Alternative passivation for silicon (100), environmentally benign manufacturing, and cooperative strategy in semiconductor industry

Abstract

My personal involvement, as a research graduate student, sponsored by Engineering Research Center, a center created by National Science Foundation and Semiconductor Research Corporation demonstrates that, through industrial research staffs' mentoring, university research can bring innovative environmentally benign manufacturing methods to the U.S. semiconductor industry. Our group has used methoxy to protect the bare silicon surface, because we have identified that the industrial standard, hydrogen passivation of silicon (H-Si) degrades rapidly when exposes to air. In this thesis, two new processing steps are added to make this methoxy passivation compatible to industrial practice. In addition, a preliminary gate oxide test demonstrated that this methoxy terminated silicon (MeO-Si) yielded a thinner ultra thin gate oxide than those wafers cleaned by IBM's conventional RCA and dilute hydrofluoric acid last clean without compromising its reliability. Furthermore, particle count results shown that this MeO-Si has the same particle resistance as H-Si. Further mechanistic and thermodynamic studies are performed such that this process is optimized. As a result, MeO-Si is 49 times more stable than H-Si against air degradation. Through this center, an Environmental Safety and Health incorporated Cost of Ownership is developed in this thesis. This is done by using in vitro studies to evaluate the toxicity of new chemicals used, and by using lifecycle analysis to calculate the amount of untreated chemical, which leaks to the environment. Both of these will give rise to an environmental figure of merit to modify the conventional cost of ownership. In the last section, a strategic analysis of this Engineering Research Center is performed to demonstrated that students are a very important media to (1) facilitating technology transfer to industry, (2) enhancing collaboration along the chain of semiconductor industrial participants.