Wafer structure and spray apparatus

Abstract

A wafer structure and a spray apparatus are provided. An exemplary wafer structure includes a wafer having a central region and a peripheral region surrounding the central region; an interlayer dielectric layer on a surface of the wafer in the central region not in the peripheral region; a buffer layer on the surface of the wafer in the peripheral region not in the central region; and a glue layer on the interlayer dielectric layer and the buffer layer. The buffer layer is used to reduce the lattice mismatch between the wafer and the glue layer; and reduce the stress between the wafer and the glue layer.

What is claimed is: 
     
         1 . A wafer structure, comprising:
 a wafer having a central region and a peripheral region surrounding the central region;   an interlayer dielectric layer formed on a surface of the wafer in the central region not in the peripheral region;   a buffer layer formed on the surface of the wafer in the peripheral region not in the central region; and   a glue layer formed on the interlayer dielectric layer and the buffer layer,.   wherein the buffer layer is used to reduce the lattice mismatch between the wafer and the glue layer; and reduce the stress between the wafer and the glue layer.   
     
     
         2 . The wafer structure according to  claim 1 , wherein:
 the interlayer dielectric layer is made of silicon oxide; and   the buffer layer is made of silicon oxide.   
     
     
         3 . The wafer structure according to  claim 1 , wherein:
 a thickness of the buffer layer is in a range of approximately 2 nm-5 nm.   
     
     
         4 . The wafer structure according to  claim 1 , wherein:
 the glue layer is made of one of TiN and Ti.   
     
     
         5 . A spray apparatus, comprising:
 a chunk, configured to hold a wafer having a central region and a peripheral region surrounding the central region;   a spray nozzle, disposed over the chunk and configured to spray a liquid to the wafer on the chunk to form a buffer layer on a surface of the wafer in the peripheral region not in the central region; and   a mixing pump, connected with the spray nozzle and configured to feed the liquid to the spray nozzle.   
     
     
         6 . The spray apparatus according to  claim 5 , wherein:
 the chunk is a movable chunk rotating around a central axis of the wafer.   
     
     
         7 . The spray apparatus according to  claim 5 , wherein:
 a rotating speed of the chunk is in a range of approximately  60  rpm/min- 300  rpm/min.   
     
     
         8 . The spray apparatus according to  claim 5 , wherein the liquid is an ozone water, the mixing pump comprises:
 a first inlet, configured to feed ozone gas;   a second inlet, configured to feed DI water; and   a mixing chamber, configured to mix the ozone gas and the DI water to form the ozone water.   
     
     
         9 . The spray apparatus according to  claim 5 , further comprising:
 a nozzle frame, configured to fix a position of the spray nozzle; and   a motor, connected with the nozzle frame and configured to control a relative position between the nozzle and the chunk.   
     
     
         10 . The spray apparatus according to  claim 9 , wherein:
 the motor is a step motor.   
     
     
         11 . The spray apparatus according to  claim 5 , further comprising:
 an enclosure surrounding the chunk, configured to prevent a splashing when the spray nozzle is spraying the liquid.   
     
     
         12 . The spray apparatus according to  claim 11 , wherein:
 the enclosure is an escalated structure, configured to enclose the chunk when the spray nozzle is spraying the liquid at a first position, and expose the chunk for conveniently changing wafer when the spray nozzle is at a second position and not spraying the liquid,   wherein the first positon is above the second position.   
     
     
         13 . The spray apparatus according to  claim 5 , further comprising:
 a recycling unit under the chunk, configured to recycle un-used liquid.