Application of molecular beam mass spectrometry to chemical vapor deposition studies

Journal Article · Tue Sep 01 04:00:00 EDT 1992 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1143225· OSTI ID:7161832

Hsu, W L; Tung, D M ^[1]

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1. Sandia National Laboratories, Livermore, California 94550 (United States)

A molecular beam mass spectrometer system has been designed and constructed for the specific purpose of measuring the gaseous composition of the vapor environment during chemical vapor deposition of diamond. By the intrinsic nature of mass analysis, this type of design is adaptable to a broad range of other applications that rely either on thermal- or plasma-induced chemical kinetics. When gas is sampled at a relatively high process pressure ({similar to}2700 Pa for our case), supersonic gas expansion at the sampling orifice can cause the detected signals to have a complicated dependence on the operating conditions. A comprehensive discussion is given on the effect of gas expansion on mass discrimination and signal scaling with sampling pressure and temperature, and how these obstacles can be overcome. This paper demonstrates that radical species can be detected with a sensitivity better than 10 ppm by the use of threshold ionization. A detailed procedure is described whereby one can achieve quantitative analysis of the detected species with an accuracy of {plus minus}20%. This paper ends with an example on the detection of H, H{sub 2}, CH{sub 3}, CH{sub 4}, and C{sub 2}H{sub 2} during diamond growth.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 7161832
• Journal Information: Review of Scientific Instruments; (United States), Journal Name: Review of Scientific Instruments; (United States) Vol. 63:9; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

440101* -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BEAMS
CHEMICAL ANALYSIS
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
DEPOSITION
DESIGN
DIAGNOSTIC TECHNIQUES
MASS SPECTROMETERS
MASS SPECTROSCOPY
MEASURING INSTRUMENTS
MOLECULAR BEAMS
NATIONAL ORGANIZATIONS
OPERATION
QUANTITATIVE CHEMICAL ANALYSIS
SANDIA LABORATORIES
SPECTROMETERS
SPECTROSCOPY
SURFACE COATING
US AEC
US DOE
US ERDA
US ORGANIZATIONS