MOS capacitor: definition · Chip Field Guide

Beginner

A metal plate, a very thin layer of glass and a slab of silicon, stacked up. It is the heart of every transistor in a chip.

Novice

A gate electrode separated from a doped silicon body by a thin insulator (originally silicon dioxide). Depending on the gate voltage the silicon surface is in accumulation, depletion or inversion. Add a source and a drain and it becomes a MOSFET.

Expert

Analyzed with $V_{\mathrm{g}} = V_{\mathrm{fb}} + \phi_{\mathrm{s}} + V_{\mathrm{ox}}$ and Gauss’s law at the interface. Its C–V curve, measured slowly (quasi-static) or at high frequency, is how $T_{\mathrm{ox}}$ , $V_{\mathrm{fb}}$ , $V_{\mathrm{T}}$ , doping and interface charge are extracted in practice.