Wafer edge exposure method in semiconductor photolithographic processes, and orientation flatness detecting system provided with a WEE apparatus

1 . A method for exposing an edge of a wafer in a photolithographic process, comprising the steps of:

(a) aligning a notch of the wafer disposed on a wafer chuck of an orientation flatness (OF) detecting system using a wafer notch-detecting sensor;

(b) performing a wafer edge exposure (WEE) process on the notch-aligned wafer;

(c) carrying the wafer to a wafer stage and then performing a wafer EGA alignment; and

(d) exposing the EGA aligned wafer.

2 . The method of claim 1 , further comprising disposing the wafer on the wafer chuck such that a center of the wafer is aligned with a center of the wafer chuck.

3 . The method of claim 1 , wherein step (a) comprises detecting the center of the wafer by a wafer center position detecting sensor unit, before disposing the wafer on the wafer chuck.

4 . The method of claim 1 , wherein step (c) is performed while exposing a preceding wafer.

5 . An orientation flatness (OF) detecting system, comprising:

(a) a wafer loader arm able to carry a wafer;

(b) a wafer center position detecting sensor unit adapted to detect a center of the wafer;

(c) a rotatable wafer chuck on which the wafer is to be disposed;

(d) a wafer notch detecting sensor unit adapted to detect a notch of the wafer; and

(e) a wafer edge exposure (WEE) apparatus including a WEE unit adapted to expose an edge of the wafer disposed on the wafer chuck, and a WEE driving unit able to move the WEE unit.

6 . The OF detecting system of claim 4 , wherein the WEE driving unit is configured to move the WEE unit in a radial direction of the wafer.