Shinku

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The reproducibility of mass spectra of a quadrupole mass filter for six hydrocarbons such as CH₄, C₂H₆, C₃H₈, C₂H₂, C₂H₄ and C₃H₆ has been examined under a specified operational condition for the purpose of obtaining fundamental data to various applications. For each sample gas, the experiment was performed for three days and the spectrum was taken three times in every day at a constant gas pressure of 5×10^-7 Torr (nitrogen equivalent value) by admitting the sample gas continuously into the vacuum system.
The average value of pattern coefficient x, the standard deviation σ and the fluctuation coefficient 2σ/x were calculated from nine mass spectra by the ordinary statistical method. The fluctuation coefficients for each gas were found to be close to 0.02 when the pattern coefficient x was larger than 30. However, rather large fluctuations weer observed for x values smaller than 20 due to the reading error for small peak heights.
It may be concluded that the quadrupole mass filter used in the present study is applicable to quantitative measurement within the error of less than 2% during a period of several days if the condition of vacuum system is carefully controlled.

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The technology of making tantalum resistors is complicated, owing to the fact that tantalum films have three structures which are α-tantalum and β-tantalum and low density structure. The α-tantalum structure has the conventional b. c. c. structure corresponding to the bulk. The β-tantalum is told to show the tetragonal structure. In this paper, tantalum films are found to be produced in the R. F. sputtering system with typical background pressure of 3×10^-6 Torr before introducing of Argon gas. In R. F. sputtering, β-tantalum tended to be obtained when sputtering was performed at high pressure of the order of 5×10^-3 Torr. The R. F. sputtered tantalum films, α-structure are obtained less than the pressure of 5×10^-3 Torr, and mixture of α- and β- structures are obtained between 6×10^-3 Torr and 8×10^-3 Torr. Above 8×10^-3 Torr, complete β-structures in the film are found.

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