Surface Fermi Level Pinning of Semipolar (11-22) n-type GaN Surfaces Grown on m-Plane Sapphire Substrates
Surface Fermi Level Pinning of Semipolar (11-22) n-type GaN Surfaces Grown on m-Plane Sapphire Substrates
Sungmin Jung(Chonbuk National University); 이성남(한국산업기술대학교); 안광순(영남대학교); 김현수(전북대학교)
9권 5호, 609~613쪽
초록
The Schottky barrier height and the S-parameter of the semipolar (1122) n-type GaN grown on m-plane sapphire substrate were investigated by using Schottky diodes fabricated with the different work functions of metals including Cu, Pd, and Pt. The Barrier inhomogeneity model applied to temperature dependent current - voltage characteristics of Schottky diodes revealed the mean barrier heights of 0.86, 0.77, and 0.82 eV for the Cu, Pd, and Pt contact, respectively. The extracted S-parameter was nearly zero, indicating a pinning of the surface Fermi level at approximately 0.8 eV below the conduction band. This could be attributed to the substantial crystallographic defects of semipolar GaN as verified from the atomic force microscope and x-ray diffraction measurements.
Abstract
The Schottky barrier height and the S-parameter of the semipolar (1122) n-type GaN grown on m-plane sapphire substrate were investigated by using Schottky diodes fabricated with the different work functions of metals including Cu, Pd, and Pt. The Barrier inhomogeneity model applied to temperature dependent current - voltage characteristics of Schottky diodes revealed the mean barrier heights of 0.86, 0.77, and 0.82 eV for the Cu, Pd, and Pt contact, respectively. The extracted S-parameter was nearly zero, indicating a pinning of the surface Fermi level at approximately 0.8 eV below the conduction band. This could be attributed to the substantial crystallographic defects of semipolar GaN as verified from the atomic force microscope and x-ray diffraction measurements.
- 발행기관:
- 대한금속·재료학회
- 분류:
- 전자/정보통신공학