Structural analysis of metalorganic chemical vapor deposited AIN nucleation layers on Si (1 1 1)

• Published in: Journal of crystal growth 2004-08, Vol.268 (3), p.515-520
• Main Authors: Zang, K.Y, Wang, L.S, Chua, S.J, Thompson, C.V
• Format: Article
• Language: English
• Subjects: A1. Atomic force microscopy; A1. Transmission electron microscopy; B1. AlN; B1. GaN; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; General studies of phase transitions; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nucleation; Physics
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2004.04.083

AlN nucleation layers are being investigated for growth of GaN on Si. The microstructures of high-temperature AlN nucleation layers on Si (1 1 1) substrates grown by metalorganic chemical vapor deposition with trimethylaluminum (TMA) pretreatments have been studied using atomic force microscopy (AFM) and transmission electron microscopy (TEM). The AFM results show that with TMA pretreatment, AlN nucleates under a pseudo-two dimensional growth mode due to the enhanced lateral growth rate and improved wetting property of AlN on silicon. In addition, with TMA pretreatment, absence of amorphous SiN x layer at the interface demonstrates good crystalline quality. Transmission electron diffraction patterns reveal epitaxial crystallographic orientation: AlN[0 0 0 1 ]||Si[1 1 1 ] and AlN[1 1 2 ̄ 0 ]||Si[1 1 0 ] . High-resolution TEM measurements also indicate a 5:4 lattice matching relationship for AlN and Si along the Si [1 1 0] direction.