Electrical evaluation of dry etching damage on the side wall of mesa structure

We propose a method for evaluating the electrical properties of damage on the sidewalls of mesa structures. In the method, current flowing through the mesa sidewalls (I_mesa) is obtained from the forward current-voltage (I_FV) characteristics for Schottky barriers formed on both the sidewalls of the mesa structures and (100) surface. In applying the method to evaluate the damage on the sidewalls of InP mesa structures fabricated by reactive ion etching (RIE) with methane (CH₄)/hydrogen (H₂), we found that Schottky barrier height φ on the mesa sidewalls is increased by RIE. This suggests that an n-type damage layer is induced by RIE on the sidewalls. We also found that the damage could be induced on the mesa-sidewall at least with comparable density to that on the (100) surface, and to a depth less than that on the (100) surface