Process Modeling for Advanced Devices

Abstract

As device lots become more and more expensive, process modeling is increasingly important. Process simulation and modeling is increasingly sophisticated but the accuracy remains a problem. There is generally a time lag between the introduction of a particular process and its accurate modeling – the problem of “yesterday's technology modeled tomorrow”. For many problems, absolute accuracy isn't required. Relative trends provide excellent information about the process in question. For this reason, process simulation is still a useful technique for guiding process development.

Perspectives and challenges in nanoscale device modeling

“…This can be the critical mission of nanoscale device modeling, requiring not huge do-it-all tools, but simulation tools with different degrees of sophistication, tailored to the particular problem at hand. The realm of 'predictive' simulation tools will probably be limited to mature technology and brute force calibration, and the problem of 'yesterday's technology modelled tomorrow' [1] will probably remain unsolved for quite some time.…”

“…The answer is not obvious, since typically Technology Computer Aided Design (TCAD) tools-including both process and device simulators-are accurate, or 'predictive', only for a sufficiently stable and 'mature' technology, and after a lengthy calibration procedure [1]. This poses the issue of the relevance (or irrelevance) of device modelling for the development of a new technology node, in which new processes and/or materials are introduced, that are not under complete control until the technology is finally released, and for which doping profiles and geometry are not known with sufficient accuracy.…”

Upcoming Challenges for Process Modeling

“…In fact, there are generally delays between the first suggestion of a technological concept, the qualitative understanding of its effects, and finally the quantitative reproduction within TCAD. This problem was summarized concisely by Mark Law by the aphorism "modeling tomorrow yesterday's technology" [9]. On the other hand, process simulation is especially helpful in the initial phase of technology development for the preselection of technological options.…”