Taking nanotechnology to market
06/01/2005
Solid State Technology asked industry experts to discuss how semiconductor companies can use what they already know to commercialize nanotechnology.
NGL may be the key to commercializing nanotechnology
 Thomas Glinsner (pictured), Helge Luesebrink, Paul Lindner, EV Group, Schärding, Austria |
Nanotechnology promises a broad range of future applications in a wide variety of disciplines. Whether the topic is precision engineering, electromechanical engineering, mainstream biological and chemical sciences, or medical research, the two fundamentally different approaches to creating nanodevices are “top-down” and “bottom-up.”
Top-down refers to making nanoscale structures with machining and etching techniques; bottom-up applies to building organic and inorganic structures atom-by-atom or molecule-by-molecule. A top-down approach, such as nanopatterning, finds a growing number of industrial applications due to its compatibility with existing manufacturing standards and its increased efficiency in throughput and fabrication costs.
Major efforts are underway to discover new ways to create electronic devices with dimensions of <50-100nm, which could ensure the applicability of Moore’s Law well into the future. Naturally, the semiconductor industry, which already has broken the 100nm barrier in specific applications, is expected to play a major role in commercializing nanotechnology.
Indeed, the International Technology Roadmap for Semiconductors (ITRS) anticipates that promise even as it presents a formidable challenge to developing the patterning techniques that will be needed to create ever-smaller feature sizes. Next-generation lithography (NGL), a post-optical fabrication alternative, is expected to provide devices at the 45nm node and smaller. NGL includes extreme-ultraviolet lithography (EUV), electron-beam projection lithography (EPL), maskless lithography, ion-projection lithography, x-ray lithography, and nanoimprint lithography (NIL). If Moore’s Law continues into the NGL era, the ITRS calls for NIL as a potential contender to optical lithography to be employed at the 35nm node in 2010.
Today’s stepper technology with a 193nm exposure wavelength has been maximized to create transistors with gate lengths for the 65nm node. To achieve even better resolution, the wavelength is reduced further to EUV for next-generation stepper technology, which is expected to meet production requirements of devices with features of 45nm and smaller; EPL is expected to meet the requirements for vias and contact holes at 50-60nm.
Semiconductor manufacturing has foreshadowed many aspects and parameters of nanoimprint technologies. Advances in substrate materials, resists, and metrology equipment are just a few examples of developments in semiconductor processing that can also be utilized for nanoimprint technologies. There are gaps in the infrastructure that must be closed, however, before the emerging nanotechnology field can capitalize on this promising method.
Nanoimprinting technologies are not a stand-alone solution. They require the application of other next-generation fabrication methods of a serial nature. For example, stamps for UV NIL as well as for hot-embossing applications are fabricated by e-beam writing in most cases. They often can be imprinted in dedicated polymers or monomers in UV NIL, which makes these methods quite cost-effective.
It should be noted that etching techniques such as dry etching or deep reactive-ion etching were developed for applications in the MEMS and semiconductor industries, and are likely to have a corresponding application in the production of nanodevices. These methods also can be employed as post-processing steps for NIL to transfer imprinted structures <100nm into the substrate underneath.
Interestingly, the first applications of these imprint techniques are expected to be seen in the bio-MEMS and optics areas. Whether they offer a potential for lithography replacement in the semiconductor industry will be determined by ongoing R&D. Similarly, NIL must first have applications in areas such as bio-MEMS and optics before it will find its place as a viable tool for the semiconductor industry.
One of the critical challenges for nanoimprinting as a potential fabrication method is the availability of supporting infrastructure. The commercial availability of stamps, stamp repair tools, resists, and metrology equipment will be crucial for NIL in semiconductors, and only after the infrastructure has been established will NIL become commercially available for nanotechnology devices.
To accelerate this progress, EV Group has founded a consortium of partners of all specific areas of NIL. NILCom (http://www.nilcom.org/Platform.htm) is a consortium and technology platform that focuses on providing an infrastructure to commercialize nanoimprint applications in nanoelectronics, life sciences, data storage, and optoelectronics. Previous work in NIL examines specific phenomena of imprint technologies and feasibility studies in feature-size resolution and its specific process challenges. NILCom serves application developers in the above-mentioned market segments and material suppliers alike to develop qualified NIL manufacturing methods. The combination of polymeric material development and availability of multiple centers of excellence provides processing expertise to accelerate prototyping and transfer from R&D to high-volume manufacturing.
