Heidelberg DWL 66+ Laser Writer
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| Tool Name | Heidelberg DWL 66+ Laser Writer |
|---|---|
| Instrument Type | Lithography |
| Staff Manager | Ana Cohen |
| Lab Location | Bay 4 |
| Tool Manufacturer | Heidelberg |
| Tool Model | DWL 66+ |
| NEMO Designation | LW-01 |
| Nearest Phone | 8-9799 |
| SOP Link | SOP |
Description
The fully automated DWL 66+ laser writing system has both binary (2D) and grayscale (2.5D) exposure capability. The pattern is broken into vertical stripes of ~500px with preset overlap. To write each stripe, the tool modulates and deflects the laser beam based on the provided pattern data while the stage moves along Y. This process repeats along the X direction until the pattern is complete.
The laser for the QNF system is 405nm wavelength (h-line). (Laser exchanged in June 2023. Previous documentation may include 365nm capability.)
Lens & Resolution
- 2 mm lens : 600 nm
- 10 mm lens : 2 µm
- 40 mm lens : 10 µm
Applications
- Patterning of photomasks
- Direct laser writing on substrates, from 6" wafers down to 10mm x 10mm pieces
Allowed Materials
- Mask Plates -- available in the QNF Stockroom pre-coated with AZ1500 and IP3500
- Resists -- must be compatible with h-line exposure
Processes
Writehead Selection
Pneumatic mode not recommended for dry etch and smaller features due to focus issues -- currently working with Heidelberg service to address.
Last confirmed July 2025.
| Write Head | Focus | Mode | Notes |
|---|---|---|---|
| 10mm | -100 | Pneumatic | active problem, see note above |
| 10mm | -70 | Optical | for >2um minimum |
| 2mm | -100 | Pneumatic | active problem, see note above |
| 2mm | +40 | Optical | for >600nm minimum |
| 40mm | -100 | Pneumatic | active problem, see note above |
Photomask Exposure
500nm resist thickness on chrome-coated soda lime. Development in TMAH 0.26N for 60s.
Last confirmed July 2025.
| Mask | Write Head | Filter(s) | Laser Power | Intensity | Notes |
|---|---|---|---|---|---|
| AZ1500 | 10mm | 50% | 60 mW | 90 | |
| IP3500 | 10mm | NONE | 120 mW | 90 | for <3um |
| AZ1500 | 2mm | 12.5% + 25% | 60 mW | 80 | |
| IP3500 | 2mm | 12.5% + 50% | 60 mW | 80 | for <1um |
| AZ1500 | 40mm | NONE | 220 mW | 60 |
Other direct write exposures
Resist on 4" silicon wafer, soft baked at 115C for 60s, development in TMAH 0.26N for 60s.
Due to the variability of resist thickness, substrate reflectivity, and the ideal profile for subsequent processes, a dose test is always recommended to confirm optimal parameters.
| Resist | Thickness/Spin Speed | Write Head | Filter(s) | Laser Power | Intensity |
|---|---|---|---|---|---|
| S1805 | 0.5um (3krpm) | 10mm | 50% | 60 mW | 70 |
| S1818 | 2.2um (3krpm) | 10mm | NONE | 130 mW | 100 |
S1818 at 3000rpm (2.2um thickness) with 10mm writehead [Feb 2024] 65mW, NO Filter, 70% intensity, + 20 focus 5um, 10um, 25um, and 50um line widths after 60s TMAH 0.26N development
