Vapour pressure-controlled Czochralski growth apparatus

摘要

An apparatus for vapour pressure-controlled Czochralski growth of AIII-BV crystals consists of a high pressure container with pressure-tight rotation and lifting systems for a seed crystal-bearing pulling shaft which extends into a tightly sealed growth vessel within the container, the vessel containing a crucible, sealing systems for the pulling shaft, a system for temperature gradient adjustment along the pulling axis, a process viewing system and a dissociating component supply system. The novelty is that: (a) the growth vessel (2) can be separated into upper and lower parts (2a, b); (b) a dome-shaped fitting (13) is positioned on the vessel upper part (2a) and has a moving conical seal (15) which encloses the pulling shaft (9) and which consists of a housed sealing cone (15a); (c) the pulling shaft (9) is positioned in a ceramic tube which is located, together with the conical seal (15), in a tube (14) passing through the dome-shaped fitting (13), the wall of the tube (14) being formed by the sealing cone housing (15b); (d) the upper end face of the sealing cone housing (15b) seals tightly with the lid of the growth vessel upper part (2a) and the lower end face of the housing (15b) is fixed to a convection barrier (30); and (e) an additional vapour pressure source (19) for the dissociating components is positioned in the upper part of the dome-shaped fitting (13).