System and method of determining process completion of post heat treatment of a dry etch process

• US 10,290,553 B2
• Filed: 01/31/2017
• Issued: 05/14/2019
• Est. Priority Date: 06/24/2015
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Theisen, Jacob, Mosden, Aelan
• Primary Examiner(s): Picardat, Kevin M
• Application Number:
  US15/420,264
• Publication Number:
  US 20170221781A1
• Time in Patent Office: 833 Days
• Field of Search: 438 8
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/67103 mainly by conduction
• CPC Class Codes: H01L 21/67115 mainly by radiation
• 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 22/26 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

Abstract

Provided is a method for determining and utilizing process completion of post heat treatment (PHT) of a dry etch process, the method comprising: providing a substrate in a process chamber, the substrate having a film layer and an underlying layer, the film layer having one or more regions; performing a dry etch process to remove the film layer or region of the film layer, the dry etch process generating a byproduct layer; measuring one or more properties of the byproduct layer; adjusting the PHT process based on the measured one or more properties of the byproduct layer; and performing the PHT process to remove the byproduct layer on the substrate; wherein the PHT process utilizes a real time in-situ process to concurrently determine when removal of the byproduct layer is complete.

Claims

1. A method for determining and utilizing process completion of post heat treatment (PHT) of a dry etch process, the method comprising:

providing a substrate in a process chamber, the substrate having a film layer and an underlying layer, the film layer having one or more regions;

performing one or more sequences of film layer or region removal on the substrate, the one or more sequences comprising;

performing a dry etch process to remove the film layer or region of the film layer, the dry etch process generating a byproduct layer; and

performing a PHT process to remove the byproduct layer on the substrate;

wherein the PHT process utilizes a real time in-situ process to concurrently determine when removal of the byproduct layer is complete, and

wherein measurement of the byproduct layer thickness is performed using a laser metrology tool, a reflectometer, an ellipsometer or a spectrometer;

wherein the real time in-situ process of determining completeness of the PHT process utilizes measurement of a composition of a gaseous product of the PHT process;

or wherein the real time in-situ process of determining completeness of the PHT process utilizes residual gas analysis (RGA).

2. The method of claim 1 wherein the dry etch process is a chemical oxide removal or an atomic layer etch process.

3. The method of claim 2 wherein the performing the dry etch process utilizes a real time in-situ process to concurrently determine when the dry etch process is complete.

4. The method of claim 3 wherein, for generating heat, the PHT process includes the use of at least one of a heated stage with cooling capability, electric heaters, and/or halogen lamps, a laser source, a plasma source, or a radio frequency (RF).

5. The method of claim 4 wherein the performing one or more sequences includes at least one of:

performing the PHT process at a temperature in a range of 50 to 275 degrees C.;

a pressure in the process chamber being in a range from 50 to 3,000 mTorr;

or a thickness of the byproduct layer generated by the dry etch process being in the range from 1 to 500 Angstroms.

6. The method of claim 1 wherein the dry etch process is a chemical oxide removal (COR) and uses at least one of a fluorine gas, hydrogen fluoride gas, ammonia as a purge gas, or one or more noble gases as the purge gas.

7. The method of claim 6 wherein a lag time from completion of byproduct layer removal until termination of the PHT process is less than 30 seconds or is in a range from 1 to 25 seconds.

8. The method of claim 7 further comprising adjusting one or more operating variables of the etch process and the PHT process, wherein the operating variables of the etch process and the PHT process include at least one of an ion current, a gas component partial pressure, an etch time, a PHT sublimation time, a PHT temperature, a PHT pressure, or a PHT lag time.

9. The method of claim 8 further comprising meeting one or more removal process objectives, wherein the removal process objectives include at least one of a PHT lag time target that is in a range from 1 to 15 seconds or less, a PHT sublimation time target, an etch time target, a PHT tool throughput target, or a byproduct layer removal target that is in a range from 80 to 100%.

