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US 12,753,067 B2Granted
MEMS structure including a buried cavity with antistiction protuberances, and manufacturing methods thereof
AssigneeSTMicroelectronics S.r.l.
InventorsMikel Azpeitia Urquia, Enri Duqi, Silvia Nicoli, Roberto Campedelli, Igor Varisco, Lorenzo Tentori
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Abstract
MEMS structure, comprising: a semiconductor body; a cavity buried in the semiconductor body; a membrane suspended on the cavity; and at least one antistiction bump completely contained in the cavity with the function of preventing the side of the membrane internal to the cavity from sticking to the opposite side, which delimits the cavity downwardly.
Claims20
A method for manufacturing a structure, the method comprising:
- forming, at a first surface region of the semiconductor body, first columnar portions having a first value of base area and separated from each other by first trenches;
- forming, at a second surface region of the semiconductor body, contiguous to said first surface region, at least one second columnar portion having a second value of base area different from the first value of base area;
- epitaxially growing, above said first and second columnar portions and said first trenches, a membrane layer of semiconductor material;
- and
- annealing that causes the migration of the semiconductor material of said first and second columnar portions concurrently forming:
- a buried cavity in the semiconductor body below the membrane layer, internally delimited by a first wall, a second wall opposite to the first wall, and third and fourth walls coupled between the first wall with the second wall;
- and
- at least one first antistiction bump, completely contained in the cavity, protruding from one of the first wall and the second wall.
5 more elements
A method for manufacturing a structure, the method comprising:
- forming, in a substrate, a first plurality of columns surrounded by a respective first plurality of trenches, each first column having a first base area;
- forming, in the substrate, a second plurality of columns surrounded by a respective second plurality of trenches, each second column having a second base area different from the first base area;
- forming a first layer on each first and second column, the first layer covering an opening of each first and second trench;
- and
- forming, in the first substrate, a cavity having a first wall on the first layer, the first wall including a first antistiction bump.
2 more elements
A method, comprising:
- forming, in a first surface of a semiconductor substrate, a plurality of first columns surrounded by a plurality of first trenches, each first column having a first base area;
- forming, in the first surface, a plurality of second columns surrounded by a plurality of second trenches, each second column having a second base area greater than the first base area;
- forming a first membrane layer on the first surface and each of the first and second columns;
- and
- forming a cavity in the semiconductor substrate, the forming the cavity including:
- a first wall on the first membrane layer, the first wall including a first antistiction bump;
- and
- a second wall opposite the first wall, the second wall including a second antistiction bump.
5 more elements
Dependencies are inferred from the claim text.