Jobert,

You can try:
- to use a typical Bosch Process and reduce the gas pulsed times and gas
flows, at low source power and pressure. With this type of process, we are
able to achieve a RMS roughness lower than 20nm for a 30um deep etch,
- to use an unpulsed process with a mixture of SF6 and C4F8.

Jean - Marc Thevenoud
Process Engineer, Alcatel ICP etcher
Phone: 781 331 4200
email: [email protected]