STS Pegasus 4/Processes/LNF Ar Descum
LNF Ar Descum uses an Ar plasma to anisotropically and indiscriminately remove a thin layer of any material on the surface of the sample. It is intended as a combination of photoresist descum and native oxide removal prior to Si etching. This recipe is already included in all of the standard recipes.
| About this Process | |
|---|---|
| Process Details | |
| Equipment | STS Pegasus 4 |
| Technology | RIE |
| Material | all |
| Mask Materials | none |
| Gases Used | Argon |
| Date Modified | 7/25/2017 |
| Authored By | Kevin Owen |
Contents
Procedure
LNF Ar Descum is included as the first process step in all standard processes, so it is not typically necessary to run as a standalone process.
The maximum etch time allowed for this process is 2 minutes.
Parameters
| Parameter | Units | Setpoint |
|---|---|---|
| ICP Power | W | 2000 |
| Bias Power (LF) | W | 80 |
| Bias Pulsing | none | |
| Pressure | mTorr | 5 |
| Ar Flow | sccm | 100 |
Capabilities
Etch rate and uniformity
All of the etch rates below (with the exception of photoresist) are characterized using LPCVD or thermal furnace films.
| Material | Etch Rate | Uniformity |
|---|---|---|
| Silicon dioxide | 100 Å/min | 13% |
| Silicon nitride | 110 Å/min | 11% |
| Low stress nitride | 115 Å/min | 10% |
| Silicon | 135 Å/min | 20% |
| SPR 220 | 190 Å/min | 8% |
Mask Selectivity
This recipe is intended for blanket descum of the wafer surface, so a mask is not necessary.
Limitations
Maximum allowed etch time is 2 min.