REVIEW OF EXPERIMENTAL ASPECTS OF HOT-ELECTRON TRANSPORT IN MOS STRUCTURES

A review of carrier mobility measurements in silicon inversion layers is given with special emphasis on high-field phenomena. Measurements reported in the literature have been performed in a range of lattice temperatures 0.03 K ≤ TL ≤ 300 K for electric drain fields 0 < E < 105 V/cm, which heat the charge carriers up to thousand and more degrees Kelvin. Numerous transport quantities have been measured in this tremendous temperature range. Special consideration is given to: conductivity, mobility, Shubnikov-de Haas effect, the warm electron coefficient β and the saturation drift velocity. Most results available are for n-channel MOS devices on (100), (110) and (111) silicon surfaces. Only few results are publised for the p-channel. The results are compared with experimental findings for bulk material. The comparison shows that no drastic differences appear at temperatures above 10 K and high electric fields. Only the saturation velocity of inversion layers is lower and the temperature and field dependence of the conductivity is weaker as compared to the bulk. At temperatures below 10 K, however, activated conductivities, giant β-coefficients and in the high field region a voltage controlled negative differential resistance are observed.