Reversible photo bleachable materials based on nano sized semiconductor particles and their optical applications

Abstract

Semiconductor nano-particles, due to their specific physical properties, can be used as reversible photo-bleachable materials for a wide spectrum, from far infrared to deep UV. Applications include, reversible contrast enhancement layer (R-CEL) in optical lithography, lithography mask inspection and writing and optical storage technologies.

1 . A reversible photo-bleachable material comprising semiconductor nano-sized particles. 
   
   
       2 . The material of  claim 1  wherein said semiconductor comprises: C, Si, Ge, CuCl, CuBr, CuI, AgCl, AgBr, AgI, Ag 2 S, CaO, MgO, ZnO, Mg x Zn 1-x O, ZnS, HgS, ZnSe, CdS, CdSe, CdTe, HgTe, PbS, BN, AlN, GaN, Al x Ga 1-x N, GaP GaAs, GaSb, InP, InAs, In x Ga 1-x As, SiC, Si 1-x Ge x, Si   3 N 4 , ZrN, CaF 2 , YF 3 , Al 2 O 3 , SiO 2 , TiO 2 , Cu 2 O, Zr 2 O 3 , ZrO 2 , SnO 2 , YSi 2 , GalnP 2 , Cd 3 P 2 , Fe 2 S, Cu 2 S, Culn 2 S 2 , MoS 2 , In 2 S 3 , Bi 2 S 3 , Culn 2 Se 2 , In 2 Se 3 , Hgl 2 , Pbl 2  and their various isomers and alloys. 
   
   
       3 . The material of  claim 1  wherein said nano-particles are in spherical, cubical, rod-like, tetragonal, single or multi-wall nano-tube or other nano-scale geometric shapes. 
   
   
       4 . The material of  claim 1  wherein said nano-particles are immersed in polymer matrix or other chemicals. 
   
   
       5 . The materials of  claim 1  wherein the nano-particles are doped with other elements. 
   
   
       6 . The materials of  claim 1  wherein the nano-particles are coated with other semiconductors or chemicals. 
   
   
       7 . A method of using reversible photo-bleachable material to create images or patterns with higher resolution than diffraction limit allows. 
   
   
       8 . A method of adjusting the relaxation time of the reversible photo-bleachable material comprising a mechanism to separate at least part of the photo-generated electrons and holes. 
   
   
       9 . A method of  claim 8  wherein said mechanism comprises providing carrier accepting surface states in said nano-particles. 
   
   
       10 . A method of  claim 8  wherein said mechanism comprises providing chemical surfactant at the surface of said nano-particles. 
   
   
       11 . A method of  claim 8  wherein said mechanism comprises providing two types of nano-particles with different band-gaps. 
   
   
       12 . A method of  claim 8  wherein said mechanism comprises providing coating of another semiconductor with different band-gap at the surface of said nano-particles. 
   
   
       13 . A method of  claim 8  wherein said mechanism comprises providing n-type nano-particle in a p-type polymer matrix. 
   
   
       14 . A method of  claim 8  wherein said mechanism comprises providing p-type nano-particle in an n-type polymer matrix. 
   
   
       15 . A method of  claim 8  wherein said mechanism comprises providing n-type nano-particle or p-type nano-particles in a non-doped polymer matrix. 
   
   
       16 . A method of  claim 8  wherein said mechanism comprises Auger recombination of multiple electron and hole pairs in said nano-particles. 
   
   
       17 - 29 . (canceled) 
   
   
       30 . A method of inspecting a lithography mask, said method comprising:
 providing R-CEL based on reversible photo-bleachable material on said mask; and   photo detectors detecting reflection or transmission of illumination of said mask.   
   
   
       31 . The method of  claim 30  wherein said illumination passes though a layer including said nano-particles before reaching said mask. 
   
   
       32 - 33 . (canceled) 
   
   
       34 . An optical storage device comprising:
 a substrate having optically-scannable information-bearing indicia thereon; and   a reversible contrast enhancement layer based on reversible photo-bleachable material disposed on at least part of said substrate.   
   
   
       35 . The optical storage device of  claim 34  wherein said reversible contrast enhancement layer contains nano-particles.