Apparatus and Method for Improving Photoresist Properties

• US 20100081285A1
• Filed: 09/30/2008
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Abandoned Application

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Sundararajan, Radha, Chen, Lee, Funk, Merritt
• Application Number:
  US12/242,065
• Publication Number:
  US 20100081285A1
• Time in Patent Office: Days
• US Class Current: 438/710
• CPC Class Codes: G03F 7/40 Treatment after imagewise removal, e.g. baking
• CPC Class Codes: H01L 21/0273 characterised by the treatment of photoresist layers
• CPC Class Codes: H01L 21/32139 using masks

Abstract

The invention can provide apparatus and methods of processing a substrate in real-time using subsystems and processing sequences created to improve the etch resistance of photoresist materials. In addition, the improved photoresist layer can be used to more accurately control gate and/or spacer critical dimensions (CDs), to control gate and/or spacer CD uniformity, and to eliminate line edge roughness (LER) and line width roughness (LWR).

Claims

1. A photoresist-hardening (P-H) subsystem, comprising:

a photoresist-hardening (P-H) chamber coupled to a transfer subsystem, wherein the P-H chamber is configured to perform a first photoresist-hardening (P-H) procedure;

a multi-output supply system coupled to an upper DC electrode configured in a first upper assembly in the P-H chamber, wherein the multi-output supply system provides a direct current (DC) voltage to the upper DC electrode;

a remote plasma system coupled to a remote plasma injection plenum configured in a second upper assembly in the P-H chamber, wherein the remote plasma injection plenum comprises a plurality of flow channels configured to provide one or more remote plasma species to a processing region in the P-H chamber;

a substrate holder coupled within the P-H chamber using a DC isolation means, wherein the substrate holder is configured to hold a patterned substrate having a patterned photoresist layer thereon;

a pressure control system configured to control pressure within the P-H chamber wherein the pressure within the P-H chamber varies between approximately 5 mTorr and approximately 400 mTorr during the first P-H procedure;

a lower electrode configured in the substrate holder;

a low frequency generator configured to apply low frequency signal power to the lower electrode to establish and maintain a first photoresist-hardening (P-H) plasma using the one or more remote plasma species; and

a controller coupled to the multi-output supply system, the remote plasma system, the pressure control system, and the low frequency generator, the controller being configured to determine material data for the patterned photoresist layer and establish the first photoresist-hardening (P-H) procedure using the determined material data.

2. The P-H subsystem of claim 1, wherein the P-H subsystem further comprises:

a gas injection system coupled to an inner gas injection plenum and an outer gas injection plenum configured in a third upper assembly in the P-H chamber, wherein the inner gas injection plenum having a plurality of inner orifices therein, and the outer gas injection plenum having a plurality of outer orifices therein.

3. The P-H subsystem of claim 2, wherein the inner gas injection plenum and the inner orifices are configured to provide a first process gas to an inner region of the P-H chamber during the first P-H procedure, wherein the first process gas includes at least one fluorocarbon gas and at least one inert gas, a first fluorocarbon gas flow rate varying between approximately 10 sccm and approximately 50 sccm and a first inert gas flow rate varying between approximately 3 sccm and approximately 20 sccm, wherein the fluorocarbon gas comprises C₄F₆, C₄F₈, C₅F₈, CHF₃, or CF₄, or any combination thereof, and the inert gas comprises Argon (Ar), Helium (He), Krypton (Kr), Neon (Ne), Radon (Rn), or Xenon (Xe), or any combination thereof, and wherein the outer gas injection plenum and the outer orifices are configured to provide a second process gas to an outer region of the P-H chamber during the first P-H procedure, wherein the second process gas includes at least one second fluorocarbon gas and at least one second inert gas, a second fluorocarbon gas flow rate varying between approximately 2 sccm and approximately 50 sccm and a second inert gas flow rate varying between approximately 2 sccm and approximately 100 sccm, wherein the second fluorocarbon gas comprises C₄F₆, C₄F₈, C₅F₈, CHF₃, or CF₄, or any combination thereof, and the second inert gas comprises Argon (Ar), Helium (He), Krypton (Kr), Neon (Ne), Radon (Rn), or Xenon (Xe), or any combination thereof.

