Oven for Semiconductor Wafer

Abstract

An oven is described that can more evenly heat the semiconductor wafer, even though the wafer may warp during heating. The oven may provide relatively uniform heating even though the type and location of warping may be unpredictable for any given wafer. The oven may have a heating surface divided into a plurality of heating zones that may each independently provide a given amount of heat to the wafer. The amount of heat provided by each zone may be determined using signals from sensors that sense the warping of the wafer.

What is claimed is: 
     
         1 . A method for heating a semiconductor wafer, comprising:
 first applying a first amount of heat to the semiconductor wafer;   sensing whether the semiconductor wafer has a warp;   in response to sensing that the semiconductor wafer has a warp, applying a second amount of heat to the semiconductor wafer, wherein the second amount of heat is different from the first amount of heat; and   in response to sensing that the semiconductor wafer does not have a warp, second applying the first amount of heat to the semiconductor wafer.   
     
     
         2 . The method of  claim 1 , wherein the step of second applying comprises applying, simultaneously, the second amount of heat to a first portion of the semiconductor wafer and the first amount of heat to a different second portion of the semiconductor wafer. 
     
     
         3 . The method of  claim 2 , further including third applying a third amount of heat to a third portion of the semiconductor wafer different from the first and second portions, simultaneously with application of the first and second amounts of heat. 
     
     
         4 . The method of  claim 2 , further including determining the first portion based on a location of the warp. 
     
     
         5 . The method of  claim 1 , wherein the step of sensing includes sensing whether a gap exists between the semiconductor wafer and a heating surface.