| Popis: |
Molecular-beam epitaxy (MBE) has been utilized to deposit single crystal films of ZnTe and CdZnTe/ZnTe onto Si(100) and Si(112) substrates. Parallel epitaxy of ZnTe(100) and CdZnTe(100)/ZnTe(100) has been observed for growth on Si(100) substrates misoriented from 0-8 degrees towards the [011] direction. With ZnTe initiation layers, high quality CdZnTe(100) films have been demonstrated on both 4° and 8° misoriented Si(100) with x-ray rocking curve FWHM as narrow as 158 arc-seconds, which is comparable to that obtained with GaAs/Si composite substrates. The observed surface morphologies are superior to those obtained on GaAs/Si composite substrates. HgCdTe(100) films with x-ray FWHM as low as 55 arcseconds and average etch pit densities of 5 x 106 cm2 have been deposited by liquid phase epitaxy on these MBE CdZnTe/ZnTe/Si(100) substrates. On vicinal Si(1 12) substrates, ZnTe films are observed to nucleate in either the (1 12) or its twin (552) orientation depending on the misorientation of the Si substrate away from (1 12). For Si(1 12) misorientations of 5° or 10° towards from the [1 1-1] direction, ZnTe nucleates in a parallel (1 12) orientation, while for misorientations of 0° or 5° away from the [1 1-1] direction, ZnTe is observed to nucleate in a (552) orientation. CdTe deposited on ZnTe/Si(112) is observed to nucleate in the same orientation as the ZnTe. CdTe(552) epilayers are of substantially higher quality than (1 12)oriented films. X-ray rocking curves as narrow as 1 10 arc-seconds have been observed for the CdTe(331) reflection in the case of (552)-oriented epitaxy. |
