2DEG Mobility in AlGaN-GaN Structures Grown by LP-MOVPE

• Published in: Physica status solidi. B. Basic research 2001-11, Vol.228 (2), p.625-628
• Main Authors: Bougrioua, Z., Farvacque, J.-L., Moerman, I., Carosella, F.
• Format: Article
• Language: English
• Subjects: 68.55.Ac; 72.10.Di; 73.61.Ey; 81.15.Kk; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electronic transport in condensed matter; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; S7.14; Scattering by phonons, magnons, and other nonlocalized excitations; Theory and models of film growth; Theory of electronic transport; scattering mechanisms; Vapor phase epitaxy; growth from vapor phase
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/1521-3951(200111)228:2<625::AID-PSSB625>3.0.CO;2-I

Two‐dimensional electron gas (2DEGs) could be tailored through the growth by LP‐MOVPE of intentionally undoped AlGaN–GaN heterostructures with 6% < xAl < 36%. The carrier density (ns) is shown to be controlled by polarisation effects. Large carrier mobilities as high as 1710 cm2 V—1 s—1 at ns ∼ 9 × 1012 cm—2 can be measured at 300 K. For larger ns, the mobility drops first smoothly, then sharply when ns > 1.4 × 1013 cm—2. A two‐subband model for 2DEG transport, taking into account phonons and impurity scattering mechanisms is proposed to explain semi‐quantitatively the soft decay regime.