Photoresist Simulation

• US 20140067346A1
• Filed: 08/28/2013
• Published: 03/06/2014
• Est. Priority Date: 11/12/2009
• Status: Active Grant

• Current Assignee: KLA-Tencor Corporation (KLA Corporation)
• Original Assignee: KLA-Tencor Corporation (KLA Corporation)
• Inventors: Biafore, John J., Smith, Mark D., Graves, John S. III, Blankenship, David
• Granted Patent: US 9,679,116 B2
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: G03F 7/0045 with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
• CPC Class Codes: G16C 20/10 Analysis or design of chemical reactions, syntheses or processes

Abstract

A processor based method for measuring dimensional properties of a photoresist profile by determining a number acid generators and quenchers within a photoresist volume, determining a number of photons absorbed by the photoresist volume, determining a number of the acid generators converted to acid, determining a number of acid and quencher reactions within the photoresist volume, calculating a development of the photoresist volume, producing with the processor a three-dimensional simulated scanning electron microscope image of the photoresist profile created by the development of the photoresist volume, and measuring the dimensional properties of the photoresist profile.

Claims

1. A processor based method for measuring dimensional properties of a simulated photoresist profile, the method comprising steps of:

determining a number of acid generators and quenchers within a virtual photoresist volume;

determining a number of photons absorbed by the virtual photoresist volume,

determining a number of the acid generators converted to acid within the virtual photoresist volume;

determining a number of acid and quencher reactions within the virtual photoresist volume;

calculating a development of the virtual photoresist volume;

producing with a processor a three-dimensional simulated scanning electron microscope image of the simulated photoresist profile created by the development of the virtual photoresist volume;

measuring the dimensional properties of the simulated photoresist profile; and

fabricating integrated circuits using processes that are based at least in part on the dimensional properties of the photoresist profile.

2. The method of claim 1, wherein the step of determining the number of acid generators and quenchers within the photoresist volume comprises specifying a desired number of acid generators and specifying a desired number of quenchers based on a hypothetical photoresist formulation.

3. The method of claim 1, wherein the step of determining the number of acid generators and quenchers within the photoresist volume comprises entering an actual number of acid generators and an actual number of quenchers based on an existing photoresist formulation.

4. The method of claim 1, wherein the step of determining the number of photons absorbed by the photoresist volume comprises specifying a desired number of photons based on a hypothetical exposure.

5. The method of claim 1, wherein the step of determining the number of photons absorbed by the photoresist volume comprises entering the number of photons based on a known exposure.

6. The method of claim 1, wherein the step of determining the number of the acid generators converted to acid comprises calculating the acid generators converted to acid via a photolysis mechanism.

7. The method of claim 1, wherein the step of determining the number of the acid generators converted to acid comprises calculating the acid generators converted to acid via an ionization mechanism.

8. The method of claim 1, wherein the step of measuring the dimensional properties of the photoresist profile comprises measuring a hard-copy output of the three-dimensional simulated scanning electron microscope image with a ruler.

9. The method of claim 1, wherein the step of measuring the dimensional properties of the photoresist profile comprises mathematically evaluating a data file of the three-dimensional simulated scanning electron microscope image.

10. A processor based method for measuring dimensional properties of a simulated photoresist profile, the method comprising steps of:

inputting photoresist and exposure parameters into a stochastic model of a photoresist process;

computing the simulated photoresist profile from the stochastic model using a processor;

measuring the dimensional properties of the simulated photoresist profile using a critical dimension scanning electron microscope simulator running on the processor; and

fabricating integrated circuits using processes that are based at least in part on the dimensional properties of the photoresist profile.