The lectures are so good. By the meantime I got some questions: 1. Why you don't want H in the RIE process? 2. What causes etched features at one edge of the wafer to have higher etch rates? 3. What causes the overall wafer-scale etch rate variation pattern observed in wafers?
1. I'm not sure I uderstand the question. Sometime you do want H (hydrogen) in the RIE process. 2&3. Across-wafer nonuniformity of etch rate is mostly due to nonuniformity is plasma properties in the etch chamber, which in turn is a function of gas flow uniformity and the ability to deliver power uniformly to that gas.
