What is short channel effect?

The short channel effect refers to the impact of the channel length on the operation of MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) devices. MOSFETs are used in integrated circuit technology to control the flow of current between the source and drain terminals.

As the channel length of a MOSFET device decreases, the effect of the drain voltage on the channel increases, leading to a reduction in the device's threshold voltage and its subthreshold slope. This phenomenon can cause changes in the device's behavior, affecting its performance and reliability.

In short-channel MOSFETs, the gate control becomes weaker and the source-drain terminals become more closely spaced, which results in the onset of several adverse effects such as Drain Induced Barrier Lowering (DIBL), Velocity Saturation and Drain-Induced Hot-Electron (DIHE) effects.

The short channel effect has become more pronounced as device sizes have decreased, impacting current designs of semiconductor technologies such as CMOS transistors. Designers of MOSFET devices employ various techniques to mitigate these effects, such as reducing the supply voltage, designing thicker oxide layers, and optimizing doping profiles.