Reference wafer for calibration and method for fabricating the same

Abstract

A reference wafer maintains laser accuracy and calibrates a camera and a laser of a semiconductor equipment. The reference wafer includes a first anti-reflection layer, an adhesive layer, a light absorption layer and a second anti-reflection layer that are stacked over a substrate, a light reflection layer formed over the second anti-reflection layer, and a protection layer formed over the light reflection layer.

1 - 12 . (canceled) 
     
     
         13 . A method for fabricating a reference wafer for calibrating a semiconductor equipment, the method comprising:
 stacking a first anti-reflection layer, an adhesive layer, a light absorption layer and a second anti-reflection layer over a substrate;   stacking a light reflection layer and a protection layer over the second anti-reflection layer;   etching the protection layer by using a photoresist pattern as an etch barrier to form a protection layer pattern having a vertical profile; and   etching the light reflection layer by using the protection pattern as an etch barrier.   
     
     
         14 . The method of  claim 13 , after etching the light reflection layer, further comprising performing a post-treatment process using a H 2 O vapor. 
     
     
         15 . The method of  claim 14 , wherein the post-treatment process is performed in a pressure of approximately 500 mTorr to approximately 5,000 mTorr. 
     
     
         16 . The method of  claim 13 , wherein the protection layer comprises a SiON layer. 
     
     
         17 . The method of  claim 13 , wherein etching the protection layer is performed in a pressure of approximately 10 mTorr to approximately 50 mTorr with a bottom power of approximately 100 W to approximately 500 W. 
     
     
         18 . The method of  claim 13 , wherein the light reflection layer comprises an Al layer. 
     
     
         19 . The method of  claim 13 , further comprising forming a micrograin layer between the light reflection layer and the protection layer. 
     
     
         20 . The method of  claim 19 , wherein the micrograin layer has a grain size smaller than that of the light reflection layer. 
     
     
         21 . The method of  claim 19 , wherein the micrograin layer comprises one of a TiN layer, a Ti layer and a stacked structure of the TiN layer and the Ti layer.