Optimal activation condition of nonpolar a-plane p-type GaN layers grown on r-plane sapphire substrates by MOCVD

• Published in: Journal of crystal growth Vol. 326; no. 1; pp. 98 - 102
• Main Authors: Son, Ji-Su, Hyeon Baik, Kwang, Gon Seo, Yong, Song, Hooyoung, Hoon Kim, Ji, Hwang, Sung-Min, Kim, Tae-Geun
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2011; Elsevier
• Subjects: A1. Activation; A1. Ambient; A3. MOCVD; Activated; Activation; Annealing; B1. a-plane p-type GaN; B2. Hole concentration; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Gallium nitrides; Magnesium; Materials science; Methods of crystal growth; physics of crystal growth; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Optimization; Photoluminescence; Physics; Sapphire; Secondary ion mass spectrometry; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; A1. Activation; A1. Ambient; B2. Hole concentration; A3. MOCVD; B1. a-plane p-type GaN; Magnesium additions; Temperature dependence; Epitaxial layers; Epitaxy; Photoluminescence; Annealing temperature; Secondary ion mass spectrometry; MOCVD; Gallium nitride; III-V compound; Thin films; Rapid thermal annealing; Optical properties; Growth mechanism; Thermal annealing; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2011.01.061

The optimal conditions of p-type activation for nonpolar a-plane (1 1 –2 0) p-type GaN films on r-plane (1 –1 0 2) sapphire substrates with various off-axis orientations have been investigated. Secondary ion mass spectrometry (SIMS) measurements show that Mg doping concentrations of 6.58×10 19 cm −3 were maintained in GaN during epitaxial growth. The samples were activated at various temperatures and periods of time in air, oxygen (O 2) and nitrogen (N 2) gas ambient by conventional furnace annealing (CFA) and rapid thermal annealing (RTA). The activation of nonpolar a-plane p-type GaN was successful in similar annealing times and temperatures when compared with polar c-plane p-type GaN. However, activation ambient of nonpolar a-plane p-type GaN was clearly different, where a-plane p-type GaN was effectively activated in air ambient. Photoluminescence shows that the optical properties of Mg-doped a-plane GaN samples are enhanced when activated in air ambient.