Abstract: Electrostatic discharges that occur during solid CO.sub.2 cleaning of a substrate (10) can be virtually eliminated by chilling the substrate so that moisture in the atmosphere, in the form of water droplets(30), condense on the substrate surface (14), thereby forming a continuous film of water (28). The water in the film (28) reacts with the solid CO.sub.2 (24) to form carbonic acid that dissociates into free ions that neutralize the charge on the solid CO.sub.2.

Abstract: An object (12) may be cleaned by CO.sub.2 reduced ESD by directing a first water mist (23) at a surface (14) of the object while imparting a relative motion between the object board and the mist to form a film of water on the object surface. As the relative motion is imparted between the board and the first mist (23), a second water mist (32) is injected into a stream (30) of solid CO.sub.2 particles (27) directed at the object surface downstream of the first mist. Water droplets in the second mist in the second mist combine with the CO.sub.2 particles to create carbonic acid that disassociates into charged ions that increase the conductivity of the water film, allowing for increased charge dissipation, thus reducing the incidence of ESD.