Accession Number:

ADP013776

Title:

Polarity Selection Process and Polarity Manipulation of GaN in MOVPE and RF-MBE Growth

Descriptive Note:

Conference paper

Corporate Author:

CHIBA UNIV (JAPAN) CENTER FOR FRONTIERELECTRONICS AND PHOTONICS

Personal Author(s):

Report Date:

2002-06-03

Pagination or Media Count:

6.0

Abstract:

The polarity-controlled growth of Gallium Nitrides GaN on a sapphire substrate by metalorganic vapor phase epitaxy MOVPE and molecular beam epitaxy MBE was demonstrated. The mechanisms for polarity reversion of GaN by TMAl preflow in MOVPE growth and high-temperature deposited Aluminum Nitride AlN intermediate layers in MBE growth were discussed based on the two monolayers of Aluminum Al model. The kinetic process of GaN polarity selection on a sapphire substrate, Al layers, and AlN surface was investigated by RF-MBE growth. Reversing Ga polarity to N polarity could also be realized by nitridation of the deposited Al layers. These results provided a comprehensive understanding of the effects of surface stoichiometry, growth temperature, and N source species ammonia or N plasma on GaN polarity. It was concluded that GaN tended to grow with Ga polarity that was kinetically favorable on thermally cleaned sapphire substrates and Al-covered surfaces. The polarity conversion of GaN by TMAl preflow, AlN intermediate layer, or Al insertion layers relied on the fact that they provided an Al platform on which the subsequent epilayer preferred to grow with Ga polarity. 9 figures, 12 refs.

Subject Categories:

  • Electrical and Electronic Equipment
  • Solid State Physics
  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE