A load lock and related method of handling a substrate involves placing a substrate onto a vertically movable poppet and moving the poppet between two vertically opposed subchambers such that in moving the poppet toward one of the subchambers, that subchamber is sealed to atmosphere. The two subchamber system allows one substrate to be placed into a buffer and another substrate to be cooled at the same time. Also, the system allows for a slow vacuum to be made on the substrate in a subchamber to avoid undesirably loading the substrate by the otherwise immediate drop in pressure.