Oxford RIE
About
Films / Materials: This is an Oxford Instruments PlasmaPro 80 reactive ion etcher (RIE) optimized for etching dielectric materials such as SiO₂, Si₃N₄, and Si, with good anisotropy and control. It is primarily used for etching dielectrics in micro- and nanofabrication processes. Hardware: Parallel-plate capacitively-coupled RF plasma system (13.56 MHz). Open-load design for fast loading/unloading of samples. No load lock; direct chamber access. Electrode/table temperature controlled at 20°C (ambient/chilled). Includes optical endpoint detection (Horiba Jobin Yvon LEM G50) for precise process stop. Gases:
- Ar (argon – physical sputtering/milling component)
- O₂ (oxygen – for ashing, oxidation, or enhancing etch rates)
- CF₄ (tetrafluoromethane – fluorine-based etching of SiO₂/Si₃N₄)
- CHF₃ (trifluoromethane – for selective SiO₂ etching, polymer sidewall passivation)
- SF₆ (sulfur hexafluoride – high-rate isotropic/fluorine etching of Si/SiO₂)
Etch Properties:
- Primarily anisotropic etching of dielectrics via ion bombardment and chemical reactions.
- Suitable for shallow to moderate depth etches (avoid deep polymer etching >1 µm due to restrictions).
- High selectivity possible depending on gas mix and power (e.g., SiO₂ over Si with CHF₃/O₂).
- Excellent process control for uniformity across up to 200 mm substrates.
Applications: Etching of dielectric layers (e.g., oxide/nitride masks, passivation removal, via openings), resist descum, surface cleaning/activation. Not for exposed metals (except Cr) or deep polymer etches; polymer may be used as a mask only.
Usage: Load sample directly (pieces to 200 mm wafers), select/load recipe, set time/power based on calibrated etch rates. Use endpoint detection for timed or auto-stop processes. Monitor particles and uniformity post-etch.
Detailed Specifications
- Model: PlasmaPro 80 reactive ion etcher
- Location: Etch Bay 1
- Substrate size: Up to 8 (200 mm) wafers (pieces/smaller possible; open loading)
- RF Power: Table RF power (max) 300 W (13.56 MHz)
- Table temperature: 20°C (chilled/controlled) / (max) 80°C
- Gases:
- CHF₃ (max) 100 sccm
- Ar (max) 100 sccm
- O₂ (max) 50 sccm
- CF₄ (max) 50 sccm
- SF₆ (max) 100 sccm
- Features: Optical endpoint detection (Horiba Jobin Yvon LEM G50), open-load design for fast access, excellent etch uniformity and rate control
Restrictions and Materials Allowed
| Restrictions | Materials Allowed |
|---|---|
|
|
Safety & Emergency
Required PPE: Safety glasses, cleanroom gloves, bunny suit. Toxic gases used: CHF₃, SF₆, CF₄ — fluorine byproducts (HF) possible. Do not open chamber if gas alarm is active. If the tool alarms or gas cabinet shows red:
- Press EMO (Emergency Machine Off) — red button on the front panel.
- Evacuate Etch Bay 1 and notify staff immediately.
- Call Nanofab staff: Chandan Ramakrishnaiah, +1 (213) 551-6726.
- After hours / life-threatening: USC DPS (213) 740-4321, or 911.
Gas leak or chemical exposure: Activate bay alarm, exit cleanroom, call DPS. Chamber vent failure: Do NOT force open. Leave tool and contact staff.
Dry Etcher Comparison
Use this table to help choose the right etching tool for your process.
| Feature | Oxford RIE | Oxford DRIE | Oxford DRIE-ALE | Oxford III-V | XeF2 Etcher |
|---|---|---|---|---|---|
| Model | PlasmaPro 80 RIE | Oxford System 100 DRIE | Oxford DRIE + ALE | PlasmaPro 100 Cobra | Custom built (Armani group) |
| Location | Etch Bay 1 | Etch Bay 1 | Etch Bay 1 | Etch Bay 1 | Deposition Bay 1 |
| Substrate Size | Up to 200 mm (8") | Up to 4" clamp; 2", 3", 4", 6", 8" possible | Up to 4" clamp; 2", 3", 4", 6", 8" possible | Up to 4" clamp; 2", 3", 4", 6", 8" possible | Up to 6" |
| Etch Type | RIE (capacitively coupled) | DRIE / Bosch (ICP) | DRIE + Atomic Layer Etch | ICP-RIE (cryo capable) | Isotropic chemical etch |
| Table RF Power | 300 W max | 300 W max | 300 W max | 1500 W max | N/A |
| ICP Power | None (RIE only) | 3000 W max | 3000 W max | 1500 W max | N/A |
| Table Temperature | 20°C | 20°C | -120°C to 200°C allowed
(-150°C to 400°C max) |
-120°C to 200°C allowed
(-150°C to 400°C max) |
20°C |
| Gases | Ar, O₂, CF₄, CHF₃, SF₆ | Ar, O₂, CF₄, CHF₃, SF₆, C₄F₈ | Ar, O₂, C₄F₈, SF₆, BCl₃, Cl₂, H₂, N₂O, CH₄, CF₄, CHF₃ | Ar, O₂, SF₆, CH₄, H₂, Cl₂, BCl₃, SiCl₄ | XeF₂ (crystal source) |
| Allowed Materials | Si, SiO₂, Si₃N₄, oxide/nitride masks, Cr | Si, SiO₂, SiN, Parylene, Polyimide, LiNbO₃, BCB | InP, InAs, GaN, AlGaAs, GaAs, InGaAsP, ITO, Si, SiC, MoS₂, WSe, Graphene | InP, InAs, GaN, AlGaAs, GaAs, InGaAsP, ITO, Si, SiC, MoS₂, WSe, Graphene | Si only |
| Disallowed | No metals except Cr; no deep polymer >1 µm | No exposed metals except Cr | No metals except Cr; no deep polymer >1 µm | No metals except Cr; no deep polymer >1 µm | None listed |
| Endpoint Detection | Optical (LEM G50) | Not Available | TBD | Optical (LEM G50) | Not Available |
| Best For | Dielectric etching, passivation removal, via openings, resist descum | Deep Si etching, high-aspect-ratio structures, Bosch process | Precise atomic-layer-level etch control | III-V semiconductors, exotic/compound materials, cryo etching | Fast isotropic Si etching, high selectivity |
| Status | Operational | Operational | Operational | Operational | Operational |
| SOP | SOP | SOP | TBD | SOP | SOP |
Documentation
- SOP
- OES SOP
- Laser Endpoint SOP
- Training video
- Training required – contact lab staff (Chandan Ramakrishnaiah) Request form
Recipes & Data
- Standard Recipes: Standard Recipe
- Process Control and Calibration Data: Standard Recipe Calibration
Recipe Control Charts
- SiO2 Etch Control Chart
- SiNx Etch Control Chart
Troubleshooting
- Plasma won't ignite
- Check gas flows are stable, pressure is in range (10–200 mTorr), and RF matching network is tuned.
- Etch rate dropped suddenly
- Chamber may need conditioning. Run an O₂ clean recipe for 30 min.
- Endpoint detector not triggering
- Verify Horiba LEM G50 is on, lens is clean, correct wavelength is selected. See OES SOP.
- Chamber pressure won't drop
- Possible vacuum leak or pump issue. Stop process, notify staff.
Acknowledgment
If results from this tool appear in a publication, please acknowledge the facility:
"This work was performed in part at the USC Nanofab at the University of Southern California, Michelson Center for Convergent Bioscience."
Please also email the citation to chandanr@usc.edu so we can track facility output.