AVS 58th Annual International Symposium and Exhibition
    Electronic Materials and Processing Division Thursday Sessions
       Session EM-ThP

Paper EM-ThP15
Substrate Template and V/III-Ratio Effects on the Surface and Structural Properties of HPCVD Grown InN Films

Thursday, November 3, 2011, 6:00 pm, Room East Exhibit Hall

Session: Electronic Materials and Processing Poster Session
Presenter: Ananta Acharya, Georgia State University
Authors: A.R. Acharya, Georgia State University
M. Buegler, Georgia State University
R. Atalay, Georgia State University
S. Gamage, Georgia State University
J.S. Tweedie, North Carolina State University
R. Collazo, North Carolina State University
N. Dietz, Georgia State University
B.D. Thoms, Georgia State University
Correspondent: Click to Email
Nucleation and growth processes in chemical vapor deposition determine the crystalline quality and orientation which also affect the surface configuration. The bulk and surface structural properties of InN layers grown by high-pressure chemical vapor deposition (HPCVD) were investigated by Raman spectroscopy, x-ray diffraction (XRD), and high resolution electron energy loss spectroscopy (HREELS). HREEL spectra of InN grown on GaN/sapphire with a group V/III precursor ratio of 630 showed surface NH species and nitrogen-termination. For this layer Raman spectroscopy and x-ray diffraction (XRD) showed c-axis film orientation. In contrast, HREEL spectra of InN grown directly on sapphire with a higher group V/III precursor ratio of 3000 revealed that the dominant surface species is NH2. For this sample, the Raman and XRD analysis indicate the existence of micro-crystallites oriented in the (01-11) direction. Two factors suggested to account for the appearance of these tilted planes are slower surface diffusion under more nitrogen-rich conditions and strain due to the larger lattice mismatch when growing on sapphire substrates.