Frequency Response of Advanced Silicon Bipolar Transistors at Low Temperature

The high-frequency behavior of advanced bipolar silicon transistors has been measured at temperatures between 83 and 350 K. The cutoff frequency, dc gain, and associated frequency-dependent parameters are reported. Although the transistors are optimized for room-temperature operation, their performance at liquid nitrogen temperature is not severely degraded. Though decreased, the current gain remains sufficiently high for use in some applications. The cutoff frequency is reduced by about a factor of two. These are the first reported detailed measurements of the frequency response of self-aligned bipolar transistors at low temperature. © 1990 IEEE