Wafer far edge temperature measurement system with lamp bank alignment

Patent metadata

Field	Value
Publication number	US-12417933-B2
Application number	US-202217697164-A
Country	US
Kind code	B2
Filing date	Mar 17, 2022
Priority date	Mar 18, 2021
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A reactor system designed to provide accurate monitoring of wafer temperatures during deposition steps. The reactor system includes a pyrometer mounting assembly supporting and positioning three or more pyrometers (e.g., infrared (IR) pyrometers) relative to the reaction chamber to measure a center wafer temperature and an edge wafer temperature as well as reaction chamber temperature. The pyrometer mounting assembly provides a small spot size or temperature sensing area with the edge pyrometer to accurately measure edge wafer temperatures. A jig assembly, and installation method for each tool setup, is provided for use in achieving accurate alignment of the IR pyrometer sensing spot (and the edge pyrometer) relative to the wafer, when the pyrometer mounting assembly is mounted upon a lamp bank in the reactor system or in tool setup. The wafer edge temperature sensing with the reactor system assembled with proper alignment ensures accurate and repeatable measurement of wafer temperatures.

First claim

What is claimed is:

1. A method of assembling a reactor system adapted for monitoring edge wafer temperatures, comprising:
placing a lamp bank, operable to provide heat to an inner chamber of a reaction chamber, on a lid adapted for supporting the lamp bank relative to the reaction chamber;
mounting an alignment jig on an upper surface of the lamp bank at a location predefined for an edge pyrometer of a temperature monitoring assembly operable to perform the monitoring of the edge wafer temperatures;
placing an edge sensor, operable to sense an edge of a wafer positioned on a susceptor in the inner chamber, in the alignment jig;
moving the lamp bank linearly relative to the lid, with the edge sensor operating, until an edge of the wafer is identified; and
securing the lamp bank to the lid.

2. The method of claim 1 , wherein the edge sensor comprises a fiber optic sensor and wherein the edge of the wafer is identified based on a difference in reflectivity of the wafer and the susceptor.

3. The method of claim 1 , further comprising removing the alignment jig from the lamp bank and replacing the alignment jig with the temperature monitoring assembly with the edge pyrometer positioned at the location predefined for the edge pyrometer.

4. The method of claim 3 , wherein the lamp bank comprises a transmission channel at the location predefined for the edge pyrometer for transmitting a signal from the wafer on the susceptor through the inner chamber and the lamp bank to the edge pyrometer and wherein the alignment jig includes a slot for receiving the edge sensor that is offset a predefined distance from the transmission channel when the alignment jig is mounted on the upper surface of the lamp bank at the location predefined for the edge pyrometer.

5. The method of claim 4 , wherein the upper surface of the lamp bank includes a pair of alignment holes on opposite sides of the transmission channel, wherein the jig comprises a body with a bottom surface for mating with the upper surface of the lamp bank, wherein the alignment jig includes a pair of alignment pins sized and positioned for insertion into the alignment holes on the lamp bank, and wherein the lamp bank further includes a second transmission channel with a center offset the predefined distance from the transmission channel, whereby a signal from the edge sensor is received from the inner chamber and through the lamp bank.

6. The method of claim 4 , wherein the predefined distance is in the range of 2 to 10 millimeters.

7. The method of claim 1 , wherein the placing of the lamp bank comprises positioning the lamp bank equidistantly from inner edges of the lid along an axis that is orthogonal to an axis along which the lamp bank is moved during the moving of the lamp bank linearly relative to the lid.

8. A reactor system adapted for monitoring edge wafer temperatures, comprising:
a reaction chamber;
a lid for supporting heat lamps relative to the reaction chamber;
a lamp bank positionable on the lid in a plurality of positions along a longitudinal axis;
an alignment jig mounted upon an upper surface of the lamp bank at a location predefined for an edge pyrometer of a temperature monitoring assembly operable to perform the monitoring of the edge wafer temperatures, wherein the lamp bank includes a first transmission channel at the location predefined for the edge pyrometer for receiving a signal from within the reaction chamber at the edge pyrometer; and
an edge sensor, operable to sense an edge of a wafer positioned on a susceptor in the reaction chamber, supported in a slot of the alignment jig,
wherein the edge sensor is oriented by the slot in the alignment jig to receive a signal through a second transmission channel, offset a predefined distance from the first transmission channel, in the lamp bank into the reaction chamber.

