Two-stage pin lifter for de-chuck operations

Patent metadata

Field	Value
Publication number	US-11430688-B2
Application number	US-201816121229-A
Country	US
Kind code	B2
Filing date	Sep 4, 2018
Priority date	Sep 4, 2018
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

Various embodiments include apparatuses to raise and lower substrates, as used in the semiconductor and allied industries, toward or away from a substrate-holding mechanism (e.g., such as an electrostatic chuck (ESC). In a specific embodiment, a substrate lift-mechanism includes a number of pins to position the substrate above a substrate-holding device. Mid-position sensors are respectively coupled to a corresponding pin. The mid-position sensors monitor an intermediate position of the corresponding pin between a maximum position and a minimum position. Other apparatuses and systems are disclosed.

First claim

What is claimed is:

1. A substrate lift-mechanism, comprising:
a plurality of pins configured to position a substrate above a substrate-holding device, each of the plurality of pins comprising a single, pneumatically-controlled pin with each of the plurality of pins being contained within a respective single actuator cylinder; and
a plurality of mid-position sensors each respectively coupled to a corresponding pin, each of the plurality of mid-position sensors is configured to monitor a mid-point position of the corresponding pin between a maximum position and a minimum position;
the mid-point position of the corresponding pin being indicative of being proximate a de-chuck position of the substrate, a respective one of the plurality of mid-position sensors to generate a signal when proximate to the de-chuck position of the substrate, the signal to be transmitted to a control system to control an operation of the corresponding pin based on being proximate to the de-chuck position, the control system is further configured to vary a setpoint pressure sent to each of the plurality of pins from a setpoint pressure applied when the pins are in a down position.

2. The substrate lift-mechanism of claim 1 , further comprising a substrate-breakage detector.

3. The substrate lift-mechanism of claim 1 , wherein the mid-position sensor is configured to monitor the mid-point position to determine whether the substrate is at the de-chuck position from the substrate-holding device.

4. The substrate lift-mechanism of claim 1 , Therein the substrate-holding device is an electrostatic chuck (ESC).

5. The substrate lift-mechanism of claim 4 , wherein the mid-position sensor is configured to monitor the mid-point position to determine when the substrate is de-chucked from the ESC.

6. The substrate lift-mechanism of claim 1 , wherein the plurality of pins comprises at least three pins.

7. The substrate lift-mechanism of claim 1 , further comprising a plurality of lowered-position sensors each respectively coupled to the corresponding pin, wherein each lowered-position sensor is configured to monitor when the substrate is in one of a lowered position and the down position, thereby indicating that the substrate is in direct contact, the down position, or near contact, the lowered position, with the substrate-holding device.

8. The substrate lift-mechanism of claim 1 , wherein each of the plurality of pins is configured to be coupled independently to a pressure-control device.

9. The substrate lift-mechanism of claim 1 , wherein at least one of the plurality of mid-position sensors is a true-position sensor.

10. The substrate lift-mechanism of claim 1 , wherein at least one of the plurality of mid-position sensors is a full-range position sensor.

11. The substrate lift-mechanism of claim 1 , wherein a velocity of at least one of the plurality of pins is decreased upon approaching the mid-point position.

12. The substrate lift-mechanism of claim 1 , wherein a velocity of the plurality of pins is increased upon detection of reaching the mid-point position to achieve the maximum position.

13. The substrate lift-mechanism of claim 1 , wherein the plurality of pins comprises linearly-actuated pins.

14. A wafer lift-mechanism, comprising:
a plurality of two-stage lift pins configured to position a wafer above an electrostatic chuck (ESC), each of the plurality of lift pins comprising a single, pneumatically-controlled pin with each of the plurality of pins being contained within a respective single actuator cylinder and being configured to be controlled independently from one another; and
a plurality of mid-position sensors each respectively coupled to a corresponding lift pin, each mid-position sensor being configured to monitor a mid-point position to determine whether the wafer is at or near a de-chuck position relative to the ESC in a de-chuck operation;
the mid-point position of the corresponding pin being indicative of being proximate the de-chuck position of the wafer, a respective one of the plurality of mid-position sensors to generate a signal when proximate to the de-chuck position of the wafer, the signal to be transmitted to a control system to control an operation of the corresponding pin based on being proximate to the de-chuck position, the control system is further configured to vary a setpoint pressure sent to each of the plurality of pins from a setpoint pressure applied when the pins are in a down position.

15. The wafer lift-mechanism of claim 14 , further comprising:
a lowered-position sensor configured to indicate when the wafer is in one of a lowered position and the down position, thereby indicating that the wafer is in direct contact, the down position, or near contact, the lowered position, with the ESC; and
a raised-position sensor configured to indicate when the wafer is in a fully-raised position.

16. The wafer lift-mechanism of claim 14 , wherein the mid-position sensor is a full-range position sensor.

17. The wafer lift-mechanism of claim 14 , wherein a velocity of at least one of the plurality of two-stage lift pins is decreased upon approaching the mid-point position.

18. The wafer lift-mechanism of claim 14 , wherein a velocity of the plurality of two-stage lift pins is increased upon detection of reaching the mid-point position to achieve a maximum position.

19. The wafer lift-mechanism of claim 14 , wherein the plurality of two-stage lift pins comprises linearly-actuated pins.

Assignees

• Lam Res Corp

Inventors

• Tian Siyuan
• Pape Eric A

Classifications

• H10P72/72

  using electrostatic chucks · CPC title

• H10P72/0616

  Monitoring of warpages, curvatures, damages, defects or the like · CPC title

• H10P72/0606

  Position monitoring, e.g. misposition detection or presence detection · CPC title

• H10P72/7612 Primary

  characterised by lifting arrangements, e.g. lift pins · CPC title

• H01L21/67259

  Electricity · mapped topic