Si delta-doped GaAs and AlGaAs by low-pressure MOVPE

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 1994-12, Vol.28 (1), p.204-208
• Main Authors: Tromby, M., Di Paola, A., Ritchie, D.M., Dellagiovanna, M., Di Egidio, M., Vidimari, F.
• Format: Article
• Language: English
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Gallium arsenide; Heterostructures; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; MOVPE; Physics; Semiconductor devices; Vapor phase epitaxy; growth from vapor phase
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/0921-5107(94)90048-5

Delta doping of Si in GaAs and Al 0.22Ga 0.78As by low-pressure MOVPE has been explored for varying growth interruption times and SiH 4 partial pressures. The resultant sheet concentrations could be interpreted according to the total amount of SiH 4 introduced. Saturations in sheet density were observed at 6.6 × 10 12 and 3.6 × 10 12 cm −2 in GaAs and Al 0.22Ga 0.78As, respectively. Mobility results were obtained for a range of different sheet concentrations at both 300 and 77 K. Hall measurements on single delta-doped pseudomorphic high electron mobility transistor devices showed a maximum sheet density of 3.4 × 10 12 cm −2 at 300 K and 4.3 × 10 12 cm −2 at 77 K with mobilities of 2350 and 2700 cm 2 V −1 s −1, respectively. The maximum extrinsic transconductance of such devices was 400 mS mm −1 with a corresponding saturation current of 360 mA mm −1 for 0.5 μm gate length devices.