# US 2016/0254166 A1 · Chemical Circulation System and Methods of Cleaning Chemicals

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2016/0254166 A1
- Document ID: US20160254166A1
- Status: Published application
- Kind: A1
- Application number: 15/149,502
- Filed: 2016-05-09
- Published: 2016-09-01
- Earliest claimed: 2013-10-09
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co. Ltd.
- Inventors: Chien-Hua Huang; Chung-Ju Lee
- Web page: https://patentgrep.com/patent/US20160254166A1

## CPC

- H10P 50/667: {by liquid etching only}
- H10P 70/27: {during, before or after processing of conductive materials, e.g. polysilicon or amorphous silicon layers}
- H10P 72/0404: {for general liquid treatment, e.g. etching followed by cleaning}
- H10P 72/0604: {Process monitoring, e.g. flow or thickness monitoring}
- H10P 74/23: {characterised by multiple measurements, corrections, marking or sorting processes}
- H10P 50/73: {using masks for insulating materials}
- H10P 72/0424: {using mainly spraying means, e.g. nozzles}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A method includes passing a chemical solution through a metal-ion absorber, wherein metal ions in the metal-ion absorber are trapped by the metal-ion absorber. The chemical solution exiting out of the metal-ion absorber is then used to etch a metal-containing region, wherein the metal-containing region includes a metal that is of a same element type as the metal ions.

## Claims

### Claim 1

A method comprising:
using a wet-clean circulation system to form an integrated circuit, the wet-clean circulation system comprising:
a storage;
a filter connected to the storage;
a metal ion absorber connected to the filter; and
a monitor connected to the metal ion absorber; and
a process chamber, wherein the storage, the filter, the metal ion absorber, the monitor, and the process chamber are connected in series to allow a chemical solution to circulate in the wet-clean circulation system.

### Claim 2 (depends on 1)

The method of claim 1 further comprising performing a process step to form the integrated circuit in the process chamber using the chemical solution.

### Claim 3 (depends on 1)

The method of claim 1 further comprising:
conducting the chemical solution through the filter;
conducting the chemical solution out of the filter through the metal ion absorber; and
monitoring an amount of metal ions in the chemical solution out of the metal ion absorber.

### Claim 4 (depends on 3)

The method of claim 3 further comprising:
in response to a result of the monitoring the amount of metal ions, rejuvenizing a metal ion exchanger in the metal ion absorber.

### Claim 5 (depends on 1)

The method of claim 1, wherein the metal ion absorber comprises a metal ion exchanger comprising:
a base material with a plurality of pores in the base material, wherein the plurality of pores is interconnected with each other to form a plurality of paths penetrating through the base material; and
a polymer coated on inner surfaces of the plurality of pores, wherein the polymer is configured to trap metal ions in the chemical solution.

### Claim 6 (depends on 1)

The method of claim 1, wherein the metal ion absorber comprises:
a first channel comprising a first metal-ion exchanger; and
a second channel comprising a second metal-ion exchanger, wherein each of the first channel and the second channel is configured to be turned on and off individually.

### Claim 7 (depends on 6)

The method of claim 6 further comprising:
switching off the first channel to stop the first metal-ion exchanger from receiving the chemical solution;
switching on the second channel to allow the second metal-ion exchanger to trap metal ions in the chemical solution; and
rejuvenizing the first metal-ion exchanger when the first channel is turned off and the second channel is turned on.

### Claim 8

A method comprising:
using a wet-clean circulation system to form an integrated circuit, the method comprising conducting a chemical solution into the wet-clean circulation system, wherein the wet-clean circulation system comprises:
a storage configured to store the chemical solution;
a filter configured to filter particles in the chemical solution;
a metal ion absorber configured to absorb metal ions in chemical solution; and
a monitor configured to monitor the chemical solution; and
using the chemical solution to manufacture the integrated circuit.

### Claim 9 (depends on 8)

The method of claim 8, wherein the wet-clean circulation system further comprises a process chamber, and the method further comprises manufacturing the integrated circuit by removing a metal-containing region of a wafer in the process chamber and using the chemical solution.

### Claim 10 (depends on 8)

The method of claim 8, wherein the filter is configured to filter particles with sizes greater than about 15 nm.

### Claim 11 (depends on 8)

The method of claim 8, wherein the wet-clean circulation system is configured to monitor an amount of metal ions in the chemical solution using the monitor, and rejuvenize a metal-ion exchanger in the metal ion absorber.

### Claim 12 (depends on 8)

The method of claim 8, wherein the metal ion absorber comprises a metal-ion exchanger, and the metal-ion exchanger comprises:
a porous base material; and
a polymer coated on surfaces of the porous base material, wherein the polymer is coated into pores of the porous base material.

### Claim 13 (depends on 8)

The method of claim 8, wherein the metal ion absorber comprises:
a first channel comprising a first metal-ion exchanger; and
a second channel parallel to the first channel, the second channel comprising a second metal-ion exchanger, wherein both the first channel and the second channel are configured to conduct the chemical solution.

### Claim 14 (depends on 13)

The method of claim 13 further comprising:
switching off the first channel to stop the first metal-ion exchanger from receiving the chemical solution; and
switching on the second channel to allow the second metal-ion exchanger to trap metal ions in the chemical solution.

### Claim 15 (depends on 8)

The method of claim 8, wherein the chemical solution passes through the storage, the filter, the metal ion absorber, and the monitor, and is conducted into a process chamber for manufacturing the integrated circuit.

### Claim 16 (depends on 15)

The method of claim 15, wherein the process chamber comprises a drain and a conducting path connecting the process chamber to the storage, and the wet-clean circulation system is configured to:
determining a quality of the chemical solution collected from the process chamber;
in response to the quality to be higher than a pre-determined quality, conducting the chemical solution back to the storage; and
in response to the quality to be lower than the pre-determined quality, drain the chemical solution.

### Claim 17

A method comprising:
using a wet-clean circulation system to form an integrated circuit, wherein the wet-clean circulation system comprises:
a metal ion absorber configured to absorb metal ions in a chemical solution;
a monitor connected to an outlet of the metal ion absorber, wherein the monitor is configured to monitor an amount of metal ions in the chemical solution; and
a process chamber configured to receive the chemical solution out of the monitor, wherein the process chamber is configured to etch a metal-containing region of a wafer in which the integrated circuit is being formed, and the metal-containing region comprises a same type of metal as the metal ions.

### Claim 18 (depends on 17)

The method of claim 17, wherein the wet-clean circulation system comprises a closed loop, with the metal ion absorber, the monitor, and the process chamber in the closed loop.

### Claim 19 (depends on 17)

The method of claim 17 further comprising:
in response to a result of monitoring the amount of metal ions, rejuvenizing a metal ion exchanger in the metal ion absorber.

### Claim 20 (depends on 17)

The method of claim 17, wherein the metal ion absorber comprises:
a first channel comprising a first metal-ion exchanger; and
a second channel comprising a second metal-ion exchanger, wherein each of the first channel and the second channel is configured to absorb ions when another one of the first channel and the second channel is being rejuvenized.