Accession Number:

ADA222072

Title:

The Role of Heat Transfer during Reactive-Ion Etching of Polymer Films

Descriptive Note:

Technical rept.

Corporate Author:

CORNELL UNIV ITHACA NY SCHOOL OF CHEMICAL ENGINEERING

Personal Author(s):

Report Date:

1990-05-07

Pagination or Media Count:

17.0

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 polymethyl methacrylate and polyalpha-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 polymethyl 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

Subject Categories:

  • Polymer Chemistry
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE