Angular dependence of the redeposition rates during SiO2 etching in a CF4 plasma

Autor: Sang Heup Moon, Gyeo-Re Lee, Sung-Wook Hwang, Byeong-Ok Cho
Rok vydání: 2001
Předmět:
Zdroj: Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 19:730-735
ISSN: 1520-8559
0734-2101
DOI: 10.1116/1.1368202
Popis: The angular dependence of the redeposition rates during SiO2 etching in a CF4 plasma was studied using three types of Faraday cages located in a transformer coupled plasma etcher. The SiO2 substrates were fixed on sample holder slopes that have different angles to the cathode. The substrate was subjected to one of three processes depending on the design of the Faraday cage, i.e., redeposition of sputtered particles from the SiO2 bottom surface (case I), substrate etching by incident ions (case II), or simultaneous etching and redeposition (case III). Both the redeposition and the etch rates were measured by changing the substrate–surface angle and the self-bias voltage in the range of −100 to −800 V. The redeposition-only rates (case I) at −450 and −800 V closely followed the quadratic curve of the angle whereas the rates at −100 V followed the cubic curve, indicating different mechanisms of the bottom SiO2 etching depending on the energy regimes. The steep increase of the redeposition rate with the angle...
Databáze: OpenAIRE