Abstract: An improved method for forming a metal contact for a silicon sensor. First, platinum is deposited over a contact area. Then the platinum is sintered to form platinum silicide. Subsequently, titanium/tungsten (TiW) is deposited over the platinum silicide. Finally, gold is deposited over the TiW.

Abstract: A unique backside mask for the backside of a silicon wafer which is to be diced in a rectangular shape to form a silicon pressure sensor. The backside mask is shaped to extend farther towards the center from portions adjacent to corners of the rectangular shape. In one embodiment, the mask has a cross-shape. The silicon is etched to form a diaphragm, with the corners etching more due to the silicon crystalline structure. This leaves corner regions which are less sloped compared to the sides of the cavity, being substantially vertical or even recessed. A glass substrate with a hole in it is then bonded to the backside to form the sensor.