Trial Production of the Double-Knudsen Cell-Mass Spectrometer and Fundamental Study on Compound-Semiconductor Materials.

质谱仪是分析复杂气体物质的最佳方法，例如砷，它是III-V族半导体中的主要元素。用双聚焦质量分析系统和装有双克努森池的小电炉组成了双克努森池-质谱仪的样机，并将其应用于砷活度的测定，在双克努森池中比较参比样品和活度未知样品的砷离子强度。对质谱计的效率进行了几方面的研究，得到了以下结果：1.测定了残余气体和砷的电离势，以及纯铜和银的蒸发热。实验结果表明，质谱仪的电离、检测系统和电炉工作准确; 2.应用Belton-Fruehan方程，用单Knudsen池法测定了Ag-Ga系中元素的活度; 3.用单Knudsen池法结合单体法测定了半导体基本系Ga-As系中砷的活度，并与单Knudsen池法进行了比较。4.采用双克努森池法测定了Cu-As系稀溶液中的砷活度，并<As>根据实验结果估算了铜熔体中的γ_0，实验结果表明，多种方法可用于复杂体系的热力学性质的质谱测定。本课题组将用双克努森质谱计测量砷、锑、磷等复杂元素稀溶液的热力学性质。

A mass spectrometer is the best method for the analysis of complex gas species such as arsenic which is a major element in the III-V semiconductors. A prototype of a double Knudsen cell - mass spectrometer which is constituted with double focusing mass analysis system and a small electric furnace contained the dual Knudsen cells has been made and was applied to measure the arsenic activities by comparing of ion intensities of arsenic between reference and activity unknown samples in the twin Knudsen cells. Several kind of studies were carried out for efficiency tests of the mass spectrometer and the following results have been obtained :1.The ionization potentials of residual gases and arsenic, and the heats of vaporization of pure Cu and Ag were measured. The experimental results suggest that the ionizing and detecting systems and the electric furnace in the mass spectrometer operates accurately.2.Activities of elements in the Ag-Ga system were determined with a single Knudsen cell method by applying the Belton-Fruehan equation.3.Arsenic activity in the Ga-As system which is a fundamental system of a semiconductors was determined by using the single Knudsen method combined with a monomer-dimmer method as well as activity of gallium.4.The double Knudsen cell method was applied to determine the arsenic activities in the dilute solution of the Cu-As system and the gamma^0_<As> in molten copper were estimated by the experimental results.Those experimental results show that several methods can be applied to complex systems for determination of the thermodynamic properties in the mass spectrometric method. The present research group will measure the thermodynamic properties at diluted solution of complex elements such as arsenic, antimony and phosphorous by the double Knudsen- mass spectrometer.