Letter to the Editor
-- Semiconductor International, 3/1/2001
The editorial that appeared in the January issue of Semiconductor International reflects a misunderstanding of the International Technology Roadmap for Semiconductors (ITRS) that I would like to clarify. Specifically, the suggestion that the ITRS "stifles creativity" is not valid.The ITRS document is devoted to defining the needs required to continue the scaling of CMOS and related semiconductor devices (Technical Requirements Tables) and to identify ongoing research directed toward meeting those needs (Potential Solutions Tables). The ITRS has never had the objective of "picking the winner." Therefore, to suggest that the ITRS process "stifles creativity" by choosing the "best" potential solution is misleading.
The most important function of the ITRS is to alert researchers to future Moore's Law barriers, the solutions of which require the investment of intellectual energy. The ITRS has been very successful in this regard, having spurred research and development at government laboratories, universities, industry consortia, semiconductor manufacturers and semiconductor equipment manufacturers. It therefore helps to nurture the "greenhouse" environment that the SI editorial claims it inhibits.
The inhibition results from the fact that there are limited resources available to support the "greenhouse." The result of this resource constraint is to impose a winnowing process in which some promising work is sometimes abandoned or supported at minimum "keep alive" levels in order to make available the expanded resources needed to bring another project to successful completion. This is certainly the case with next-generation lithography, where resources made available for potential solutions such as X-ray projection, ion-beam projection and others were reduced or eliminated in order to support the commercialization of the two candidates deemed to have the highest potential for success: EUV and EPL.
I am not in a position to assess whether the "correct" choice was made in narrowing down the NGL options. However, my understanding is that it came about as a result of international collaboration and discussion by lithography experts. No one suggests that this is a perfect process, and history may also prove that this narrowing process incorrectly chose to prioritize the "wrong" candidates. However, it is very clear that the International Technology Roadmap for Semiconductors had nothing to do with inhibiting the pursuit of alternate approaches. These inhibitions were imposed by resource constraints.
Walter Class
Axcelis Technologies
Co-Chairman, U.S. ITRS Front-End Process Technology Working Group
