Fundamental Quantum 1/F Noise in Ultrasmall Semi Conductor Devices and Their Optimal Design Principles.

Abstract

Abstract : As a first step of a more general study of 1/f noise in semiconductor devices n(+)(-)p diodes have been investigated with emphasis on HgCdTe photodetectors. Quantum 1/f noise has been calculated in the surface and bulk recombination currents, in the diffusion and field currents, and in the tunneling currents. Due to the large localized electric field at the surface, a larger fractional quantum 1/f noise power is obtained for surface recombination currents than for similar bulk recombination currents. All quantum 1/f noise calculations are first principles calculations with no free parameters, based on the quantum 1/f effect in scattering and recombination cross sections, as well as in tunneling rates. Together, the quantum 1/f mobility fluctuations, bulk and surface recombination speed fluctuations and tunneling rate fluctuations can account for the observed 1/f noise and can be used for optimizing small devices, as indicated by experiments at SBRC, Univ. of Minnesota and Florida. Some suggestions are given at the end of Sec. II. For devices larger than 10 microns coherent state quantum 1/f noise becomes important, according to a new interpolation formula. The new interpolation formula which bridges the gap between conventional (incoherent) quantum 1/f noise and coherent state quantum 1/f noise is in general agreement with measurements in p-n diodes and transistors, and will be tested in more detail in the near future. The theory has also been successfully applied to SQUIDs.