| 摘要 |
PURPOSE:To obtain a dense GaN film minimal in pinholes, by exposing a substrate held at the prescribed temp. or below to an N-containing gaseous compound and a Ga-containing gaseous compound, by evacuating the gases in the vicinity of the substrate with each operation mentioned above, and by repeating the above course plural times. CONSTITUTION:A gas composed of [Ga(C2H5)2] diluted with H2 and an NH3 gas diluted with H2 are prepared so that they are introduced into a reaction chamber 1 from a pipe 7 and a pipe 8, respectively. Subsequently, solenoid valves 9, 10 are closed and the inside of the reaction chamber 1 is evacuated 6 to about 10<-4>torr. During the course of the above procedure, temp. of the substrate 2 composed of fused quartz plate is held at about 750 deg.C by means of a heater 4. Then, for example, the valve 9 alone is opened for one second, and both of the valves 9, 10 are closed for 0.5sec. Successively, the valve 10 alone in opened for one second, and both of the valves 9, 10 are closed for 0.5sec, and the above-mentioned operations are repeated, e.g., one hundred times. As a result, the film formed on the substrate 2 proves to be a polycrystalline film of GaN by an X-ray diffraction experiment.
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