9. The reactor system of claim 8 , wherein, during assembly of the reactor system, the lamp bank is linearly movable between two or more of the plurality of positions with the edge sensor operating until the edge sensor identifies the edge of the wafer.

10. The reactor system of claim 9 , wherein the edge sensor comprises a fiber optic sensor and wherein the edge of the wafer is identified based on a difference in reflectivity of the wafer and the susceptor.

11. The reactor system of claim 8 , wherein the upper surface of the lamp bank includes a pair of alignment holes on opposite sides of the first transmission channel, wherein the jig comprises a body with a bottom surface for mating with the upper surface of the lamp bank, wherein the jig includes a pair of alignment pins sized and positioned for insertion into the alignment holes on the lamp bank, whereby the signal to the edge sensor is transmitted from the inner chamber through the lamp bank during operations of the edge sensor.

12. The reactor system of claim 8 , wherein the predefined distance is in the range of 2 to 10 millimeters.

13. The reactor system of claim 8 , further comprising, with the alignment jig removed from the lamp bank, the temperature monitoring assembly including a mounting stand supporting the edge pyrometer on the upper surface of the lamp bank with the edge pyrometer at the predefined location for the edge pyrometer, whereby a signal to the edge pyrometer is transmitted through the first transmission channel of the lamp bank from a spot on the wafer proximate to the edge of the wafer.

14. The reactor system of claim 13 , wherein the spot has an outer diameter in the range of 2 to 10 millimeters.

15. The reactor system of claim 14 , wherein the mounting stand is configured to define a lens of the edge pyrometer with a length greater than a length of a lens of a center pyrometer of the temperature monitoring assembly to define a size of the spot and wherein an outlet of the first transmission channel acts as a signal clipping aperture for the signal received at the edge pyrometer to further define the size of the spot.

16. The reactor system of claim 15 , wherein the center pyrometer senses a temperature of the wafer at a center location of the wafer with a spot having an outer diameter greater than the spot of the edge pyrometer, whereby temperatures of the wafer are concurrently monitored at two or more locations.

17. An alignment jig adapted for aligning an edge pyrometer with a wafer edge in a reactor system, comprising:
a body;
a slot extending through the body for receiving a fiber optic sensor; and
a pair of alignment pins on a surface of the body, wherein the pair of alignment pins are spaced apart a distance matching a spacing distance between alignment holes on a surface of a lamp bank at a location for an edge pyrometer,
wherein a center axis of the slot is offset a predefined distance from a location between the pair of alignment pins associated with a transmission channel in the lamp bank configured to transmit a signal from the edge pyrometer.

18. The alignment jig of claim 17 , wherein the predefined distance is in the range of 2 to 10 millimeters.

19. The alignment jig of claim 17 , further comprising a clamp for fastening the fiber optic sensor to the body.

20. The alignment jig of claim 17 , further comprising a pair of holes in the body for receiving a pair of fasteners at spaced apart locations matching a spacing between a pair of threaded holes in the surface of the lamp bank provided for fastening a mounting stand for the edge pyrometer to the lamp bank.

Assignees

• Asm Ip Holding Bv

Inventors

• Naik Rutvij
• Huang Shujin
• Su Junwei
• Lin Xing

Classifications

• H10P72/0436

  mainly by radiation · CPC title

• H10P72/0602 Primary

  Temperature monitoring · CPC title

• H05B31/0081

  Controlling of arc lamps · CPC title

• G01J5/0806

  Focusing or collimating elements, e.g. lenses or concave mirrors · CPC title

• G01J5/0007 Primary

  of wafers or semiconductor substrates, e.g. using Rapid Thermal Processing · CPC title