This application relates to an apparatus and method for processing a wafer. In an embodiment of this application, an apparatus for processing a wafer includes: a heater including a pedestal, where a top portion of the pedestal includes an annular edge step and a wafer pocket recessed relative to the annular edge step to accommodate a wafer; a side ring, including an outer portion and a top portion, where the outer portion surrounds an outer side wall of the pedestal, and the top portion covers an outer portion of the annular edge step and includes a centripetal slant bevel; and a shadow ring, a bottom portion thereof including a slant bevel matching the centripetal slant bevel of the top portion of the side ring.