Defect Control and Denuded Trap Zones in the III-V Semiconductors
Abstract
The effects of a variety of different treatments on the diffusion lengths in GaAs wafers were investigated. Sealed ampule proximity-capped anneals of 16 hours at 950 C were found to increase minority carrier (hole) diffusion lengths in 1 x 10 to the 17th power Si doped GaAs from initial values of about 0.8 microns to 1.9 microns. This improvement appears to be associated with the reduction in density of a hole trap at E sub v + 0.3 eV which has a capture cross-section in the 10 to the minus 14th to 10 to the minus 15th sq cm range. The proximity anneal also greatly reduced the densities of electron traps, including EL2, but there was no direct correlation of electron trap density and improved carrier lifetime. In other studies the effects of isoelectronic In and Sb doping on the hole traps in Be-doped p-GaAs and electron traps in Si-doped n- GaAs (100) grown by molecular beam epitaxy (MBE) were investigated. The addition of 0.2 to 1% indium causes large reductions of electron trap densities in layers grown at 550 C and also reduces certain hole traps. Homojunction GaAs bipolar transistors npn and pnp have been fabricated with base layers containing In isoelectronic doping and are found to have significantly better characteristics than if the In is omitted. Keywords: Gallium arsenide; Diffusion lengths; Carrier lifetime; MBE; Isoelectronic doping; Indium; Charge carriers; Electron capture; Antimony; Beryllium.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 20, 1989
- Accession Number
- ADA214099
Entities
People
- Arthur G. Milnes
- Tuviah E. Schlesinger
Organizations
- Carnegie Mellon University