Integrated optic devices and processes for the fabrication of integrated optic devices

Abstract

Processes for fabricating integrated optics devices are provided. According to one process, a photosensitive sol-gel glass material including a volatile photosensitizer is prepared. A film of the sol-gel is then produced on a substrate. The film is then imprinted with an image of an optical device by exposing the photosensitive sol-gel film to light energy patterned in the negative or positive image of the desired device, thereby photolyzing photosensitizer within the exposed portion in proportion to the amount of light energy delivered. The image of the written optical device is then fixed in the exposed film, thereby forming a planar device layer having an embedded optical device. The photoinduced refractive index change between the optical device and the surrounding region is preferably greater than or equal to 0.001. A variety of passive and active integrated optic devices may be fabricated using the disclosed processes and are also described.

1 . A process for fabricating an integrated optic device, comprising: 
 a. preparing a photosensitive sol-gel glass material that includes a highly volatile photosensitizer;    b. producing a film of said photosensitive sol-gel on at least a portion of a substrate;    c. imprinting said photosensitive sol-gel film with an image of an optical device by exposing at least a portion of said photosensitive sol-gel film to light energy patterned in the positive or negative image of said device to photolyze photosensitizer within the exposed portion; and    d. fixing the image of said optical device in said exposed sol-gel film to thereby form a planar device layer having an embedded optical device.    
     
     
         2 . The process according to  claim 1 , wherein preparing said photosensitive sol-gel glass material comprises the steps of a.) forming a sol-gel by mixing a metal alkoxide, water, and a polysilane plasticizer, b.) adding said highly volatile photosensitizer to the sol-gel, said photosensitizer including a photo labile moiety and an inorganic glass modifying constituent; and c) mixing said photosensitizer with said sol-gel.  
     
     
         3 . The process of  claim 1 , wherein said photosensitizer is an organometallic photosensitizer having the form R-M-X, wherein R is a branched, unbranched or cyclo-alkyl group each of less than 20 carbons, M is a metal or semi-metal, and X is a photo labile moiety selected from the group of halogens and carbonyls (CO).  
     
     
         4 . The process of  claim 3 , wherein M is a metal selected from the Group IVA, VA, VIA, VIIA, VIIIA, IIB, IIIB, IVB, and VIB metals and rare earth metals or a semi-metal selected from the semi-metals within the Group IIIB, IVB, VB, and VIB elements.  
     
     
         5 . The process of  claim 4 , wherein M is selected from the group consisting of Ge, Sn, Pb, Se, Te, Fe, Co, Ni, Ti, Zn, Nd, Er, Eu, Pr, Th, B, Si, and P.  
     
     
         6 . The process of  claim 3 , wherein said X is selected from the group consisting of: fluorine, chlorine bromine, iodine and carbonyl (CO).  
     
     
         7 . The process of  claim 3 , wherein the photosensitizer is selected from the group consisting of trimethyl-tin-iodide, cyclopentadienyl titanium dichloride and iron pentacarbonyl.  
     
     
         8 . The process of claims  1  or  3 , wherein said photosensitizer has a vapor pressure greater than or equal to approximately 20 mm Hg at 25° C.  
     
     
         9 . The process of claims  1  or  3 , wherein said photosensitizer has a vapor pressure greater than or equal to approximately 40 mm Hg at 25° C.  
     
     
         10 . The process of  claim 1 , wherein said imprinting step comprises exposing said photosensitive sol-gel film to light energy passed through a photolithography mask.  
     
     
         11 . The process of  claim 10 , wherein said photolithography mask comprises a binary mask, a gray scale mask, or a phase mask.  
     
     
         12 . The process of  claim 1 , wherein said photosensitive sol-gel film is imprinted with said device image using a laser writing process.  
     
     
         13 . The process of  claim 1 , further comprising using a light source having a wavelength in the range of 150 to 700 nm to produce the light energy.  
     
     
         14 . The process of  claim 13 , wherein said light source is an arc lamp or a laser.  
     
     
         15 . The process of  claim 14 , wherein said light source is selected from the group consisting of a mercury discharge lamp, a frequency multiplied YAG laser, a frequency multiplied Nd:YAG laser, an excimer laser, and an argon ion laser.  
     
