Oxford RIE

About

Oxford PlasmaPro 80 RIE tool in Etch Bay

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
No exposed metals except Cr No deep polymer etching (> 1 µm) Polymers allowed only as masks Not intended for metal etching Avoid uncalibrated deep or high-aspect-ratio processes	SiO₂ Si₃N₄ Si Oxide masks Nitride masks Passivation removal Via openings Resist descum Surface cleaning and activation Chromium (Cr) as exposed metal

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