Surface polarity dependence of decomposition and growth of GaN studied using in situ gravimetric monitoring

• Published in: Journal of crystal growth Vol. 246; no. 3; pp. 230 - 236
• Main Authors: Koukitu, Akinori, Mayumi, Miho, Kumagai, Yoshinao
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2002; Elsevier
• Subjects: A1. Etching; A1. Surface processes; A3. Vapor phase epitaxy; B1. Nitrides; B2. Semiconducting gallium compounds; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Vapor phase epitaxy; growth from vapor phase; A1. Etching; A1. Surface processes; A3. Vapor phase epitaxy; B1. Nitrides; B2. Semiconducting gallium compounds; Inorganic compounds; Crystal orientation; Thermal decomposition; Gallium nitrides; Surfaces; VPE; Crystal growth from vapors; Experimental study; Hydrochloric acid; Thin films; Anisotropy; MOVPE method; Growth mechanism; Reaction mechanism; Polarity; Kinetics; Low temperature; Homojunctions; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(02)01746-3

The influence of lattice polarity of wurzite GaN(0 0 0 1) on its decomposition rate was investigated using an in situ gravimetric monitoring (GM) method with freestanding GaN(0 0 0 1) substrates. At temperatures between 800°C and 850°C, the decomposition rate of GaN(0 0 0 1) was faster than that of GaN( 0 0 0 1 ̄ ). On the other hand, the decomposition rate of GaN( 0 0 0 1 ̄ ) was faster than that of GaN(0 0 0 1) at temperatures between 900°C and 950°C. The relation between the decomposition rate and the H 2 partial pressure ( P H 2 ) indicates that the rate-limiting reactions are N(surface)+ 3 2 H 2(g)→NH 3(g) at lower temperatures, but Ga(surface)+ 1 2 H 2(g)→GaH(g) at higher temperatures. In addition, we used the GM method to measure the growth rate of GaN(0 0 0 1) on freestanding GaN(0 0 0 1) substrates. In the low-temperature region, GaN( 0 0 0 1 ̄ ) grew faster than GaN(0 0 0 1), whereas GaN(0 0 0 1) grew faster than GaN( 0 0 0 1 ̄ ) in the high-temperature region.