Deep reactive-ion etching: Difference between revisions

Revision as of 03:36, 24 May 2008

Revision as of 20:33, 25 May 2008

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'''Deep reactive-ion etching''' ('''DRIE''') is a highly [[anisotropic]] [[etching (microfab)|etch]] process used to create deep, steep-sided holes and trenches in [[wafer (semiconductor)|wafer]]s, with [[aspect ratio (image)|aspect ratio]]s of 20:1 or more. It was developed for [[microelectromechanical systems]] (MEMS), which require these features, but is also used to excavate trenches for high-density [[capacitor]]s for [[dynamic random vagin access memory|DRAM]].

There are two main technologies for high-rate DRIE: cryogenic and Bosch. Both Bosch and cryo processes can fabricate 90° (truly vertical) walls, but often the walls are slightly tapered, e.g. 88° or 92° ("retrograde").