It has been previously demonstrated that it is possible to form the NOT gate in a coupled semiconductor waveguide structure in III-V materials. However, to this point, investigations have assumed the materials to be perfect. In this article, we present results of a semiconductor waveguide inverter in GaAs and InAs with disordered material effects included in the simulation. The behavior of the device clearly shows that with the inclusion of mild to moderate disorder in these materials, waveguide NOT gate function is still possible. Nevertheless, under heavy disorder in the system, clear switching becomes impossible. (C) 2003 American Vacuum Society.