Accelerometer with compatibility to complementary metal-oxide-semiconductor technologies

A semiconductor device, comprising:

• a substrate including a first cavity;
• a seismic mass formed of a portion of the substrate and a first electrode,
• a first surface of the seismic mass being adjacent to the first cavity, and
• a second surface of the seismic mass being adjacent to a second cavity,
• the first electrode being located at the second surface of the seismic mass, and
• the first surface of the seismic mass and the second surface of the seismic mass being on opposite sides of the seismic mass;
• an oxide layer that defines the second cavity;
• and
• a second electrode separated from the second surface of the seismic mass by a portion of the oxide layer and the second cavity.

A method for manufacturing a semiconductor device, the method comprising:

• obtaining a substrate including a first cavity below a surface of the substrate;
• forming a first oxide layer on the surface of the substrate;
• forming a first electrode layer on the first oxide layer to form a first electrode;
• etching one or more trenches in the first electrode layer, the first oxide layer, and a portion of the substrate to form a seismic mass that includes the first electrode, a portion of the first oxide layer, and the portion of the substrate,
• the portion of the substrate being located between the first cavity and the surface of the substrate;
• forming a sacrificial layer on at least the seismic mass;
• forming a second oxide layer on the sacrificial layer;
• forming a second electrode layer on the second oxide layer to form a second electrode;
• and
• removing the sacrificial layer to form a second cavity,
• the second electrode being separated from the seismic mass by a portion of the second oxide layer and the second cavity.