Photolithography focus improvement by reduction of autofocus radiation transmission into substrate

Abstract

An anti-reflective coating material, a microelectronic structure that includes an anti-reflective coating layer formed from the anti-reflective coating material and a related method for exposing a resist layer located over a substrate while using the anti-reflective coating layer provide for attenuation of secondary reflected vertical alignment beam radiation when aligning the substrate including the resist layer located thereover. Such enhanced vertical alignment provides for improved dimensional integrity of a patterned resist layer formed from the resist layer, as well as additional target layers that may be fabricated while using the resist layer as a mask.

1 . An anti-reflective coating material comprising a composition of matter that exhibits a first absorption peak in a wavelength range greater than about 800 nanometers, the first absorption peak corresponding with an exposure apparatus vertical alignment beam wavelength. 
   
   
       2 . The anti-reflective coating material of  claim 1  wherein the first absorption peak is in a range from about 900 nanometers to about 1200 nanometers. 
   
   
       3 . The anti-reflective coating material of  claim 1  wherein the composition of matter further exhibits a second absorption peak in a wavelength range less than about 300 nanometers, that corresponds with an exposure wavelength of the exposure apparatus. 
   
   
       4 . The anti-reflective coating material of  claim 3  wherein:
 the first absorption peak has a first absorbance greater than about 0.4; and   the second absorption peak has a second absorbance from about 0.1 to about 0.7.   
   
   
       5 . The anti-reflective coating material of  claim 4  wherein the first absorbance is greater than the second absorbance. 
   
   
       6 . The anti-reflective coating material of  claim 4  wherein the second absorbance is greater than the first absorbance. 
   
   
       7 . The anti-reflective coating material of  claim 3  wherein the composition of matter does not exhibit a third absorption peak interposed between the first absorption peak and the second absorption peak. 
   
   
       8 . The anti-reflective coating material of  claim 1  wherein the composition of matter includes an organic polymer base material and an infrared absorbing dye contained within the organic polymer base material. 
   
   
       9 . A microelectronic structure comprising:
 a substrate;   a resist layer located over the substrate; and   an anti-reflective coating layer also located over the substrate, where the anti-reflective coating layer includes a composition of matter that exhibits a first absorption peak corresponding with an exposure apparatus vertical alignment beam wavelength.   
   
   
       10 . The microelectronic structure of  claim 9  wherein the anti-reflective coating layer is located interposed between the resist layer and the substrate. 
   
   
       11 . The microelectronic structure of  claim 9  wherein the resist layer is located interposed between the anti-reflective coating layer and the substrate. 
   
   
       12 . The microelectronic structure of  claim 9  wherein the resist layer and the anti-reflective coating layer comprise a single layer. 
   
   
       13 . The microelectronic structure of  claim 9  wherein the first absorption peak is in a range greater than about 800 nanometers. 
   
   
       14 . The microelectronic structure of  claim 13  wherein:
 the composition of matter exhibits a second absorption peak corresponding with an exposure wavelength; and   the exposure wavelength is less than about 300 nanometers.   
   
   
       15 . The microelectronic structure of  claim 14  wherein the composition of matter does not exhibit a third absorption peak interposed between the first absorption peak and the second absorption peak. 
   
   
       16 . The microelectronic structure of  claim 15  wherein the composition of matter has an absorbance less than about 0.1 interposed between the first absorption peak and the second absorption peak. 
   
   
       17 . A method for exposing a resist layer comprising:
 forming layered over a substrate a target layer, an anti-reflective layer located over the target layer and a resist layer also located over the target layer to form a layered substrate, the anti-reflective coating layer including a composition of matter that exhibits a first absorption peak corresponding with an exposure apparatus vertical alignment beam wavelength;   vertically aligning the layered substrate within an exposure apparatus while using an exposure apparatus vertical alignment beam and horizontally aligning the layered substrate within the exposure apparatus while using an exposure apparatus horizontal alignment beam to yield an aligned layered substrate; and   exposing the resist layer within the aligned layered substrate within the exposure apparatus while using an exposure beam.   
   
   
       18 . The method of  claim 17  further comprising:
 developing the resist layer to form a patterned resist layer; and   treating the target layer while using the patterned resist layer as a mask.   
   
   
       19 . The method of  claim 17  wherein the first absorption peak is in a range greater than about 800 nanometers. 
   
   
       20 . The method of  claim 19  wherein:
 the composition of matter exhibits a second absorption peak corresponding with an exposure wavelength; and   the exposure wavelength is less than about 300 nanometers.   
   
   
       21 . The method of  claim 20  wherein the composition of matter does not exhibit a third absorption peak interposed between the first absorption peak and the second absorption peak. 
   
   
       22 . The method of  claim 17  wherein the anti-reflective coating layer is interposed between the resist layer and the target layer. 
   
   
       23 . The method of  claim 17  wherein the resist layer is interposed between the anti-reflective coating layer and the target layer. 
   
   
       24 . A method for exposing a resist layer comprising:
 positioning within an exposure apparatus a microelectronic structure that includes a reflective layer located over a substrate and a resist layer located over the reflective layer;   vertically aligning the microelectronic structure within the exposure apparatus while attenuating a reflection of a vertical alignment beam from the reflective layer, to provide an aligned substrate; and   exposing the aligned substrate within the exposure apparatus.   
   
   
       25 . The method of  claim 24  wherein the resist layer comprises an infrared absorptive dye.