Preliminary and fundamental remarks:
- SAFETY OPERATOR MANUAL TO OPERATE ON CMi WETBENCHES (HERE)
The baths of the Plade Metal in zone 2 are arranged as depicted in figure 1 and they target etching / removal of Aluminum, Titanium and Silicon based layers (polymorphous, amorphous, oxides, nitrides).
Depending on the application, the bath may be fitted with a temperature adjusting system and with a circulating pumping system to activate etching.
Circulating bath, heating system.
Static bath, room temperature.
| Reclaim (HF 50%)|
Bath filled on demand.
Static bath, heating system.
Bath filled on demand.
|Application||Patterning / Removal of Aluminum||Removal of Titanium or of native oxides on samples with metallic contents||Removal of oxides (Thermal, TEOS, LTO or PVD oxide) and nitrides (stoechiometric or low stress)||Removal of silicon based layers (amorphous silicon, semi-cristallin silicon and polycrystalline silicon or polysilicon)|
|Material||Bath N°||Chemicals||Mask||Etch rates (nm/min)||T (°C)|
H3PO4 85% + CH 3COOH 100% + HNO3 70%
|–|| SiO2: 1500|
|aSi, PolySi||7||Poly Etch|
- Login on the Plade Metal using zone 2 computer
- If applicable, activate the circulating system and the heating system after having checked/changed the set point. If working at room temperature, there is no need to activate the heating system
- Adjust the timer according to the etch rate and the wanted result
- Load the wafers in one of the dedicated Teflon carrier and put the handle on
- Full protection is now required (apron, face shield, chemical gloves) before going further
- Once the wanted temperature is reached, open the lid of the bath and gently plunge the carrier into it
- Start the timer (with clean hand)
- Rinse the gloves and gently clean the bath’s surroundings with a moist paper (several cleanings/rinsings are necessary)
- Wait the end of the etching. Remove the individual protective equipment if waiting time is long. Please fill-in a chemical label to inform other users about your running process
- If needed, get ready with the individual protective equipment a few minutes before etching is supposed to finish
- A buzzer indicates the end; press once on the timer button to stop the buzzer
- Open the FFR lid and gently transfer the Teflon carrier from the etching bath to FFR
- Activate the FFR button
- If applicable, stop the heating system and the circulating system of etching bath
- During FFR, rinse the gloves and gently clean the etching bath’s surroundings with a moist paper (several cleanings/rinsings are necessary)
- When FFR is finished, switch the Teflon carrier to the Trickle Tank TT
- Once resistivity is reached (~12 Mohm.cm), put the carrier in the spin rinser and dryer SRD (the carrier’s handle must be removed)
- A recipe is already selected. Just press STOP and the START
- When the SRD is finished, get the wafers back and put the carrier where it belongs
- Carefully check the cleanliness of the wetbench before taking off the chemical protection (apron, face shield, chemical gloves)
- Perform wetbench logout on zone 2 computer