| 摘要 |
PURPOSE:To grow a crystal with gradient distribution of doping carrier concentration in an active layer by a method wherein, during an active layer growing process, specified impurity is doped to be grown for specified time and then the concentration of hydrogen chloride gas in a reaction system is controlled. CONSTITUTION:After growing a buffer layer, main valves 10b are closed and a bypass valve 10a is opened simultaneously flowing H2S gas diluted with H2 gas in a branching pipe 7 to feed H2S gas to a reaction pipe 2 at the flow rate e.g. 18cc/min as well as evaporated gas of AsCl3 in another branching pipe 5 to be grown for 1min. Later H2 gas fed to the other branching pipe 6 is reduced from e.g. 300cc/min to 30cc/min and then the main valves 10b are opened and the bypass valve 10a is closed to feed the evaporated gas of AsCl3 to the reaction pipe 2 to be grown for 3min. Resultantly a crystal with an active layer 0.3mum thick and gradient distribution of carrier concentration can be grown.
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