Monolithic silicon integrated circuit chip for a thermal ink jet printer

A thermal ink jet printing module comprising an ink channel structure with a plurality of nozzles at one end and an ink supply at the other end, said structure fixedly adjoined to

• an integrated circuit which contains driver logic and resistive ink heating elements formed on the surface of a common silicon wafer, said circuit comprising,
• a p-type silicon substrate with a patterned field oxide layer grown on said substrate, followed by gate oxide growth to form a gate oxide layer,
• at least one transistor switch having a source and drain region formed on said substrate surface said drain region comprising a lightly doped n-type drift region and an n.sup.+ ion implanted region laterally displaced from the drift region, said transistor switch having an n.sup.- type polysilicon gate formed upon said gate oxide layer and in close physical proximity to said source and drain regions, and
• conductive vias contacting said source and drain regions at said n.sup.+ ion implanted region, said vias providing electrical connection between said transistor switch and said resistive elements whereby said n.sup.+ ion implanted region in at least the drain region creates a carrier depletion region upon application of input signals to the vias resulting in a reduction in the electric field at the gate-drain p-n junction.