Challenges in Semiconductor Etch Development and Opportunities for Plasma Modeling: An Industrial Perspective

The cutting-edge plasma etch tools and processes applied in semiconductor device manufacturing are incredible marvels of human ingenuity. However, the day-to-day development of the etch technology is much less glamorous. To achieve desired electrical performances, morphological targets need to be met often at nanometer accuracy. Unfortunately, there are no physical knobs such as “profile shape”, “roughness”, “etch rate” or “selectivity” on production tools. It is rather the users who must convert these process metrics on silicon into equipment input variables such as “power”, “pressure”, “flow rates”, etc. Although Modeling and Simulation (M&S) has been instrumental for making such connections, in practice engineers still revert to trial-error cycles and intuitions. In this talk, we will discuss the true effectiveness of M&S in industrial etch development, especially in the backdrop of today’s increasing degree of hardware sophistication and atomic level control tolerances. We will point out some of the major shortcomings of M&S that prevented it from its wide adoption in the industry, including the issues in chemistry database, computation efficiency, and the wildcard of surface reaction mechanisms. We will also discuss the unique role of analytical models, especially its potential in accelerating process tuning and reducing numerical computations.