     
         16 . The process according to  claim 15 , wherein said light source is an excimer laser selected from the group consisting of a KrF excimer laser and a ArF excimer laser.  
     
     
         17 . The process according to  claim 1 , wherein said device layer is at least 2 μm thick and is less than or equal to 20 μm thick.  
     
     
         18 . The process according to  claim 17 , further comprising forming said device layer from a single photosensitive sol-gel film.  
     
     
         19 . The process according to  claim 18 , wherein said photosensitive sol-gel film is at least 4 μm thick.  
     
     
         20 . The process according to  claim 18 , wherein said photosensitive sol-gel film is at least 6 μm thick.  
     
     
         21 . The process according to  claim 1  or  18 , wherein said preparing step further comprises adding a polysilane plasticizer to said photosensitive sol-gel glass material.  
     
     
         22 . The process according to  claim 21 , wherein said polysilane plasticizer is selected from the group consisting of organotrialkoxysilanes, organotriaminosilanes, and organotrihalosilanes.  
     
     
         23 . The process according to  claim 17 , further comprising forming said device layer from a plurality of photosensitive sol-gel films by repeating steps b, c, and d sequentially at least two times.  
     
     
         24 . The process according to  claim 23 , wherein each of said photosensitive sol-gel films produced in accordance with step b is at least 2 μm thick.  
     
     
         25 . The process according to  claim 23 , wherein each of said photosensitive sol-gel films produced in accordance with step b is at least 4 μm thick.  
     
     
         26 . The process according to  claim 1 , further comprising forming a buffer layer on said substrate prior to producing said photosensitive sol-gel film, and wherein said photosensitive sol-gel film is further produced over said buffer layer.  
     
     
         27 . The process according to  claim 26 , further comprising forming said buffer layer from a sol-gel glass material.  
     
     
         28 . The process according to  claim 26 , wherein said buffer layer is at least 2 μm thick and is less than or equal to 20 μm thick.  
     
     
         29 . The process according to  claim 28 , further comprising forming said buffer layer from a sol-gel glass material including a polysilane plasticizer selected from the group consisting of organotrialkoxysilanes, organotriaminosilanes, and organotrihalosilanes, and forming said buffer layer from a single coating of said sol-gel glass material.  
     
     
         30 . The process according to  claim 1 , further comprising forming a cladding layer over said device layer.  
     
     
         31 . The process according to  claim 30 , further comprising forming said cladding layer from a sol-gel glass material.  
     
     
         32 . The process according to  claim 30 , wherein said cladding layer is at least 2 μm thick and is less than or equal to 20 μm thick.  
     
     
         33 . The process according to  claim 32 , further comprising forming said cladding layer from a sol-gel glass material including a polysilane plasticizer selected from the group consisting of organotrialkoxysilanes, organotriaminosilanes, and organotrihalosilanes, and forming said cladding layer from a single coating of said sol-gel glass material.  
     
     
         34 . The process according to  claim 1 , further comprising forming a protective layer over said device layer, said protective layer forming a moisture barrier layer.  
     
     
         35 . The process according to  claim 34 , wherein said protective layer is from 5 μm thick to 100 μm thick.  
     
     
         36 . The process according to  claim 34 , wherein said protective layer is formed by forming a polymer coating over said device layer.  
     
     
         37 . The process according to  claim 34 , wherein said protective layer is formed by forming a metal coating over said device layer.  
     
     
         38 . The process according to  claim 34 , further comprising forming a cladding layer over said devise layer prior to forming said protective layer.  
     
     
         39 . The process according to  claim 1 , wherein said photosensitive sol-gel film is imprinted with a channel waveguide.  
     
     
         40 . The process according to  claim 1 , wherein said photosensitive sol-gel film is imprinted with at least one optical device selected from the group consisting of a channel waveguide, a coupler, a splitter, a filter, a combiner, a fiber spacing concentrator, a beam expander, a beam concentrator, an optical add-drop, an arrayed waveguide, and a diffraction grating.  
     
     
         41 . The process according to  claim 1 , wherein said fixing step comprises subjecting said exposed sol-gel film to at least one heat treatment within the temperature range of 80° C. to 1000° C.  
     
     
         42 . The process according to  claim 41 , wherein said fixing step includes heating said exposed sol-gel film to a temperature of approximately 80° C. to approximately 150° C. for a time sufficient to evaporate unphotolyzed photosensitizer from the exposed sol-gel film.  
     
     
         43 . The process according to  claim 42 , wherein the unphotolyzed photosensitizer is evaporated in 60 minutes or less.  
     
     
         44 . The process according to  claim 1 , further comprising drying said photosensitive sol-gel film at room temperature prior to said imprinting step.  
     
     
         45 . The process according to  claim 1 , further comprising exposing at least two regions within the exposed portion of the photosensitive sol-gel film to different amounts of light energy, thereby photolyzing different amounts of photosensitizer within each of the regions.  
     
     
         46 . The process according to  claim 1 , wherein said imprinting step comprises delivering sufficient light energy to the exposed portion to result in a photoinduced Δn value of at least 0.07% between the embedded optical device and a surrounding region of said device layer.  
     
     
         47 . The process according to  claim 1 , wherein said imprinting step comprises delivering sufficient light energy to the exposed portion to result in a photoinduced Δn value of at least 0.14% between the embedded optical device and a surrounding region of said device layer.  
     
     
         48 . The process according to  claim 1 , wherein said imprinting step includes writing a continuously graded refractive index region within the exposed portion by continuously grading the amount of light energy delivered to said photosensitive film over said region from a first amount to a second amount.  
     
     
         49 . The process according to  claim 1 , wherein said imprinting step includes writing a quasi-continuously graded refractive index region within the exposed portion by periodically grading the amount of light energy delivered to said photosensitive film over said region from a first amount to a second amount.  
     
     
         50 . The process according to  claim 1 , wherein the substrate comprises a semiconductor substrate.  
     
     
         51 . A process for fabricating an integrated optic device, comprising: 
 a. preparing a photosensitive-sol-gel glass material that includes a highly volatile photosensitizer, said photosensitizer including a photo labile moiety and an inorganic glass modifying constituent;    b. producing a film of said photosensitive sol-gel on at least a portion of a substrate;    c. imprinting said photosensitive sol-gel film with an image of an optical device by exposing at least a portion of said photosensitive sol-gel film to photolyzing light energy patterned in the positive or negative image of said device, thereby photolyzing photosensitizer within the exposed portion and irreversibly binding the photodissociated glass modifying constituents to the sol-gel glass material, wherein the exposed portion comprises at least one region and the amount of light energy delivered to each region within the exposed portion determines the amount of the photosensitizer that is photolyzed within that region; and    d. fixing the image of said optical device in the exposed sol-gel film and thereby forming a planar device layer having an embedded optical device by heating said exposed sol-gel film to evaporate unphotolyzed photosensitizer remaining in said exposed film and to polymerize said exposed sol-gel film to form a glass matrix, said glass matrix being modified in each region of the exposed portion by the inorganic glass modifying constituents photodissociated within that region.    
     
     
         52 . The process of  claim 51 , wherein said photosensitizer is an organometallic photosensitizer having the form R-M-X, wherein R is a branched, unbranched or cyclo-alkyl group each of less than 20 carbons, M is a metal or semi-metal, and X is a photo labile moiety selected from the group of halogens and carbonyls (CO).  
     
     
         53 . The process according to  claim 51 , wherein said device layer is at least 2 μm thick and is less than or equal to 20 μm thick.  
     
     
         54 . The process according to  claim 53 , further comprising forming said device layer from a single photosensitive sol-gel film.  
     
     
         55 . The process according to  claim 54 , wherein said photosensitive sol-gel film is at least 4 μm thick.  
     
     
         56 . The process according to  claim 54 , wherein said photosensitive sol-gel film is at least 6 μm thick.  
     
     
         57 . The process according to  claim 51  or  54 , wherein said preparing step further comprises adding a polysilane plasticizer selected from the group consisting of organotrialkoxysilanes, organotriaminosilanes, and organotrihalosilanes to said photosensitive sol-gel glass material.  
     
     
         58 . The process according to  claim 51 , wherein said photosensitive sol-gel film is imprinted with a waveguide.  
     
     
         59 . The process according to  claim 51 , wherein said fixing step comprises subjecting said exposed sol-gel film to at least one heat treatment within the temperature range of 80° C. to 1000° C.  
     
