Method for manufacturing semiconductor pressure sensor having reference pressure chamber
AssigneeDenso Corporation
InventorsSeiichiro Ishio, Inao Toyoda, Yasutoshi Suzuki
Life of this patent
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Abstract
In a method for manufacturing a semiconductor pressure sensor, after a reference pressure chamber is formed inside a semiconductor substrate and a diaphragm is formed from a part of the semiconductor substrate, a heat treatment is performed to form an insulation film, an element, or the like on the semiconductor substrate. At that time, a heat treatment temperature is controlled to be lower than (−430P0+1430)° C. where P0 is an internal pressure (atm) of the reference pressure chamber at a room temperature. Accordingly, crystal defects can be prevented from being produced in the diaphragm.
Claims7
A method for manufacturing a semiconductor pressure sensor, comprising:
- forming a cavity on a semiconductor substrate;
- closing the cavity to form a reference pressure chamber;
- forming a diaphragm from a part of the semiconductor substrate corresponding to the reference pressure chamber;
- performing a first heat treatment to the semiconductor substrate after the reference pressure chamber is formed, at a first temperature T1 that satisfies a relation of:
- T1<(−430P0+1430)° C.
- where P0 is an internal pressure (atm) of the reference pressure chamber at a room temperature.
Dependencies are inferred from the claim text.