ENGINEERING SERVICES ON TRANSISTORS.
Abstract
Planar germanium transistors with 0.2-mil-wide emitter stripes and a 0.1-mil base-contact-to-emitter separation were fabricated. Terminal f sub T values from 3 to 5 Gc, unilateral gain of 14 db at 1 Gc, and a gain figure of 32 db at 1 Gc were measured. Although this performance is comparable to that of good mesa units, an appreciably higher performance should be achievable with this structure. Base contact resistance is a primary limitation on performance of these devices. Beam-lead technology has potential application in microwave transistor assembly. Relatively large beam-lead parasitics (0.3 nh inductance, 0.1 pf capacitance-to-collector) will cause some degradation in high-frequency performance of structures under current development but can probably be tolerated in the low-microwave region. More advanced beam-lead designs, in which the total inductance of lead and package is 0.15 nh or less, offer the possibility of achieving a performance equal or superior to that obtainable with conventional bonded-wire mounting. Increasing the disparity between emitter and collector barrier heights slowly degrades the collector efficiency when electron-phononinduced collector back-scatter in a hot-electron transistor is considered. Si is shown to be preferable to Ge and GaAs as a collector and appears capable of 85-percent collector efficiency with a collector field of 300,000 v/cm. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 30, 1964
- Accession Number
- AD0611591
Entities
People
- C. R. Crowell
- R. L. Pritchett
- Robert G. Edwards
- S. M. Sze