STS Pegasus DRIE Equipment Log

STS Standard Operating Procedures

Tool Operation 1. Verify that the tool not in use and activate your reservation on the scheduler 2. Log into the log book 3. Verify that you have a proper wafer with CLEAN & SMOOTH BACKSIDE

a. Never put resist that has not been fully cured into this tool 4. For etches deeper than 400µm, a carrier wafer is required – follow wafer mating

procedure 5. Loading wafers:

b. In the Automatic Window, press Load and wait for lock to vent c. Load wafers flat towards center, close lid and secure latch d. The lock will automatically pump down and map your wafers

6. Press Recipe 7. Select PEG1 -> Process Module 8. Select the name/title of the desired recipe 9. Make a copy of the recipe – press copy 10. Select “Process Module” on the tree 11. Press Paste, change name, then Apply to save 12. Expand the tree of your copied recipe and select DRIE 13. Under general, adjust process (etch) time and press Apply to save 14. Press Automatic, select Generic 2 recipe Batch xx min IPC

a. Run 1min IPC for etches etches <20min, 3min for others 15. Press Start 16. Select appropriate wafer slots and recipes and press next, & start 17. When wafer is loaded, check Backside Gas Leak Check

a. This should be <150mT/min b. If not <150mT/min, manually unload wafer and clean backside

18. When recipe is finished, wafers are replaced in loadlock, to unload wafer: e. In the Automatic Window, press Load and wait for lock to vent f. Load wafers (optional), close lid and secure latch g. The lock will automatically pump down and map your wafers

Wafer Mating Procedure 1. Heat carrier wafer on hotplate at 110C for 1min

2. Apply Crystalbond

a. Press crystalbond stick to center of wafer, wait for 1-1.5” puddle to form

3. Place device wafer on top of carrier

4. Continue to bake on hotplate for 3-5 minutes

a. Vacuum optional

5. Remove from hotplate and cool

Wafer Unmating Procedure 1. Heat mated wafers on hotplate at 110C for 1min

2. Slide device wafer off of carrier

3. Rinse wafers in solvent (Acetone/IPA) or water to remove crystalbond residue

Waste Products 1. Broken wafers shall be placed in the broken glass container.

• Report all accidents (injuries, spills, fires) to the SSEL On Call or other SSEL staff. For emergencies during non-business hours, call the SSEL Emergency Response Team at (734) 764-4127 or Department of Public Safety at (734) 763-1311.

Recipe Overview LNF Standard Recipe 1 This recipe is designed for general DRIE silicon etching. It etches a large range of feature sizes well with very straight and smooth sidewalls and minimal feature undercut.

Recipe Capabilities

• Smallest Trench: 0.7um • Smallest Freestanding line: 1.7um • 2um Etch Rate: 2.76 um/min (PR selectivity 32:1) • 10um Etch Rate: 4.02 um/min (PR selectivity 47:1) • 100um Etch Rate: 5.6 um/min (PR selectivity 66:1) • PR Etch Rate (SPR220): 84nm/min • Scalloping Width/Depth: 86nm/321nm • Undercut: 75nm

Etch Rate (um/min) vs Feature Size (um)

LNF Standard Recipe 1 SEMs

20min etch 2um feature

20min etch 10um feature

20min etch 100um feature

LNF Standard Recipe 2 This recipe is designed for fast through wafer etching of larger features. It has high etch rates and high PR selectivity, but poorer resolution, sidewall roughness and undercut.

Recipe Capabilities

• Smallest Trench: 0.8um • Smallest Freestanding line: 7.4um • 2um Etch Rate: 4.69 um/min (PR selectivity 77:1) • 10um Etch Rate: 7.25 um/min (PR selectivity 118:1) • 100um Etch Rate: 12.1 um/min (PR selectivity 198:1) • PR Etch Rate (SPR220): 61nm/min • Scalloping Width/Depth: 0.515um/2.28um • Undercut: 1.06um

Etch Rate (um/min) vs Feature Size (um)

LNF Standard Recipe 2 SEMs

20min etch 2um feature

20min etch 10um feature

20min etch 100um feature

LNF Standard Recipe 3 This recipe is similar to recipe 2, but further optimized for higher percentage of open area.

Recipe Capabilities

• Smallest Trench: 0.618um • Smallest Freestanding line: 4.29um • 2um Etch Rate: 4.63 um/min (PR selectivity 38:1) • 10um Etch Rate: 7.1 um/min (PR selectivity 57:1) • 100um Etch Rate: 12.5 um/min (PR selectivity 88:1) • PR Etch Rate (SPR220): 77nm/min • Scalloping Width/Depth: 0.463um/2.19um • Undercut: 483nm

Etch Rate (um/min) vs Feature Size (um)

LNF Standard Recipe 3 SEMs

20min etch 2um feature

20min etch 10um feature

20min etch 100um feature

LNF Standard Recipe 4 This recipe is designed for high aspect ratio and high resolution small features. It is only suitable for small areas (<<100um), larger open areas will develop significant grass.

Recipe Capabilities

• Smallest Trench: 0.242um • Smallest Freestanding line: 1.16um • 2um Etch Rate: 2.3 um/min (PR selectivity 38:1) • 10um Etch Rate: 3.4 um/min (PR selectivity 57:1) • 100um Etch Rate: 5.25 um/min (PR selectivity 88:1) • PR Etch Rate (SPR220): 60nm/min • Scalloping Width/Depth: 80nm/300nm • Undercut: 225nm

Etch Rate (um/min) vs Feature Size (um)

LNF Standard Recipe 4 SEMs

20min etch 2um feature

20min etch 10um feature

20min etch 100um feature