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/sub mesa/) is obtained from the forward current-voltage (I/sub F/V) 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 (CH/sub 4/)/hydrogen (H/sub 2/), we found that Schottky barrier height /spl phi/ 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.