LAM 9400/Processes/LNF Aluminum
Jump to navigation
Jump to search
| About this Process | |
|---|---|
| Process Details | |
| Equipment | LAM 9400 |
| Technology | RIE |
| Material | Aluminum |
| Mask Materials | Photoresist, SiO2 |
| Gases Used | BCl3, HBr |
| Date Created | November 2018 |
| Authored By | Ashley Jian & Shawn Wright |
This is a fast anisotropic aluminum etch.
Etch Profile
 |
 |
 |
Etch Rates
These were measured using 1cm pieces on a 6" Si carrier. At this point we have limited data on how stable these etch rates are.
Main Etch
- Aluminum: 536 nm/min
- ALD Al2O3: 11 nm/min (49:1)
- SPR: 41 nm/min (13:1)
- SiO2: 36 nm/min (15:1)
- PMMA: 36 nm/min (15:1)
- ZEP: 29 nm/min (18:1)
Break Through
The breakthrough step is typically set to ~10 seconds, or enough time to get through any native oxide on the aluminum.
- Aluminum: 88 nm/min
- ALD Al2O3: 28 nm/min
- SPR: 29.6 nm/min
- SiO2: 48.4 nm/min
- PMMA: 73.4 nm/min
- ZEP: 49.4 nm/min
SF6 Ash
This is a short ashing step intended to replace Cl embedded in the sidewalls of the features with F in order to reduce how much corrosion happens when the sample encounters moisture in the air. Even small amounts of Cl on the surface of aluminum can form a HCl corrosion cell that can continually corrode aluminum. Below is an example of HCl corrosion on aluminum.
Parameters
| Parameter | Break Through | Main Etch | SF6 Ash |
|---|---|---|---|
| Pressure | 5 mTorr | 20 mTorr | 20 mTorr |
| TCP Power | 600 W | 600 W | 400 W |
| Bias Power | 50 W | 50 W | - |
| HBr Flow | 25 sccm | 40 sccm | - |
| BCl3 Flow | 25 sccm | 10 sccm | - |
| SF6 Flow | - | - | 90 sccm |
| O2 Flow | - | - | 10 sccm |
| Time | 10 sec (typ) | Variable | 20 sec (typ) |
