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

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6070629

Gorbatkin, S M; Berry, L A ^[1]; Swyers, J ^[2]

---

1. Oak Ridge National Lab., TN (United States)
2. SEMATECH, Austin, TX (United States)

In this study, mirror field and single coil 2.45 GHz electron cyclotron resonance (ECR) 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, photo-resist selectivity, and etch uniformity. RF 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 >3000 {Angstrom}/min, Si/SiO{sub 2} etch selectivities >25, and 150-mm diam etch uniformities >2% at 1 sigma were obtained but not simultaneously. Tradeoffs in choosing operating conditions for optimum poly-Si etch performance will be discussed.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6070629
• Report Number(s): CONF-911132-11; ON: DE92005114
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
CURRENT DENSITY
ECR HEATING
ELEMENTS
ETCHING
FILMS
HEATING
HIGH-FREQUENCY HEATING
ION SOURCES
MAGNETIC FIELDS
PLASMA
PLASMA HEATING
SEMIMETALS
SILICON
SURFACE FINISHING
THIN FILMS