Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Poly-Si etching using electron cyclotron resonance microwave plasma sources with multipole confinement

Journal Article · · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)
DOI:https://doi.org/10.1116/1.578242· OSTI ID:7034541
;  [1];  [2]
  1. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
  2. SEMATECH, Austin, Texas 78741 (United States)

In this study, mirror field and single coil 2.45 GHz electron cyclotron resonance microwave plasma sources were coupled to a multipole, multicusp plasma confinement system and used to produce chlorine plasmas for poly-Si etching. Scanning Langmuir probes were used to study the effect of process parameters on plasma potentials, plasma density, plasma density uniformity, and electron temperature, while poly-Si etching experiments on 150 mm diam wafers were used to relate process parameters and Langmuir probe results to etch rate, SiO{sub 2} selectivity, photoresist selectivity, and etch uniformity. Radio-frequency substrate bias at 13.56 MHz was used for ion energy control, and the addition of a third coil below the substrate plane was found useful for fine-tuning the radial plasma uniformity. Undoped poly-Si etch rates {gt}3000 A/min, Si/SiO{sub 2} etch selectivities {gt}25 and 150 mm diam etch uniformities {lt}2% at 1 {sigma} were obtained, but not simultaneously. Tradeoffs in choosing operating conditions for optimum poly-Si etch performance will be discussed.

DOE Contract Number:
AC05-84OR21400
OSTI ID:
7034541
Journal Information:
Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 10:4; ISSN 0734-2101; ISSN JVTAD
Country of Publication:
United States
Language:
English