Patent ID: 6370793
Filing Date: 2002-04-16
Classification: G03F,H01L,Y10S

Abstract:
The combination of a wafer pre-alignment stage, and temperature controlling apparatus for controlling the temperature of a wafer transferred to the stage, said combination comprising:a rotary wafer chuck; an edge sensor, adjacent one peripheral portion of the wafer chuck, so as to sense for a peripheral edge feature of a wafer held by said chuck; an air supplier; an air injection head disposed above said chuck and connected to said air supplier so as to receive air therefrom, said air injection head being having an interior space and including a bottom plate having a plurality of injection holes extending therthrough in open communication with said interior space so as to inject air received from said air supplier towards a wafer held by said chuck; and a flow rate controlling plate disposed in said interior space and dividing the space into a first space portion and a second space portion, the second space portion being adjacent the region of the edge sensor and the first space portion being remote from the region of the edge sensor, the flow rate controlling plate regulating the amounts of air introduced from the air supplier into said first and second space portions, respectively, so as to guide a predetermined amount of the air to the region of the edge sensor, whereby the air guided by the flow rate controlling plate will flow towards a portion of a chucked wafer adjacent the edge sensor to thereby cool the portion of the wafer and compensate for a relatively high temperature condition created at the region of the edge sensor by the operation of the edge sensor.