Oxygen Plasma System Recipes

Back to Dry Etching Recipes.

Ashers (Technics PEII)

CF4/O2 PEii

Gas is CF₄ / O₂ (88%/12%)

SiN Etching

• Pressure = 300mT–350mT
• Power = 100W
• Etch Rate ≈ 50-100 nm/min. Varies.

Chamber Clean after CF4 Etching

• Pressure = 300mT–350mT
• Power = 300W
• Time = 10min
• Set power back to 100W before shutting off plasma!

O2 Ashing

O2; 300mT / 100W - on either Technics asher.

~15sec to make a surface hydrophilic, eg. before wet etching or applying photoreist.

~30-120sec to improve wirebonding pad metal prior to deposition of liftoff metal.

~1-5min to remove polymerized photoresist/scum after dry etching

~5-10min to strip ~0.5-1.0µm photoresist. Rotate wafer 180° halfway through etch. Optionally increase to 200W for faster etching.

Use glass slides to prevent wafers from sliding on platen.

Plasma Clean (Gasonics 2000)

Recipes are posted at the tool, with photoresist etch rates.

Plasma Clean (YES EcoClean)

• Various Resists at 150C-3kW
• SPR220-7 at 3kW various Temps

3kW recipes appear to gradually heat wafers beyond the hotplate temperature, and also expose the underside of the wafer. Very efficient cleaning of positive photoresists.

Some negative photoresists (eg. UVN) do not strip well without ion bombardment (requiring Technics PEii or RIE/ICP instead).

Low melting-point metals (Au) should only use low temps. (100°C), and short times (1min), or use the low-power (0.7kW) recipes.

UV Ozone Reactor

The UV Ozone Reactor is used for two purposes:

• Etch away organic residue with no ion bombardment
• Oxidize surface (monolayers) of a substrate, which has been used for
  • Providing a wet-etchable sacrifical surface layer which is removed prior to deposition or regrowth
  • Controlled digital etching, by wet etching the oxide and then repeating the oxidation/etch cycle.

Plasma Activation (EVG 810)

O2 and N2 plasma activation recipes are available on this tool.

These are the qualified recipes provided by EVG and will not require adjustment of the RF Match:

• ExSitu_0.4mbar – 0.4mbar, N₂, 100/75W
• ExSitu_0.4mbar_Line2 – 0.4mbar, O₂, 100/75W
• ExSitu_0.8mbar – 0.8mbar, N₂, 100/75W
• ExSitu_0.8mbar_Line2 – 0.8mbar, O₂ 100/75W
• Dis 0.2mbar_Line2 – 0.2mbar, O₂, 125/75W