# US 2013/0157387 A1 · Multi-zone EPD Detectors

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- Number: US 2013/0157387 A1
- Document ID: US20130157387A1
- Status: Published application
- Kind: A1
- Application number: 13/328,172
- Filed: 2011-12-16
- Published: 2013-06-20
- Earliest claimed: 2011-12-16
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Inventors: Chien-An Chen; Yen-Shuo Su; Ying Xiao; Chin-Hsiang Lin
- Web page: https://patentgrep.com/patent/US20130157387A1

## CPC

- H01J 37/32963: {End-point detection}
- H01J 37/3299: {Feedback systems}
- H10P 50/283: {by chemical means}
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

The present disclosure relates to a semiconductor body etching apparatus having a multi-zone end point detection system. In some embodiments, the multi-zone end point detection system has a processing chamber that houses a workpiece that is etched according to an etching process. A plurality of end point detector (EPD) probes are located within the processing chamber. Respective EPD probes are located within different zones in the processing chamber, thereby enabling the detection of end point signals from multiple zones within the processing chamber. The detected end point signals are provided from the plurality of EPD probes to an advanced process control (APC) unit. The APC unit is configured to make a tuning knob adjustment to etching process parameters based upon the detected end point signals and to thereby account for etching non-uniformities.

## Claims

### Claim 1

A semiconductor body etching apparatus, comprising:
a processing chamber configured to house a semiconductor workpiece having a processing layer that is to be etched according to an etching process;
a multi-zone end point detection system configured to detect end point signals, which indicate when the processing layer is removed, at different locations within the processing chamber; and
an advanced process control unit connected to the multi-zone end point detection system and configured to make a tuning knob adjustment of etching process parameters based upon the end point signals detected at different locations within the processing chamber.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the multi-zone end point detection system comprises a plurality of end point detection probes located within the processing chamber.

### Claim 3 (depends on 2)

The apparatus of claim 2, wherein the plurality of end point detection probes comprise optical spectrometers configured to monitor an emission spectrum of an etching plasma within the processing chamber.

### Claim 4 (depends on 3)

The apparatus of claim 3, wherein the advanced process control unit is configured:
calculate an absolute value of a time difference between a spectral intensity peak of end point signals detected in one of the plurality of zones and a predetermined value;
comparing the absolute value of the time difference with a threshold; and
making the tuning knob adjustment of etching process parameters if the absolute value of the time difference is greater than or equal to the threshold.

### Claim 5 (depends on 2)

The apparatus of claim 2,
wherein the processing chamber comprises a plurality of zones spatially distinct from one another; and
wherein each zone comprises one or more of the plurality of end point detection probes, which are configured to monitor etching within the zone.

### Claim 6 (depends on 5)

The apparatus of claim 5, wherein a plurality of zones, comprise:
a center zone located within a center of the processing chamber;
a wafer edge zone located along a perimeter of the processing chamber; and
a middle zone located radially between the center zone and the wafer edge zone.

### Claim 7 (depends on 5)

The apparatus of claim 5, further comprising:
an etchant gas source connected to the processing chamber by way of a plurality of etchant gas conduits;
wherein the advanced process control unit is configured to control a ratio of etchant gases that are provided from the etchant gas source to each of the plurality of zones based upon the end point signals detected at different locations within the processing chamber.

### Claim 8 (depends on 5)

The apparatus of claim 5, further comprising:
a tuning gas source connected to the processing chamber by way of a plurality of tuning gas conduits;
wherein the advanced process control unit is configured to control a flow of a tuning gas from the tuning gas source to each of the plurality of zones based upon the end point signals detected at different locations within the processing chamber.

### Claim 9 (depends on 5)

The apparatus of claim 5, further comprising:
an electrostatic wafer chuck comprising a plurality of channels configured to circulate a cooling liquid within the electrostatic chuck to regulate a temperature of the electrostatic wafer chuck;
wherein the advanced process control unit is configured to control a temperature of the cooling liquid within each of the plurality of zones based upon the end point signals detected at different locations within the processing chamber.

### Claim 10

An end point detection (EPD) system, comprising:
a processing chamber comprising a plurality of zones spatially distinct from one another; and
a plurality of end point detection probes, wherein one or more of the plurality of end point detection probes are located within each of the plurality of zones and are configured generate an end point signal corresponding to an etching process within the zone, so that non-uniformities in the etching process can be detected within different zones based upon a difference in the end point signals.

### Claim 11 (depends on 10)

The EPD system of claim 10, wherein the plurality of zones comprise:
a center zone located within a center of the processing chamber;
a wafer edge zone located along a perimeter of the processing chamber; and
a middle zone located radially between the center zone and the wafer edge zone.

### Claim 12 (depends on 10)

The EPD system of claim 10, further comprising:
an advanced process control (APC) unit connected to the plurality of end point detection probes and configured to make a tuning knob adjustment to one or more etching process parameters based upon the end point signals generated at different zones.

### Claim 13 (depends on 12)

The EPD system of claim 12, wherein the tuning knob adjustment of the etching process parameters comprises:
an adjustment of a ratio of etchant gases that are provided to each of the plurality of zones;
an adjustment of a flow of a tuning gas to each of the plurality of zones; or
an adjustment of a temperature of a cooling liquid provided to a wafer chuck within each of the plurality of zones.

### Claim 14

A method for improving etching uniformity, comprising:
initiating an etching process recipe to form an etching plasma within a processing chamber;
collecting end point signal data from a plurality of different zones within the processing chamber; and
making one or more tuning knob adjustments of etching process parameters based upon the collected end point signal data.

### Claim 15 (depends on 14)

The method of claim 14, wherein making the one or more tuning knob adjustments of etching process parameters, comprises:
calculating an absolute value of a time difference between a spectral intensity peak of end point signals detected in one of the plurality of different zones and a predetermined value;
comparing the absolute value of the time difference with a threshold; and
making the one or more tuning knob adjustments of etching process parameters if the absolute value of the time difference is greater than or equal to the threshold.

### Claim 16 (depends on 14)

The method of claim 14, wherein the end point signals comprise an optical spectrometer intensity of an emission spectrum of the etching plasma.

### Claim 17 (depends on 14)

The method of claim 14, wherein making one or more tuning knob adjustments of etching process parameters, comprises:
adjusting a ratio at which etchant gases are provided to the plurality of zones within the processing chamber based upon the end point signals detected at different locations within the processing chamber.

### Claim 18 (depends on 14)

The method of claim 14, wherein making the one or more tuning knob adjustments of etching process parameters, comprises:
adjusting a flow of a tuning gas to the plurality of zones within the processing chamber based upon the end point signals detected at different locations within the processing chamber.

### Claim 19 (depends on 14)

The method of claim 14, wherein making the one or more tuning knob adjustments of etching process parameters, comprises:
adjusting a temperature of a cooling liquid within the plurality of zones within the processing chamber based upon the end point signals detected at different locations within the processing chamber.

### Claim 20 (depends on 14)

The method of claim 14, further comprising:
etching a next wafer based upon the adjusted etching process parameters.