Process for manufacturing a MEMS micromirror device, and associated device
AssigneeSTMicroelectronics S.r.l.
InventorsEnri Duqi, Lorenzo Baldo, Roberto Carminati, Flavio Francesco Villa
Life of this patent
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Abstract
A buried cavity is formed in a monolithic body to delimit a suspended membrane. A peripheral insulating region defines a supporting frame in the suspended membrane. Trenches extending through the suspended membrane define a rotatable mobile mass carried by the supporting frame. The mobile mass forms an oscillating mass, supporting arms, spring portions, and mobile electrodes that are combfingered to fixed electrodes of the supporting frame. A reflecting region is formed on top of the oscillating mass.
Claims27
A process for manufacturing a micromirror device in MEMS technology, comprising the steps of:
- forming a buried cavity in a monolithic body of semiconductor material having a first and a second main surfaces, the buried cavity delimiting a suspended membrane arranged between the buried cavity and the first main surface;
- forming an opening in the monolithic body from the second main surface, the opening extending as far as and joining to the buried cavity;
- defining the suspended membrane to form a supporting frame and a mobile mass carried by the supporting frame and rotatable about an axis parallel to the first main surface, wherein the mobile mass has a width less than a width of the opening;
- and
- forming a reflecting region on top of the mobile mass.
A process, comprising:
- forming a buried cavity in a monolithic body of semiconductor material having a first main surface and a second main surface, the buried cavity delimiting a suspended membrane arranged between the buried cavity and the first main surface;
- forming an electrical insulating region extending completely through said suspended membrane and peripherally surrounding a supporting frame;
- defining in said suspended membrane a rotatable mobile mass carried by the supporting frame;
- removing a portion of the monolithic body of semiconductor material from the second main surface to reach the buried cavity to thereby form an opening having a width greater than a width of the rotatable mobile mass;
- and
- forming a reflecting region on a top surface of the rotatable mobile mass.
A process for manufacturing a MEMS device, comprising the steps of:
- forming a buried cavity in a monolithic body of semiconductor material having a first and a second main surfaces, the buried cavity delimiting a suspended membrane arranged between the buried cavity and the first main surface;
- forming an opening in the monolithic body from the second main surface, the opening extending as far as and joining to the buried cavity;
- forming an electrical insulating region extending peripherally around the suspended membrane;
- forming a plurality of holes in the suspended membrane, the holes extending from the first main surface to the buried cavity and spaced from each other by suspension bridges to thereby form a mobile mass that is rotatable about an axis parallel to the first main surface, wherein the mobile mass has a width less than a width of the opening;
- and
- completely thermally oxidizing the suspension bridges.
Dependencies are inferred from the claim text.