Electron–Phonon Interaction in n‐Si

For pt.I see ibid., vol.20, no.13, p.1985 (1987). A general formula for the phonon-drag contribution to the thermopower of quasi-2D electrons coupled to 3D phonons is evaluated for low temperatures when the electrons are in the electric quantum limit and the phonons are in the boundary scattering regime. The formula is most simply applied to GaAs/AlGaAs heterojunctions. An extension of the theory is required before it can be applied to Si MOSFETs due to the anisotropic nature of Si. In both cases good agreement is found between theoretical predictions and recent experimental results.

https://iopscience.iop.org/article/10.1088/0022-3719/20/13/015/pdf

A calculation of the phonon-drag contribution to the thermopower of quasi-2D electrons coupled to 3D phonons. II. Applications

Calculations of the carrier mobility of electrons and holes vs the electrical field strength E are presented. The calculations have been performed based on a Maxwellian distribution and taking into account a repopulation of carriers among different valleys in the case of n‐channel silicon inversion layers. The energy loss of the carriers to the lattice and the drift velocity or mobility are treated as two dimensional. Formulas for the energy loss are presented for both high and very low temperatures considering scattering by optical and acoustical phonons. The calculations are compared with experimental values given by Fang and Fowler and by Sato et al. Good agreement is found for the high‐temperature case using coupling constants as given by Sah et al. Quite large differences between theory and experiment appear at very low temperatures. The origin of these differences is discussed in a final section.

Hot carriers in silicon surface inversion layers

Electron energy relaxation time in Si and Ge

Preparing a review on a topic developing as rapidly as nonlinear transport is a complicated problem. The material should be comprehensive for those new in the field and at the same time interesting in the sense that the basic principles are covered in the most efficient form. Also future applications should be pointed out whenever possible. In the past, the largest impetus to hot electron research came from device applications such as transistor characteristics, interface transport, and above all the Gunn effect. It is easy enough to guess that the largest impact in the future will come from very large scale integration (VLSI), which necessarily involves high electric fields, and from studies of multilayer heterojunction structures. It is not clear which of the hot electron effects will be important for these applications. Current device concepts are based on drift, diffusion, and generation-recombination. Therefore, I will concentrate in this review on the effects of hot electrons arising from these three basic mechanisms. It is my intention not only to give an introduction to hot carrier effects, but also to supply a complete “recipe” on how hot carrier effects can be calculated within the so-called carrier temperature model. In addition, I will discuss the cases of the largest deviations from this model.

H. Heinrich

Papers

Galvanomagnetic effects of hot electrons in n-type silicon