Method for stacking multi-layer wafers, and system for stacking mult-layer wafers
A method for stacking multi-layer wafers, and a system for stacking multi-layer wafers. The method includes bonding a wafer to a carrier wafer; a first feature pattern being defined in the wafer; acquiring overlay deviation values of different positions of the first feature pattern relative to the carrier wafer; fitting the overlay deviation values corresponding to the different positions and obtaining an actual deviation value of the wafer; and compensating an exposure process of the wafer based on the actual deviation value. In this way, an occurrence of the wafer failing to be exposed and being scrapped due to an alignment accuracy between the wafer and the carrier wafer being lower may be reduced.
1 . A method for stacking multi-layer wafers, comprising:
bonding a wafer to a carrier wafer; wherein a first feature pattern is defined in the wafer;
acquiring overlay deviation values of different positions of the first feature pattern relative to the carrier wafer;
fitting the overlay deviation values corresponding to the different positions and obtaining an actual deviation value of the wafer; and
compensating an exposure process of the wafer based on the actual deviation value;
wherein the fitting the overlay deviation values corresponding to the different positions and obtaining an actual deviation value of the wafer, comprises:
performing a ternary fitting process for horizontal offsets in a horizontal axis direction corresponding to the different positions, horizontal offsets in a vertical axis direction corresponding to the different positions, and rotating arc lengths corresponding to the different positions, and obtaining the actual deviation value of the wafer, wherein a rotating arc length of each position is a product of a distance between the position and a center of the wafer and a corresponding rotating angle.
2 . The method for stacking multi-layer wafers according to claim 1 , wherein the bonding a wafer to a carrier wafer, comprises:
providing the wafer and the carrier wafer, wherein the wafer comprises a substrate, a dielectric layer arranged on a side surface of the substrate, and a metal layer embedded in the dielectric layer; and
defining the first feature pattern on a side surface of the substrate away from the dielectric layer.
3 . The method for stacking multi-layer wafers according to claim 1 , wherein the bonding a wafer to a carrier wafer, comprises:
providing the wafer and the carrier wafer, wherein the wafer comprises a substrate, a dielectric layer arranged on a side surface of the substrate, and a metal layer embedded in the dielectric layer; and
defining the first feature pattern on a side surface of the dielectric layer away from the substrate.
4 . The method for stacking multi-layer wafers according to claim 3 , wherein the dielectric layer comprises:
a covering layer, arranged on a side surface of the substrate;
a bonding layer, arranged on a side surface of the covering layer away from the substrate; and
a protecting layer, arranged on a side surface of the bonding layer away from the covering layer;
wherein the defining the first feature pattern on a side surface of the dielectric layer away from the substrate, comprises:
defining the first feature pattern in a process of fabricating the protecting layer.
5 . The method for stacking multi-layer wafers according to claim 1 , wherein the bonding a wafer to a carrier wafer, comprises:
providing the wafer and the carrier wafer, wherein the wafer comprises a substrate, a dielectric layer arranged on a side surface of the substrate, a metal layer embedded in the dielectric layer, and a bonding pad connected to the metal layer and exposed to a side surface of the dielectric layer away from the substrate;
arranging a barrier layer on the side surface of the dielectric layer away from the substrate, such that the bonding pad is covered by the barrier layer; and
defining the first feature pattern on the barrier layer.
6 . The method for stacking multi-layer wafers according to claim 1 , wherein the acquiring overlay deviation values of different positions of the first feature pattern relative to the carrier wafer, comprises:
acquiring actual coordinates of the different positions of the first feature pattern relative to the carrier wafer and rotating angles of the different positions of the first feature pattern relative to the carrier wafer; and
acquiring difference values between the actual coordinates corresponding to the different positions and corresponding theoretical coordinates, and acquiring the horizontal offsets in the horizontal axis direction corresponding to the different positions and the horizontal offsets in the vertical axis direction corresponding to the different positions.
7 . The method for stacking multi-layer wafers according to claim 1 , wherein the different positions of the first feature pattern comprise multiple spacing points of the first feature pattern arranged at intervals along the same direction.
8 . The method for stacking multi-layer wafers according to claim 7 , wherein the multiple spacing points are arranged at an equal interval.
