Wafer processing equipment having capacitive micro sensors

Patent metadata

Field	Value
Publication number	US-10083883-B2
Application number	US-201615187717-A
Country	US
Kind code	B2
Filing date	Jun 20, 2016
Priority date	Jun 20, 2016
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

Embodiments include devices and methods for detecting particles, monitoring etch or deposition rates, or controlling an operation of a wafer fabrication process. In an embodiment, a particle monitoring device for particle detection includes several capacitive micro sensors mounted on a wafer substrate to detect particles under all pressure regimes, e.g., under vacuum conditions. In an embodiment, one or more capacitive micro sensors is mounted on a wafer processing tool to measure material deposition and removal rates in real-time during the wafer fabrication process. Other embodiments are also described and claimed.

First claim

What is claimed is:

1. A particle monitoring device, comprising:
a wafer substrate including wafer electronics and a support surface;
a capacitive micro sensor mounted on the support surface at a location, wherein a capacitance of the capacitive micro sensor changes when a material is deposited on or removed from the capacitive micro sensor; and
a barrier layer between the capacitive micro sensor and the wafer substrate, wherein the capacitive micro sensor is electrically connected to the wafer electronics through the barrier layer, and wherein the capacitive micro sensor is strippable by a plasma and the barrier layer is not strippable by the plasma.

2. The particle monitoring device of claim 1 , wherein the capacitive micro sensor includes a pair of conductors having a first conductor and a second conductor mounted on a substrate, wherein the first conductor includes a plurality of first elongated conductors, and wherein the second conductor includes a plurality of second elongated conductors interdigitated with the plurality of first elongated conductors.

3. The particle monitoring device of claim 2 , wherein the capacitive micro sensor includes a coating over one or more of the first conductor or the second conductor, wherein the coating includes the material, and wherein the capacitance of the capacitive micro sensor changes when the material is removed from the coating.

4. The particle monitoring device of claim 2 , wherein the capacitive micro sensor includes a coating over one or more of the first conductor or the second conductor, wherein the coating includes a plurality of pores, and wherein the capacitance of the capacitive micro sensor changes when the material is deposited in the pores.

5. The particle monitoring device of claim 1 , wherein the wafer electronics includes a processor operably coupled to the capacitive micro sensor to record the location when the capacitance changes.

6. The particle monitoring device of claim 5 , wherein the wafer substrate includes a top layer and a bottom layer, and further comprising a power source between the top layer and the bottom layer, wherein the power source is electrically coupled to the processor to power the processor.

7. The particle monitoring device of claim 6 further comprising a barrier seal between the top layer and the bottom layer around the power source.

8. A wafer processing tool, comprising:
a process chamber having a chamber wall around a chamber volume; and
a capacitive micro sensor mounted on the wafer processing tool at a location, wherein a capacitance of the capacitive micro sensor changes in response to a wafer fabrication process performed by the wafer processing tool, wherein the capacitive micro sensor is mounted on one or more of a load lock, a gas line, a robot, or a pressure control valve of the wafer processing tool.

9. The wafer processing tool of claim 8 , wherein the capacitive micro sensor includes a pair of conductors having a first conductor and a second conductor mounted on a substrate, wherein the first conductor includes a plurality of first elongated conductors, and wherein the second conductor includes a plurality of second elongated conductors interdigitated with the plurality of first elongated conductors.

10. The wafer processing tool of claim 9 , wherein the capacitive micro sensor includes a coating over one or more of the first conductor or the second conductor, wherein the coating includes a material, and wherein the capacitance of the capacitive micro sensor changes when the material is removed from the coating during the wafer fabrication process.

11. The wafer processing tool of claim 9 , wherein the capacitive micro sensor includes a coating over one or more of the first conductor or the second conductor, wherein the coating includes a plurality of surface area increasing structures, and wherein the capacitance of the capacitive micro sensor changes when a material is deposited in the surface area increasing structures during the wafer fabrication process.

12. A method, comprising:
loading a wafer of a semiconductor material into a process chamber of a wafer processing tool, wherein the process chamber includes a chamber wall around a chamber volume, wherein the wafer includes a DC bias;
initiating a wafer fabrication process in the process chamber, wherein a material is deposited on or removed from the wafer during the wafer fabrication process;
detecting, in response to the wafer fabrication process, a change of a capacitance of a capacitive micro sensor mounted on the wafer processing tool at a location;
controlling, based on the detected change, the wafer fabrication process; and
inserting the capacitive micro sensor through a lift pin hole to the location within the chamber volume;
inducing a varied capacitance, wherein the capacitance is between the wafer and the capacitive micro sensor; and
measuring the DC bias based on the varied capacitance.

13. The method of claim 12 , wherein the capacitance changes when the material is deposited on or removed from the capacitive micro sensor during the wafer fabrication process, and wherein the location is in proximity to one or more of the chamber wall, a lift pin, a load lock, a gas line, a robot, or a pressure control valve of the wafer processing tool.

14. The method of claim 13 further comprising:
determining an endpoint of the wafer fabrication process based on the change of the capacitance; and
stopping the wafer fabrication process in response to determining the endpoint.

15. The method of claim 13 , wherein the wafer processing tool includes a second capacitive micro sensor mounted on the wafer processing tool at a second location, and further comprising:
detecting, in response to the wafer fabrication process, a change of a second capacitance of the second capacitive micro sensor; and
determining a uniformity of the wafer fabrication process based on the change of the capacitance of the capacitive micro sensor and the change of the second capacitance of the second capacitive micro sensor.

16. The method of claim 13 further comprising:
detecting, by a measurement device, a process parameter of the wafer fabrication process; and
determining a root cause of the change of the capacitance of the capacitive micro sensor based on the detected process parameter.

17. The method of claim 13 further comprising:
determining, based on the change of the capacitance of the capacitance sensor, an amount of the material deposited on the capacitive micro sensor within the chamber volume during the wafer fabrication process; and
removing, based on the determined amount, the amount of the material from the chamber wall to clean the process chamber.

18. A method, comprising:
loading a wafer of a semiconductor material into a process chamber of a wafer processing tool, wherein the process chamber includes a chamber wall around a chamber volume;
initiating a wafer fabrication process in the process chamber, wherein a material is deposited on or removed from the wafer during the wafer fabrication process;
detecting, in response to the wafer fabrication process, a change of a capacitance of a capacitive micro sensor mounted on the wafer processing tool at a location; and
controlling, based on the detected change, the wafer fabrication process, wherein the capacitance changes when the material is deposited on or removed from the capacitive micro sensor during the wafer fabrication process, and wherein the location is in proximity to one or more of the chamber wall, a lift pin, a load lock, a gas

Assignees

• Applied Materials Inc

Inventors

• Tedeschi Leonard
• Ramaswamy Kartik
• Mccormick Daniel Thomas
• Meagley Robert Paul

Classifications

• H10P74/207

  Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics · CPC title

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P74/27 Primary

  Structural arrangements therefor · CPC title

• H10P72/0604

  Process monitoring, e.g. flow or thickness monitoring · CPC title

• H10P74/238 Primary

  comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement · CPC title