Acknowledgment
NILCom is a registered trademark.
For more information, contact Thomas Glinsner, deputy chief technology manager, at EV Group, ph 43/7712-5311-0, e-mail [email protected].
Applying semiconductor manufacturing to nanotechnology?
 Charles Hayward, Pall Process Technologies, East Hills, New York |
Ask a room full of people to define nanotechnology, and you’ll likely get a range of definitions. It’s not because nanotechnology is indefinable. The dictionary says it’s any fabrication technology in which objects are designed and built by the specification and placement of individual atoms or molecules, or where at least one dimension is on a scale of nanometers. You will get divergent answers, however, because nanotechnology promises to bring so many new developments to many aspects of life - from faster, smaller electronics and the diagnosis of disease right down to the very fibers that make up the fabrics in our clothes.
Yes, the future has nanotechnology written all over it - great news for semiconductor industry suppliers because, despite the field’s broad scope, there is a common thread that runs through its inexorable development: semiconductor manufacturing knowledge. More specifically, the manufacturing techniques (deposition, lithography, etching, and contamination control) that are fundamental to semiconductor production are the very building blocks of nanotechnology today.
Nanotube and nanowire production, for example, relies on the same chemical-vapor and atomic-layer deposition techniques that we now use to produce semiconductor devices. In the same vein, just as semiconductor process gases must be purified to remove oxygen and moisture beyond the parts-per-trillion level, gases for nanotube and nanowire production also require purification methods, except the purification goals are much more stringent (in some cases, orders-of-magnitude greater).
When Pall began working with nanotechnology applications six years ago, it first looked to the experience and knowledge of its microelectronics team, even though the company employs experts in other areas that nanotechnology will touch, such as medical technologies. The reason for tapping the microelectronics team is simple: Semiconductor manufacturing is the most relevant technology in the development of nanotechnology.
Today, modified sublimation and gas purification techniques are being used that were originally developed for the semiconductor industry to vaporize nanomaterials for organic light-emitting devices (OLED). Some of the key semiconductor manufacturing lessons learned over the past several decades are also being applied to nanomaterial development. For instance, when we began working with light-emitting polymer nanomaterials, we knew we needed a clean, solvent-compatible membrane that wouldn’t release contaminants into the OLED manufacturing process. OLED molecules can be designed to emit white, blue, red, green, and every other color of the spectrum, but contamination will render an OLED of any color useless. Ten years of experience with and testing of PFA and PTFE materials for use in semiconductor production led to a nanomaterial fluid-filtration system that uses PTFE.
Problem solvers
The value semiconductor manufacturing experience brings to nanotechnology development goes far beyond the application of technology. The methodologies used to resolve semiconductor process challenges in the past have taught us how to clear nanotechnology development hurdles.
Working with a variety of end users - many of which are small companies with great ideas and limited technology resources - has enabled the development of new nano applications simply by applying the same problem-solving techniques used to resolve semiconductor process challenges.
The process begins with the same basic questions asked every time a new filtration technology or application is developed.
- What needs to be removed or transmitted?
- How clean does the filter technology in the fluid need to be?
- Is a batch or continuous process needed?
- What cost constraints need to be considered?
- Can the answer be tested with existing technology?
- Can existing technology be used, or does the project call for a new class of product?
So while the challenge at hand may vary from one nanotechnology application to another, the steps taken to find answers remain constant.
But can you analyze it?
Once filtration, purification, or separation solutions are developed for a nanotechnology project, complex analytical methods are needed to test and evaluate whether target purity levels have been achieved.
Again, these analytical methods haven’t been developed for nanotechnology’s sake. Rather, they’re the same Class 100 cleanroom capabilities, chemical analysis, microscopy, and surface metrology tools developed for the semiconductor industry. What this means is that the industry can leverage the extensive investments it has made in semiconductor analysis and measurement.
So the way we see it, nanotechnology isn’t a revolution at all - rather, it’s the extension, adaptation, and refinement of the semiconductor manufacturing technologies and knowledge we’ve been perfecting over the past four decades.
More specifically, contamination control (via filtration, separation, and purification technologies) is an essential ingredient in making nanotechnology feasible and available. Many concepts can be developed in the lab, but only through filtration can process variables be reduced, making the incorporation of nanotechnology practical.
For more information, contact Charles Hayward, senior marketing manager for Pall Process Technologies; ph 516/801-9586, e-mail [email protected].