Structure in which cylindrical microstructure is maintained in anisotropic groove, method for fabricating the same, and semiconductor device, TFT driving circuit, panel, display and sensor using the structure in which cylindrical microstructure is maintained in anisotropic groove
View Patent ↗A method for fabricating a structure according to the present invention includes the steps of: forming a groove in a substrate, dropping a solution in which microstructures such as nanowires are dispersed into the groove and the step of evaporating the solution to arrange the microstructures in the groove in a self-organizing manner.
1. A method for fabricating a structure holding a microstructure, the method comprising the steps of:
a) supplying a fluid containing a microstructure having a cylindrical shape in at least one anisotropic groove provided on a substrate; and
b) evaporating the fluid so that the microstructure is arranged so as to extend in a longitudinal direction of said at least one anisotropic groove,
the method further comprising, before the step a), the step c) of forming said at least one anisotropic groove, and
after the step c) and before the step a), the step d) of increasing an affinity with respect to the fluid in a surface of said at least one anisotropic groove to a higher level than an affinity in a surface of the substrate excluding part of the substrate in which said at least one anisotropic groove is formed, wherein:
in the step d), the affinity with respect to the fluid is increased in the surface of said at least one anisotropic groove to a higher level than the affinity in the surface of the substrate excluding part of the substrate in which said at least one anisotropic groove is formed by covering, with a first coating film, the part of the substrate in which said at least one anisotropic groove is formed and covering, with a second coating film, the part of the substrate excluding the part of the substrate in which said at least one anisotropic groove is formed,
in the step c), said at least one anisotropic groove is formed by etching the substrate using a hydrophobic film formed on the substrate as a mask, the hydrophobic film being used as the second coating film, and
in the step d), a hydrophilic film used as the first coating film is formed on the surface of said at least one anisotropic groove.
2. The method of claim 1 , wherein in the step d), the affinity with respect to the fluid is increased in the surface of said at least one anisotropic groove to a higher level than the affinity in the surface of the substrate excluding the part of the substrate in which said at least one anisotropic groove is formed by covering, with a coating film, the part of the surface of the substrate in which said at least one anisotropic groove is formed.
3. The method of claim 1 , wherein in the step a), the fluid is supplied using selective deposition.
4. The method of claim 3 , wherein in the step a), the fluid is supplied using an inkjet technique.
5. The method of claim 1 , wherein in the step c), said at least one anisotropic groove is formed using imprint lithography.
6. A method for fabricating a semiconductor device which includes the method of claim 1 , further comprising the step e) of forming a first electrode and a second electrode which are to be connected to the microstructure.
7. A method for fabricating a semiconductor device which includes the method of claim 6 , wherein in the step e), a source electrode is formed as the first electrode and a drain electrode is formed as the second electrode, and
wherein the method further includes the steps of:
forming a gate insulating film for covering the microstructure on the substrate; and
forming a gate electrode on the gate insulating film.
8. A method for fabricating a sensor which includes the method of claim 1 , wherein the substrate is an insulating substrate, and
wherein the method further includes the step of forming a first electrode and a second electrode which are to be connected to the microstructure.
9. A method for fabricating a sensor which includes the method of claim 8 , further comprising the step of chemically modifying a surface of the microstructure.
10. The method of claim 1 , wherein in the step b), the microstructure is arranged so as to extend in the longitudinal direction of said at least one anisotropic groove by evaporating the fluid containing the microstructure and thereby making a lateral capillary force due to surface tension and a force generated by a fluid flow accompanying evaporation of a wet film act on the microstructure.
11. A method for fabricating a structure holding a microstructure, the method comprising the steps of:
a) supplying a fluid containing a microstructure having a cylindrical shape in at least one anisotropic groove provided on a substrate; and
b) evaporating the fluid so that the microstructure is arranged so as to extend in a longitudinal direction of said at least one anisotropic groove,
the method further comprising, before the step a), the step c) of forming said at least one anisotropic groove, and
after the step c) and before the step a), the step d) of increasing an affinity with respect to the fluid in a surface of said at least one anisotropic groove to a higher level than an affinity in a surface of the substrate excluding part of the substrate in which said at least one anisotropic groove is formed, wherein:
in the step d), the affinity with respect to the fluid is increased in the surface of said at least one anisotropic groove to a higher level than the affinity in the surface of the substrate excluding the part of the substrate in which said at least one anisotropic groove is formed by covering, with a coating film, part of the substrate excluding the part of the substrate in which said at least one anisotropic groove is formed,
in the step c), after formation of a hydrophilic film on the substrate, said at least one anisotropic groove is formed by removing the hydrophilic film together with the substrate, and the hydrophilic film remains on part of the substrate at which said at least one anisotropic groove is not formed thereby serving as the coating film, and
in the step a), a lipid fluid containing the microstructure is supplied in the at least one anisotropic groove.
12. The method of claim 11 , wherein in the step d), the affinity with respect to the fluid is increased in the surface of said at least one anisotropic groove to a higher level than the affinity in the surface of the substrate excluding the part of the substrate in which said at least one anisotropic groove is formed by covering, with a coating film, the part of the surface of the substrate in which said at least one anisotropic groove is formed.
13. The method of claim 11 , wherein in the step a), the fluid is supplied using selective deposition.
14. The method of claim 13 , wherein in the step a), the fluid is supplied using an inkjet technique.
15. The method of claim 11 , wherein in the step c), said at least one anisotropic groove is formed using imprint lithography.
16. A method for fabricating a semiconductor device which includes the method of claim 11 , further comprising the step e) of forming a first electrode and a second electrode which are to be connected to the microstructure.
17. A method for fabricating a semiconductor device which includes the method of claim 16 , wherein in the step e), a source electrode is formed as the first electrode and a drain electrode is formed as the second electrode, and
wherein the method further includes the steps of:
forming a gate insulating film for covering the microstructure on the substrate; and
forming a gate electrode on the gate insulating film.
18. A method for fabricating a sensor which includes the method of claim 11 , wherein the substrate is an insulating substrate, and
wherein the method further includes the step of forming a first electrode and a second electrode which are to be connected to the microstructure.
19. A method for fabricating a sensor which includes the method of claim 18 , further comprising the step of chemically modifying a surface of the microstructure.
20. The method of claim 11 , wherein in the step b), the microstructure is arranged so as to extend in the longitudinal direction of said at least one anisotropic groove by evaporating the fluid containing the microstructure and thereby making a lateral capillary force due to surface tension and a force generated by a fluid flow accompanying evaporation of a wet film act on the microstructure.