| 摘要 |
PURPOSE:To obtain a single crystal of group III-V compound semiconductor of high quality in a liquid seal pull method, by adjusting the temp. of the melt of the starting material for the crystal to the optimum temp. corresponding to the pulling speed by comparing the weight signal of the seed crystal and the signal of the current value to the referential signal. CONSTITUTION:A specified amt. of group III and V element are charged in a crucible 3 provided in a high pressure vessel 1 and a liquid seal agent such as B2O3 is added thereto. The crucible 3 is heated in a heater 2 to form a melt layer 11 of B2O3 and a melt layer 12 of the group III-V compound. The weight of the seed crystal 7 formed before the contact of the seed crystal 7 with the layer 12 of the melt of the compound is measured by a sensor 8. On one hand, the current value passing between the seed crystal 7 and the melt 12 by the impression of voltage is detected. Both signals are inputted to an operation circuit 13 and are compared with a referential pattern of the optimum temp. corresponding to the pulling speed. The difference is inputted to a controlling circuit 14 for the source of the heater to adjust the heating temp. and maintain the melt 12 at the optimum temp., thereafter, the pulling operation of the crystal is performed. |
