REVERSIBLE PHOTO BLEACHABLE MATERIALS BASED ON NANO SIZED SEMICONDUCTOR PARTICLES AND THEIR OPTICAL APPLICATIONS
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.