Methods and systems for wafer bonding alignment compensation

Patent metadata

Field	Value
Publication number	US-10529694-B2
Application number	US-201816046689-A
Country	US
Kind code	B2
Filing date	Jul 26, 2018
Priority date	May 16, 2018
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

Embodiments of methods and systems for wafer bonding alignment compensation are disclosed. The method comprises bonding a first pair of wafers including multiple bonding alignment mark pairs on the first pair of wafers; first analyzing a translational misalignment and a rotational misalignment between the first pair of wafers based on a measurement of at least two bonding alignment mark pairs; controlling a wafer position adjustment module to compensate for the translational misalignment and the rotational misalignment during bonding of a second pair of wafers based on the first analysis; second analyzing a mean run-out misalignment between the first pair of wafers based on a measurement of the multiple bonding alignment mark pairs; and controlling a wafer deformation adjustment module to compensate for the run-out misalignment during bonding of a third pair of wafers based on the second analysis.

First claim

What is claimed is:

1. A method for wafer bonding alignment compensation, comprising:
bonding a first pair of wafers including a bottom wafer and a top wafer, wherein a plurality of bonding alignment mark pairs are on the first pair of wafers, each bonding alignment mark pair includes a bottom bonding alignment mark on the bottom wafer and a top bonding alignment mark on the top wafer;
first analyzing a translational misalignment and a rotational misalignment between the first pair of wafers based on a measurement of at least two bonding alignment mark pairs;
controlling a wafer position adjustment module to compensate for the translational misalignment and the rotational misalignment during bonding of a second pair of wafers based on the first analysis;
second analyzing a mean run-out misalignment between the first pair of wafers based on a measurement of the plurality of bonding alignment mark pairs; and
controlling a wafer deformation adjustment module to compensate for the run-out misalignment during bonding of a third pair of wafers based on the second analysis.

2. The method of claim 1 , further comprising:
determining whether the translational misalignment and the rotational misalignment are within an allowable error range;
in response to determining that the translational misalignment and the rotational misalignment are outside the allowable error range, controlling the wafer position adjustment module to compensate the translational misalignment and the rotational misalignment during bonding of the second pair of wafers;
determining whether the run-out misalignment is within an allowable error range; and
in response to determining that the run-out misalignment is outside the allowable error range, controlling the wafer deformation adjustment module to compensate the run-out misalignment during bonding of the third pair of wafers.

3. The method of claim 1 , wherein first analyzing the translational misalignment and the rotational misalignment between the first pair of wafers comprises:
calculating a first misalignment between a first bonding alignment mark pair in a first direction;
calculating a second misalignment between the first bonding alignment mark pair in a second direction; and
calculating a third misalignment between a second bonding alignment mark pair in the second direction.

4. The method of claim 3 , wherein calculating the first misalignment between the first bonding alignment mark pair in the first direction comprises:
determining a first distance between a center of the top wafer and a center of the bottom wafer in the first direction;
determining a second distance between the bottom bonding alignment mark of the first bonding alignment mark pair and the center of bottom wafer;
determining an angle between the first direction and a connection line of the bottom bonding alignment mark of the first bonding alignment mark pair and the center of bottom wafer; and
calculating the first misalignment between the first bonding alignment mark pair in the first direction based on the first distance, the second distance, and the angle.

5. The method of claim 3 , wherein calculating the second misalignment between the first bonding alignment mark pair in the second direction comprises:
determining a first distance between a center of the top wafer and a center of the bottom wafer in the second direction;
determining a second distance between the bottom bonding alignment mark of the first bonding alignment mark pair and the center of bottom wafer;
determining an angle between the first direction and a connection line of the bottom bonding alignment mark of the first bonding alignment mark pair and the center of bottom wafer; and
calculating the second misalignment between the first bonding alignment mark pair in the second direction based on the first distance, the second distance, and the angle.

6. The method of claim 3 , wherein calculating the third misalignment between the second bonding alignment mark pair in the second direction comprises:
determining a first distance between a center of the top wafer and a center of the bottom wafer in the second direction;
determining a second distance between the bottom bonding alignment mark of the second bonding alignment mark pair and the center of bottom wafer;
determining an angle between the first direction and a connection line of the bottom bonding alignment mark of the second bonding alignment mark pair and the center of bottom wafer; and
calculating the third misalignment between the second bonding alignment mark pair in the second direction based on the first distance, the second distance, and the angle.

7. The method of claim 3 , wherein controlling the wafer position adjustment module to compensate for translational misalignment and the rotational misalignment during bonding of the second pair of wafers based on the first analysis comprises:
adjusting a position of at least one of the second pair of wafers based on the first misalignment, the second misalignment, and the third misalignment.

8. The method of claim 1 , wherein second analyzing the mean run-out misalignment between the first pair of wafers comprises:
calculating a run-out misalignment between each bonding alignment mark pair; and
calculating an average of the run-out misalignments corresponding to the plurality of bonding alignment mark pairs as the mean run-out misalignment between the pair of wafers.

9. The method of claim 8 , wherein calculating the run-out misalignment between each bonding alignment mark pair comprises:
determining a first distance between a center of the top wafer and a top bonding alignment mark in a bonding alignment mark pair;
determining a second distance between the top bonding alignment mark and a bottom bonding alignment mark in the bonding alignment mark pair;
determining an angle between a connection line of the bonding alignment mark pair and a radiation direction of the top bonding alignment mark on the top wafer; and
calculating the run-out misalignment between the bonding alignment mark pair based on the first distance, the second distance, and the angle.

10. The method of claim 1 , wherein controlling the wafer deformation adjustment module to compensate the run-out misalignment during bonding of the third pair of wafers based on the second analysis comprises:
adjusting a deformation of at least one of the third pair of wafers based on the mean run-out misalignment.

11. A system for bonding wafers, comprising:
a wafer support module configured to support a first pair of wafers including a plurality of bonding alignment mark pairs, wherein the first pair of wafers including a bottom wafer and a top wafer, and each bonding alignment mark pair includes a bottom bonding alignment mark on the bottom wafer and a top bonding alignment mark on the top wafer;
an alignment monitoring module configured to measure positions of the plurality of bonding alignment mark pairs;
a hardware processor configured to analyze a translational misalignment and a rotational misalignment between the first pair of wafers based on a measurement of at least two bonding alignment mark pairs, and to analyze a mean run-out misalignment between the first pair of wafers based on a measurement of the plurality of bonding alignment mark pairs;
a wafer position adjustment module configured to compensate the translational misalignment and the rotational misalignment during bonding of a second pair of wafers; and
a wafer deformation adjustment module configured to compensate the mean run-out misalignment during bonding of a third pair of wafers.

12. The system of claim 11 , wherein the hardware pro

Assignees

• Yangtze Memory Tech Co Ltd

Inventors

• Guo Shuai

Classifications

• H10P74/23

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• H10W46/301

  for alignment · CPC title

• H10W46/00

  Marks applied to devices, e.g. for alignment or identification · CPC title

• H10W90/00 Primary

  Package configurations · CPC title

• H10W46/501

  for use before dicing · CPC title