Method of fabricating a low frequency quartz resonator
First Claim
1. A method for fabricating a low frequency quartz resonator, the method comprising:
- forming a first cavity in a silicon handle;
metalizing a top-side of a quartz wafer with a metal etch stop;
depositing a first metal layer over the top-side of the quartz wafer and over the metal etch stop;
patterning the first metal layer to form a top electrode for the low frequency quartz resonator;
aligning and bonding the quartz wafer to the silicon handle so that the top electrode and the metal etch stop are within the first cavity in the silicon handle;
thinning the quartz wafer to a desired thickness;
depositing and patterning a second metal layer over a bottom-side of the quartz wafer to form a hard etch mask for masking the etching of the quartz wafer;
etching the quartz wafer to form a first quartz area for the resonator and to form a via through the quartz wafer for contacting the top electrode;
removing the hard etch mask without removing the metal etch stop;
depositing a third metal layer on the bottom side of the quartz wafer;
applying and patterning photoresist over the third metal layer to form a soft mask;
etching areas left unmasked by the soft mask of the third metal layer to form a bottom electrode for the low frequency quartz resonator;
removing the photoresist to form a quartz resonator on the silicon handle;
depositing a fourth metal layer for a substrate bond pad onto a host substrate wafer;
aligning and bonding the quartz resonator on the silicon handle to the substrate bond pad; and
removing the silicon handle.
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Accused Products
Abstract
A method for fabricating a low frequency quartz resonator includes metalizing a top-side of a quartz wafer with a metal etch stop, depositing a first metal layer over the metal etch stop, patterning the first metal layer to form a top electrode, bonding the quartz wafer to a silicon handle, thinning the quartz wafer to a desired thickness, depositing on a bottom-side of the quartz wafer a hard etch mask, etching the quartz wafer to form a quartz area for the resonator and to form a via through the quartz wafer, removing the hard etch mask without removing the metal etch stop, forming on the bottom side of the quartz wafer a bottom electrode for the low frequency quartz resonator, depositing metal for a substrate bond pad onto a host substrate wafer, bonding the quartz resonator to the substrate bond pad, and removing the silicon handle.
15 Citations
18 Claims
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1. A method for fabricating a low frequency quartz resonator, the method comprising:
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forming a first cavity in a silicon handle; metalizing a top-side of a quartz wafer with a metal etch stop; depositing a first metal layer over the top-side of the quartz wafer and over the metal etch stop; patterning the first metal layer to form a top electrode for the low frequency quartz resonator; aligning and bonding the quartz wafer to the silicon handle so that the top electrode and the metal etch stop are within the first cavity in the silicon handle; thinning the quartz wafer to a desired thickness; depositing and patterning a second metal layer over a bottom-side of the quartz wafer to form a hard etch mask for masking the etching of the quartz wafer; etching the quartz wafer to form a first quartz area for the resonator and to form a via through the quartz wafer for contacting the top electrode; removing the hard etch mask without removing the metal etch stop; depositing a third metal layer on the bottom side of the quartz wafer; applying and patterning photoresist over the third metal layer to form a soft mask; etching areas left unmasked by the soft mask of the third metal layer to form a bottom electrode for the low frequency quartz resonator; removing the photoresist to form a quartz resonator on the silicon handle; depositing a fourth metal layer for a substrate bond pad onto a host substrate wafer; aligning and bonding the quartz resonator on the silicon handle to the substrate bond pad; and removing the silicon handle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for fabricating a plurality of low frequency quartz resonators on a host substrate starting with a silicon handle and a quartz wafer, the method for forming each of the low frequency quartz resonators of the plurality of low frequency quartz resonators on the host substrate comprising:
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forming a first cavity in the silicon handle; metalizing a top-side of a quartz wafer with a metal etch stop; depositing a first metal layer over a top-side of the quartz wafer and over the metal etch stop; patterning the first metal layer to form a top electrode for the low frequency quartz resonator; aligning and bonding the quartz wafer to the silicon handle so that the top electrode and the metal etch stop are within the first cavity in the silicon handle; thinning the quartz wafer to a desired thickness; depositing and patterning a second metal layer over a bottom-side of the quartz wafer to form a hard etch mask for masking the etching of the quartz wafer; etching the quartz wafer to form a first quartz area for the resonator and to form a via through the quartz wafer for contacting the top electrode; removing the hard etch mask without removing the metal etch stop; depositing a third metal layer on the bottom side of the quartz wafer; applying and patterning photoresist over the third metal layer to form a soft mask; etching areas left unmasked by the soft mask of the third metal layer to form a bottom electrode for the low frequency quartz resonator; removing the photoresist to form a quartz resonator on the silicon handle; depositing a fourth metal layer for a substrate bond pad onto a host substrate wafer; aligning and bonding the quartz resonator on the silicon handle to the substrate bond pad; and removing the silicon handle. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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Specification