XeF2 Etch (Xetch)

XeF2 Etch (Xetch) Tool Type Dry Etch Location Bay 2 Supervisor Bill Millerski Supervisor Phone (805) 893-2655 Supervisor E-Mail wmillerski@ucsb.edu Description XeF2 Gas Etcher Manufacturer Xactix Inc Dry Etch Recipes Sign up for this tool

About

The applications of this tool are mainly in MEMS-device fabrication areas (releasing a MEMS structure by etching a sacrificial layer below), in which Si or Ge or even some metals, such as Mo, can be isotropically dry etched using gaseous XeF₂ (no plasma enhancement or heating is needed) with the use of photoresist or SiO₂ or Al as an etch mask at room temperature.

The XeF₂ etch process is a purely chemical one and usually results in a rough etched surface. The tool is operated in a pulsed mode in which the etch chamber is repeatedly filled with XeF₂ gas and, then, pumped out (to 0.3 Torr). You can also add N₂ gas, together with XeF₂ gas, into the etch chamber for some applications.

There is a microscope attached to this tool, with which you can monitor the etch process of your sample. You can change the number of etch cycles during a run, which will be effective in that run. Also, you can manually stop a run based on microscope observations.

Maximum Wafer size is 6".

For users who want to etch through or very deep into a Si wafer, they should use the Si Deep RIE tool in the lab.

Documentation

• System Manual
• Si Etching Profile & Results
• XACTI XeF2 etch Operating Instructions