Reverse leakage current

Reverse leakage current in a semiconductor device is the current from that semiconductor device when the device is reverse biased.

When a semiconductor device is reverse biased it should not conduct any current, however, due to increased barrier potential, the free electrons on the p side are dragged to the battery's positive terminal, while holes on the n side are dragged to the battery's negative terminal. This produces a current of minority charge carriers and hence its magnitude is extremely small. For constant temperature reverse current is almost constant though applied reverse voltage is increased up to certain limit. Hence it is also called as reverse saturation current.

The term is particularly applicable to mostly semiconductor junctions, especially diode and thyristor.

Reverse leakage current is also known as "zero gate voltage drain current" with MOSFETs. The leakage current increased with temperature. As an example the Fairchild Semiconductor FDV303N has a reverse leakage of up to 1 microamp at room temperature rising to 10 microamp with a junction temperature of 50 degree Celsius. For all basic purposes, leakage current is very small, and, thus, is normally negligible.