An apparatus may include a substrate holder configured to hold a substrate. The substrate holder may include a first chucking region having a first area and an adjacent region extending from the chucking region. The apparatus may also include a superstrate holder configured to hold a superstrate. The superstrate holder may include a second chucking region having a second area. The second area may be larger than the first area and the superstrate holder faces the substrate holder forming a first gap between the adjacent region surface and the superstrate and a second gap between the substrate and the superstrate. The apparatus may also include a gas supply system between the first gap and the second gap. The superstrate holder may alter a shape of the held superstrate to decrease the first gap and increase the second gap.