Systematic oxygen impurity reduction in smooth N-polar GaN by chemical potential control
Abstract
Process chemical potential control and dislocation reduction were implemented to control oxygen concentration in N-polar GaN layers grown on sapphire substrates via metal organic chemical vapor deposition (MOCVD). As process supersaturation was changed from ∼30 to 3400, the formation energy of the oxygen point defect increased, which resulted in a 25-fold decrease in oxygen incorporation. Reducing dislocations by approximately a factor of 4 (to ∼109 cm−3) allowed for further reduction of oxygen incorporation to the low-1017 cm−3 range. Smooth N-polar GaN layers with low oxygen content were achieved by a two-step process, whereas first a 1 µm thick smooth N-polar layer with high oxygen concentration was grown, followed by low oxygen concentration layer grown at high supersaturation.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 29, 2021
- Source ID
- 10.1088/1361-6641/ac3638
Entities
People
- Dennis Szymanski
- Felix Kaess
- Ke Wang
- Pramod Reddy
- Ramón Collazo
- Ronny Kirste
- Seiji Mita
- Zlatko Sitar
Organizations
- National Science Foundation
- United States Army Research Laboratory