DEVICE FOR VAPOR-PHASE GROWING OF THIN FILM

• Main Author: YASHIRO MASAAKI
• Format: Patent
• Language: English
• Published: 24.05.1983
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SEMICONDUCTOR DEVICES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PURPOSE:To enable accurate control of the flow rate of an organometallic gas by providing a light absorbing cell in the middle of a pipe supplying the organometallic gas, and by controlling the flow rate of the gas according to the degree of light absorption detected by the light absorbing cell. CONSTITUTION:A light emitted from a light source 6 is turned into a monochromatic light by a spectroscope 7, and this light is applied to an organometallic gas, e.g. a trimethyl aluminum (TMA) gas, in a supply pipe 4B through the intermediary of a light absorbing cell 5, and is detected by a photodetector 8. Therefore, with a graph of comparison between the intensity of the light detected by the detector 8 and the density of TMA prepared beforehand, the intensity of the light at that time is detected by the detector 8, the density of TMA is read out of the graph, and thereby the flow rate of TMA at the time can be determined. Thereby the flow rate of TMA can be quantified, and the control of the flow rate can be performed accurately.