Arsine analysis by sealed inductively coupled plasma spectroscopy

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:5651172

Jacksier, T

An enclosed inductively coupled plasma (ICP) was designed to overcome the limitations of the conventional ICP torch for the analysis of toxic and reactive gases. The extreme toxicity of arsine prevents safe application of a standard ICP torch and gas exhaust for the direct determination of impurities in arsine. The enclosed ICP provides containment of toxic gases in a quartz discharge container. The total volume of toxic gas consumed is minimized. Parameter characterization of a sealed ICP system was investigated. The choice and role of the additive gas, effect of flow rate, discharge container size and geometry, rf power, signal reproducibility, operating parameters, and procedures were determined. Modifiers were investigated to prevent deposition of arsenic and metallic impurities to the cooler container walls. The first reported direct qualitative analysis of semiconductor-grade arsine is described. Chlorine was found to be the most effective additive gas for arsenic vaporization for both flowing and static ICP operation. Chlorine addition to the argon stream extended the arsine introduction to concentrations of up to 10% into the discharge. An rf generator (40.68 MHz) power of 1.0 kW and 30% chlorine content for 7.11% arsine in a 65-mm diameter spherical container were applied to identify eight impurities qualitatively: C, Fe, Ge, Mg, Mo, Ni, Sn, and V. A vapor phase introduction system was developed to calibrate the SICP. Theoretical detection limits for tin in arsine and chlorine were calculated as 2.00 and 0.218 ppb. A hypothesis was formulated to describe the stability of the chlorine-containing arsine plasma. The absolute noise power spectra of atomic emission signals from the SICP for flowing and static operation demonstrated that noise below 5 Hz was lower than observed in conventional ICP discharges. White noise levels were lower for the SICP than a conventional ICP.

• Research Organization: Massachusetts Univ., Amherst, MA (United States)
• OSTI ID: 5651172
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
ARGON
ARSENIC
CHEMICAL ANALYSIS
CHLORINE
ELEMENTS
EMISSION SPECTROSCOPY
FLUIDS
GASES
HALOGENS
METALS
MULTI-ELEMENT ANALYSIS
NOISE
NONMETALS
OPTIMIZATION
PLASMA
RARE GASES
SEMIMETALS
SENSITIVITY
SPECTROSCOPY
TIN