VPE Growth of (Al, Ga)As.
Abstract
The organometallic vapor phase epitaxial (OMVPE) growth process was utilized for the growth of Alx Ga1-x As alloys in both hot wall and cold wall reactor systems. Growth parameters including substrate temperature, V/III ratio, flow ratio, etc. were studied together with their influence on the electrical transport and luminescent properties of the epitaxial layers. Both p-type (Zn)and n-type (Te) dopants were used to achieve the desired doping profiles. Carbon and oxygen were found to be significant contaminants in these layers and two approaches to minimizing their concentration were studied. In the hot wall system HCl was added to the gas stream; in the cold wall system the use of graphite baffles was found to reduce the concentration of non-radiative centers. The photoluminescence efficiency of layers grown under optimized conditions were found to be comparable to that of LPE layers. Deep level transient spectroscopy (DLTS) measurements revealed two characteristic levels at approximately 0.41 eV and 0.49 eV respectively, with a weak dependence on compositions. Double heterostructure lasers were successfully fabricated from these layers and exhibited threshold current densities within a factor of 2 of layers of the same geometry using LPE material. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1979
- Accession Number
- ADA078264
Entities
People
- Gerald B. Stringfellow