Mosfet device physics and operations ebook free download pdf
A field effect transistor (FET) operates as a conducting semiconductor channel with two ohmic contacts the source and the drain where the number of charge carriers in the channel is controlled by a third contact – the gate. In the vertical direction, the gate-channel-substrate structure (gate junction)can be regarded as an orthogonal two-terminal device, which is either a MOS structure or a reverse-biased rectifying device that controls the mobile charge in the channel by capacitive coupling (field effect). Examples of FETs based on these principles are metal-oxide-semiconductor FET (MOSFET), junction FET (JFET), metal-semiconductor FET (MESFET), and hetero structure FET (HFETs). In all cases, the stationary gate-channel impedance is very large at normal operating conditions.