Study of 1/f Noise in Solids.

Abstract

Abstract : In the introduction an overview is given of the status of 1/f noise at the end of the contract period. We indicate that the 1/f noise observed in our laboratory, as well as in other places, quite often yields Hooge parameters of order 10-5 to 10-8, i.e., two to five orders less than a decade ago. Much of this noise can be seen as quantum 1/f noise which is the limiting noise that can be observed. Our measurements on submicron gallium arsenide devices, microwave narrow base transistors, and gold films at below the Debye temperature, and in radioactive decay and partition 1/f noise, all point in this direction. Over and above this limiting noise, additional 1/f-like noise is often observed. For this, the standard physical mechanisms, involving activation energy processes or tunneling processes, usually apply. More research on this larger 1/f noise is still needed. In the section on experimental work, we discuss the status of 1/f noise in transistors and in gold films. Also, we discuss the high frequency intervalley scattering noise in gallium arsenide devices. Good agreement with Monte Carlo simulations is obtained. New results are also presented for noise in radioactive decay. Both 1/f noise and Lorentzian flicker noise are observed. The flicker floor is lower for lower alpha-particle energies, in agreement with the quantum theory of 1/f noise. In the theory section of quantum 1/f noise is applied to electron phonon scattering. Explicit results for the resulting mobility-fluctuation noise and for the Hooge parameters involved are obtained. Numerical computations are in progress. keywords include: 1/f noise, metal films, transistors, radioactive decay, intervalley noise, GaAs.