DEVELOPMENT OF A 1 KW, 1 KV AUDIO TRANSISTOR AND DRIVER TRANSISTOR FOR SONAR APPLICATIONS.
Abstract
Efforts were continued on a program to develop and fabricate an audio output power transistor and a suitable driver power transistor for sonar applications. Problems encountered in the epitaxial refill of the emitter-base overlay wafer are discussed in detail. Experiments on the glassing of high-voltage collector junctions are described which show that the problem of degradation of voltage in glassing is due to positive charge formation in the oxide-silicon nitride system. Significant improvement in breakdown voltage after glassing was realized by eliminating the thermal oxide and depositing silicon nitride directly on the base junction. Collector voltages as high as 1400 volts were observed on glassed transistors. A method of diffusing the collector contact region is also described. The characteristics of driver transistors fabricated during this interval are given and the test conditions described. These devices had a BV sub CEO (sus) greater than 400 volts.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1967
- Accession Number
- AD0822203