摘要 |
<p>A wafer for use in a MEMS device having two doped layers surrounding an undoped layer of silicon is described. By providing two doped layers around an undoped core, the stress in the lattice structure of the silicon is reduced as compared to a solidly doped layer. Thus, problems associated with warping and bowing are reduced. The wafer may have a pattered oxide layer to pattern the deep reactive ion etch. A first deep reactive ion etch creates trenches in the layers. The walls of the trenches are doped with boron atoms. A second deep reactive ion etch removes the bottom walls of the trenches. The wafer is separated from the silicon substrate and bonded to at least one glass wafer.</p> |