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US 9,176,018 B2Granted
Micromachined ultra-miniature piezoresistive pressure sensor and method of fabrication of the same
OwnerBin Qiinventor
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Abstract
A method of fabrication of one or more ultra-miniature piezoresistive pressure sensors on silicon wafers is provided. The diaphragm of the piezoresistive pressure sensors is formed by fusion bonding. The piezoresistive pressure sensors can be formed by silicon deposition, photolithography and etching processes.
Claims20
A method of fabricating a piezoresistor pressure sensor, comprising:
- providing a first silicon-on-insulator structure comprising a first silicon layer deposited on a first oxide layer over a first bulk silicon layer;
- providing a second silicon-on-insulator structure comprising a second silicon layer deposited on a second oxide layer over a second bulk silicon layer;
- bonding the first silicon layer and the second silicon layer together with the first silicon layer and the second silicon layer facing each other;
- removing the second bulk silicon layer;
- removing the second oxide layer, thereby leaving the second silicon layer of the second silicon-on-insulator structure overlying the first silicon layer;
- forming one or more openings of predetermined shape and dimension to expose a portion of the second silicon layer;
- forming one or more piezoresistors on the one or more openings of the second silicon layer;
- forming a patterned trench within the second silicon layer and the first silicon layer, stopping at the first oxide layer;
- removing the first bulk silicon layer, thereby forming the piezoresistor pressure sensor within the patterned trench.
6 more elements
A method of fabricating a piezoresistor pressure sensor, comprising:
- providing a first silicon-on-insulator structure comprising a first silicon layer deposited on a first oxide layer over a first hulk silicon layer;
- forming a patterned cavity on the surface of the first silicon layer of the silicon-on-insulator structure;
- providing a second silicon-on-insulator structure comprising a second silicon layer deposited on a second oxide layer over a second bulk silicon layer;
- bonding the first silicon layer and the second silicon layer together with the first silicon layer and the second silicon layer facing each other;
- removing the second bulk silicon layer;
- removing the second oxide layer, thereby leaving the second silicon layer of the second silicon-on-insulator structure overlying the first silicon layer;
- forming one or more openings of predetermined shape and dimension to expose a portion of the second silicon layer;
- forming one or more piezoresistors on the one or more openings of the second silicon layer;
- forming a patterned trench within the second silicon layer and the first silicon layer, stopping at the first oxide layer;
- removing the first bulk silicon layer, thereby forming the piezoresistor pressure sensor within the patterned trench.
7 more elements
A method of fabricating a piezoresistor pressure sensor, comprising:
- providing a first silicon-on-insulator structure comprising a patterned cavity formed on a surface of a first silicon layer deposited on a first oxide layer over a first bulk silicon layer;
- providing a second silicon-on-insulator structure comprising a second silicon layer deposited on a second oxide layer over a second bulk silicon layer;
- bonding the first silicon layer and the second silicon layer together with the first silicon layer and the second silicon layer facing each other;
- removing the second bulk silicon layer;
- removing the second oxide layer, thereby leaving the second silicon layer of the second silicon-on-insulator structure overlying the first silicon layer;
- forming a silicon oxide insulation layer on the second silicon layer after the second oxide layer is removed;
- forming one or more openings of predetermined shape and dimension to expose a portion of the second silicon layer;
- forming one or more piezoresistors on the one or more openings of the second silicon layer;
- forming a patterned trench within the second silicon layer and the first silicon layer, stopping at the first oxide layer;
- removing the first bulk silicon layer, thereby forming the piezoresistor pressure sensor within the patterned trench.
7 more elements
Dependencies are inferred from the claim text.