Mitsubishi Monsanto Chemical Co., Ltd.

Mitsubishi Chemical Industries Limited

Fumio Orito

Toshihiko Ibuka

Shin-ichiro Kawabata

Yutaka Yamada

Yuichi Seta

A method for producing a semiconductor device comprises the steps of: preparing a III.sub.b -V.sub.b group compound single crystalline semiconductor substrate produced by a liquid encapsulated Czochralski process, the single crystalline semiconductor substrate having a carbon concentration of 1.times.10.sup.15 cm.sup.-3 or less, implanting conductive impurity ions into the single crystalline semiconductor substrate and then annealing, and a semiconductor device produced by this method.

Method for producing semiconductor device and semiconductor device

When the growth of a single crystalline III.sub.b -V.sub.b group compound is carried out employing the horizontal Bridgeman method or the gradient freeze method, it is likely that polycrystals will be grown, crystal defects will form, and the distribution of impurities will not be uniform, especially if the diameter of the single crystal is large. In the present invention, the cooling rate of the melt is controlled in an inconstant manner. Namely, crystal growth is interrupted at least once and/or the cooling rate at an earlier growth period is controlled at a high value. From 40 to 65% of the total melt crystallizes at the time when 30% of the total time required for growth has elapsed. The high yield of a single crystal is attained according to the present invention.

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Tsuchiura, Japan

Fumio Orito