Use of electric probes in silane radio frequency discharges

Journal Article · Thu Sep 01 04:00:00 EDT 1983 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.332758· OSTI ID:5602414

Mosburg, Jr, E R; Kerns, R C; Abelson, J R

The use of electrostatic probe techniques for measurement of the electron temperature kT/sub e/ and the electron density n/sub e/ in pure and BF/sub 3/ doped silane radio frequency (13.56 MHz) discharges is demonstrated to be feasible even though amorphous silicon is being deposited on the probe surfaces. The required conductivity of such deposited silicon surface layers is examined and compared with the measured photoconductivity and thermally induced conductivity of amorphous silicon. An equation is derived for the double probe current--voltage (I--V) curve which includes the first order effect of ac fields and can be used to determine the electron density. During typical depositions of thin films of amorphous silicon from such discharges, values of kT/sub e/ = 2--2.5 eV and n/sub e/ = (1--1.5) x 10/sup 9/ cm/sup -3/ were obtained. These values are consistent with those obtained by other workers using microwave and optical techniques. In BF/sub 3/ doped silane an abrupt step is observed in the Langmuir I--V curves which indicates the presence of a group of fast, anisotropic electrons. In diborane doped silane, probe measurements become unstable and irreproducible. For this reason we investigate a rf probe technique. The advantages and constraints inherent in using this method in our rf discharges are examined and analyzed.

• Research Organization: Solar Energy Research Institute, Golden, Colorado 80401
• DOE Contract Number: AC02-77CH00178
• OSTI ID: 5602414
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 54:9; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
ALTERNATING CURRENT
AMORPHOUS STATE
BORON COMPOUNDS
BORON FLUORIDES
CURRENTS
DATA
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRIC DISCHARGES
ELECTRIC FIELDS
ELECTRICAL PROPERTIES
ELECTRON DENSITY
ELECTRON TEMPERATURE
EQUATIONS
EXPERIMENTAL DATA
FLUORIDES
FLUORINE COMPOUNDS
FREQUENCY RANGE
HALIDES
HALOGEN COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
MATERIALS
MHZ RANGE
NUMERICAL DATA
PHOTOCONDUCTIVITY
PHYSICAL PROPERTIES
PROBES
SILANES
SILICON COMPOUNDS
TEMPERATURE EFFECTS