Controlling cleaning of a layer on a substrate using nozzles

• US 9,735,026 B2
• Filed: 11/27/2013
• Issued: 08/15/2017
• Est. Priority Date: 11/27/2012
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Brown, Ian J., Printz, Wallace P., Rathsack, Benjamen M.
• Primary Examiner(s): Golightly, Eric
• Assistant Examiner(s): Rivera-Cordero, Arlyn I
• Application Number:
  US14/091,923
• Publication Number:
  US 20140144463A1
• Time in Patent Office: 1,357 Days
• Field of Search: None
• CPC Class Codes: G03F 7/42 Stripping or agents therefor
• CPC Class Codes: G03F 7/423 containing mineral acids or salts thereof, containing mineral oxidizing substances, e.g. peroxy compounds
• CPC Class Codes: G03F 7/425 containing mineral alkaline compounds; containing organic basic compounds, e.g. quaternary ammonium compounds; containing heterocyclic basic compounds containing nitrogen
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/67051 using mainly spraying means, e.g. nozzles
• CPC Class Codes: H01L 21/67115 mainly by radiation

Abstract

Provided is a method for cleaning an ion implanted resist layer or a substrate after an ashing process. A duty cycle for turning on and turning off flows of a treatment liquid using two or more nozzles is generated. The substrate is exposed to the treatment liquid comprising a first treatment chemical, the first treatment chemical with a first film thickness, temperature, total flow rate, and first composition. A portion of a surface of the substrate is concurrently irradiated with UV light while controlling the selected plurality of cleaning operating variables in order to achieve the two or more cleaning objectives. The cleaning operating variables comprise two or more of the first temperature, first composition, first film thickness, UV wavelength, UV power, first process time, first rotation speed, duty cycle, and percentage of residue removal are optimized to achieve the two or more cleaning objectives.

Claims

1. A method for cleaning a layer on a substrate using a cleaning system, the cleaning system comprising a processing chamber and a treatment delivery system, the treatment delivery system comprising a first delivery device and a second delivery device, the method comprising:

providing a substrate in the cleaning system, the substrate having an ion implanted resist layer or a substrate after an ashing process;

selecting two or more cleaning objectives and a plurality of cleaning operating variables to be optimized for achieving the two or more cleaning objectives;

selecting an arrangement of two or more nozzles of the first delivery device and creating a duty cycle for turning on and turning off flow of a treatment liquid through the two or more nozzles, the sum of the flow of the treatment liquid through the two or more nozzles being a first total flow rate;

exposing the substrate in the treatment liquid comprising a first treatment chemical, the first treatment chemical including a pH control additive, the first treatment chemical with a first film thickness, a first temperature, the first total flow rate, and a first composition, the exposing performed with the first delivery device and concurrently irradiating a portion of a surface of the substrate with ultra-violet (UV) light, the UV light having a wavelength and having a UV power, the irradiating operationally configured to be completed in a first process time, the irradiating performed while the substrate is in a first rotation speed;

obtaining continuous metrology feedback for calculating the two or more cleaning objectives, generating two or more calculated cleaning values;

comparing the two or more calculated cleaning values to the two or more cleaning objectives; and

if the two or more cleaning objectives are not met, adjusting the selected two or more cleaning operating variables or selecting a different two or more cleaning operating variables and iterating the obtaining continuous metrology feedback, comparing the two or more calculated cleaning values to the two or more cleaning objectives, and adjusting the two or more selected cleaning operating variables until the two or more cleaning objectives are met,

wherein the plurality of cleaning operating variables comprise two or more of the first temperature, the first composition, first film thickness, the UV wavelength, the UV power, the first process time, the first rotation speed, the pH of the treatment liquid;

the duty cycle of the first delivery device, and percentage of residue removal.

2. The method of claim 1, wherein the first treatment chemical is a hydrogen peroxide solution, the two or more cleaning objectives are selected from the first film thickness, the first process time, and the percentage of residue removal, and wherein the selected two or more cleaning operating variables are selected from the first rotation speed, the pH of the treatment liquid;

and the duty cycle of the first delivery device.

3. The method of claim 1, wherein exposing the substrate in the treatment liquid comprising the first treatment chemical utilizes a spray nozzle configured to spread out and thin the first treatment chemical across the substrate.

4. The method of claim 3, wherein the spray nozzle utilizes a nitrogen or air jet to generate the spray in the spray nozzle.

5. The method of claim 1, further comprising:

dispensing onto the substrate a second treatment chemical using the second delivery device, the second treatment chemical at a second temperature, a second flow rate, and a second composition, the second treatment chemical dispensed onto a portion of a surface of the substrate at a dispense temperature, the dispensing operationally configured to be completed in a second process time and the dispensing performed while the substrate is in a second rotation speed.

