| 摘要 |
PROBLEM TO BE SOLVED: To realize a steep doping change at the time of successively growing layers of different impurity density by making the number of open molecular beam cells different when adjacent layers of different impurity are formed by using plural molecular beam cells for supply of material to the same material of the desired layer. SOLUTION: Though each one molecular beam cell is used for As and Be cells, a p-GaA layer 19a is grown by setting Ga1 cell and Ga2 cell and a p+- GaAs layer 19b by Ga1 cell in such a way that each cell generates molecular beam. Accordingly, two Ga cells are used. For the layer 19b, since the molecular beam amount of Ga is a half of that of the layer 19a, the molecular beam amount of the Be cell is constant but the doping density can be twice. Furthermore, at the time of starting the layer 19b, since the doping density is changed only by closing the Ga2 cell, there is no flux transient phenomenon and a very steep change in doping density can be obtained.
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