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

Dry Etcher Comparison

Use this table to help choose the right etching tool for your process.

Feature	★ Oxford RIE (this tool)	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	TBD (commissioning)	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	TBD	1500 W max	N/A
ICP Power	None (RIE only)	3000 W max	TBD	1500 W max	N/A
Table Temperature	20°C	20°C	TBD	-120°C to 200°C	20°C
Gases	Ar, O₂, CF₄, CHF₃, SF₆	Ar, O₂, CF₄, CHF₃, SF₆, C₄F₈	TBD	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	TBD	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	TBD	No metals except Cr; no deep polymer >1 µm	None listed
Endpoint Detection	✓ Optical (LEM G50)	✓ Optical	TBD	✓ Optical (LEM G50)	✗
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	⚠ Being commissioned	✓ 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