Эмиссионный спектральный анализ в технологических процессах радиоэлектроники
Measuring installation is created and the procedure of carrying out of a spectrum analysis of a gas intermixture of laser data unit (LD) is fulfilled, the invariance dependences are removed, the relative intensity of a line of nitrogen from partial pressure of nitrogen in a working gas intermixture. It has allowed to enter a procedure of an issue spectrum analysis of a composition of a gas intermixture into a technological route of manufacturing LD. Designed installation for a spectrum analysis had single, but rather essential deficiency - major time of recording of required spectral sites. The long-lived time of recording is bound to use the photoelectric multiplier as the registrar of a photosignal. For recording the necessary spectral interval it is necessary to turn slowly a diffraction grating of a monochromator with the help of the step-by-step drive, consistently transiting from a smaller wave length to the greater. Velocity of scanning on a wave length is bound to necessity of achievement of necessary sensitivity of measurings of a spectral line intensity. Time of recording of required spectral sites borrowed about 90 seconds. For recording the relative spectral line intensity of nitrogen it is required 12 seconds, for CO – 40 seconds, for hydrogen – 90 seconds. In result we did not manage to fix small concentrations of the impurity gases, due to intensive uptake by their cold cathode. For an impurity of hydrogen it is the most sensitive, as presence of hydrogen at a working intermixture starts to affect parameters LD already at his partial pressure 10-2 Па though for other impurities this quantity on the order is more.
For improvement of quality of a spectrum analysis, precision of forecasting of a retentivity discharge monoblock LD it was necessary to reduce sharply time of recording of a spectrum of spontaneous radiation of the discharge. It became possible only at use of the modern analytical inventory - installations of firm Andor.
Use of analytical measuring installation with a lattice of 1200 pieces/mm has allowed to pick a spectral interval in which spectral lines of all chemical elements interesting us as now there is a basic line necessary for measurings concerning which defined an impurity concentration would be observed.