NIST CNST Nanofab Equipment
Dry Etch

Certain commercial equipment, and software, are identified in this documentation to describe the subject adequately. Such identification does not imply recommendation or endorsement by the NIST, nor does it imply that the equipment identified is necessarily the best available for the purpose.

• H2 (high-temp InP etching with the Ar/Cl2 process, with CH4 for alternative InP etching)
• Ar (physical milling of most III-V semiconductors)
• He (improving etch selectivity; e.g. of GaAs over AlGaAs)
• Cl2 (reactive gas for etching III-V semiconductors)
• BCl3 (alternative source of chlorine for etching III-V semiconductors)
• SiCl4 (source gas for III-V etching, e.g., for InP-based materials)
• CH4 (used with H2 for InP etching)

• SF6 (reactive gas for etching Si and SiN)
• C4F8 (with SF6 in Si/SiN etching; also in SiO2 etching)
• CF4 (in Si/SiO2 etching)
• CHF3 (For SiO2 etching in RIE mode)
• O2 (used in SiO2 etching and as a cleaning gas)
• H2 (selective etching of SiO2 over Si)
• HBr (used in etching of polysilicon)

• Etching of Silicon at rates from 1 µm/min to 15 µm/min
• Selectivity to SiO2 ≥ 100 to 1
• Selectivity to Photoresist ≥ 40 to 1

• Small size samples (using thermal grease or resist)
• 3", 4", and 6" wafer sizes

• Silicon, Silicon Dioxide, Silicon Nitride, Silicon Oxynitride, photoresist, PMMA, and Polyimide materials are allowed.
• Metal layers can be placed in the chamber only if protected from the plasma by an allowed material.

• Anisotropic etching of metal films.
• Etches Titanium, Tungsten, etc.
• Fluoride based system, SF6, CF4, or CHF3.

• Anisotropic thin film etch
• Etches Silicon Dioxide, Silicon Nitride, Silicon, and Organics
• Descum and Oxygen cleaning

• PMMA, photoresist, Aluminum, Gold, Titanium, Chromium, and Tungsten masking materials allowed.
• Silicon, Silicon Dioxide, Glass, Sapphire, mica, and ceramic substrates allowed.
• All other materials need approval

• Anisotropic etching of metal films
• Etches Chromium, Aluminum, Titanium and other Chlorine-based etchable metals
• Chlorine-based system utilizing Boron Trichloride and Chlorine

• Pieces big enough to fit on top of handling wafer.
• Wafer sizes, 3", 4", and 6" holders

• Almost infinite selectivity of Silicon to photoresist, silicon dioxide, silicon nitride and Aluminum.
• Utilizes Xenon Difluoride (XeF2) in vapor phase.
• Used as a release etch for membranes, cantilevers and other suspended devices.

• Silicon substrates allowed.
• All other materials must be approved.
• Glass and Silicon Substrates allowed.

• Photoresist stripping (Ashing) after plasma metal-etch and after high temperature processes including ion implant, sputter etching and RIE.
• Surface cleaning of semiconductor wafers as often employed after wet etch develop of photoresist prior to wet or plasma etching (descuming).
• Surface cleaning after extended storage.
• Removal of organic passivation layers and resist.
• Etching of Silicon, Silicon Nitride, Polyimide, and other films consistent with isotropic oxygen or fluorine chemistry plasma etching.