Heater assembly for heating a wafer

摘要

A heater assembly of a semiconductor device manufacturing apparatus minimizes a temperature difference between a peripheral portion and a central portion of the wafer being processed in the apparatus. The heater assembly includes a unitary resistive heating member in the form of a disc, heat blocks that divide the peripheral portion and central portion of the upper surface of the disc into respective heating sections, a support for supporting the heating member, and an electric power source for supplying electric current to the unitary heating member. The widths of the heating sections become greater towards the center of the heater, and thus the electrical resistance of the heater also increases in a direction towards the center of the heater. As a result, more heat is generated at the peripheral portion of the heater than at the central portion of the heater. The power source for the heater includes a lead that extends from the bottom surface of the heater to a bottom portion of the heater support. The lead is thus prevented from being damaged by thermal stress and form being corroded by deposition gas and other by-products of the manufacturing process.