Patent ID: 8304847
Filing Date: 2012-11-06
Classification: G01L,H01L

Abstract:
1. A semiconductor pressure sensor for measuring pressure of an exhaust gas of a combustion engine, the exhaust gas containing corrosive components, wherein: the whole area of a semiconductor chip, except for pads for wire bonding and probe pads for characteristic confirmatory check which function as electrical input and output portions, is coated with a corrosion-resistant material such as silicon nitride; an adhesion ensuring-diffusion preventative layer is formed on aluminum electrodes at the pads for wire bonding and the probe pads; the surface of the adhesion ensuring-diffusion preventative layer is coated with gold; the adhesion ensuring-diffusion preventive layer is made of tungsten-titanium; the tungsten-titanium layer as the adhesion ensuring-diffusion preventative layer covers over the whole of a top face of each aluminum electrode and spreads across a boundary between the aluminum electrode and the silicon nitride layer as the corrosion-resistant material so as to overhang the silicon nitride layer; and the gold coating spreads across a boundary between the adhesion ensuring-diffusion preventative layer of tungsten-titanium and the corrosion-resistant material of silicon nitride.