A chuck for releasably retaining a substrate, where the chuck has a body with a substrate receiving surface disposed in an X-Y coordinate plane and adapted to receive the substrate. The body has gas pressure delivery channels and gas vacuum drawing channels, where the gas pressure delivery channels and gas vacuum drawing channels are mutually exclusive within the body. The substrate receiving surface has gas pressure delivery portions in communication with the gas pressure delivery channels, for delivering a gas pressure against the substrate while the substrate is retained by the chuck, and thereby keeping the substrate from contacting the substrate receiving surface. The substrate receiving surface also has gas vacuum drawing portions in communication with the gas vacuum drawing channels, for drawing a gas vacuum against the substrate while the substrate is retained by the chuck, and thereby retaining the substrate proximate the substrate receiving surface. Retaining means retain the substrate in X-Y directions from sliding off of the substrate receiving surface.