Method for heat-treating gallium arsenide monocrystals
AssigneeShin-Etsu Handotai Company Limited of Japan
InventorsYutaka Kitagawara, Susumu Kuwahara, Takao Takenaka
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Abstract
A heat-treating method for an indium-doped dislocation-free gallium arsenide monocrystal having a low carbon concentration and grown in the Liquid Encapsulated Czochralski method, comprising a two-step heat treatment: (i) heating the monocrystal at a temperature between 1050.degree. C. and 1200.degree. C. for a predetermined time length, and cooling the monocrystal quickly; and (ii) heating the monocrystal at a temperature between 750.degree. C. and 950.degree. C. for a predetermined time length, and cooling the monocrystal quickly.
Claims1
A heat-treating method for producing a semiconducting indium-doped dislocation-free gallium arsenide monocrystal having a resistivity of 10.sup.7 .OMEGA.cm or greater, said heat-treating method comprising conducting the following steps after a monocrystal having a low carbon concentration of 2.times.10.sup.15 cm.sup.-3 or lower is grown in a liquid encapsulated Czochralski method:
- (i) heating the monocrystal to a temperature between 1050.degree. C. and 1200.degree. C. for at least 30 minutes;
- (ii) cooling the monocrystal at a cooling rate of from 10.degree. C. per minute to 200.degree. C. per minute;
- (iii) heating the monocrystal at a temperature between 750.degree. C. and 950.degree. C. for at least 30 minutes;
- and
- (iv) cooling the monocrystal until the temperature reaches 300.degree. C. or lower at a cooling rate of from 10.degree. C. per minute to 200.degree. C. per minute.
Dependencies are inferred from the claim text.