| 摘要 |
Process for producing a single crystal of the semiconductive indium phosphide (InP) compound using the Czochralski pulling method by liquid encapsulation, in parallel with the crystallographic <111> axis defined with the phosphorus (P) face facing towards the bath, this process comprising, in order to reduce the dislocation content in the body of the ingot, the formation of a narrowing in the diameter of the ingot (or neck) at the beginning of pulling under the seed, characterised in that it additionally comprises the formation, at the solid-liquid interface of the pulling, of a planar face with a diameter slightly smaller than the diameter of the ingot obtained along a crystallographic facet perpendicular to the pulling axis, second means resulting in the formation of a discontinuity between the central region of the crystal resulting from the pulling from the planar part of the solid-liquid interface and the peripheral region of the crystal originating from the pulling from the nonplanar region external to this interface and resulting in the existence, as a result of the thermal gradients at the pulling temperature, of a relative variation DELTA ao/ao in the lattice parameter ao of the undoped indium phosphide (InP) on each side of the discontinuity, and the introduction of dopant ions into the pulling bath in a concentration which produces a relative variation DELTA a/a in the lattice parameter a of the doped crystal, a variation DELTA a/a substantially equal and opposite in sign to the relative variation DELTA ao/ao. <IMAGE> |
