Method of fabricating a semiconductor device
First Claim
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1. A method of fabricating a piezoresistive semiconductor pressure sensor having a predetermined diaphragm configuration, comprising the steps of:
- forming a highly doped region, in a single crystal semiconductor substrate with first and second principal planes facing each other, by covering at least part of said first principal plane by a mask for defining said predetermined diaphragm configuration, said mask having substantially the same configuration as said predetermined diaphragm configuration, and selectively introducing impurities into the portion thereof which is not covered by said mask;
forming an epitaxial semiconductor region on said second principal plane;
forming semiconductor regions for gauge resistors by selectively introducing impurities into the principal plane of the epitaxial semiconductor region positioned on a portion in which said highly doped region is not formed; and
etching a portion of said first principal plane in which said highly doped region is not formed, to thereby form said predetermined diaphragm configuration, whereby a controlled recess providing the predetermined diaphragm configuration, independent of the crystal orientation of the semiconductor substrate, is formed.
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Abstract
This invention relates to the method of forming a semiconductor device having a diaphragm.
A highly doped semiconductor region is formed in the peripheral portion of the semiconductor substrate around the part in which the diaphragm is to be formed, and then that part is etched. Thereby, the diaphragm of a semiconductor pressure sensor can be formed very accurately to a desired shape.
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Citations
12 Claims
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1. A method of fabricating a piezoresistive semiconductor pressure sensor having a predetermined diaphragm configuration, comprising the steps of:
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forming a highly doped region, in a single crystal semiconductor substrate with first and second principal planes facing each other, by covering at least part of said first principal plane by a mask for defining said predetermined diaphragm configuration, said mask having substantially the same configuration as said predetermined diaphragm configuration, and selectively introducing impurities into the portion thereof which is not covered by said mask; forming an epitaxial semiconductor region on said second principal plane; forming semiconductor regions for gauge resistors by selectively introducing impurities into the principal plane of the epitaxial semiconductor region positioned on a portion in which said highly doped region is not formed; and etching a portion of said first principal plane in which said highly doped region is not formed, to thereby form said predetermined diaphragm configuration, whereby a controlled recess providing the predetermined diaphragm configuration, independent of the crystal orientation of the semiconductor substrate, is formed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification