Method and apparatus for electrostatically maintaining substrate flatness

Abstract

An apparatus and method for holding a substrate on a support layer in a processing chamber. The method includes the steps of positioning the substrate a predetermined distance from the support layer, introducing a plasma in the processing chamber, lowering the substrate to a point where the substrate engages the support layer, and maintaining the plasma for a predetermined time. The apparatus is directed to a susceptor system for a processing chamber in which a substrate is electrostatically held essentially flat. The apparatus includes a substrate support and a support layer composed of a dielectric material disposed on the substrate support. At least one lift pin is used for supporting the substrate relative to the support layer. Means are provided for moving each lift pin relative to the support layer. Means are also provided for producing a plasma within the processing chamber.

1 . A method for holding a substrate on a support layer in a processing chamber, comprising the steps of: 
 positioning the substrate a predetermined distance from the support layer;    introducing a plate-charge inducing plasma within the processing chamber;    lowering the substrate onto the support layer;    maintaining the plasma for a predetermined time.    
   
   
       2 . The method of  claim 1 , wherein the method further comprise the steps of: 
 introducing a reactive gas in the processing chamber; and    depositing a material from the reactive gas on the substrate.    
   
   
       3 . The method of  claim 1 , wherein the plasma constitutes an inert gas.  
   
   
       4 . The method of  claim 3 , wherein the inert gas is selected from the group consisting of nitrogen, hydrogen, argon, helium, or mixtures thereof.  
   
   
       5 . The method of  claim 3 , wherein the pressure of the gas is in a range of from about 200 mTorr to about 1 Torr.  
   
   
       6 . The method of  claim 3 , wherein the power of the plasma is in a range of from about 100 watts to about 1000 watts.  
   
   
       7 . The method of  claim 3 , wherein the power density of the plasma is in a range of from about 0.02 watts per square centimeter of substrate area to about 0.5 watts per square centimeter of substrate area.  
   
   
       8 . The method of  claim 3 , wherein the power density of the plasma is in a range of from about 0.4 watts per cubic centimeter of chamber volume to about 4 watts per cubic centimeter of chamber volume.  
   
   
       9 . The method of  claim 1 , wherein the substrate is made of glass.  
   
   
       10 . The method of  claim 1 , wherein the substrate is made of ceramic.  
   
   
       11 . The method of  claim 1 , wherein the support layer is a dielectric material.  
   
   
       12 . The method of  claim 11 , wherein the dielectric material is anodized aluminum.  
   
   
       13 . The method of  claim 11 , wherein the dielectric material is alumina (Al 2 O 3 ).  
   
   
       14 . The method of  claim 1 , further comprising the step of depositing a coating on top of the support layer.  
   
   
       15 . The method of  claim 14 , wherein the coating is selected from the group consisting of silicon nitrides, silicon oxides, and mixtures thereof.  
   
   
       16 . A processing chamber including a susceptor system in which a substrate is electrostatically held essentially flat, comprising: 
 a substrate support having a support layer composed of a dielectric material;    at least one lift element positionable at an intermediate height and at a processing height relative to the support layer surface;    means for moving the at least one lift element relative to the support layer, the means operable to maintain the substrate at either of the heights, the moving means receiving commands from a controller; and    means for producing a plate-charge inducing plasma within the processing chamber while the substrate is at least in the intermediate position.    
   
   
       17 . The susceptor system of  claim 16 , wherein the dielectric material is anodized aluminum.  
   
   
       18 . The susceptor system of  claim 16 , wherein the dielectric material is alumina (Al 2 O 3 ).  
   
   
       19 . The susceptor system of  claim 16 , further comprising a coating disposed on top of the support layer.  
   
   
       20 . The susceptor system of  claim 19 , wherein the coating is selected from the group consisting of silicon nitrides, silicon oxides, or mixtures thereof.  
   
   
       21 . A method for processing a substrate in a processing chamber, comprising the steps of: 
 positioning the substrate a predetermined distance from a support layer;    starting a plasma in the processing chamber;    lowering the substrate to a point where the substrate engages the support layer;    maintaining the plasma for a predetermined time; and    depositing or growing a thin film on the substrate.