Method for producing a micro optical semiconductor lens

Claim 3

The method as recited in claim 1, wherein the step of coating the layer of photoresist material over the entire surface of the side of the substrate wafer further comprises the step of providing the substrate wafer of a material selected from the group consisting of indium phosphide, gallium arsenide, indium arsenide, and gallium phosphide.

Claim 4

The method as recited in claim 1, wherein the step of coating the layer of photoresist material further comprises the step of providing the photoresist material from the group consisting of 2-ethoxyethylacetate+n-butyl acetate in xylen, 2-ethoxyethylacetate+n-butyl acetate in xylen and hexamethyldisilozane, 2-ethoxyethylacetate+n-butyl acetate in xylen and silicon dioxide (SiO 2 ), and 2-ethoxyethylacetate+n-butyl acetate in xylen and silicon nitride (Si 3 N 4 ), silicon dioxide (SiO 2 ) and complex silicon nitride (Si x N y ), or aluminum oxide (Al 2 O 3 ).

Claim 5

The method as recited in claim 1, wherein the step of baking the substrate wafer further comprises the step of soft baking the substrate wafer at a temperature of approximately 100° C.

Claim 6

The method as recited in claim 1, wherein the step of baking the substrate wafer further comprises the step of soft baking the substrate wafer for a period of approximately 45 minutes.

Claim 7

The method as recited in claim 1, wherein the step of providing the mask to determine the quantity and shape of the lens formed on the substrate wafer farther comprises the step of providing the mask to form an array of lenses.

Claim 8

The method as recited in claim 1, wherein the step of providing the mask to determine the quanitity and shape of the lens formed on the substrate wafer further comprises the step of providing the mask to render the lens shape spherical.

Claim 9

The method as recited in claim 1, wherein the step of providing the mask to determine the quantity and shape of the lens formed on the substrate wafer further comprises the step of providing the mask to render the lens shape semi-spherical.

Claim 10

The method as recited in claim 1, wherein the step of providing the mask to determine the quantity and shape of the lens formed on the substrate wafer further comprises the step of providing the mask to render the lens shape aspherical.

Claim 11

The method as recited in claim 1, wherein the step providing the mask to determine the quantity and shape of the lens formed on the substrate wafer further comprises the step of providing the mask to render the lens shape semi-cylindrical.

Claim 12

The method as recited in claim 1, wherein the step of providing the mask to determine the quantity and shape of the lens formed on the substrate wafer further comprises the step of providing the mask to render the lens shape gausian-cylindrical.

Claim 13

The method as recited in claim 1, wherein the step of selectively etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of wet chemical etching.

Claim 14

The method as recited in claim 1, wherein the step of selectively etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises providing a wet-chemical etch solution selected from the group consisting of deionized water:potassium dichromate:acetic acid:hydrobromic acid (H 2 O:K 2 Cr 2 O 7 :H 3 CCOOH:HBr), bromine:methanol (Br 2 :H 3 COH), bromine:isopropanol (Br 2 :H 5 C 2 OH), deionized water:hydrobromic acid:acetic acid (H 2 O:HBr:H 3 CCOOH), deionized water:potassium dichromate:sulfuric acid:hydrochloric acid (H 2 O:K 2 Cr 2 O 7 :H 2 SO 4 :HCl), phosphoric acid:hydrochloric acid (H 3 PO 4 :HCl), phosphoric acid:hydrochloric acid:deionized water (H 3 PO 4 :HCl:H 2 O), phosphoric acid:hydrochloric acid:hydrogen peroxide (H 3 PO 4 :HCl:H 2 O 2 ), iron chloride:hydrochloric acid (FeCl 3 :HCl) under illumination, potassium periodide:hydrochloric acid (KIO 3 :HCl), hydrochloric acid:acetic acid:hydrogen peroxide (HCl:acetic acid:H 2 O 2 ), hydrochloric acid:hydrogen peroxide:deionized water (HCl:H 2 O 2 :H 2 O), sulfuric acid:hydrogen peroxide:deionized water (H 2 SO 4 :H 2 O 2 :H 2 O), citric acid:hydrogen peroxide:deionized water (citric acid:H 2 O 2 :H 2 O), bromine:methanol (Br 2 :CH 3 OH), nitric acid:hydrofloric acid:deionized water (HNO 3 :HF:H 2 O), and hydrogen peroxide:amonium hydroxide:deionized water (H 2 O 2 :NH 4 OH:H 2 O).

Claim 15

The method as recited in claim 1, wherein the step of selectively etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of dry etching.

