THE ROLE OF ACCELERATED CRUCIBLE ROTATION IN THE GROWTH OF HG1-XCDXTEAND CDTE CDZNTE/

Bulk growth methods for producing Hg1-xCdxTe (MCT), CdTe and CdZnTe ar e still important for a number of applications. Infrared detectors, pa rticularly photoconductors, are still made in bulk-grown MCT and the C dTe/CdZnTe family of materials are crucial as lattice-matched substrat es in the growth of layers of MCT by several epitaxial techniques, par ticularly Liquid Phase Epitaxy, (LPE). For many years the Accelerated Crucible Rotation Technique, (ACRT), has been used in the Bridgman gro wth of MCT and more recently in the Bridgman growth of CdTe/CdZnTe and in the Travelling Heater Method, (THM), for both MCT and CdTe. This p aper reviews tile various applications of ACRT to the growth of these important semiconductor materials. ACRT is shown to produce increases in stable growth rates, marked improvements in compositional uniformit y, larger single crystal regions, better crystalline quality, lower se cond phase precipitate levels and improved control of segregation beha viour. All of these changes are compared, where possible, to tile equi valent growth technique used in tile absence of ACRT. Theroretical con siderations of the fluid flows produced by ACRT can help in understand ing the differences in material properties obtained. Mass and heat tra nsfer effects have been studied but there is, as yet, no complete mode l which can explain the interactions between heat, mass and fluid flow s and their combined effect on tile growth process.