-time alignment metrology is an important aspect of quality, high-volume wafer-bonding production. A unique approach to wafer-bond alignment metrology allows 24/7 production with minimum intervention, and the ability to self-regulate process drifts. The metrology system uses pattern-recognition hardware, and software, compatible with a variety of target designs. The baseline repeatability of the measurement system has been measured under various conditions and found to be acceptable for a variety of applications. The 0.1µm, 3 sigma alignment measurement capability is critical for high-end aligned bonding applications approaching micron-level registry. Reproducibility in the system enhances development efforts for bonding technology development.

SHARI FARRENS, chief scientist, and JAMES HERMANOWSKI, director of technical support, may be contacted at SUSS MicroTec, Inc. 228 Suss Drive Waterbury Center, VT 05677; 802/244 5181; E-mail:[email protected], [email protected]

Ambios releases Isochamber


August 30, 2006

Aug. 30, 2006 — Ambios Technology, a Santa Cruz, Calif.-based maker of high performance, low cost bench top metrology and measurement equipment, announced its Isochamber, an environmental isolation system designed to optimize the performance of AFMs and other surface imaging tools.

The device is intended to offer a superior environmental chamber for isolating high resolution metrology instrumentation from building vibrations, interior acoustic noise, and thermally induced drift in order to get top performance.

The Isochamber provides 30dB of acoustic isolation, and features an integral 0.5Hz vibration isolation platform from Minus K Technology. Ambios says the result is better than 99 percent isolation efficiency acoustically and mechanically in key frequency regimes.

August 30, 2006 – Semiconductor manufacturers are increasingly trying to cut expenses and spending, and the first casualty appears to be metrology equipment investments, according to a new report from The Information Network.

Semiconductor yields have reached a point where chipmakers are relaxing wafer sampling and are looking for ways to cut capital expenditures, stated Robert Castellano, president of the New Tripoli, PA-based market research firm. Metrology tool throughput now typically exceeds 130 wafers/hour, meaning faster measurements and less need for metrology capacity, saving both capital expenses and cleanroom space, he said. “Simply put, the performance of the current crop of metrology/inspection systems has gotten too good.” Chipmakers are also deferring purchases of integrated metrology tools in favor of standalone equipment for thin-film measurements, allowing them to sample only some sites on some wafers, he added.

Castellano projects the process control sector will grow about 9.6% in 2006, compared with 15.8% for the overall equipment industry. The macrodefect inspection surged 63% in 2005 vs. just 1.5% for the overall inspection/metrology market, and a 9.5% decrease in overall frontend equipment. But that segment, led by August Technology with 44% share (including Rudolph Technologies), represents just 3.3% of the overall metrology/inspection market, and Castellano says it is now “overcrowded.”

August 25, 2006 – Bede X-ray Metrology and European research consortium IMEC have entered into a collaboration to investigate the use of X-ray metrology for process control and characterization of new semiconductor materials used at the 45nm node and below.

Under the agreement, Bede’s X-ray metrology system will be installed at IMEC’s 300mm research facility, to measure critical process control parameters needed in the use of advanced semiconductor materials for device fabrication, according to Luc Van den hove, IMEC’s VP of silicon process and device technology. Specifically, IMEC will be using the BedeMetrix-L, which uses a combination of high-resolution X-ray diffraction, X-ray diffraction, and X-ray reflectivity techniques, targeting front- and backend process control applications including strained silicon, high-k gate dielectrics, metal gates, barrier metals, interconnects, and porous low-k ILD. The system’s optics capabilities enable measurement of strain silicon parameters in scribe lines and metrology pads used in 45nm processing, according to the company.

For Bede, the collaboration “will enable us to benefit from [IMEC’s] expertise in the latest process technologies and advanced materials,” enabling both companies to jointly “offer solutions for the various IMEC partners on critical process control,” stated Frank Hochstenbach, director of sales and marketing, and responsible for customer partnerships.