9 . A system for stacking multi-layer wafers, comprising:
a measuring device, configured to acquire overlay deviation values of different positions of a first feature pattern on a wafer relative to a carrier wafer after bonding the wafer to the carrier wafer, and configured to fit the overlay deviation values corresponding to the different positions and obtain an actual deviation value of the wafer; and
a compensating device, connected to the measuring device and configured to compensate an exposure process of the wafer based on the actual deviation value;
wherein the measuring device is further configured to perform a ternary fitting process for the horizontal offsets in the horizontal axis direction corresponding to the different positions, the horizontal offsets in the vertical axis direction corresponding to the different positions, and rotating arc lengths corresponding to the different positions, and obtain the actual deviation value of the wafer, wherein a rotating arc length of each position is a product of a distance between the position and a center of the wafer and a corresponding rotating angle.
10 . The system for stacking multi-layer wafers according to claim 9 , further comprising:
a bonding device, configured to bond the wafer to the carrier wafer.
11 . The system for stacking multi-layer wafers according to claim 10 , wherein the bonding device is configured to:
provide the wafer and the carrier wafer, wherein the wafer comprises a substrate, a dielectric layer arranged on a side surface of the substrate, and a metal layer embedded in the dielectric layer; and
define the first feature pattern on a side surface of the substrate away from the dielectric layer.
12 . The system for stacking multi-layer wafers according to claim 10 , wherein the bonding device is configured to
provide the wafer and the carrier wafer, wherein the wafer comprises a substrate, a dielectric layer arranged on a side surface of the substrate, and a metal layer embedded in the dielectric layer; and
define the first feature pattern on a side surface of the dielectric layer away from the substrate.
13 . The system for stacking multi-layer wafers according to claim 12 , wherein the dielectric layer comprises:
a covering layer, arranged on a side surface of the substrate;
a bonding layer, arranged on a side surface of the covering layer away from the substrate; and
a protecting layer, arranged on a side surface of the bonding layer away from the covering layer;
wherein the bonding device is further configured to define the first feature pattern in a process of fabricating the protecting layer.
14 . The system for stacking multi-layer wafers according to claim 10 , wherein the bonding device is configured to
provide the wafer and the carrier wafer, wherein the wafer comprises a substrate, a dielectric layer arranged on a side surface of the substrate, a metal layer embedded in the dielectric layer, and a bonding pad connected to the metal layer and exposed to a side surface of the dielectric layer away from the substrate;
arrange a barrier layer on the side surface of the dielectric layer away from the substrate, such that the bonding pad is covered by the barrier layer; and
define the first feature pattern on the barrier layer.
15 . The system for stacking multi-layer wafers according to claim 9 , wherein the measuring device is further configured to
acquire actual coordinates of the different positions of the first feature pattern relative to the carrier wafer and rotating angles of the different positions of the first feature pattern relative to the carrier wafer; and
acquire difference values between the actual coordinates corresponding to the different positions and corresponding theoretical coordinates, and acquire horizontal offsets in a horizontal axis direction corresponding to the different positions and horizontal offsets in a vertical axis direction corresponding to the different positions.
16 . The system for stacking multi-layer wafers according to claim 9 , wherein the different positions of the first feature pattern comprise multiple spacing points of the first feature pattern arranged at intervals along the same direction.
17 . The system for stacking multi-layer wafers according to claim 16 , wherein the multiple spacing points are arranged at an equal interval.
18 . A system for stacking multi-layer wafers, comprising:
a measuring device, configured to acquire overlay deviation values of different positions of a first feature pattern on the wafer relative to a carrier wafer after bonding the wafer to the carrier wafer; and configured to fit the overlay deviation values corresponding to the different positions and obtain an actual deviation value of the wafer;
a compensating device, connected to the measuring device and configured to compensate an exposure process of the wafer based on the actual deviation value; and
an exposing device, connected to the compensating device and configured to perform an exposure process for the multi-layer wafers;
wherein the measuring device is further configured to perform a ternary fitting process for the horizontal offsets in the horizontal axis direction corresponding to the different positions, the horizontal offsets in the vertical axis direction corresponding to the different positions, and rotating arc lengths corresponding to the different positions, and obtain the actual deviation value of the wafer, wherein a rotating arc length of each position is a product of a distance between the position and a center of the wafer and a corresponding rotating angle.