The apparent degradation of mobility in field-effect-device channels

The mobility of the carriers in field-effect-device channels appears to decrease as the channel conductance increases. A comparison is made between the contributions to this effect in MOS devices from surface scattering and from any parasitic series resistance. Experiments on a variety of devices over a range of temperatures indicate that the latter effect is generally dominant and may be the only effect. This has implications in the modelling of such devices and the theory of scattering of carriers in the inversion layer.