4. The P-H subsystem of claim 3, wherein the first process gas includes CO and a first CO flow rate varies between approximately 2 sccm and approximately 10 sccm, and wherein the second process gas includes CO and a second CO flow rate varies between approximately 2 sccm and approximately 20 sccm.

5. The P-H subsystem of claim 1, wherein the substrate holder comprises dual backside gas elements coupled to a backside gas system and temperature control elements coupled to a temperature control system configured to establish a first edge temperature and a first center temperature for the patterned substrate.

6. The P-H subsystem of claim 5, wherein the first edge temperature and the first center temperature are between approximately 0 degrees Celsius and approximately 100 degrees Celsius,

7. The P-H subsystem of claim 1, wherein the low frequency generator is configured to operate in a first frequency range from approximately 10 Hz. to approximately 100 kHz and the low frequency signal power ranges from approximately 10 watts to approximately 700 watts during the first P-H procedure.

8. The P-H subsystem of claim 1, wherein the DC supply voltage ranges from approximately −

2000 volts (V) to approximately 1000 V.

9. The P-H subsystem of claim 1, wherein the remote plasma injection plenum and the plurality flow channels are configured to provide a first remote plasma species into the P-H chamber during the first P-H procedure, wherein the first remote plasma species includes Argon (Ar) and a first Ar flow rate varying between approximately 10 sccm and approximately 50 sccm wherein the remote plasma system is configured to provide the first remote plasma species to the remote plasma injection plenum during a first time.

10. The P-H subsystem of claim 9, wherein the remote plasma injection plenum and the plurality flow channels are configured to provide a second remote plasma species into the P-H chamber during the first P-H procedure, wherein the second remote plasma species includes carbon monoxide (CO) and a first CO flow rate varying between approximately 10 sccm and approximately 50 sccm wherein the remote plasma system is configured to provide the second remote plasma species to the remote plasma injection plenum during a second time.

11. The P-H subsystem of claim 1, wherein the upper DC electrode comprises an inner DC electrode and an outer DC electrode configured in the first upper assembly, wherein the multi-output supply system provides a first DC supply voltage to the inner DC electrode and provides a second DC supply voltage to the outer DC electrode.

12. The P-H subsystem of claim 1, wherein the remote plasma injection plenum comprises an inner remote plasma injection plenum and an outer remote plasma injection plenum configured in the second upper assembly in the P-H chamber, wherein the inner remote plasma injection plenum comprises a plurality of inner flow channels configured to provide a first remote plasma species to an inner processing region in the P-H chamber, and the outer remote plasma injection plenum comprises a plurality of outer flow channels configured to provide a second remote plasma species to an outer processing region in the P-H chamber.

13. A method of processing a patterned substrate using a photoresist-hardening (P-H) subsystem, the method comprising:

transferring the patterned substrate into a photoresist-hardening (P-H) chamber using a transfer subsystem coupled to the P-H chamber, the patterned substrate having a patterned photoresist layer thereon;

positioning the patterned substrate on a substrate holder configured within the P-H chamber, wherein the substrate holder is coupled to the P-H chamber using a DC isolation means;

determining material data for the patterned photoresist layer; and

establishing a first photoresist-hardening (P-H) plasma in the P-H chamber using a first photoresist-hardening (P-H) procedure determined using the material data in the patterned photoresist layer.

