A dry etching process is described for the fabrication of through-wafer via holes in GaAs-based monolithic microwave integrated circuits by magnetron ion etching using SiCl4. The process has been used to etch via holes through 80 μm GaAs substrates with good anisotropy and etch rates exceeding 1 μm/min for via holes as small as 18×20 μm2. Etch anisotropy appears to be due to an etch-inhibiting layer, which forms on the sidewalls but can be removed readily using a brief SF6/O2 etch. The process also exhibits good selectivity to Au and Ni frontside metal.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures|
|State||Published - Sep 1998|
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Electrical and Electronic Engineering