| 摘要 |
PURPOSE:To contrive reduction of dislocation of crystal and prevention of generation of twin and lineage in the case of producing single crystal with a liquid sealing Czochralski process by specifying the relation of the pulling-up velocity at a time for seeding and the respective velocities at a time for forming a shoulder, at a time for forming a straight drum part and at a time for finishing formation thereof. CONSTITUTION:A solid raw material and a liquid sealer 3 are introduced into a crucible 1 supported freely rotatably and elevatingly on a lower shaft 8 and pressure is exerted by inert gas and the solid raw material is made to melt 2 by heating it with a heating element 5. Then seed crystal 7 is dipped into the melt 2 and pulled up while rotating the seed crystal 7 and thereby single crystal 4 is pulled up. In the production of compound semiconductor single crystal, when the pulling-up velocity at a time for seeding is U, the velocity at a time for forming a shoulder part is V, the velocity at a time for forming a straight drum part is X and the velocity at a time for finishing formation of the straight drum part is W, the following inequalities are defined. U<V<X, W<=X. The generation of twin is made little by V<X and etched pit density is little because X can be made speedy and lineage of the rear part of crystal is made difficult-to be caused.
|
