The salient properties of charge flow (or current) along the MOSFET’s inversion layer are shown to be analogous to a river’s flow in a gravitational potential field, insofar as both are fundamentally governed by energy conservation principles, and their laminar and turbulent conditions determined by friction losses at shallow depths. We formulate an accurate model for a non–uniform mobile charge density giving rise to a mean potential across an inversion layer of finite extent, which we measure by a sensitive experimental method …