RESEARCH AND DEVELOPMENT TO OBTAIN SEMICONDUCTOR DIODES FOR ELECTRONIC TUNING.
Abstract
The devices required are being made by planar epitaxial silicon technology, with diffusion of a heavily-doped p-type region into an n-type layer on an n+ substrate. Additional studies were made of the factors influencing avalanche breakdown at the Si-Si 2 interface of largearea planar diodes, and additional devices were fabricated using techniques which result in a lower electric field in reverse-biased junctions. Analysis indicates that the guard-ring structure, plus the use of HC1 etching immediately prior to epitaxial growth, improved photolithographic techniques, and gettering increase the yield of large-area planar diodes with breakdown voltage > or = 200 V. The over-all yield of diodes meeting the Device 'B' specification in every respect was approximately 9% during the latter part of the pilot production period. The principal problem was attaining the 200-V breakdown voltage. The median electrical characteristics of the in-specification devices were significantly better than required in the case of Q and log C vs. log V slope, and appreciably better than required in the case of I sub R. It was demonstrated that the log C vs. log V slope could be improved by modification of the diffusion depth of the main region of the diodes, a procedure which can be done with the guard-ring structure without adversely affecting the breakdown voltage level.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 26, 1964
- Accession Number
- AD0608950