     
         60 . The process according to  claim 59 , wherein said fixing step includes heating said exposed sol-gel film to a temperature of approximately 80° C. to approximately 150° C. for a time sufficient to evaporate unphotolyzed photosensitizer from the exposed sol-gel film.  
     
     
         61 . The process according to  claim 60 , wherein the unphotolyzed photosensitizer is evaporated in 60 minutes or less.  
     
     
         62 . The process according to  claim 51 , further comprising exposing at least two regions within the exposed portion of the photosensitive sol-gel film to different amounts of light energy, thereby photolyzing different amounts of photosensitizer within each of the regions.  
     
     
         63 . The process according to  claim 51 , wherein said imprinting step includes writing a continuously graded refractive index region within the exposed portion by continuously grading the amount of light energy delivered to said photosensitive film over said region from a first amount to a second amount.  
     
     
         64 . The process according to  claim 51 , wherein said imprinting step includes writing a quasi-continuously graded refractive index region within the exposed portion by periodically grading the amount of light energy delivered to said photosensitive film over said region from a first amount to a second amount.  
     
     
         65 . A process for fabricating an integrated optic device, comprising: 
 a. preparing a photosensitive sol-gel glass material that includes a volatile photo sensitizer;    b. producing a film of said photosensitive sol-gel on at least a portion of a substrate;    c. imprinting said photosensitive sol-gel film with an image of an optical device by exposing at least a portion of said photosensitive sol-gel film to photolyzing light energy patterned in the positive or negative image of said device to photolyze photosensitizer within the exposed portion, wherein the exposed portion comprises at least one region and the amount of light energy delivered to each region within the exposed portion determines the amount of the photosensitizer that is photolyzed within that region; and    d. fixing the image of said optical device in the exposed sol-gel film and thereby forming a planar device layer having an embedded optical device by heating said exposed sol-gel film under a vacuum to evaporate unphotolyzed photosensitizer remaining in said exposed film and to polymerize said exposed sol-gel film to form a glass matrix, said glass matrix being modified in each region of the exposed portion by the inorganic glass modifying constituents photodissociated within that region.    
     
     
         66 . The process of  claim 65 , wherein said photosensitizer is an organometallic photosensitizer having the form R-M-X, wherein R is a branched, unbranched or cyclo-alkyl group each of less than 20 carbons, M is a metal or semi-metal, and X is a photo labile moiety selected from the group of halogens and carbonyls (CO).  
     
     
         67 . The process of  claim 66 , wherein said photosensitizer has a vapor pressure less than 20 mm Hg at 25° C. and wherein the vacuum employed in the fixing step is at least 0.001 Torr.  
     
     
         68 . The process according to  claim 67 , wherein said fixing step includes heating said exposed sol-gel film to a temperature of approximately 80° C. to approximately 150° C. for a time sufficient to evaporate unphotolyzed photosensitizer from the exposed sol-gel film.  
     
     
         69 . The process according to  claim 68 , wherein the unphotolyzed photosensitizer is evaporated in 60 minutes or less.  
     
     
         70 . The process according to  claim 65 , wherein said preparing step further comprises adding a polysilane plasticizer selected from the group consisting of organotrialkoxysilanes, organotriaminosilanes, and organotrihalosilanes to said photosensitive sol-gel glass material, and wherein said device layer is greater than 2 μm thick and is less than or equal to 20 μm thick and is formed from a single photosensitive sol-gel film.  
     
     
         71 . The process according to  claim 70 , wherein said photosensitive sol-gel film is at least 4 μm thick.  
     
     
         72 . The process according to  claim 65 , further comprising exposing at least two regions within the exposed portion of the photosensitive sol-gel film to different amounts of light energy, thereby photolyzing different amounts of photosensitizer within each of the regions.  
     
     
         73 . The process according to  claim 65 , wherein said imprinting step includes writing a continuously graded refractive index region within the exposed portion by continuously grading the amount of light energy delivered to said photosensitive film over said region from a first amount to a second amount.  
     
     
         74 . The process according to  claim 65 , wherein said imprinting step includes writing a quasi-continuously graded refractive index region within the exposed portion by periodically grading the amount of light energy delivered to said photosensitive film over said region from a first amount to a second amount.  
     
     
         75 - 144 . (canceled)