Specific Process Knowledge/Lithography/DUVStepperLithography

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The contents on this page, including all images and pictures, was created by DTU Nanolab staff unless otherwise stated.

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Spin coater: Süss stepper

The SÜSS Spinner-Stepper is placed in F-3

This spinner is dedicated for spinning DUV resists. The spinner is fully automatic and can run up to 25 substrates in a batch 4", 6", and 8" size (8" requires tool change). The machine is equipped with the 3 resist lines (DUV42S-6, KRF M230Y, and KRF M35G), as well as a syringe dispense system.

The user manual, quality control procedures and results, user APVs, and contact information can be found in LabManager:

Equipment info in LabManager - requires login

DUV resist overview

The spinning process will be performed by the customer together with the Photolith group of Nanolab. In case you would like to do DUV lithography please contact Lithography team, who will consult you and run your wafers together with you.


Bottom Anti Reflection Coating (BARC):


Positive DUV resist for spin coating in 600-300nm thickness range:


Positive DUV resist for spin coating in 1600-800nm thickness range:


Negative DUV resist for spin coating in 1400-800nm or diluted with EC Solvent in 1:1 in 400-200nm thickness range:

Process information

Equipment performance and process related parameters

Purpose
  • Spin coating and soft baking of BARC
  • Spin coating and soft baking of DUV resists
  • Post exposure baking
Resist
  • BARC DUV42S-6
  • Positive tone resist KRF M230Y
  • Positive tone resist KRF M35G
  • Negative tone resist UVN2300-0.8
Performance Coating thickness
  • BARC DUV42S-6 60-90nm
  • Positive tone resist KRF M230Y 300-600nm
  • Positive tone resist KRF M35G 800-1600nm
  • Negative tone resist UVN2300-0.8 200-1400nm
Process parameters Spin speed

  10 - 5000 rpm

Spin acceleration

  100 - 10000 rpm/s

Hotplate temperature
  • 175°C for BARC baking
  • 130°C for positive tone resist soft baking and post exposure baking
  • 100°C for negative tone resist soft baking and post exposure baking
Substrates Substrate size
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers (requires tool change)
Allowed materials
  • Any standard cleanroom material
Batch

  1 - 25


DUV Stepper

DUV Stepper is placed in F-3

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The deep-UV stepper FPA-3000EX4 from Canon is an advanced exposure system designed for mass-production of 6 and 8 inch wafers/ devices having a throughput of up to 90 wafers per hour. The largest applicable thickness of the wafers/ devices is 1,2 mm. Also 4" wafers/ devices can be processed with some restrictions concerning throughput, resolution, uniformity and maximum allowed wafer thickness. The system is equipped with a KrF Excimer laser from Cymer (wavelength 248 nm). Its projection lens’ NA is variable over a range between 0,4 and 0,6. Additionally, the partial coherence factor (σ) of the illumination system can be adjusted and different off-axis illumination modes can be selected.

The critical dimension (CD) of patterns that can be realized is specified at around 250nm for arbitrary formed patterns in the standard illumination mode (NA=0,6; σ =0,65). However, the best achievable resolution is different for each pattern type, pattern shape and pitch. So linewidths down to 160 nm could be achieved for geometrically simple patterns or pattern arrays (single and multiple line or pin-hole structures).


The user manual(s), quality control procedure(s) and results and contact information can be found in LabManager: Equipment info in LabManager

Process information

Equipment performance and process related parameters

Purpose

Exposure system designed for mass/production of devices with linewidth down to 250nm

Specifications Magnification

1:5

Projection lens Numerical Aperture

0,4 - 0,60

Illumination system's σ

0,2 - 0,75 (standard illumination mode: σ = 0,65)

Exposure source

KrF laser

Wavelength

248nm

Illumination intensity

2800 W/m2

Illumination uniformity

1,2%

Maximum printed field size

22 x 26 mm (maximum on wafer)

Alignment accuracy

3 sigma = 50 nm

Substrates Substrate size
  • 100 mm wafers (in trays)
  • 150 mm wafers
  • 200 mm wafers (requires tool change)
Allowed materials
  • Any standard cleanroom material
Batch

1 - 25


Developer: TMAH Stepper

The Developer-TMAH-Stepper is placed in F-3

This developer is dedicated for development of DUV resists. The developer is fully automatic and can run up to 25 substrates in a batch 4", 6", and 8" size (8" requires tool change). The machine is equipped with 1 developer line, in our case 2,38% TMAH in water (AZ 726 MIF), 1 topside rinse line with water, 1 backside rinse line with water and 1 N2 line for drying.


The user manual and contact information can be found in LabManager - requires login


Process information

The SEM picture of 250 nm pillars and lines. Exposure dose is 140 J/m2.

The development process will be performed by the customer together with the Photolith group of DTU Nanolab. In case you would like to do DUV lithography please contact Lithography team, who will consult you and run your wafers together with you.

Here you can find a chart‎ demonstrating a dependence between 250 nm line width/pillars diameter and exposure dose.

Standard processes

Post-exposure bake sequences:

  • (1000) DCH PEB 130C 60s 60s baking at 130°C; 20s cooling
  • (1001) DCH PEB 130C 90s 90s baking at 130°C; 20s cooling

Development sequences:

  • (1004) DCH DEV 60s 60s single puddle development

Combined PEB and development sequences:

  • (1002) DCH PEB_60s and DEV_60s 60s baking at 130°C followed by 60s single puddle development
  • (1003) DCH PEB_90s and DEV_60s 90s baking at 130°C followed by 60s single puddle development

The standard developer process consists of:

  • pre-wetting with water (2.5s @ 1000rpm)
  • developer dispense (2.5s @ 40rpm, corresponding to ~9ml)
  • development (60s @ 0rpm)
  • water rinse with BSR (5s @ 3000rpm)
  • nitrogen drying (7s @ 4000rpm)

and has a cycle time of ~2 minutes


Equipment performance and process related parameters

Purpose

Development of DUV resist: KRF M230Y and KRF M35G

Developer

2,38% water based TMAH

Process parameters Spin speed

10 - 5000 rpm

Spin acceleration

100 - 10000 rpm/s

Hotplate temperature

130°C for post exposure baking

Substrates Substrate size
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers (requires tool change)
Allowed materials
  • Any standard cleanroom material
Batch

1 - 25