Safety drain voltage avoiding avalanche breakdown in MOSFET

It has been found that the avalanche breakdown voltage of MOSFET is independent of substrate bias and increases linearly with gate voltage in an operation regime. Applying this body-effect independency of breakdown, we obtain a maximum safety drain bias, below which avalanche breakdown is completely avoided. This safety drain voltage can be expressed in an empirical form of where Leffis the effective channel length and and ν are coefficients, dependent upon device architecture.