WAFER PROCESSING EQUIPMENT HAVING CAPACITIVE MICRO SENSORS

• US 20170365531A1
• Filed: 06/20/2016
• Published: 12/21/2017
• Est. Priority Date: 06/20/2016
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Tedeschi, Leonard, Ramaswamy, Kartik, McCormick, Daniel Thomas, Meagley, Robert Paul
• Granted Patent: US 10,083,883 B2
• Time in Patent Office: Days
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01D 5/2405 by varying dielectric
• CPC Class Codes: G01N 15/1031 by measuring electrical or magnetic effects
• CPC Class Codes: G01N 2015/0046 in gas, e.g. smoke
• CPC Class Codes: G01N 2015/1029 Particle size
• CPC Class Codes: G01N 27/221 by investigating the dielectric properties using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26
• CPC Class Codes: G01N 27/227 Sensors changing capacitance upon adsorption or absorption of fluid components, e.g. electrolyte-insulator-semiconductor sensors, MOS capacitors G01N27/225 takes precedence
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32
• CPC Class Codes: H01L 22/30 Structural arrangements specially adapted for testing or measuring during manufacture or treatment, or specially adapted for reliability measurements

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.

Claims

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.

6. 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.

7. The particle monitoring device of claim 6, 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.

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

5. (canceled)

9. 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 at the location in proximity to one or more of a load lock, a gas line, a robot, or a pressure control valve of the wafer processing tool.

10. The wafer processing tool of claim 9, 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.

11. The wafer processing tool of claim 10, 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.

12. The wafer processing tool of claim 10, 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.

13. (canceled)

14. 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.

15. The method of claim 14, 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.

16. The method of claim 15 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.

17. The method of claim 15, 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.

18. The method of claim 15 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.

19. The method of claim 15 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.

20. (canceled)

21. 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 line, a robot, or a pressure control valve of the wafer processing tool, wherein the wafer processing tool includes a second capacitive micro sensor mounted on the wafer processing tool at a second location, and the method 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.