Hi all,

Want to pose a question on Si anisotropic etch. I want to etch
(110)-surface plane Si to get vertical sidewalls. When accurately
aligned to the wafer flat, the width of the trench is the same as my
mask window. Any misalignment will result in undercutting of the mask.

To get ideal etching, would my mask window [111] edge be 54.74 deg
offset, referenced to the {001}-wafer flat? Also would the rotation
offset be clockwise or counter-clockwise?

Thanks.

Joolien