Claim 16

The method as recited in claim 1, wherein the step of selectively etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises providing a dry etch mixture selected from the group consisting of argon and hydrochloric acid (Ar/HCl), argon hydrogen and chlorine (Ar/Cl 2 /H 2 ), argon and hydrobromic acid (Ar/Hbr), argon and bromine (Ar/Br 2 ), argon and chlorine (Ar/Cl 2 ), argon and methane and hydrogen (Ar/CH 4 /H 2 ), methyl iodide (H 3 CI), bromine iodide (IBr 3 ), methane and hydrogen and sulfur flouride (CH 4 /H 2 /SF 6 ), ethyl iodide (C 2 H 5 I), isoethyl iodide (C 3 H 7 I), hexaflouride carbon and hydrogen(C 2 F 6 /H 2 ), and dichloro-difluoro carbon and oxygen (CCl 2 F 2 /O 2 ).

Claim 17

The method as recited in claim 1, wherein the step of dry etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of using electron cyclotron resonance (ECR) etching.

Claim 18

The method as recited in claim 1, wherein the step of dry etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of using inductive couple plasma (ICP) etching.

Claim 19

The method as recited in claim 1, wherein the step of dry etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of using reactive-ion (RIE) etching.

Claim 20

The method as recited in claim 1, wherein the step of selectively etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of etching the surface of the side of the substrate wafer at a temperature of from 40° C. to 60° C.

Claim 21

The method as recited in claim 1, wherein the step of removing the photoresist mask and cleaning the surface of the substrate wafer comprises the steps of: removing the photoresist mask using a solution of acetone; removing the acetone from the surface of the substrate using isopropanol; removing the isopropanol from the surface of the substrate using deionized water; removing oxides from the surface of the substrate using potassium hydroxide (KOH); and removing etching solution from the surface of the substrate using a solution of sulfuric acid:hydrogen peroxide:deionized water (H 2 SO 4 :H 2 O 2 :H 2 O).

Claim 22

The method as recited in claim 1, wherein the step of selectively etching the entire surface of the side of the substrate wafer to form the lens further comprises providing a wet-chemical etch solution selected from the group consisting of deionized water:potassium dichromate:acetic acid:hydrobromic acid (H 2 O:K 2 Cr 2 O 7 :H 3 CCOOH:HBr), bromine:methanol (Br 2 :H 3 COH), bromine:isopropanol (Br 2 :H 5 C 2 OH), deionized water:hydrobromic acid:acetic acid (H 2 O:HBr:H 3 CCOOH), deionized water:potassium dichromate:sulfuric acid:hydrochloric acid (H 2 O:K 2 Cr 2 O 7 :H 2 SO 4 :HCl), phosphoric acid:hydrochloric acid (H 3 PO 4 :HCl), phosphoric acid:hydrochloric acid:deionized water (H 3 PO 4 :HCl:H 2 O), phosphoric acid:hydrochloric acid:hydrogen peroxide (H 3 PO 4 :HCl:H 2 O 2 ), iron chloride:hydrochloric acid (FeCl 3 :HCl) under illumination, potassium periodide:hydrochloric acid (KIO 3 :HCl), hydrochloric acid:acetic acid:hydrogen peroxide (HCl:acetic acid:H 2 O 2 ), hydrochloric acid:hydrogen peroxide:deionized water (HCl:H 2 O 2 :H 2 O), sulfuric acid:hydrogen peroxide:deionized water (H 2 SO 4 :H 2 O 2 :H 2 O), citric acid:hydrogen peroxide:deionized water (citric acid:H 2 O 2 :H 2 O), bromine:methanol (Br 2 :CH 3 OH), nitric adic:hydrofloric acid:deionized water (HNO 3 :HF:H 2 O), and hydrogen peroxide:amonium hydroxide:deionized water (H 2 O 2 :NH 4 OH:H 2 O).

Claim 23

The method as recited in claim 1, wherein the step of selectively etching the entire surface of the side of the substrate wafer to form the lens further comprises the step of etching the surface of the side of the substrate wafer at a temperature of from 30° C. to 40° C.

Claim 24

The method as recited in claim 1, wherein the step of coating the entire surface of the substrate wafer with the antireflectivity coating further comprises using a coating process selected from the group consisting of e-beam evaporation, sputtering, and chemical vapor deposition.

Claim 25

The method as recited in claim 1, wherein the step of coating the entire surface of the substrate wafer with the antireflectivity coating further comprises the step of depositing at least one layer of antireflectivity coating containing magnesium flouride (MgF), aluminum oxide (Al 2 O 3 ), hafnium flouride (HfF), silicon dioxide (SiO 2 ), and silicon nitride (Si 3 N 4 ).

