Plasma etching nitride, oxide, silicon, polyimide and photoresist in a Glow Research AutoGlow 200 plasma system. Results below show results for etching nitride, oxide, silicon and photoresist removal.
“Autoglow 200 is simple yet powerful, and makes it easy to remove silicon nitride passivation from semiconductor devices.”
Customer: Volodymyr Pikhur” with Hardware Root Research LLC
Here are some before plasma nitride etch (left) and after plasma nitride etch (right) pictures of the 8″ wafer:
Showing nitride removal in the AutoGlow 200. Left = before, Right = after etch.
SF6 or CF4 gas can be used for removing oxide layers or nitride layers. Results on the AutoGlow show the following etch rates for various films as reported from Customers:
- Etching nitride: 800 mTorr, 200 watts, 2 min.,150mm wafer = 212 Angstroms/min (Power can be increased to increase etch rate)
- Etching oxide: 800 mTorr, 400 watts, 10 min, 150mm wafer = 800 Angstroms /min (Power can be increased to increase etch rate)
- Etching silicon: One Customer reports etch rate for silicon of: 1 um/min at 300W and 600 mT.
- Removing photoresist: 750 mTorr, 300 watts, 10 min, 2″ x 2″ substrate = 1000 Angstroms/min. Another Customer reports a removal rate of 2000 Angstroms/min on a 6″ wafer.
The AutoGlow 200 is a cost effective way to perform Plasma etching passivation nitride, oxide, silicon and photoresist.
AutoGlow 200 for plasma etching, activation and cleaning
The AutoGlow 1000 can also be used for processing 300mm wafers for production applications. Also used for various production plasma treatment, plasma cleaning and photoresist descum.
AutoGlow 1000 production plasma system used for etching, cleaning and surface activation
AutoGlow 1000–showing two sets of electrode shelves
SCOPE:
Using The Glow Research AutoGlow 200 for removing Nitride, Oxide layers on patterned wafers, and parts of wafers. Polyimide was removed as well.
Nitride and Oxide Process:
- Preheat chamber for 15 minutes using CF4/O2 @ 200 Watts, 0.800 Torr.
- Run each set of samples separately—vary the time from 1-10 min.
- Gas used for nitride and oxid: 90% CF4, 10% O2
- Gas used for polyimide: O2
- Power: 200 watts
- Pressure: .8 Torr
Nitride + Oxide patterned
Polyimide (blanket layer)
Configuration:
AutoGlow 200
2 Gas configuration
300W, 13.56 Mhz generator
Electrodes in RIE configuration (see diagram below)
Summary
Each category of samples (Nitride + Oxide patterned, and Polyimide) were processed in the AutoGlow 200 system. The time of process was varied for each category to be able to show the degree of etch. Visually, each category shows that the plasma process has removed the desired material.
The AutoGlow 200 system shows removal of oxide, nitride and polyimide.
The final process was to determine uniformity across a single 6” blanket oxide wafer. This wafer was positioned, centered, on the powered electrode (RIE mode). Uniformity shows 10.9%. Uniformity measurements defined and calculated using: Maximum measurement – Minimum measurement / 2x the Average
| Test Point | Measurement before process | Measurement after process | Etch removal in Angstroms |
| 1 | 10200 | 2964 | 7236 |
| 2 | 10230 | 3345 | 6885 |
| 3 | 10260 | 2611 | 7649 |
| 4 | 10133 | 3984 | 6149 |
| 5 | 10158 | 3811 | 6347 |
Average Etch Rate = 6853.2
Uniformity = 10.9%
For more process information on oxide etch results in the AutoGlow 1000 click HERE
For more process information on photoresist descum in the AutoGlow 1000, click HERE
For more AutoGlow 200/300 information and a video click HERE
For a partial list of Glow Research Customers click HERE.
Other papers that discuss plasma etching of passivation nitride and oxide–click HERE
