The effects of a sinusoidally corrugated boundary on the generation and propagation of slow plasma waves are studied. The intention is to seek a method of minimizing surface wave energy in lower-hybrid-heating schemes. Firstly, an analysis is presented of the mode structure that can be supported by a periodic boundary. Significant coupling to slow plasma waves can occur for a wide range of conditions and penetration of waves into the plasma leads to dissipation of the surface fields. Secondly, the reflection of waves propagating from the interior of the plasma onto the boundary is considered. The presence of the corrugated wall modifies the parallel refractive index of the reflected wave components and, for particular geometrical conditions, leads to complete backscattering of the incident energy.