High aspect ratio tilted gratings through local electric field modulation in plasma etching

The anisotropic nature of plasma etching is usually exploited to realize vertical nano-/micro- silicon structures by deep reactive ion etching. However, some applications require tilted instead perpendicular profiles with respect the substrate. Here, a controlled realized introducing set metal electric field modulator(s), which modify near sample surface potential. ions from body are accelerated under influence distorted field, and hit certain incident angle. A model built finite elements method, taking into account geometry experiment chamber conditions during process. thickness inter-distance Al slabs have been varied in range 0.5–3 mm 10–25 mm, respectively. tilt angle ranging 0° 22.6° has measured validates simulation results, showing that desired profile can be achieved proper parameters tuning. Examples 1D 2D modulations reported linear chessboard slanted gratings for X-ray imaging applications.