Method of manufacturing a micro-electrical-mechanical system
First Claim
1. A method of fabricating a micro-electrical-mechanical system (MEMS) device, the method comprising:
- preparing a substrate having a first side, a second side, a first semiconductor layer on the first side, a second semiconductor layer on the second side, and a sacrificial layer sandwiched between the first and second semiconductor layers, the substrate including a plurality of chip areas, each chip area including a peripheral area and an interior area disposed within the peripheral area;
selectively etching the substrate from both the first side and the second side to remove part of the first semiconductor layer and part of the second semiconductor layer from the interior area of each chip area without removing the sacrificial layer, thereby leaving a frame in the peripheral area and forming, within each interior area, a microstructure having a movable member, the movable member being immobilized to the frame by the sacrificial layer;
preparing a sheet having an adhesive surface;
attaching the adhesive surface of the sheet to the remaining parts of the second side of the substrate;
dicing the substrate from the first side down at least to the adhesive surface of the sheet, thereby dividing the substrate into chips;
etching exposed parts of the sacrificial layer, thereby freeing the movable member from the frame, after the substrate has been diced into chips; and
detaching the chips from the sheet.
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Accused Products
Abstract
Micro-electrical-mechanical systems are fabricated in a substrate having a sacrificial layer sandwiched between two semiconductor layers. The semiconductor layers are selectively etched to create non-etched frames and etched microstructures immobilized within the frames by the sacrificial layer. An adhesive sheet is attached to one surface of the substrate, and the substrate is diced into chips, each including one frame and one immobilized microstructure. The sacrificial layer is then selectively etched to free a movable member in each microstructure. Finally, the chips are detached from the adhesive sheet, each chip becoming a micro-electrical-mechanical system. This fabrication method provides a simple and inexpensive way to avoid damage to the microstructure during the dicing process.
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Citations
18 Claims
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1. A method of fabricating a micro-electrical-mechanical system (MEMS) device, the method comprising:
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preparing a substrate having a first side, a second side, a first semiconductor layer on the first side, a second semiconductor layer on the second side, and a sacrificial layer sandwiched between the first and second semiconductor layers, the substrate including a plurality of chip areas, each chip area including a peripheral area and an interior area disposed within the peripheral area; selectively etching the substrate from both the first side and the second side to remove part of the first semiconductor layer and part of the second semiconductor layer from the interior area of each chip area without removing the sacrificial layer, thereby leaving a frame in the peripheral area and forming, within each interior area, a microstructure having a movable member, the movable member being immobilized to the frame by the sacrificial layer; preparing a sheet having an adhesive surface; attaching the adhesive surface of the sheet to the remaining parts of the second side of the substrate; dicing the substrate from the first side down at least to the adhesive surface of the sheet, thereby dividing the substrate into chips; etching exposed parts of the sacrificial layer, thereby freeing the movable member from the frame, after the substrate has been diced into chips; and detaching the chips from the sheet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification