Top notch slit profile for MEMS device
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorTing-Jung Chen
Life of this patent
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Abstract
Various embodiments of the present disclosure are directed towards a microelectromechanical systems (MEMS) device in which a slit at a movable mass of the MEMS device has a top notch slit profile. The MEMS device may, for example, be a speaker, an actuator, or the like. The slit extends through the movable mass, from top to bottom, and has a width that is uniform, or substantially uniform, from the bottom of the movable mass to proximate the top of movable mass. Further, in accordance with the top notch slit profile, top corner portions of the MEMS substrate in the slit are notched, such that a width of the slit bulges at the top of the movable mass. The top notch slit profile may, for example, increase the process window for removing an adhesive from the slit while forming the MEMS device.
Claims20
A method comprising:
- performing a first etch into a first side of a substrate to form a notch extending into the substrate to a first depth;
- performing a second etch into the first side of the substrate to form a trench extending into the substrate to a second depth greater than the first depth, wherein the trench overlaps with the notch and has a lesser width than the notch;
- bonding a carrier substrate to the first side of the substrate with an adhesive filling the notch and the trench and covering the first side of the substrate;
- thinning the substrate from a second side of the substrate, opposite the first side;
- and
- removing the carrier substrate and the adhesive after the thinning;
- wherein the first and second etches are performed with a mask in place to form the notch and the trench underlying an opening in the mask.
A method comprising:
- forming a piezoelectric actuator on a first side of a substrate and extending in a closed path around a central area of the substrate;
- performing a first etch into the central area of the substrate from the first side of the substrate and with a mask in place to form a slit, wherein the first etch is isotropic and laterally undercuts the mask at the slit;
- performing a second etch into the central area of the substrate from the first side of the substrate to extend a depth of the slit, wherein the second etch is anisotropic and is performed with the mask in place;
- and
- performing a third etch into the central area of the substrate from a second side of the substrate, opposite the first side of the substrate, to form a cavity exposing the slit.
A method comprising:
- performing a first etch into a first side of a substrate, through an opening in a mask, to form a notch, which is spaced from a second side of the substrate, opposite the first side of the substrate, and has a greater width than the opening;
- performing a second etch into the first side of the substrate through the opening in the mask to form a trench, which extends from the notch to the second side of the substrate and is confined to directly under the opening;
- bonding a carrier substrate to the first side of the substrate with an adhesive filling the notch and the trench;
- bonding an integrated circuit (IC) chip to the second side of the substrate;
- removing the carrier substrate and the adhesive after the bonding of the IC chip to the second side of the substrate;
- and
- bonding a cap substrate to the first side of the substrate after the removing, wherein the cap substrate has a cavity overlying the notch and the trench.
Dependencies are inferred from the claim text.