Fabrication of single-crystal silicon structures using sacrificial-layer wafer bonding
First Claim
1. A method for fabricating a thin micromechanical device in a way that is mechanically compatible with wafer handling for conventional-thickness wafers, the method comprising steps of:
- providing a fabrication wafer;
providing a substantially conventional-thickness handle wafer;
bonding the fabrication wafer to the handle wafer by a removable bonding layer to form a bonded wafer pair;
forming the micromechanical device in the fabrication wafer by subjecting the bonded wafer pair to processing including wafer handling for conventional-thickness wafers, the micromechanical device being formed to include part of the fabrication wafer;
etching through the fabrication wafer to form a trench surrounding the micromechanical device, the trench separating the micromechanical device from the fabrication wafer and being interrupted by at least one tether connecting the micromechanical device to the fabrication wafer, the fabrication wafer being etched through from a face thereof remote from the handle wafer; and
removing the bonding layer underlying the micromechanical device to release the micromechanical device from the handle wafer.
3 Assignments
0 Petitions
Accused Products
Abstract
A thin micromechanical device is fabricated in a way that is mechanically compatible with wafer handling for conventional-thickness wafers. A removable bonding layer bonds a fabrication wafer to a substantially conventional-thickness handle wafer to form a bonded wafer pair. The micromechanical device is formed in the fabrication wafer by subjecting the bonded wafer pair to processing including wafer handling for conventional-thickness wafers. The micromechanical device is formed to include part of the fabrication wafer. Finally, the bonding layer underlying the micromechanical device is removed to release the micromechanical device from the handle wafer.
229 Citations
19 Claims
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1. A method for fabricating a thin micromechanical device in a way that is mechanically compatible with wafer handling for conventional-thickness wafers, the method comprising steps of:
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providing a fabrication wafer; providing a substantially conventional-thickness handle wafer; bonding the fabrication wafer to the handle wafer by a removable bonding layer to form a bonded wafer pair; forming the micromechanical device in the fabrication wafer by subjecting the bonded wafer pair to processing including wafer handling for conventional-thickness wafers, the micromechanical device being formed to include part of the fabrication wafer; etching through the fabrication wafer to form a trench surrounding the micromechanical device, the trench separating the micromechanical device from the fabrication wafer and being interrupted by at least one tether connecting the micromechanical device to the fabrication wafer, the fabrication wafer being etched through from a face thereof remote from the handle wafer; and removing the bonding layer underlying the micromechanical device to release the micromechanical device from the handle wafer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for fabricating a thin micromechanical device in a way that is mechanically compatible with wafer handling for conventional-thickness wafers, the method comprising steps of:
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providing a fabrication wafer; providing a substantially conventional-thickness handle wafer; bonding the fabrication wafer to the handle wafer by a removable bonding layer to form a bonded wafer pair; forming the micromechanical device in the fabrication wafer by subjecting the bonded wafer pair to processing including wafer handling for conventional-thickness wafers, the micromechanical device including part of the fabrication wafer, the step of forming the micromechanical device in the fabrication wafer including a step of; etching through the fabrication wafer to form a trench surrounding the micromechanical device, the trench separating the micromechanical device from the fabrication wafer, and being interrupted by at least one tether connecting the micromechanical device to the fabrication wafer, the fabrication wafer being etched through from a face thereof remote from the handle wafer; removing the bonding layer underlying the micromechanical device to release the micromechanical device from the handle wafer, the micromechanical device remaining connected to the fabrication wafer by the at least one tether; and breaking the at least one tether to release the micromechanical device from the fabrication wafer. - View Dependent Claims (16, 17)
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18. A method for fabricating a thin micromechanical device in a way that is mechanically compatible with wafer handling for conventional-thickness wafers, the method comprising steps of:
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providing a fabrication wafer; providing a substantially conventional-thickness handle wafer; bonding the fabrication wafer to the handle wafer by a removable bonding layer to form a bonded wafer pair; forming the micromechanical device in the fabrication wafer by subjecting the bonded wafer pair to processing including wafer handling for conventional-thickness wafers, the micromechanical device including part of the fabrication wafer, the step of forming the micromechanical device including a step of; anisotropically etching through the fabrication wafer to form a trench surrounding the micromechanical device and to define a tether anchor in the fabrication wafer, the trench separating the micromechanical device from the fabrication wafer, the micromechanical device having a maximum etch distance, the trench being interrupted by at least one tether connecting the micromechanical device to the tether anchor, the tether anchor being dimensioned to have an etch distance greater than the maximum etch distance of the micromechanical device, the fabrication wafer being anisotropically etched through from a face thereof remote from the handle wafer; removing the bonding layer underlying the micromechanical device to release the micromechanical device from the handle wafer, the micromechanical device remaining connected to the bonded wafer pair by the at least one tether, the tether anchor, and part of the bonding layer underlying the tether anchor; and breaking the at least one tether to release the micromechanical device from the bonded wafer pair. - View Dependent Claims (19)
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Specification