MEMS ANTI-PHASE VIBRATORY GYROSCOPE
First Claim
1. A MEMS anti-phase vibratory gyroscope, comprising:
- two measurement structures, each measurement structure including an outer frame, an inner frame located within the outer frame, and a mass located within the inner frame, wherein the two measurement structures are coupled with each other in the vertical direction through the outer frame, the inner frame is coupled with the outer frame by a plurality of first elastic beams, and the mass is coupled with the inner frame by a plurality of second elastic beams;
a top cap and a bottom cap, each coupled with a respective one of the measurement structures; and
a comb structure provided along opposite sides of the outer frame and the inner frame;
wherein the two masses vibrate toward the opposite vertical direction, and the comb structure measures the angular velocity of rotation.
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Accused Products
Abstract
A MEMS anti-phase vibratory gyroscope includes two measurement masses with a top cap and a bottom cap each coupled with a respective measurement mass. The measurement masses are oppositely coupled with each other in the vertical direction. Each measurement mass includes an outer frame, an inner frame located within the outer frame, and a mass located within the inner frame. The two measurement masses are coupled with each other through the outer frame. The inner frame is coupled with the outer frame by a plurality of first elastic beams. The mass is coupled with the inner frame by a plurality of second elastic beams. A comb coupling structure is provided along opposite sides of the outer frame and the inner frame. The two masses vibrate toward the opposite direction, and the comb coupling structure measures the angular velocity of rotation.
11 Citations
21 Claims
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1. A MEMS anti-phase vibratory gyroscope, comprising:
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two measurement structures, each measurement structure including an outer frame, an inner frame located within the outer frame, and a mass located within the inner frame, wherein the two measurement structures are coupled with each other in the vertical direction through the outer frame, the inner frame is coupled with the outer frame by a plurality of first elastic beams, and the mass is coupled with the inner frame by a plurality of second elastic beams; a top cap and a bottom cap, each coupled with a respective one of the measurement structures; and a comb structure provided along opposite sides of the outer frame and the inner frame; wherein the two masses vibrate toward the opposite vertical direction, and the comb structure measures the angular velocity of rotation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A fabrication technique for a gyroscope, the gyroscope having two measurement structures, a top cap and a bottom cap each coupled with a respective one of the measurement structures, each measurement structure including an outer frame, an inner frame located within the outer frame, and a mass located within the inner frame, wherein the two measurement structures are coupled with each other in the vertical direction through the outer frame, the inner frame is coupled with the outer frame by a plurality of first elastic beams, the mass is coupled with the inner frame by a plurality of second elastic beams, and a comb structure is provided along opposite sides of the outer frame and the inner frame, comprising the following steps:
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(i) growing an epilayer on the surface of a top silicon layer of a silicon on insulator silicon wafer; (ii) forming, by use of thermal oxidation or chemical deposition, a silicon dioxide layer on the surface of the epilayer; (iii) forming, by use of photolithography and etching, a plurality of holes with depth to the epilayer at outer and inner portions of the surface of the silicon dioxide layer; (iv) etching, by use of photolithography and deep etching, through the epilayer from the holes located at the outer portion of the silicon on insulator wafer, and deep etching the top silicon layer to a certain depth; (v) removing photoresist, and deep etching the holes located at the outer portion of the silicon on insulator wafer to the buried oxide layer in order to form an outer frame and a plurality of first elastic beams, and forming at the inner portion, by etching, a plurality of holes which have depth to the top silicon layer in order to form a plurality of second elastic beams; (vi) removing the silicon dioxide layer; (vii) forming a protection layer by depositing silicon nitride or silicon dioxide on the surface of the top silicon layer and the epilayer; (viii) removing the protection layer in the horizontal direction, then bonding the silicon on insulator wafer with a top cap; (ix) thinning and polishing the bottom silicon layer to certain thickness, then growing or depositing a layer of silicon dioxide on the surface of the bottom silicon layer; (x) removing, by use of photolithography and etching, the silicon dioxide layer located at the inner portion, thus exposing the inner portion of the bottom silicon layer; (xi) etching, by use of chemical corrosion or deep etching, the inner portion of the bottom silicon layer to the buried oxide layer; (xii) removing, by etching, the buried oxide layer located at the inner portion of the bottom silicon layer and the silicon dioxide layer located on the surface of the bottom silicon layer; (xiii) etching the exposed portion of the silicon on insulator wafer until the inner portion reaches the epilayer and the bottom silicon layer reaches the buried oxide layer;
thus forming an inner frame and a mass;(xiv) removing, by use of photolithography and etching, the buried oxide layer located on the surfaces of the inner frame, the first elastic beams, and the mass; (xv) removing the protection layer by etching; and (xvi) performing a back-to-back silicon-silicon bonding with two silicon on insulator wafers thereby forming a MEMS anti-phase vibratory gyroscope. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A MEMS anti-phase vibratory gyroscope, comprising:
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a top measurement structure and a bottom measurement structure contained within an outer frame, each measurement structure having an inner frame, a mass, a plurality of first elastic beams and a plurality of second elastic beams, wherein each of the first elastic beams is coupled with the inner frame and the outer frame, and wherein each of the second elastic beams is coupled with the inner frame and the mass, a top cap coupled with the top measurement mass; a bottom cap coupled with the bottom measurement mass; and a comb structure provided along opposite sides of the outer frame and the inner frame, wherein the masses vibrate toward the opposite vertical direction, and the comb structure measures the angular velocity of rotation.
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21. A method for fabricating the MEMS anti-phase gyroscope, comprising
(i) growing an epilayer on the surface of the top silicon layer of the silicon on insulator (SOI) silicon wafer; -
(ii) forming a silicon dioxide layer on the surface of the epilayer; (iii) forming a plurality of holes with depth to the epilayer at outer and inner portions of the surface of the silicon dioxide layer; (iv) etching through the epilayer from the holes located at the outer portion of the silicon on insulator wafer, and deep etching the top silicon layer to a certain depth; (v) removing photoresist, and deep etching the holes located at the outer portion of the silicon on insulator wafer to the buried oxide layer in order to form an outer frame and a plurality of first elastic beams; (vi) forming at the inner portion, by etching, a plurality of holes which have depth to the top silicon layer in order to form a plurality of second elastic beams; (vii) removing the silicon dioxide layer; (viii) forming a protection layer on the surface of the top silicon layer and the epilayer; (ix) removing the protection layer in the horizontal direction, then bonding the silicon on insulator wafer with a top cap; (x) thinning and polishing the bottom silicon layer to a certain thickness, then growing or depositing a layer of silicon dioxide on the surface of the bottom silicon layer; (xi) removing the silicon dioxide layer located at the inner portion, thus exposing the inner portion of the bottom silicon layer; (xii) etching the inner portion of the bottom silicon layer to the buried oxide layer; (xiii) removing the buried oxide layer located at the inner portion of the bottom silicon layer and the silicon dioxide layer located on the surface of the bottom silicon layer; (xiv) etching the exposed portion of the silicon on insulator wafer until the inner portion reaches the epilayer and the bottom silicon layer reaches the buried oxide layer, thus forming an inner frame and a mass; (xv) removing the buried oxide layer located on the surfaces of the inner frame, the first elastic beams, and the mass; (xvi) removing the protection layer by etching; and (xvii) performing a back-to-back silicon-silicon bonding with two silicon on insulator wafers thereby forming a MEMS anti-phase vibratory gyroscope.
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Specification