Spatial optical emission spectroscopy for etch uniformity

Patent metadata

Field	Value
Publication number	US-11668602-B2
Application number	US-202117234940-A
Country	US
Kind code	B2
Filing date	Apr 20, 2021
Priority date	Apr 20, 2021
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

An apparatus includes a base component and collimators housed within the base component. The collimators correspond to collection cylinders for sampling optical emission spectroscopy (OES) signals with respect to locations of a wafer in an etch chamber. The apparatus further includes a guide, operatively coupled to the plurality of collimators, to guide the sampling of the OES signals along paths for sampling the OES signals.

First claim

What is claimed is:

1. An apparatus comprising:
a base component;
a plurality of collimators housed within the base component, each collimator of the plurality of collimators corresponding to a respective collection cylinder of a plurality of collection cylinders for collecting a plurality of optical emission spectroscopy (OES) signals with respect to a plurality of locations of a wafer in an etch chamber to perform spatial OES, wherein the plurality of locations comprises a center location of the wafer, a plurality of inner ring locations along an inner ring of the wafer, and a plurality of outer ring locations along an outer ring of the wafer; and
a guide, operatively coupled to the plurality of collimators, to guide each OES signal of the plurality of OES signals along a respective path of a plurality of paths for sampling the plurality of OES signals, wherein the plurality of paths comprises a first set of radially symmetric paths with respect to the inner ring and a second set of radially symmetric paths with respect to the outer ring.

2. The apparatus of claim 1 , wherein the guide comprises a plurality of scallops.

3. The apparatus of claim 1 , wherein the inner ring comprises 3 inner ring locations and the outer ring comprises 3 outer ring locations, and the plurality of collimators comprises 7 collimators.

4. The apparatus of claim 1 , wherein the base component comprises:
an upper clamp for securing a set of optical channels, wherein each collimator of the plurality of collimators is attached to a respective end of an optical channel of the set;
a base; and
a plurality of ports formed within the base, wherein each collimator of the plurality of collimators is inserted into a respective port of the plurality of ports.

5. A system comprising:
a spatial optical emission spectroscopy (OES) apparatus comprising:
a guide to guide each OES signal of a plurality of OES signals along a respective path of a plurality of paths during an iteration of an etch process to etch a wafer using an etch recipe with respect to a plurality of locations of the wafer, wherein the plurality of locations comprises a center location of the wafer, a plurality of inner ring locations along an inner ring of the wafer, and a plurality of outer ring locations along an outer ring of the wafer, and wherein the plurality of paths comprises a first set of radially symmetric paths with respect to the inner ring and a second set of radially symmetric paths with respect to the outer ring; and
an optical detector to generate a spatial OES analysis based on a sampling of the plurality of OES signals;

a memory; and
a processing device operatively coupled to the memory and the spatial OES apparatus, the processing device to facilitate an etch rate uniformity monitoring process by performing a plurality of operations comprising:
initiating the iteration of the etch process to etch the wafer using the etch recipe;
receiving, from the spatial OES apparatus, the spatial OES analysis of the plurality of OES signals; and
performing one or more actions related to etch uniformity based on the spatial OES analysis.

6. The system of claim 5 , wherein the spatial OES sampling apparatus further comprises:
a plurality of collimators operatively coupled to the guide, each collimator of the plurality of collimators corresponding to a respective collection cylinder of a plurality of collection cylinders.

7. The system of claim 5 , wherein the processing device is operatively coupled to a switch device to enable the plurality of OES signals to be selectively analyzed with the optical detector.

8. The system of claim 5 , wherein the spatial OES analysis determines etch rates with respect to each location of the plurality of locations.

9. The system of claim 5 , wherein performing the one or more actions comprises optimizing the etch recipe for etch uniformity.

10. The system of claim 5 , wherein performing the one or more actions comprises monitoring etch uniformity.

11. The system of claim 5 , wherein performing the one or more actions comprises controlling etch uniformity.

12. The system of claim 5 , wherein the inner ring comprises 3 inner ring locations and the outer ring comprises 3 outer ring locations.

13. A method comprising:
initiating, by a processing device, an iteration of an etch process to etch a wafer using an etch recipe with respect to a plurality of locations of the wafer, wherein the plurality of locations comprises a center location of the wafer, a plurality of inner ring locations along an inner ring of the wafer, and a plurality of outer ring locations along an outer ring of the wafer;
receiving, by the processing device, a spatial optical emission spectroscopy (OES) analysis of a plurality of spatial OES signals sampled during the iteration of the etch process with respect to the plurality of locations of the wafer, and wherein the plurality of signals comprises a first set of signals sampled radially symmetric with respect to the inner ring and a second set of signals sampled radially symmetric with respect to the outer ring; and
performing, by the processing device, one or more actions related to etch uniformity based on the spatial OES analysis.

14. The method of claim 13 , wherein the spatial OES analysis determines etch rates with respect to each location of the plurality of locations.

15. The method of claim 13 , wherein performing the one or more actions comprises optimizing the etch recipe for etch uniformity.

16. The method of claim 13 , wherein performing the one or more actions comprises monitoring etch uniformity.

17. The method of claim 13 , wherein performing the one or more actions comprises controlling etch uniformity.

18. The method of claim 13 , wherein the inner ring comprises 3 inner ring locations and the outer ring comprises 3 outer ring locations.

Assignees

• Applied Materials Inc

Inventors

• Erickson Blake
• Berding Keith
• Kutney Michael
• Zhu Zhaozhao
• Wu Tsung Feng
• Willwerth Michael D
• Ludwig Jeffrey

Classifications

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title

• G01J3/0291

  Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements · CPC title

• G01N21/211

  Ellipsometry (optical thickness measurement G01B11/06) · CPC title

• G01N21/68 Primary

  using high frequency electric fields · CPC title

• G01N21/255

  Details, e.g. use of specially adapted sources, lighting or optical systems · CPC title