Nitride Semiconductors for Ultraviolet Detection
Abstract
Monocrystalline thin films of A1N and GaN have been deposited on vicinal alpha(6H)-SiC(0001) wafers via gas-source MBE and cold-wall metalorganic (MO) CVD and extensively investigated via high-resolution TEM. Elemental metal sources combined with activated nitrogen generated using an ECR plasma were employed in the MBE system; triethylgallium, triethylaluminum and ammonia were used in the MOCVD system. The MBE research has also included n-(Si) and p- TYPE(Mg) doping and the creation of p-n junctions. The effects on growth of T, P and MO flux have been investigated in the MOCVD work. Below the critical thickness, A1N only contains threading dislocations emanating from the misfit dislocations; above this thickness, defects parallel to the growth surface greatly increase. The defect density of A1N grown on SiC at 1100 deg C is much lower than that contained in materials deposited at 700 deg C. Deposition of GaN on an A1N buffer layer previously deposited on sapphire or SiC results in a larger number of dislocations parallel to the growth surface. A system for the deposition of InN and its solid solutions which addresses the problems of the low decomposition pressure has also been designed. The feasibility of designing an ammonia cracker cell for the MBE system to provide an alternative source of activated nitrogen is being investigated. microelectronic and optoelctronic device designs have been produced and device related activities including contact studies involving Zn/au and Cr/Au and Au, reactive ion etching and optical characterization have been inundated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1993
- Accession Number
- ADA274246
Entities
People
- Bradley T. Perry
- D. Hanser
- K. Gruss
- L. Smith
- Robert F Davis
Organizations
- North Carolina State University