Lateral Epitaxial Overgrowth of GaN on Si(111)
Abstract
The lateral epitaxial overgrowth of GaN on Si(111) substrates was achieved using an extension of our standard LEO process on GaN/Al2O3 substrates, and the reduction of the dislocation density was demonstrated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The growth on the Si(111) substrate was initiated with the deposition of a thin AlN buffer layer to avoid the formation of potentially detrimental silicon nitride at the interface. The wafers were then patterned with a SiO2 layer in which 5 micron wide opening separated by 35 microns were etched using buffered HF. After reloading the samples in the MOCVD chamber, the LEO growth was performed using our standard parameters. There are a few unresolved issues concerning the effect of the AlN buffer thickness and its chemical compatibility with the SiO2 mask layer, but after a basic optimization we were able to obtain ^ 5 microns of lateral overgrowth with smooth sidewalls in a reproducible manner. We are currently investigating the use of mask materials other than SiO2 to achieve LEO on Si(111) over a wider range of process parameters.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1998
- Accession Number
- ADA353896
Entities
Organizations
- University of California, Santa Barbara