A lithography apparatus is provided. The lithography apparatus includes a wafer stage configured to secure a semiconductor wafer and having a plurality of electrodes. The lithography apparatus also includes an exposure tool configured to perform an exposure process by projecting an extreme ultraviolet (EUV) light on the semiconductor wafer. The lithography apparatus further includes a controller configured to control power supplied to the electrodes to have a first adjusted voltage during the exposure process for a first group of exposure fields on the semiconductor wafer so as to secure the semiconductor wafer to the wafer stage. The first adjusted voltage is in a range from about 1.6 kV to about 3.2 kV.