Uniform oxygen plasma etching is critical in semiconductor plasma processing, where even slight variations in material removal can affect device performance, manufacturing yield, and process repeatability. Whether producing semiconductors, MEMS devices, sensors, or advanced electronic components, maintaining consistent plasma etch uniformity across an entire wafer is essential for high-quality manufacturing.
This study evaluated the MARCH AP-600 Plasma System to determine its ability to deliver highly uniform oxygen plasma processing across a 100 mm wafer while maintaining stable etch rates over multiple processing times.
Why Is Plasma Etch Uniformity Important?
In plasma-based manufacturing, the distribution of reactive species inside the chamber directly affects material removal across the wafer. Poor plasma uniformity can result in:
- Uneven thin film removal
- Variable critical dimensions
- Reduced device performance
- Lower manufacturing yields
- Increased process variability
A highly uniform plasma process ensures every area of the wafer receives nearly identical treatment, improving consistency from wafer to wafer and batch to batch.
Objective
The purpose of this evaluation was to measure the uniformity and repeatability of oxygen plasma etching on a 100 mm wafer using the MARCH AP-600 Plasma System.
The study focused on:
- Plasma etch rate consistency
- Wafer-to-wafer process repeatability
- Plasma uniformity across multiple measurement locations
Equipment Used
| Component | Specification |
|---|---|
| Plasma System | MARCH AP-600 |
| Process Gas | Oxygen (O₂) |
| Wafer Size | 100 mm |
Oxygen Plasma Process Parameters
| Parameter | Value |
|---|---|
| RF Power | 250 W |
| Process Gas | Oxygen |
| Gas Flow | 50 sccm |
| Chamber Pressure | 296 mTorr |
| Base Pressure | 100 mTorr |
| Wafer Size | 100 mm |
Material removal was evaluated after three plasma exposure times:
- 120 seconds
- 180 seconds
- 240 seconds
Film thickness measurements were collected at five locations across each wafer to evaluate etch rate uniformity and overall process consistency.
Results
Average Material Removed
Material removal increased nearly linearly as plasma exposure time increased, demonstrating stable oxygen plasma performance throughout the evaluation.
| Process Time | Average Material Removed |
|---|---|
| 120 sec | 1,736.6 Å |
| 180 sec | 2,696.2 Å |
| 240 sec | 3,493.3 Å |
Average Oxygen Plasma Etch Rate
The oxygen plasma etch rate remained remarkably consistent throughout testing.
| Process Time | Average Etch Rate |
|---|---|
| 120 sec | 868 Å/min |
| 180 sec | 899 Å/min |
| 240 sec | 873 Å/min |
The narrow variation in etch rate demonstrates stable RF plasma conditions and repeatable process performance.
Wafer Uniformity
One of the most significant findings was the excellent plasma etch uniformity achieved across the entire wafer.
| Process Time | Wafer Uniformity |
|---|---|
| 120 sec | 1.99% |
| 180 sec | 2.15% |
| 240 sec | 1.98% |
Uniformity remained approximately 2% throughout every processing condition, indicating highly consistent plasma distribution across the wafer surface.
Engineering Discussion
Achieving excellent plasma process control requires consistent plasma density throughout the processing chamber. Variations in plasma intensity can produce uneven film removal, creating defects that reduce device performance and manufacturing yield.
During this evaluation, the MARCH AP-600 Plasma System demonstrated several indicators of a well-controlled oxygen plasma process:
- Material removal increased proportionally with process time.
- Average etch rates remained stable throughout testing.
- Wafer uniformity stayed near 2% across every process duration.
- Measurements collected from multiple wafer locations showed excellent consistency.
These results indicate that the AP-600 provides highly repeatable oxygen plasma etching suitable for manufacturing environments that require tight process control and reliable wafer-to-wafer repeatability.
Typical Applications
Uniform oxygen plasma processing is commonly used for:
- Semiconductor manufacturing
- MEMS fabrication
- Sensor manufacturing
- Wafer cleaning
- Photoresist removal
- Surface preparation before deposition
- Thin film etching
- Advanced electronics manufacturing
Conclusion
Testing demonstrated that the MARCH AP-600 Plasma System delivers highly uniform oxygen plasma etching on 100 mm wafers, making it well suited for semiconductor and advanced electronics manufacturing.
The evaluation showed consistent material removal, stable etch rates, and excellent plasma uniformity throughout every processing condition tested.
Key Findings
- Approximately 2% wafer uniformity
- Stable oxygen plasma etch rates between 868 and 899 Å/min
- Nearly linear material removal as processing time increased
- Excellent wafer-to-wafer process repeatability
- Reliable plasma process control for precision wafer manufacturing
For manufacturers requiring repeatable wafer plasma etching, thin film processing, photoresist removal, and other precision semiconductor applications, the MARCH AP-600 Plasma System provides the consistency and process stability needed for high-yield production.