A static capacitance probe structure for resolving the sidewall skew angle of Silicon Deep Reactive-Ion Etching

This work presents a static capacitive probe structure that enables quantitative characterization of the effective sidewall skew angle of the Silicon Deep-Reactive-Ion-Etching (DRIE) using static LCR prober at ambient environment. The design is capable of resolving sidewall skew angles around both in-plane axes independently and simultaneously with the same sensitivity. The measured distributions of the sidewall skew angle across 8-inch wafers conform to empirical expectation and correlate tightly with quadrature error distributions measured gyroscopes from the same wafers. This work provides an easy, accurate and batch solution to the long existing challenge of resolving such process features in an industrial manufacturing environment.