Metrics for asymmetric wafer shape characterization

Patent metadata

Field	Value
Publication number	US-2020402252-A1
Application number	US-202016897258-A
Country	US
Kind code	A1
Filing date	Jun 9, 2020
Priority date	Jun 18, 2019
Publication date	Dec 24, 2020
Grant date	—

Abstract

Using data about the geometry of the wafer, the geometry of the wafer is measured along at least three diameters originating at different points along a circumference of the wafer. A characterization of the geometry of the wafer is determined using the three diameters. A probability of wafer clamping failure for the wafer can be determined based on the characterization.

First claim

What is claimed is:

1 . A detection system comprising:
an imaging system configured to measure geometry of a wafer; and a processor in electronic communication with the imaging system, wherein the processor is configured to:
obtain data about the geometry of the wafer;
measure the geometry of the wafer along at least three diameters originating at different points along a circumference of the wafer; and
determine a characterization of the geometry of the wafer using the three diameters.

2 . The detection system of claim 1 , wherein the characterization includes a magnitude and direction of maximum shape change for the wafer across the three diameters.

3 . The detection system of claim 1 , wherein the characterization includes an angular warp.

4 . The detection system of claim 1 , wherein the characterization includes a peak point or a valley point.

5 . The detection system of claim 1 , wherein the characterization includes curvature.

6 . The detection system of claim 1 , wherein the processor is further configured to determine a probability of wafer clamping failure for the wafer based on the characterization.

7 . The detection system of claim 1 , wherein the geometry is measured along at least thirty-two diameters.

8 . The detection system of claim 1 , further comprising a chuck configured to hold the wafer.

9 . A method comprising:
receiving data about the geometry of the wafer at a processor; measuring, using the processor, the geometry of the wafer along at least three diameters originating at different points along a circumference of the wafer; and determining, using the processor, a characterization of the geometry of the wafer using the three diameters.

10 . The method of claim 9 , further comprising imaging the wafer with an imaging system.

11 . The method of claim 9 , wherein the wafer is a 3D NAND wafer or a DRAM wafer.

12 . The method of claim 9 , wherein the characterization includes a magnitude and direction of maximum shape change for the wafer across the three diameters.

13 . The method of claim 9 , wherein the characterization includes an angular warp.

14 . The method of claim 9 , wherein the characterization includes a peak point or a valley point.

15 . The method of claim 9 , wherein the characterization includes curvature.

16 . The method of claim 9 , further comprising determining, using the processor, a probability of wafer clamping failure for the wafer based on the characterization.

17 . The method of claim 9 , wherein the geometry is measured along at least thirty-two diameters.

18 . The method of claim 9 , wherein two of the three diameters are perpendicular to each other.

19 . The method of claim 9 , wherein the data is for an entire surface of the wafer.

20 . A non-transitory computer readable medium storing a program configured to instruct a processor to execute the method of claim 9 .

Assignees

• Kla Corp

Inventors

• Agarwal Shivam
• Jain Priyank
• Zhong Yuan
• Chee Chiou Shoei

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• G01B11/24 Primary

  for measuring contours or curvatures · CPC title

• G06T7/0004 Primary

  Industrial image inspection · CPC title

• G01B2210/48

  for measurement of a wafer · CPC title

• G01B2210/56

  Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth · CPC title