14. The method of claim 13, further comprising:

providing one or more remote plasma species to a processing region above the patterned substrate in the P-H chamber using a remote plasma system coupled to a remote plasma injection plenum configured in an upper assembly in the P-H chamber, wherein the remote plasma injection plenum comprises a plurality of flow channels configured to provide the one or more remote plasma species to the processing region in the P-H chamber;

providing a DC voltage to an upper DC electrode in the upper assembly during the P-H procedure, wherein a direct current (DC) supply system is coupled to the upper DC electrode and is configured to provide the DC voltage to the upper DC electrode;

establishing a pressure within the P-H chamber, wherein a pressure control system is coupled to the P-H chamber and is configured to control the pressure within the P-H chamber, the pressure within the P-H chamber varying between approximately 5 mTorr and approximately 400 mTorr during the first P-H procedure;

applying a low frequency signal power to a lower electrode configured in the substrate holder, wherein a low frequency generator is coupled to the lower electrode and is configured to apply the low frequency signal power to the lower electrode to establish and/or maintain the first photoresist-hardening (P-H) plasma using the one or more remote plasma species.

15. The method of claim 14, wherein an inner gas injection plenum and inner orifices are configured to provide a first process gas to an inner region of the P-H chamber during the first P-H procedure, wherein the first process gas includes at least one fluorocarbon gas and at least one inert gas, a first fluorocarbon gas flow rate varying between approximately 10 sccm and approximately 50 sccm and a first inert gas flow rate varying between approximately 3 sccm and approximately 20 sccm, wherein the fluorocarbon gas comprises C₄F₆, C₄F₈, C₅F₈, CHF₃, or CF₄, or any combination thereof, and the inert gas comprises Argon (Ar), Helium (He), Krypton (Kr), Neon (Ne), Radon (Rn), or Xenon (Xe), or any combination thereof, and wherein an outer gas injection plenum and outer orifices are configured to provide a second process gas to an outer region of the P-H chamber during the first P-H procedure, wherein the second process gas includes at least one second fluorocarbon gas and at least one second inert gas, a second fluorocarbon gas flow rate varying between approximately 2 sccm and approximately 50 sccm and a second inert gas flow rate varying between approximately 2 sccm and approximately 100 sccm, wherein the second fluorocarbon gas comprises C₄F₆, C₄F₈, C₅F₈, CHF₃, or CF₄, or any combination thereof, and the second inert gas comprises Argon (Ar), Helium (He), Krypton (Kr), Neon (Ne), Radon (Rn), or Xenon (Xe), or any combination thereof.

16. The method of claim 15, wherein the first process gas includes CO and a first CO flow rate varies between approximately 2 sccm and approximately 10 sccm during the first P-H procedure, and wherein the second process gas includes CO and a second CO flow rate varies between approximately 2 sccm and approximately 20 sccm during the first P-H procedure.

17. The method of claim 14, wherein the substrate holder comprises dual backside gas elements coupled to a backside gas system and temperature control elements coupled to a temperature control system configured to establish a first edge temperature and a first center temperature for the patterned substrate, wherein the first edge temperature and the first center temperature are between approximately 0 degrees Celsius and approximately 100 degrees Celsius,

18. The method of claim 14, wherein the low frequency generator is configured to operate in a first frequency range from approximately 10 Hz. to approximately 100 kHz and the low frequency signal power ranges from approximately 10 watts to approximately 700 watts during the first P-H procedure.

19. The method of claim 14, wherein the DC supply voltage ranges from approximately −

2000 volts (V) to approximately 1000 V during the first P-H procedure.

20. The method of claim 14, wherein the remote plasma injection plenum and the plurality flow channels are configured to provide a first remote plasma species into the P-H chamber during the first P-H procedure, wherein the first remote plasma species includes Argon (Ar) and a first Ar flow rate varying between approximately 10 sccm and approximately 50 sccm wherein the remote plasma system is configured to provide the first remote plasma species to the remote plasma injection plenum during a first time.

21. The method of claim 20, wherein the remote plasma injection plenum and the plurality flow channels are configured to provide a second remote plasma species into the P-H chamber during the first P-H procedure, wherein the second remote plasma species includes carbon monoxide (CO) and a first CO flow rate varying between approximately 10 sccm and approximately 50 sccm wherein the remote plasma system is configured to provide the second remote plasma species to the remote plasma injection plenum during a second time.