The invention relates to an overvoltage protection circuit for MOS components consisting of a resistor (R), a field oxide transistor (FOX) and a thin oxide transistor (DOX).

The wafer is then thermally oxidized such that a field oxide having a first thickness is grown over the isolation region and a thin oxide having a second thickness is grown over the active region.

A second gate structure (118) includes a gate (122) that does not overlap a sidewall (142) of a field oxide (106).