CMOS and pressure sensor integrated on a chip and fabrication method

A method of fabricating a pressure sensor comprising:

• forming a structural layer on a first silicon layer of a silicon-on-insulator (SOI) substrate, said SOI substrate having said first silicon layer, a second silicon layer, and an insulator layer interposed between said first and second silicon layers, and said structural layer having a first conductivity type;
• forming a well region in said structural layer, said well region having a second conductivity type that is opposite from said first conductivity type;
• forming at least one resistor in said well region;
• forming a first cavity extending through said metallization structure overlying said well region;
• and
• forming a second cavity extending through said second silicon layer of said SOI substrate, said second cavity stopping at one of said first silicon layer and said insulator layer, wherein said well region interposed between said first and second cavities defines a diaphragm of said pressure sensor.

A device comprising:

• a silicon-on-insulator (SOI) substrate, said SOI substrate having a first silicon layer, a second silicon layer, and an insulator layer interposed between said first and second silicon layers;
• a structural layer formed on said first silicon layer of said SOI substrate, said structural layer having a first conductivity type;
• a pressure sensor having a well region and at least one resistor formed in said structural layer;
• a complementary metal oxide semiconductor (CMOS) integrated circuit on said first silicon layer of said SOI substrate in said structural layer;
• and
• metallization structure formed over said well region, said at least one resistor, and said CMOS integrated circuit, wherein a first cavity extends through said metallization structure overlying said well region and a second cavity extends through said second silicon layer of said SOI substrate, said second cavity stopping at one of said first silicon layer and said insulator layer, and wherein said well region interposed between said first and second cavities defines a diaphragm of said pressure sensor.