Alignment marker and lithographic apparatus and device manufacturing method using the same

Abstract

An apparatus includes a first support structure configured to support an element that has an alignment marker provided with at least one height difference. The apparatus also includes an alignment sensor comprising a light source that is configured to provide a light beam that illuminates the alignment marker; and at least one detector configured to detect the at least one height difference of the alignment marker by analyzing the light beam reflected by the alignment marker. Such an apparatus may be used to align of the element with respect to the first support structure.

1 . An apparatus comprising: 
 a first support structure configured to support an element, said element including an alignment marker provided with at least one height difference; and    an alignment sensor comprising: 
 a light source configured to provide a light beam that illuminates the alignment marker; and  
 at least one detector arranged to receive a reflection of the light beam from said alignment marker and configured to detect the at least one height difference of the alignment marker, based on the reflection, to enable an alignment of said element.  
   
   
   
       2 . The apparatus according to  claim 1 , wherein said apparatus is configured to align said element with respect to said first support structure based on the at least one height difference.  
   
   
       3 . The apparatus according to  claim 1 , wherein the alignment sensor comprises imaging optics configured to control at least one of the group consisting of a trajectory of said reflection and a characteristic of said reflection.  
   
   
       4 . An apparatus according to  claim 3 , wherein the imaging optics and the at least one detector are configured to align said element by at least one of the group consisting of diffraction, scattering, diffuse reflection, and phase-contrast.  
   
   
       5 . The apparatus according to  claim 1 , wherein the element comprises a patterning structure configured to receive a beam of radiation and to produce a patterned beam having a pattern in its cross-section, said apparatus comprising: 
 an illumination system configured to provide the beam of radiation;    a second support structure configured to support a substrate; and    a projection system configured to project the patterned beam onto a target portion of the substrate.    
   
   
       6 . An apparatus according to  claim 5 , wherein the beam of radiation comprises EUV radiation, and the light beam has a wavelength in a range of about four hundred (400) to fifteen hundred (1500) nanometers.  
   
   
       7 . An apparatus according to  claim 5 , wherein the alignment sensor is independent of the illumination system.  
   
   
       8 . The apparatus according to  claim 5 , wherein the patterning structure comprises a reflective patterning structure and the alignment marker comprises a reflective marker.  
   
   
       9 . The apparatus according to  claim 8 , wherein the reflective marker comprises a reflecting surface upon which, in at least one area, a radiation-absorbing layer is deposited, the radiation-absorbing layer introducing at least one height difference and being arranged to absorb radiation with a wavelength corresponding to a wavelength of the beam of radiation provided by the illumination system.  
   
   
       10 . An apparatus according to  claim 9 , wherein the radiation-absorbing layer has a thickness of about 50 (fifty) to 500 (five hundred) nanometers.  
   
   
       11 . An apparatus according to  claim 9 , wherein the radiation-absorbing layer comprises a material selected from the group consisting of Cr, TaN, TaSiN, TiN and SiMo.  
   
   
       12 . An apparatus according to  claim 1 , wherein the alignment marker comprises at least one marker selected from the group consisting of a single edge marker, a grating, and a grid.  
   
   
       13 . An apparatus according to  claim 1 , wherein the alignment sensor is provided within the apparatus to enable in-situ alignment.  
   
   
       14 . A semiconductor device manufactured using the apparatus of  claim 1 .  
   
   
       15 . A device manufacturing method comprising: 
 patterning a beam of radiation with a patterning structure according to a desired pattern, said patterning structure being supported by a support structure;    projecting the patterned beam of radiation onto a target portion of a substrate; and    prior to said patterning, aligning the patterning structure with respect to the support structure,    wherein said aligning comprises: 
 directing a light beam onto an alignment marker disposed on the patterning structure, said alignment marker including at least one height difference, and  
 detecting the at least one height difference of the marker with at least one detector.  
   
   
   
       16 . A semiconductor device manufactured according to the method of  claim 15 .  
   
   
       17 . A patterning structure comprising: 
 a pattern configured to pattern a beam of radiation within its cross-section; and    an alignment marker;    wherein the pattern and the alignment marker are manufactured in parallel using the same manufacturing process.    
   
   
       18 . A patterning structure according to  claim 17 , wherein the marker is configured to be illuminated by a light beam and wherein the beam of radiation and the light beam have different wavelengths.  
   
   
       19 . A patterning structure according to  claim 18 , wherein the beam of radiation is EUV radiation, and the light beam has a wavelength in a range of 400 (four hundred) to 1500 (fifteen hundred) nanometers.  
   
   
       20 . A method of aligning an element comprising an alignment marker, the alignment marker being provided with at least one height difference, the method comprising: 
 illuminating said alignment marker with a light beam; and    detecting the at least one height difference of the alignment marker based on a reflection of the light beam from said alignment marker.    
   
   
       21 . An apparatus according to  claim 1 , wherein the at least one detector includes at least one of the group consisting of a position-sensitive detector, a quad cell, and a camera having a charge-coupled device.  
   
   
       22 . An apparatus configured to align a patterning structure with respect to a support structure on which the patterning structure is disposed, the apparatus comprising: 
 a light source configured to direct a light beam onto at least one alignment marker arranged on said patterning structure, said light beam having an angle of incidence and a principal angle of reflectance; and    a detector configured to receive a reflection of a portion of the light beam by said at least one alignment marker at an angle other than the principal angle of reflectance.    
   
   
       23 . The apparatus according to  claim 22 , wherein said detector is configured to detect at least one height difference within said at least one alignment marker based on the reflection of a portion of the light beam.  
   
   
       24 . The apparatus according to  claim 22 , said apparatus comprising an imaging system configured to project the reflection of a portion of the light beam onto said detector.  
   
   
       25 . The apparatus according to  claim 22 , wherein said at least one height difference includes an elevation formed by said at least one alignment marker on said patterning structure.