DocumentCode :
3551907
Title :
An NPN germanium double-diffused mesa transistor
Author :
Jacobs, R.A. ; Abshire, R.H. ; Wilson, R.W. ; Anetsmann, Herbert
Author_Institution :
Motorola, Inc., Phoenix, Ariz.
Volume :
7
fYear :
1961
fDate :
1961
Firstpage :
22
Lastpage :
22
Abstract :
A double-diffused NPN germanium mesa transistor has been designed for ultra-high Speed switching applications. This device is intended for switching circuit use in the 1 to 100 mA range, affording the advantages of complementary circuitry in conjuction with such standard PNP devices as the 2N705 and 2N828. Switching times of the device described here are, however, lower by a factor of from two to three than in the PNP devices. The geometry of the active device approaches the smallest compatible with fabrication techniques. The fabrication of the device involves the use of tunnel PN junction ohmic contacts, the selective masking of diffusions, and the formation of ohmic contacts by photo-resist processes. Some effects of surface passivation on this NPN germanium device are also discussed. By virtue of its small geometry and the higher minority carrier mobility inherent in the NPN structure, frequency response is much improved over the standard PNP mesa transistors. Current gain bandwidth products as high as 1500 MCPS are commonly observed.
Keywords :
Bandwidth; Fabrication; Frequency; Geometry; Germanium; Jacobian matrices; Ohmic contacts; Passivation; Switching circuits;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electron Devices Meeting, 1961 Internationa
Type :
conf
DOI :
10.1109/IEDM.1961.187219
Filename :
1473055
Link To Document :
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