An integrated circuit chip and a method of fabricating the IC chip to include a transistor having a thick gate oxide in combination with STI. The method provides a wafer for which a source region location, a drain contact region location, an extended drain region location and a gate region location have been defined and forms an STI structure overlying the extended drain region location. After growing a gate oxide layer over the gate region location and a portion of the extended drain region location, the method forms a gate structure on the gate oxide layer, the gate structure having a gap overlying the intersection of an edge of the STI structure with the gate oxide layer.