approved: Redacted for privacy Pr;o-fessor James C Looney Low temperature noise measurements on junction field-effect transistors tend to substantiate a theory of low frequency field-effect transistor noise based on the presence of generation centers in the gate-channel depletion region. Measurements of device noise voltage versus temperature reveal pronounced maxima and minima over the temperature range of 300° K to 77° K. Analysis of the maxima can yield information on time constants, capture

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... cross-sections and energy levels of generation centers in the depletion region. The pertinent theories of junction FET noise are reviewed with regard to temperature-dependent phenomena. Contributions due to thermal noise, shot noise, induced gate noise, surface leakage and generation centers are considered. Techniques for measuring the temperature dependence of FET noise are discussed, and a practical approach is described. Measurements are made in a typical circuit configuration in order that the results may be directly related to device applications. Measured data on the temperature dependence of noise in the 300° K to 77°K range is presented for 14 n-and p-channel FET's. Salient features of the data are analyzed and correlated with theoretical predictions. 65 17. No. 3 noise voltage versus temperature. 67 18. No. 5 noise versus reciprocal temperature. 69 19. Activation energy near 200°K. 71 20. Time constants for n-channel FET's. 74 21. No. 5 low-temperature noise maximum. 76