The Role of Heat Transfer during Reactive-Ion Etching of Polymer Films
Abstract
A study of the kinetics of oxygen and argon reactive-ion etching (RIE) of organic polymer films and an analysis of substrate heat transfer was carried out. Radiative heat transfer played a significant role in determining the substrate temperature profile during RIE. At the relatively low pressure of 5 milliTorr, where anisotropic etch profiles are typically achieved, radiative heat transfer accounted for nearly 85% of the total energy (heat) flux away from the substrate. RIE processing time (substrate temperarture) drastically affected the RIE rate of chain-scissioning polymers which included poly(methyl methacrylate) and poly(alpha-methylstyrene), while processing time had absolutely no effect on etch rates of cross-linking polymers. To confirm the role of radiative heat transfer during RIE, the underside of a silicon wafer was painted flat-black, which increased the total radiative surface emittance and lowered the steady-state substrate temperature for poly(methyl methacrylate) under a given set of RIE conditions. Thermal bonding alleviated substrate heating and greatly improved etch rate control, but the practical use of this method in a state-of-the-art system remains doubtful. (jg)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 07, 1990
- Accession Number
- ADA222072
Entities
People
- B. C. Dems
- Francisco J. Medellı́n-Rodrı́guez
Organizations
- Cornell University School of Chemical and Biomolecular Engineering