Heteroepitaxy of CdTe on GaAs and silicon substrates

✍ Scribed by J.P. Faurie; R. Sporken; Y.P. Chen; M.D. Lange; S. Sivananthan

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 619 KB
• Volume: 16
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(93)90012-c

✦ Synopsis

CdTe can be grown directly by molecular beam epitaxy on substrates such as GaAs or silicon, which exhibit very large lattice mismatches of 14.6% and 19% respectively. The occurrence of dual epitaxy, which has been previously reported for growth on (100)GaAs, has also been found recently for growth on (211)GaAs. The (133)CdTe-( 211)GaAs heterointerface presents a smooth continuation of the tetrahedral bond network from GaAs to CdTe, which is not the case for the (211)CdTe-(211)GaAs interface. Single-domain, twin-free CdTe(111)B films are currently obtained on Si(100) surface where single atomic steps are dominant. The crystalline quality of CdTe/Si films has been dramatically improved as confirmed by X-ray diffraction, photoluminescence and electron microscopy investigations. The narrowest rocking curves obtained for as-grown epilayers are 70 arcsec for (133)CdTe/(211)GaAs, 50 arcsec for a flash-annealed (211 )CdTe/(211 )GaAs and 140 arcsec for ( 111)B CdTe/(100)Si. These results confirm that CdTe/GaAs and CdTe/Si composite substrates should be viewed as prime candidates to replace bulk CdTe substrates.