DC plasma etching of silicon by sulfur hexafluoride. Mass spectrometric study of the discharge products
Polycrystalline silicon wafers were etched in dc discharges of SF/sub 6/. SF sub x species were extracted from the discharges and measured with a mass spectrometer. A synstematic procedure was used to measure the SF sub x 2= signals such that they are indicators of events in the discharge close to the sample undergoing etching. The picture that emerges is remarkably simple and shows the relative stability of several SF sub x species including SF/sub 6/, SF/sub 4/, SF/sub 2/, and SF which are shown to be extracted from the discharge both in the presence and absence of the silicon sample. When silicon is being etched on the cathode of the discharge cell, the only significant additional products are SiF/sub 4/ and S/sub 2/F/sub 2/. A comparison of blank and sample data for opposite substrate polarities shows that there is only a small cation-assisted etching effect and suggests that ions do not play an important role in the etching of silicon by SF/sub 6/ discharges.
- Research Organization:
- Department of Chemistry and Laboratory for Surface Studies, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211
- OSTI ID:
- 6848130
- Journal Information:
- Plasma Chem. Plasma Process.; (United States), Journal Name: Plasma Chem. Plasma Process.; (United States) Vol. 1:2; ISSN PCPPD
- Country of Publication:
- United States
- Language:
- English
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