10. A method for determining and utilizing process completion of post heat treatment (PHT) of a dry etch process, the method comprising:

providing a substrate in a process chamber, the substrate having a film layer and an underlying layer, the film layer having one or more regions;

performing one or more sequences of film layer or region removal on the substrate, the one or more sequences comprising;

performing a dry etch process to remove the film layer or region of the film layer, the dry etch process generating a byproduct layer; and

performing a PHT process to remove the byproduct layer on the substrate;

wherein the PHT process utilizes a real time in-situ process to concurrently determine when removal of the byproduct layer is complete,

wherein performing the PHT process further comprises;

measuring one or more properties of the byproduct layer; and

adjusting the PHT process based on the measured one or more properties of the byproduct layer.

11. The method of claim 10 wherein measuring one or more properties of the byproduct layer includes using one or more in situ online metrology devices selected from a laser metrology tool, a reflectometer, an ellipsometer or a spectrometer, the one or more in situ devices coupled to the process chamber and to a controller, and wherein the controller is used to perform the adjusting before and/or during the PHT process.

12. The method of claim 11 wherein the measuring includes measuring the thickness of the byproduct layer, and wherein the adjusting includes adjusting the number of heating devices set to an on position and/or adjusting the temperature of the heating devices set to an on position.

13. The method of claim 11 wherein a lag time from completion of byproduct layer removal until termination of the PHT process in response to the instruction from the controller is less than 15 seconds.

14. A method for determining and utilizing process completion of post heat treatment (PHT) of a dry etch process, the method comprising:

providing a substrate in a process chamber, the substrate having a film layer and an underlying layer, the film layer having one or more regions;

performing one or more sequences of film layer or region removal on the substrate, the one or more sequences comprising;

performing a dry etch process to remove the film layer or region of the film layer, the dry etch process generating a byproduct layer; and

performing a PHT process to remove the byproduct layer on the substrate;

wherein the PHT process utilizes a real time in-situ process to concurrently determine when removal of the byproduct layer is complete,

wherein the real time in-situ process of determining completeness of the PHT process utilizes measurement of a composition of a gaseous product of the PHT process;

or the real time in-situ process of determining completeness of PHT process utilizes residual gas analysis (RGA).

15. A fabrication system configured to determine and utilize process completion data of a post heat treatment (PHT) of a dry etch process for use in process control, the fabrication system comprising:

a process chamber of a PHT system;

a chemical oxide removal (COR) system coupled to the PHT system;

a controller coupled to the PHT system and to the COR system; and

a fabrication sub-system comprising one or more of a deposition system, a plasma etch system, a dry etch system, a wet etch system, a cleaning system, an annealing system, or a doping system, the fabrication system coupled to the controller, the COR system, and the PHT system;

wherein the COR system processes a substrate by performing a dry etch process to remove a film layer on the substrate or region of the film layer, the dry etch process generating a byproduct layer; and

wherein the PHT system processes the substrate by performing a PHT process to remove the byproduct layer on the substrate; and

wherein the PHT process utilizes a real time in-situ process to concurrently determine when removal of the byproduct layer is complete, the real time in-situ process including one or more in-situ online metrology devices to collect metrology data.

16. A method for determining and utilizing process completion of post heat treatment (PHT) of a dry etch process, the method comprising:

providing a substrate in a process chamber, the substrate having a film layer and an underlying layer, the film layer having one or more regions;

performing one or more sequences of film layer or region removal on the substrate, the one or more sequences comprising;

performing a dry etch process to remove the film layer or region of the film layer, the dry etch process generating a byproduct layer; and

performing a PHT process to remove the byproduct layer on the substrate;

wherein the PHT process utilizes a real time in-situ process to concurrently determine when removal of the byproduct layer is complete,

wherein the real time in-situ process comprises using one or more in situ online metrology devices to collect metrology data.

17. The method of claim 16 wherein the one or more in situ online metrology devices are coupled to the process chamber and to a controller, the real time in-situ process further comprising using the metrology data to determine when removal of the byproduct layer is complete, and using the controller to send instructions to terminate the PHT process when it is determined that removal of the byproduct layer is complete.

18. The method of claim 16 wherein the one or more in situ online metrology devices are selected from a laser metrology tool, a reflectometer, an ellipsometer or a spectrometer.