Low-temperature metalorganic chemical vapour deposition of AlN for surface passivation of GaAs

✍ Scribed by Shinji Fujieda; Masashi Mizuta; Yoshishige Matsumoto

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 559 KB
• Volume: 6
• Category: Article
• ISSN: 1616-301X
• DOI: 10.1002/(sici)1099-0712(199605)6:3<127::aid-amo228>3.0.co;2-f

✦ Synopsis

Aluminium nitride (AIN) thin films have been grown by low-temperature metalorganic chemical vapour deposition (MOCVD) to passivate GaAs. By utilizing hydrazine (N2H4), highly resistive amorphous-like AIN films were obtained at growth temperatures around 400 "C. At the AIN-GaAs interface, three deep trap levels were found: 0.6 eV (DL1) and 0.9 eV (DL2) below the conduction band minimum and 0.5eV (DL3) above the valence band maximum. The number of DL1 levels was reduced by preparing As-dimer-stabilised surfaces of GaAs. The capture cross-sections and time constants of DL1 -DL3 suggest that these levels originated from point defects, not from precipitates or disorder. Neither precipitation nor reaction was detectable by Auger electron spectroscopy after annealing at 900°C for 20 min, indicating that the AIN-GaAs interfaces are thermally stable. These results demonstrate that these AIN films are applicable as capping films for processing GaAs as well as passivation films.