# US 2022/0285202 A1 · Wafer lift pin system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0285202 A1 - Document ID: US20220285202A1 - Status: Published application - Kind: A1 - Application number: 17/249,566 - Filed: 2021-03-05 - Published: 2022-09-08 - Earliest claimed: 2021-03-05 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd. - Applicants: Taiwan Semiconductor Manufacturing Company, Ltd. - Inventors: Yu-Chen CHEN; Yi-Fam SHIU; Cheng-Lung WU; Yang-Ann CHU; Jiun-Rong PAI - Web page: https://patentgrep.com/patent/US20220285202A1 ## CPC - H10P 72/7612: {characterised by lifting arrangements, e.g. lift pins} - H10P 72/0604: {Process monitoring, e.g. flow or thickness monitoring} - H10P 72/7624: {characterised by the mechanical construction of the susceptor, stage or support} - C30B 25/12: Substrate holders or susceptors - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR ## Abstract A wafer lift pin system is capable of dynamically modulating or adjusting the flow of gas into and out of lift pins of the wafer lift pin system to achieve and maintain a consistent pressure in supply lines that supply the gas to the lift pins. This enables the wafer lift pin system to precisely control the speed, acceleration, and deceleration of the lift pins to achieve consistent and repeatable lift pin rise times and fall times. A controller and various sensors and valves may control the gas pressures in the wafer lift pin system based on various factors, such as historic rise times, historic fall times, and/or the condition of the lift pins. This enables smoother and more controlled automatic operation of the lift pins, which reduces and/or minimizes wafer shifting and wafer instability, which may reduce processing defects and maintain or improve processing yields. ## Claims ### Claim 1 A method, comprising: providing, by a pressure sensor included in a wafer lift pin system, pressure sensor data to a controller included in the wafer lift pin system; determining, by the controller and based on the pressure sensor data, that a gas is being supplied to the wafer lift pin system; transmitting, by the controller and based on determining that the gas is being supplied to the wafer lift pin system, an indication of a pressure setting to a proportional valve included in the wafer lift pin system; and providing, by the proportional valve, a supply of the gas to one or more lift pins to cause the one or more lift pins to raise a semiconductor wafer that is supported on the one or more lift pins, wherein the proportional valve modulates the supply of the gas to the one or more lift pins such that the gas is supplied to the one or more lift pins approximately at the pressure setting. ### Claim 2 (depends on 1) The method of claim 1, further comprising: maintaining, by the proportional valve, a pressure of the supply of the gas to the one or more lift pins at the pressure setting after the semiconductor wafer has been raised to an extended configuration. ### Claim 3 (depends on 1) The method of claim 1, wherein providing the supply of the gas to the one or more lift pins comprises: determining, by the proportional valve, a pressure of the supply of the gas to the one or more lift pins; and modulating the supply of the gas to the one or more lift pins such that the pressure of the gas is within a threshold of the pressure setting. ### Claim 4 (depends on 3) The method of claim 3, wherein determining the pressure of the supply of the gas to the one or more lift pins comprises: determining the pressure of the supply of the gas to the one or more lift pins based on pressure sensor data generated by another pressure sensor associated with the proportional valve. ### Claim 5 (depends on 1) The method of claim 1, further comprising: determining the pressure setting to achieve a particular rise time for raising the semiconductor wafer. ### Claim 6 (depends on 5) The method of claim 5, wherein determining the pressure setting to achieve the particular rise time for raising the semiconductor wafer comprises: determining the pressure setting to compensate for elastic fatigue of springs included in the one or more lift pins. ### Claim 7 (depends on 1) The method of claim 1, further comprising: determining the pressure setting based on data associated with the one or more lift pins indicating historical rise times and associated pressures for the one or more lift pins. ### Claim 8 A wafer lift pin system, comprising: a pressure sensor configured to generate pressure sensor data associated with a first supply flow of a gas to a storage tank included in the wafer lift pin system; the storage tank configured to receive the first supply flow of the gas and to store the gas; a proportional valve configured to selectively: provide a second supply flow of the gas in the storage tank to a plurality of lift pins included in the wafer lift pin system, or purge gas from the plurality of lift pins; and a controller configured to: selectively determine: a first pressure at which the proportional valve is to provide the second supply flow of the gas in the storage tank to the plurality of lift pins, or a second pressure at which the proportional valve is to purge the gas from the plurality of lift pins. ### Claim 9 (depends on 8) The wafer lift pin system of claim 8, further comprising: a manifold configured to split the second supply flow of the gas into respective supply flows of the gas for corresponding ones of the plurality of lift pins. ### Claim 10 (depends on 9) The wafer lift pin system of claim 9, further comprising: respective gas supply lines configured to provide the respective supply flows of the gas to corresponding ones of the plurality of lift pins. ### Claim 11 (depends on 8) The wafer lift pin system of claim 8, further comprising: a one-way solenoid valve configured to provide the first supply flow of the gas to the storage tank. ### Claim 12 (depends on 11) The wafer lift pin system of claim 11, further comprising: a check valve configured to prevent the gas in the storage tank from backflowing out through the one-way solenoid valve. ### Claim 13 (depends on 8) The wafer lift pin system of claim 8, further comprising: an gas supply line configured to provide the second supply flow of the gas in the storage tank to the proportional valve; and an gas purge line configured to purge the gas, that is purged from the plurality of lift pins, from the wafer lift pin system. ### Claim 14 (depends on 8) The wafer lift pin system of claim 8, further comprising: another gas supply line configured to provide the first supply flow of the gas to the storage tank. ### Claim 15 A method, comprising: generating, by a pressure sensor included in a wafer lift pin system, pressure sensor data associated with a gas in the wafer lift pin system; providing, by the pressure sensor, the pressure sensor data to a controller included in the wafer lift pin system; determining, by the controller and based on the pressure sensor data, that a first pressure of the gas satisfies a pressure threshold; transmitting, by the controller and based on determining that the first pressure of the gas satisfies the pressure threshold, an indication of a second pressure to a proportional valve included in the wafer lift pin system; and purging, by the proportional valve, the gas from one or more lift pins approximately at the second pressure to cause the one or more lift pins to retract below a wafer stage, wherein the retracting the one or more lift pins causes a semiconductor wafer, supported on the one or more lift pins, to be lowered onto the wafer stage. ### Claim 16 (depends on 15) The method of claim 15, wherein purging the gas from the one or more lift pins comprises: dynamically adjusting, by the proportional valve, a rate at which the gas is purged from the one or more lift pins to achieve the second pressure. ### Claim 17 (depends on 16) The method of claim 16, wherein dynamically adjusting the rate at which the gas is purged from the one or more lift pins comprises: dynamically adjusting the rate at which the gas is purged from the one or more lift pins based on pressure sensor data generated by another pressure sensor associated with the proportional valve. ### Claim 18 (depends on 15) The method of claim 15, further comprising: maintaining, by the proportional valve, a pressure of the gas in the one or more lift pins approximately at a third pressure prior to purging the gas from the one or more lift pins. ### Claim 19 (depends on 18) The method of claim 18, wherein maintaining the pressure of the gas in the one or more lift pins approximately at the third pressure comprises: providing a supply flow of the gas from a storage tank included in the wafer lift pin system to maintain the pressure of the gas in the one or more lift pins approximately at the third pressure. ### Claim 20 (depends on 15) The method of claim 15, further comprising: maintaining, by a check valve included in the wafer lift pin system, a third pressure of a gas in a storage tank included in the wafer lift pin system prior to purging the gas from the one or more lift pins.