PRODUCTION ENGINEERING MEASURES (PEM) FOR A GERMANIUM MICROWAVE TRANSISTOR.
Quarterly progress rept. no. 2, 30 Sep-31 Dec 64,
TEXAS INSTRUMENTS INC DALLAS
Pagination or Media Count:
The 1.5 Gc and 3.0 Gc noise figure of planar germanium devices using the L-78A pattern is typically 4.8 db and 9.5 db, respectively. The L-78A devices f sub T value at low emitter currents was below expectation considering the magnitude of reduction of apparent emitter area from the parent L-78 pattern. Limited data on planar L-78A devices using a modified emitter alloying process showed an f sub T increase at 2.0 ma from 1700 mc to 1950 mc. Additional material is being processed using the new emitter alloying process to verify the reproducibility of the technique. Problems encountered during the latter part of the second quarter in material processing have hampered efforts directed toward device improvement and technique reproducibility. A new pattern -- designed L-93A -- in comparison with the L-78A, features a smaller emitter, closer spacing between the emitter and base stripes, reduced base diffusion area, and smaller expanded contacts. Preliminary data have been obtained on the contribution of the base stripe contact resistance to the total value of the extrinsic-base resistance. The generator source impedance, r sub g, for measuring noise figure of the germanium PEM device is considered. Optimum generator impedance for measuring noise figure at 1.5 Gc is computed to be approximately 83 ohms. Quality and reliability assurance data on Group B inspection of planar L-78 devices are analyzed. Author