Claim 28

The method as recited in claim 25, wherein the step of cleaning the surface of the substrate wafer comprises the steps of: removing oxides from the surface of the substrate using potassium hydroxide (KOH); and removing etch residue from the surface of the substrate using a solution of sulfuric acid:hydrogen peroxide:deionized water (H 2 SO 4 :H 2 O 2 :H 2 O).

Claim 29

The method as recited in claim 25, wherein the step of selectively etching the surface of the side of the substrate wafer to polish the lens further comprises providing a wet-chemical etch solution selected from the group consisting of deionized water:potassium dichromate:acetic acid:hydrobromic acid (H 2 O:K 2 Cr 2 O 7 :H 3 CCOOH:HBr), bromine:methanol (Br 2 :H 3 COH), bromine:isopropanol (Br 2 :H 5 C 2 OH), deionized water:hydrobromic acid:acetic acid (H 2 O:HBr:H 3 CCOOH), deionized water:potassium dichromate:sulfuric acid:hydrochloric acid (H 2 O:K 2 Cr 2 O 7 :H 2 SO 4 :HCl), phosphoric acid:hydrochloric acid (H 3 PO 4 :HCl), phosphoric acid:hydrochloric acid:deionized water (H 3 PO 4 :HCl:H 2 O), phosphoric acid:hydrochloric acid:hydrogen peroxide (H 3 PO 4 :HCl:H 2 O 2 ), iron chloride:hydrochloric acid (FeCl 3 :HCl) under illumination, potassium periodide:hydrochloric acid (KIO 3 :HCl), hydrochloric acid:acetic acid:hydrogen peroxide (HCl:acetic acid:H 2 O 2 ), hydrochloric acid:hydrogen peroxide:deionized water (HCl:H 2 O 2 :H 2 O), sulfuric acid:hydrogen peroxide:deionized water (H 2 SO 4 :H 2 O 2 :H 2 O), citric acid:hydrogen peroxide:deionized water (citric acid:H 2 O 2 :H 2 O), bromine:methanol (Br 2 :CH 3 OH), nitric acid:hydrofloric acid:deionized water (HNO 3 :HF:H 2 O), and hydrogen peroxide:amonium hydroxide:deionized water (H 2 O 2 :NH 4 OH:H 2 O).

Claim 30

The method as recited in claim 25, wherein the step of selectively etching the entire surface of the side of the substrate wafer to polish the lens further comprises the step of etching the surface of the side of the substrate wafer at a temperature of from 30° C. to 40° C.

Claim 31

The method as recited in claim 25, wherein the step of coating the entire surface of the substrate wafer with the antireflectivity coating further comprises using a coating process selected from the group consisting of e-beam evaporation, sputtering, and chemical vapor deposition.

Claim 32

The method as recited in claim 25, wherein the step of coating the entire surface of the substrate wafer with the antireflectivity coating further comprises the step of depositing at least one layer of antireflectivity coating containing magnesium flouride (MgF), aluminum oxide (Al 2 O 3 ), hafnium flouride (HfF), silicon dioxide (SiO 2 ), and silicon nitride (Si 3 N 4 ).

Claim 35

The method as recited in claim 31, wherein the step of coating the layer of photoresist material over the entire surface of the side of the substrate wafer further comprises the step of providing the substrate wafer of a material selected from the group consisting of indium phosphide, gallium arsenide, indium arsenide, and gallium phosphide.

Claim 36

The method as recited in claim 31, wherein the step of coating the layer of photoresist material over the entire surface of the side of the substrate wafer further comprises the step of providing the photoresist material of 2-ethoxyethylacetate+n-butyl acetate in xylen and hexamethyldisilozane.

Claim 37

The method as recited in claim 31, wherein the step of baking the substrate wafer further comprises the step of soft baking the substrate wafer at temperature of approximately 100° C.

Claim 38

The method as recited in claim 31, wherein the step of baking the substrate wafer further comprises the step of soft baking the substrate wafer for a period of approximately 45 minutes.

Claim 39

The method as recited in claim 31, wherein the step of providing the mask to determine the quantity and shape of the lens arm formed on the substrate wafer further comprises the step of providing the mask to form an array of lens arms.

Claim 40

The method as recited in claim 31, wherein the step of selectively aligning the mask to the substrate wafer further comprises the step of performing the alignment with an infra-red camera to align the lens arm mask with the lens formed on the side of the substrate wafer opposite the side containing the lens arm.

