Sputtering of Si for SiO2 films - NanoLabStaff/nanolab GitHub Wiki

by Renato Bugge ([email protected])

Machinery needed: AJA sputter with Silicon sputter target inserted (DC sputter).

  1. Step

    - Insert sample into machine, start rotation and open shutter relay on e-beam controller

  2. Step

    - Use 62sccm Argon + 5 sccm Oxygen
- Initially set the pressure to 30 mT
- Ignite plasma with 50W power

  3. Step

    - Reduce pressure to 5 mT and ramp plasma power to 200W (1W/sec).
- Reduce pressure to 3 mT. If plasma is unstable or switches off, go back to step 2.

  4. Step

    - Start depositing by opening the Silicon target shutter. Start timer.
- Nominal deposition rate is 1.2Å/s but may vary over longer time periods. If you need highly accurate films it is recommended to calibrate the film thickness using a dummy sample prior to your active sample.

  5. Step

    - Stop deposition by closing the Silicon target shutter after the needed thickness has been reached.

This process has been shown to yield SiO2 with an refractive index of 1.46 (632nm). Thickness variation of less than 0.3% over a 50mm wafer can be expected on a flat wafer.

Increasing pressure may reduce deposition rate.

Reducing oxygen content of the plasma may increase the refractive index and/or give less oxidised films.

Increasing deposition power may increase the refractive index and/or give less oxidised films. It may also reduce the homogeneity of the film.

Discuss this protocol!