6. The method of claim 5, wherein the pH control additive is hydrochloric acid, hydrofluoric acid, or nitric acid when an acidic pH is required and tetramethyl ammonium hydroxide (TMAH) or ammonium hydroxide when a basic pH is required.

7. The method of claim 5, wherein the layer to be cleaned is an ion implanted resist that formed a residue during an ion implantation process or wherein the substrate to be cleaned is a substrate after an ashing process, and wherein the two or more cleaning objectives comprise a percentage of residue removal and a total process time, the total process time being the sum of the first process time and the second process time;

and

wherein the cleaning operating variables further include the second temperature, the second composition, the second process time, the second rotation speed, and the dispense temperature.

8. The method of claim 7,

wherein the first treatment chemical is a hydrogen peroxide solution and the second treatment chemical is a sulfuric acid peroxide mixture (SPM);

or

wherein the first treatment chemical is hydrogen peroxide and the second treatment chemical is a sulfuric acid and ozone mixture (SOM);

or wherein the first chemical is water, hydrogen peroxide aqueous solution, or hydrogen peroxide semi-aqueous solution with organic co-solvents, ammonia aqueous, or ammonia semi-aqueous solution; and

wherein the organic co-solvents include isopropyl alcohol (WA), n-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), or acetone;

wherein the peroxide or hydroperoxide aqueous or semi-aqueous solutions includes a structure R—

O—

H—

R′

wherein R is any organic or inorganic species including benzoyl peroxide, tert-butyl hydroperoxide (TBHP), methyl ethyl ketone peroxide, or acetone peroxide.

9. The method of claim 8, wherein the percentage of residue removal is 95.0 percent or higher and the UV light is in a range of 172 to 300 nm, and the UV power is 20 mJ/cm² or higher.

10. The method of claim 8,

wherein the first temperature is in a range of 25 to 100 degrees C. and the second treatment chemical is in a range of 140 to 200 degrees C.;

and/or

wherein the second treatment chemical is dispensed onto the substrate at 150 degrees C. or lower.

11. The method of claim 8, wherein the SPM comprises a mixture of 10:

1 to 30;

1 sulfuric acid solution to hydrogen peroxide.

12. The method of claim 8,

wherein the two or more cleaning operating variables comprise the first rotation speed and first flow rate;

or

wherein the two or more cleaning objectives comprise the percentage of residue removal and total process time.

13. The method of claim 8, wherein the two or more cleaning objectives comprise cost of ownership per unit throughput and total process time.

14. The method of claim 8,

wherein the cleaning system comprises a stack of two or more ultra-violet peroxide (UVP) units and a stack of two or more recycle sulfuric acid peroxide mixture (rSPM) units or a stack of two or more of all-in-one spin chambers each further comprising a combined ultra-violet peroxide (UVP) and recycle sulfuric acid peroxide mixture (rSPM) units;

and/or

wherein the first delivery device is the same as the second delivery device.

15. The method of claim 8, further comprising recycling the first treatment chemical and/or the second treatment chemical;

wherein the two or more nozzles are spray nozzles.

16. The method of claim 8, further comprising:

injecting a jet of nitrogen or air to spread out and make the first treatment chemical thinner across the substrate surface.

17. The method of claim 16, wherein the first temperature, first film thickness, the UV wavelength, the UV power, the first process time, the first rotation speed, the pH of the treatment liquid, the second process time, and the duty cycle of the first delivery device are concurrently optimized to meet the cleaning objectives of 100% residue removal at the first rotation speed of 2,000 rpm or less, the first process time of 180 seconds or less, and the second process time of 60 seconds or less.

18. The method of claim 8,

wherein the total process time is 240 seconds or less;

or

wherein the first process time is in a range of 40 to 80 seconds and the second process time is in a range of 40 to 80 seconds; and

/or

wherein the first rotation speed is in a range of 300 to 12,000 rpm; and

/or

wherein the hydrogen peroxide solution is in a range of 10 wt % to 35 wt %.

19. The method of claim 18,

wherein setting a nozzle of the two or more nozzles as a central nozzle at below 75 mL/min flow of treatment liquid and positioning one or more additional nozzles of the two or more nozzles at between 5 to 145 mm from the central nozzle until complete wetting of the substrate is achieved;

and

wherein the first total flow rate is in a range from 250 to 2,500 mL/min or wherein the two or more nozzles is in a range from 2 to 20 nozzles.

20. The method of claim 19, wherein the duty cycle flow on is from 1.5 to 5 seconds and the flow off is from 1.5 to 2.5 seconds.