Claim 41

The method as recited in claim 31, wherein the step of etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises providing a dry etch mixture selected from the group consisting of argon and hydrochloric acid (Ar/HCl), argon and chlorine (Ar/Cl 2 H 2 ), a rgon and hydrobromic acid (Ar/Hbr), argon and bromine (Ar/Br 2 ), argon and chlorine (Ar/Cl 2 ), argon and metha ne and hydrogen (Ar/CH 4 /H 2 ), methyl iodide (H 3 CI), bromine iodide (IBr 3 ), methane and hydrogen and sulfur flouride (CH 4 /H 2 /SF 6 ), ethyl iodide (C 2 H 5 I), isoethyl iodide (C 3 H 7 I), hexaflouride carbon and hydrogen(C 2 F 6 /H 2 ), and dichloro-difluoro carbon and oxygen (CCl 2 F 2 /O 2 ).

Claim 42

The method as recited in claim 31, wherein the step of etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of dry etching using electron cyclotron resonance (ECR) etching.

Claim 43

The method as recited in claim 31, wherein the step of etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of dry etching using inductive couple plasma (ICP) etching.

Claim 44

The method as recited in claim 31, wherein the step of etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of dry etching using reactive-ion (RIE) etching.

Claim 45

The method as recited in claim 31, wherein the step of etching the side of the substrate wafer in the areas surrounding the photoresist mask further comprises the step of dry etching using an ion milling etching.

Claim 46

The method as recited in claim 31, wherein the step of removing the photoresist mask and cleaning the surface of the substrate wafer comprises the steps of: removing the photoresist mask using acetone; removing the acetone from the surface of the substrate using isopropanol; removing the isopropanol from the surface of the substrate using deionized water; removing oxides from the surface of the substrate using potassium hydroxide (KOH); and removing etching solution from the surface of the substrate using a solution of sulfuric acid:hydrogen peroxide:deionized water (H 2 SO 4 :H 2 O 2 :H 2 O).

Claim 47

The method as recited in claim 31, wherein the step of metallizing the lens arm comprises the steps of: coating a layer of photoresist material over the entire surface of the side of the substrate wafer containing the lens arm; baking the layer of photoresist material; exposing the layer of photoresist material; developing the side of the substrate containing the layer of photoresist material; evaporating a combination of metal layers over the lens arm; and removing the photoresist mask from the surface of the substrate wafer by a metal liftoff process.

Claim 48

The method as recited in claim 44, wherein the step of coating the layer of photoresist material over the entire surface of the side of the substrate further comprises the step of providing the photoresist material of 2-ethoxyethylacetate+n-butyl acetate in xylen.

Claim 49

The method as recited in claim 44, wherein the step of coating the layer of photoresist material over the entire surface of the side of the substrate further comprises the step of coating the photoresist material to a thickness sufficient to coat the trough area surrounding the lens arm to render only approximately one-half of the photoresist material coating in the trough area prone to exposure.

Claim 50

The method as recited in claim 44, wherein the step of coating the layer of photoresist material over the entire surface of the side of the substrate wafer further comprises the step of coating the layer of photoresist material at a spin speed of approximately 2000 rpm.

Claim 51

The method as recited in claim 44, wherein the step of baking the substrate wafer further comprises the step of soft baking the substrate wafer at temperature of approximately 80° C. to 135° C.

Claim 52

The method as recited in claim 44, wherein the step of baking the substrate wafer further comprises the step of soft baking the substrate wafer for a period of approximately 45 minutes.

Claim 53

The method as recited in claim 44, wherein the step of exposing the layer of photoresist material further comprises the step of float exposing the layer of photoresist material.

Claim 54

The method as recited in claim 44, wherein the step of exposing the layer of photoresist material further comprises the step of exposing the layer of photoresist material to an ultraviolet light source.

Claim 55

The method as recited in claim 44, wherein the step of evaporating a combination of metal layers over the lens arm comprises the steps of: evaporating a layer of titanium (Ti) over an exposed surface of the lens arm; evaporating a layer of platinum (Pt) over the layer of titanium; evaporating a layer of gold (Au) over the layer of platinum; and applying an alloy treatment to the metal layers to adhere the titanium to the surface of the lens arm, the layer of platinum to the layer of titanium, and the layer of gold to the layer of platinum.

Claim 56

The method as recited in claim 31, wherein the step of mounting the lens to the micro-optical device further comprises the step of soldering the lens to a surface of the micro-optical device.