Methods of slicing ingots of semiconductor material into wafers using a wire saw. The wire saw includes a wire that is movable in a forward direction and a reverse direction for slicing the ingots. The methods include defining an identification region of each wafer to be sliced from the ingots and aligning an alignment feature of the ingots in approximately the same position relative to the wire saw for each of the ingots. The identification region of the wafer is adapted for marking with an identification mark after slicing. The methods also include slicing the ingot into wafers with the wire saw. The slicing step includes moving the wire in the forward and reverse directions during slicing except when slicing in the identification region of each wafer and moving the wire only in the forward direction when slicing in the identification region of each wafer. In slicing the ingot into wafers, thickness variations relative to the size of the identification mark are reduced in the identification region.