Process for forming a semiconductor structure with closely coupled substrate temperature sense element

摘要

MOSFET devices or circuits incorporating an improved substrate temperature sensing element are obtained by forming a PN junction directly on a thin (gate) dielectric region. The temperature sense junction is desirably formed in a poly layer. By mounting it directly on thin (gate) dielectric its thermal response to temperature changes in the substrate is improved while still being electrically isolated from the substrate. It is desirable to provide over-voltage protection elements coupled to the junction to avoid rupture of the underlying thin dielectric. Because the sense diode and all the over-voltage protection devices may be made of poly with junctions perpendicular to the substrate, the structure is particularly compact and simple to fabricate.