METHOD TO FORM RECESSED CAVITIES WITH MIRROR FLAT BOTTOM SURFACES
Original Publication Date: 1998-Mar-01
Included in the Prior Art Database: 2002-Jun-25
Some semiconductor device technologies require wafer processing in etched recesses microns to tens of microns deep. In particular, microme- chanical device development may require the formation of recessed regions in a silicon wafer. These recesses can be formed from a variety of wet and dry methods including both isotropic and anisotropic etch chemistries. Applications requiring very smooth bottom surfaces with uniform depths may not be feasible using existing recess methods due to manufacturing issues. An alternative method is proposed which provides a mirror-polished bottom surface of uniform depth and a complete etch stop for most anisotropic etchants resulting in a non- critical etch time. The method requires no tixturing and produces a completely defined final geometry of the recess.