Silicon Etching in LAPPS
Abstract
Initial tests using LAPPS to etch silicon with sulfur hexafluoride-containing plasmas were carried out. Material removal rates and anisotropy were determined with respect to gas composition and substrate RF-induced self-bias level. At room temperature, the removal rate increased linearly with substrate bias. Mixtures of argon and sulfur hexalluoride etched approximately ten times faster (5000 A/min) than similar mixtures of oxygenisulfur hexalluoride (^500 A/min), with the difference being attributed to the passivation of the silicon by involatile silicon oxyfluoride (SiO(x)F(y),) compounds. At low-incident ion energies, these involatile species are believed to cause the observed tapered feature profiles, which became more vertical with increasing ion energy. Plasma and surface chemistry are also discussed, including the negative ion character of these plasmas.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 14, 2003
- Accession Number
- ADA412285
Entities
People
- D. D. Blackwell
- D. Leonhardt
- Richard F. Fernsler
- Robert A. Meger
- Scott G. Walton
Organizations
- United States Naval Research Laboratory