System and method to control PVD deposition uniformity

Patent metadata

Field	Value
Publication number	US-11390940-B2
Application number	US-202016850678-A
Country	US
Kind code	B2
Filing date	Apr 16, 2020
Priority date	Apr 19, 2019
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

A physical vapor deposition chamber comprising a rotating substrate support having a rotational axis, a first cathode having a radial center positioned off-center from a rotational axis of the substrate support is disclosed. A process controller comprising one or more process configurations selected from one or more of a first configuration to determine a rotation speed (v) for a substrate support to complete a whole number of rotations (n) around the rotational axis of the substrate support in a process window time (t) to form a layer of a first material on a substrate, or a second configuration to rotate the substrate support at the rotation speed (v).

First claim

What is claimed is:

1. A substrate processing method comprising:
supporting a substrate having a horizontal surface on a rotating substrate support in a physical vapor deposition chamber, the substrate support having a rotational axis and a rotation speed (v) to complete a whole number of rotations (n) in a process window time (t);
starting rotation of the substrate support prior to starting deposition of material from a target surface on the horizontal surface of the substrate, the target surface being non-horizontal with respect to the horizontal substrate surface;
determining a zeroing position on the rotating substrate support and starting a physical vapor deposition process immediately after the rotating substrate support is at the zeroing position to start deposition of a first layer of a first material on the substrate;
continuing the physical vapor deposition process for the process window time (t) to form the first layer of the material on the substrate utilizing a dynamic rotation speed profile comprising angle-dependent rotation speeds, wherein the physical vapor deposition process is performed in a multi-cathode physical vapor deposition chamber including a first cathode having a radial center that is offset from the rotational axis of the substrate support and a second cathode having a radial center that is offset from the rotational axis of the substrate support, wherein the dynamic rotation speed profile compensates for deposition non-uniformity as a result of the target surface being non-horizontal with respect to the horizontal substrate surface;
depositing a second layer of a second material on the first layer according to the dynamic rotation speed profile to form a pair of layers comprising the first material and the second material; and
forming multiple pairs of layers, each of the first layer and the second layer having a thickness of 4 nm or less to form a Bragg reflector including a multilayer stack comprising the multiple pairs of layers, wherein the multilayer stack exhibits a thickness non-uniformity across a 132 mm×132 mm area of the substrate of less than 0.04 nm.

2. The method of claim 1 , further comprising forming additional pairs of layers of the first material and the second material to form the Bragg reflector.

3. The method of claim 2 , wherein the first layer comprises silicon and the second layer comprises molybdenum.

4. A physical vapor deposition chamber comprising:
a rotating substrate support having a rotational axis, a first cathode having a radial center positioned off-center from a rotational axis of the substrate support, and a process controller configured to determine a dynamic rotation speed profile for a substrate support to complete a whole number of rotations (n) around the rotational axis of the substrate support in a process window time (t) to form a layer of a first material from a target surface on a horizontal surface of a substrate, to start rotation of the substrate support prior to starting deposition of the first material on the horizontal surface of the substrate, the target surface being non-horizontal with respect to the horizontal substrate surface and to adjust rotation speed during deposition as a function of substrate support rotation angle, wherein the dynamic rotation speed profile compensates for deposition non-uniformity as a result of the target surface being non-horizontal with respect to the horizontal substrate surface;
a zeroing flag associated with the rotating substrate support; and
a sensor to detect the zeroing flag, wherein the controller is configured to send a signal when the sensor detects the zeroing flag to start deposition of the first layer of the first material on the substrate, wherein the process controller is configured to control deposition of alternating layers comprising a first layer of a first material and a second layer of a second material to form a layer pair and to repeat deposition of the alternating layers to form a Bragg reflector in which the first material layer and the second material layer each have a thickness of 4 nm and less and the Bragg reflector exhibits a thickness non-uniformity across a 132 mm×132 mm area of the substrate of less than 0.04 nm.

5. The physical vapor deposition chamber of claim 4 , further comprising at least the first cathode and a second cathode, each of the first cathode and the second cathode having a radial center that is offset from the rotational axis of the substrate support.

6. The physical vapor deposition chamber of claim 4 , wherein the controller is configured to send a signal to apply power to the first cathode when the sensor detects the zeroing flag.

7. The physical vapor deposition chamber of claim 5 , further including a non-transitory computer-readable storage medium including instructions, that, when executed by the process chamber controller, causes the physical vapor deposition chamber to perform the operations of: rotating the substrate supported on the substrate support; and applying power to the first and second cathodes within the physical vapor deposition chamber to cause the first and second material layers to be deposited on the substrate.

8. A substrate processing method comprising:
placing a substrate having a horizontal surface in a physical vapor deposition chamber on a substrate support;
starting rotation of the substrate support prior to starting deposition of material on the substrate;
rotating the substrate support around a rotational axis at a dynamic rotation speed profile in a physical vapor deposition chamber, the dynamic rotation speed profile varying with angular position of the substrate support relative to the rotational axis;
depositing a first layer of a first material physical vapor deposition from a target surface on the horizontal surface of the substrate, the target surface being non-horizontal with respect to the horizontal surface of the substrate, while rotating the substrate support at the dynamic rotation speed profile, wherein the dynamic rotation speed profile compensates for deposition non-uniformity as a result of the target surface being non-horizontal with respect to the horizontal substrate surface;
depositing a second layer of a second material on the first layer according to the dynamic rotation speed profile to form a pair of layers comprising the first material and the second material; and
forming multiple pairs of layers, each of the first layer and the second layer having a thickness of 4 nm or less to form a Bragg reflector including a multilayer stack comprising the multiple pairs of layers, wherein the multilayer stack exhibits a thickness non-uniformity across a 132 mm×132 mm area of the substrate of less than 0.04 nm.

9. The method of claim 8 , further comprising compiling the dynamic rotation speed profile as a function of rotation position relative to the rotational axis of the substrate support.

10. The method of claim 9 , wherein the dynamic rotation speed profile comprises angle-dependent rotation speeds for the substrate support.

11. The method of claim 10 , further comprising rotating the substrate support around the rotational axis at the dynamic rotation speed profile to complete a whole number of rotations (n) in a process window time (t) to deposit the material layer on the substrate.

Assignees

• Applied Materials Inc

Inventors

• Xiao Wen
• Jindal Vibhu
• Bhat Sanjay

Classifications

• C23C14/3407

  Cathode assembly for sputtering apparatus, e.g. Target · CPC title

• H01J37/3464

  Operating strategies · CPC title

• H01J2237/20214

  Rotation · CPC title

• H01J2237/3323

  uniformity · CPC title

• C23C14/352

  using more than one target (C23C14/56 takes precedence) · CPC title