Method and device for predicting inclination angle, and method and device for monitoring etching device

Patent metadata

Field	Value
Publication number	US-12176252-B2
Application number	US-202117452358-A
Country	US
Kind code	B2
Filing date	Oct 26, 2021
Priority date	Jan 14, 2021
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

A method for predicting an inclination angle of an etched hole can include operations as follows. A preset change range of an etching rate of an etching device for an object to be etched on a surface of a monitored sample in different operation stages is determined. An etching rate change curve of the etching device for the object to be etched on the surface of a monitored sample in a current operation stage is acquired. When the etching rate change curve exceeds the preset change range, it is determined that an inclination angle of an etched hole of an etched product currently etched by the etching device exceeds a preset angle.

First claim

What is claimed is:

1. A method for predicting an inclination angle of an etched hole, comprising:
determining a preset change range of an etching rate of an etching device for an object to be etched on a surface of a monitored sample in different operation stages;
acquiring an etching rate change curve of the etching device for the object to be etched on the surface of a monitored sample in a current operation stage; and
responsive to that the etching rate change curve exceeds the preset change range, determining that an inclination angle of an etched hole of an etched product etched by the etching device exceeds a preset angle.

2. The method of claim 1 , wherein the determining the preset change range of the etching rate of the etching device for the object to be etched on the surface of the monitored sample in different operation stages comprises:
etching the monitored sample and an etched sample under a same etching condition of the etching device in the different operation stages, wherein the etched sample and the monitored sample have a same structural size;
acquiring a time-varying curve of the etching rate for the object to be etched on the surface of the monitored sample;
detecting a maximum inclination angle of the etched hole in the etched sample; and
responsive to that the maximum inclination angle is less than or equal to the preset angle, determining the preset change range according to the time-varying curve of the etching rate.

3. The method of claim 2 , wherein the determining the preset change range according to the time-varying curve of the etching rate comprises:
setting a maximum etching rate curve and a minimum etching rate curve with taking the time-varying curve of the etching rate as a reference; and
determining a region between the maximum etching rate curve and the minimum etching rate curve as the preset change range.

4. The method of claim 2 , wherein the object to be etched on the surface of the monitored sample is one or more of oxides, nitrides, and organic silicide.

5. The method of claim 2 , wherein the etched hole in the etched sample comprises etched holes of the etched sample in different regions.

6. The method of claim 5 , wherein the acquiring the time-varying curve of the etching rate for the object to be etched on the surface of the monitored sample comprises:
acquiring time-varying curves of etching rates for objects to be etched in different regions on the surface of the monitored sample.

7. The method of claim 6 , wherein in a case that the etched sample is a wafer, the different regions on the surface of the monitored sample comprise at least one of a center region, a side edge region, a region close to a center or a region close to a side edge.

8. The method of claim 5 , wherein in a case that the etched sample is a wafer, the different regions on the surface of the monitored sample comprise at least one of a center region, a side edge region, a region close to a center or a region close to a side edge.

9. The method of claim 8 , wherein the determined preset change range of the etching rate ranges from 450 to 600 nm/s.

10. The method of claim 1 , wherein the determining the preset change range of the etching rate of the etching device for the object to be etched on the surface of the monitored sample in different operation stages comprises:
acquiring first ratios of the etching rates of the etching device for the objects to be etched at different etching positions on the surface of the monitored sample in an initial operation stage to a first reference etching rate;
determining a first preset ratio distance change curve according to the first ratios and distances from the different etching positions on the surface of the monitored sample to the center position of the monitored sample;
acquiring second ratios of the etching rates of the etching device for the objects to be etched at the different etching positions on the surface of the monitored sample in a later operation stage to a second reference etching rate;
determining a second preset ratio distance change curve according to the second ratios and the distances from the different etching positions on the surface of the monitored sample to the center position of the monitored sample;
detecting inclination angles of etched holes at the different etching positions of an etched sample in the later operation stage, wherein the etched sample and the monitored sample have a same structural size; and
in a case that the inclination angles are less than or equal to the preset angle, determining the preset change range according to the first preset ratio distance change curve and the second preset ratio distance change curve.

11. The method of claim 10 , wherein the acquiring the etching rate change curve of the etching device for the object to be etched on the surface of the monitored sample in the current operation stage comprises:
determining third ratios of etching rates at the different etching positions on a surface of a current monitored sample to a third reference etching rate; and
determining the etching rate change curve according to the third ratios and the distances from the different etching positions on the surface of the current monitored sample to the center position of the monitored sample.

12. The method of claim 11 , wherein the first reference etching rate is an average etching rate at the center position on the surface of the monitored sample in the initial operation stage;
the second reference etching rate is an average etching rate at the center position on the surface of the monitored sample in the later operation stage; and
the third reference etching rate is an average etching rate at the center position on the surface of the current monitored sample.

13. The method of claim 1 , wherein the preset angle is 5 degrees.

14. The method of claim 1 , further comprising:
responsive to that the inclination angle of the etched hole exceeds the preset angle, replacing a focus ring of the etching device.

15. A method for monitoring an etching device, comprising:
determining whether an inclination angle of an etched hole of an etched product exceeds a preset angle according to the method for predicting an inclination angle of an etched hole of claim 1 ; and
responsive to that the inclination angle of the etched hole exceeds the preset angle, sending alarm information to an etching device.

16. A device for monitoring the etching device implementing the method for predicting the inclination angle of the etched hole of claim 1 , the device comprising:
a processor;
an input/output interface; and
a memory configured to store executable instructions of the processor,
wherein the processor is configured to execute the executable instructions to:
determine whether the inclination angle of the etched hole of an etched product exceeds the preset angle; and
responsive to that the inclination angle of the etched hole exceeds the preset angle, control the input/output interface to send alarm information to the etching device.

Assignees

• Changxin Memory Tech Inc

Inventors

• Shao Bo
• Liu Xinran
• Wang Chunyang

Classifications

• H10P74/27

  Structural arrangements therefor · CPC title

• H10P74/203 Primary

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

• G01B11/22

  for measuring depth · CPC title

• G01B2210/56

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

• G01B21/22

  for measuring angles or tapers; for testing the alignment of axes · CPC title