Patent ID: 7719005

Claim:
A thermal absorption detection (TAD) structure comprising: a substrate comprising a base layer of silicon having at least two closed frame-shaped portions; an oxide layer disposed within trenches in the substrate and having at least two closed frame-shaped portions; a polysilicon layer disposed on top of the base layer and having at least two closed frame-shaped portions; wherein the frame-shaped portions of the base layer, oxide layer and polysilicon layer are arranged to form a pattern of frame-shaped structures having a same shape but different sizes, and collocated with each other; wherein the base layer is exposed between the frame-shaped portions of the oxide layer and the frame-shaped portions of the polysilicon layer; wherein the frame-shaped structures are arranged, from an outermost one of the at least two frame-shaped portions of the oxide layer to an innermost one of the at least two frame-shaped portions of the oxide layer, with a selected one of the frame-shaped portions of the base layer or the polysilicon layer disposed within each of the at least two frame-shaped portions of the oxide layer; further comprising an innermost portion of the oxide layer disposed within an innermost one of the selected frame-shaped portions of the base layer or the polysilicon layer; and a test structure formed on the innermost one of the oxide layers.