Method and apparatus for reducing plasma-induced damage in a semiconductor device

Abstract

Some embodiments discussed relate to an apparatus for etching a semiconductor wafer and method for fabricating it, comprising a plurality of electrodes coupled to a power supply for generating a plasma stream and at least one electromagnetic radiation source and a wafer support to position a wafer for etching using the plasma stream and the wafer support having a plurality of apertures to allow passage of electromagnetic radiation from an electromagnetic radiation source through the wafer support to impinge on a surface of the wafer during etching.

1 . An apparatus comprising:
 a plurality of electrodes coupled to a power supply for generating a plasma stream for etching a semiconductor wafer;   at least one electromagnetic radiation source; and   a wafer support to position a wafer while etching using the plasma stream, the wafer support coupled to ground and configured to drain charge accumulation on a surface of the semiconductor wafer during etching and having a plurality of apertures configured to allow passage of electromagnetic radiation from the at least one electromagnetic radiation source through a window and the wafer support to impinge on a surface of the wafer during etching.   
   
   
       2 . The apparatus of  claim 1 , wherein at least some of the electromagnetic radiation has a wavelength between about 400 nm and about 1500 nm. 
   
   
       3 . The apparatus of  claim 1 , wherein the plasma stream is generated using a gas mixture comprising a material selected from the group consisting of Argon, CF 4 , CHF 3 , BCl 3 , Nitrogen, Fluorine, Chlorine, Bromine, Oxygen and Sodium. 
   
   
       4 . The apparatus of  claim 1 , wherein the electromagnetic radiation impinges on a bottom surface of the wafer. 
   
   
       5 . The apparatus of  claim 4 , further comprising a mirror adapted to reflect the electromagnetic radiation generated by the plasma onto the surface of the wafer. 
   
   
       6 . The apparatus of  claim 4 , wherein the wafer support is conductively coupled to a source of reference potential. 
   
   
       7 . The apparatus of  claim 4 , wherein at least some apertures of the plurality of apertures are circular. 
   
   
       8 . The apparatus of  claim 4 , wherein at least some apertures of the plurality of apertures are hexagonal. 
   
   
       9 . The apparatus of  claim 4 , wherein at least some apertures of the plurality of apertures are rectangular. 
   
   
       10 . An apparatus comprising:
 a plasma stream generated in a chamber for etching a semiconductor wafer, the chamber having a gas mixture;   a wafer support supporting a substrate and coupled to around and configured to drain charge accumulation in the semiconductor wafer during etching, the substrate having a first surface positioned in the plasma stream and a second surface disposed over the wafer support;   a first electromagnetic radiation beam configured to illuminate the first surface of the substrate; and   a second electromagnetic radiation beam configured to illuminate the second surface of the substrate through a window in the chamber.   
   
   
       11 . The apparatus of  claim 10 , wherein the wafer support has a plurality of apertures to allow passage of the second electromagnetic radiation beam through the window in the chamber and the wafer support to impinge on the second surface of the substrate during etching of the first surface of the substrate. 
   
   
       12 . The apparatus of  claim 10 , wherein the plasma stream is generated using the gas mixture comprising a material selected from the group consisting of Argon, CF 4 , CHF 3 , BCl 3 , Nitrogen, Fluorine, Chlorine, Bromine, Oxygen and Sodium. 
   
   
       13 . The apparatus of  claim 11 , wherein at least some apertures of the plurality of apertures are circular. 
   
   
       14 . The apparatus of  claim 11 , wherein at least some apertures of the plurality of apertures are hexagonal. 
   
   
       15 . The apparatus of  claim 11 , wherein at least some apertures of the plurality of apertures are rectangular. 
   
   
       16 - 20 . (canceled) 
   
   
       21 . The apparatus of  claim 10 , wherein the first electromagnetic radiation beam comprising electromagnetic radiation having at least one of the wavelengths between about 400 nm and about 1500 nm. 
   
   
       22 . The apparatus of  claim 10 , wherein the second electromagnetic radiation bean comprising electromagnetic radiation having at least one of the wavelengths between about 400 nm and about 1500 nm. 
   
   
       23 . The apparatus of  claim 10 , wherein the wafer support including an electrode, wherein the electrode is coupled to a power supply. 
   
   
       24 . The apparatus of  claim 1 , wherein the wafer support including an electrode, wherein the electrode is coupled to a power supply. 
   
   
       25 . A system, comprising:
 a plurality of electrodes coupled to a power supply and configured to generate a plasma stream in a chamber;   an electromagnetic radiation source; and   a wafer support configured to support a semiconductor substrate and coupled to ground and configured to drain charge accumulation on a surface of the semiconductor wafer during etching, wherein the wafer support includes a plurality of apertures adapted to provide illumination on a surface of the semiconductor substrate using the electromagnetic radiation source and the electromagnetic radiation generated by the electromagnetic radiation source passes through a window in the chamber.