Method of manufacturing field emission device

1. A method of forming stacked layers in an electronic device, comprising:

preparing a multi-layer structure comprising a substrate, a cathode on the substrate, a gate electrode having a through-hole, and a gate insulation layer disposed between the cathode and the gate electrode and having a gate hole corresponding to the through-hole;

forming a sacrificial layer by coating a positive photoresist having polymers on the multi-layer structure, the polymers comprising at least 50 mole % of monomers having structures selected from the group consisting of Formulae 1 through 3;

forming a photomask on a position of the sacrificial layer corresponding to the gate hole;

exposing a portion of the sacrificial layer uncovered by the photomask to light;

forming a well in the sacrificial layer by etching the unexposed portion of the sacrificial layer covered by the photomask using one of TCE and CH 2 Cl 2 solvents;

filling the well by applying an electron emitting material paste which is able to be hardened by light to the sacrificial layer;

hardening a lower portion of the electron emitting material paste filled in the well by radiating light from the bottom of the substrate; and

forming an electron emitting material layer having a predetermined height on the cathode by removing the sacrificial layer and the unexposed electron emitting material paste:

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms;

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and the joining of R 1 and R 2 , or R 1 and either R 3 or R 4 , or R 2 and either R 3 or R 4 forms a 5-, 6-, or 7-membered ring,

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and the joining of R 1 and R 2 , or R 1 and either R 3 or R 4 , or R 2 and either R 3 or R 4 forms a 5-, 6-, or 7-membered ring.

2. The method of claim 1 , wherein the preparation of the multi-layer structure comprises:

forming the cathode on the substrate;

sequentially forming the gate insulation layer and the gate electrode on the cathode;

forming a mask layer by coating a photoresist on the gate electrode layer;

first baking the mask layer at a first temperature;

exposing the mask layer to light with a predetermined pattern;

second baking the mask layer at a second temperature;

developing the mask layer to form an etch window in the mask layer;

etching the gate electrode through the etch window;

repeating at least twice the exposing to the developing; and

removing the mask layer.

3. The method of claim 2 , wherein the second temperature is 100 to 130° C.

4. The method of claim 1 , wherein the polymer is selected from the group consisting of 1-ehtoxyethyl methacrylate, 1-ehtoxyethyl acrylate, 1-butoxyethyl methacrylate, 1-butoxyethyl acrylate, 1-ethoxy-1-propyl methacrylate, 1-ethoxy-1-propyl acrylate, tetrahydropyranyl methacrylate, tetrahydropyranyl acrylate, tetrahydropyranyl p-vinylbenzoate, 1-ethoxy-1-propyl p-vinylbenzoate, 4-(2-tetrahydropyranyloxy)benzyl methacrylate, 4-(2-tetrahydropyranyloxy)benzyl acrylate, 4-(1-butoxyethoxy)benzyl methacrylate, 4-(1-butoxyethoxy)benzyl acrylate, t-butyl methacrylate, t-butyl acrylate, neopentyl methacrylate, neopentyl acrylate, 1-Bicyclo{2,2,2}octyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{2,2,1}heptyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{2,1,1}hexyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{1,1,1}pentyl methacrylate (or acrylate) and their derivatives, and 1-adamantyl methacrylate (or acrylate) and their derivatives.

5. The method of claim 4 , wherein the photoresist further comprises 0.5 to 30 mole % of photoacid generator and 10 to 1,000 ppm of photosensitizer.

6. The method of claim 1 , wherein the photoresist further comprises 0.5 to 30 mole % of photoacid generator and 10 to 1,000 ppm of photosensitizer.

7. The method of claim 1 , wherein the electron emitting material paste is a carbon nanotube paste.

8. A method of forming an electron emitting material layer in an electronic device having a multi-layer structure, comprising:

preparing the multi-layer structure, the multi-layer structure comprising a substrate, a cathode formed on the substrate, a first layer on the cathode, and a second layer on the first layer, the first layer having a first hole exposing a portion of the cathode, the second layer having a second hole corresponding to the first hole;

applying photoresist to the multi-layer structure to form a photoresist layer which is formed on the second layer and fills the first hole and the second hole, the photoresist having polymers comprising at least 50 mole % of monomers having structures selected from the group consisting of Formulae 1 through 3;

first baking the photoresist layer at a first temperature range;

positioning a photomask on the photoresist layer at a position above the exposed portion of the cathode;

exposing the photoresist layer to light;

second baking the photoresist layer at a second temperature range;

removing an unexposed portion of the photoresist layer to form a well in the photoresist layer;

filling the well by applying an electron emitting material paste which is able to be hardened by light;

hardening a lower portion of the filled electron emitting material paste by radiating light from the bottom of the substrate; and

removing the photoresist layer and the unexposed electron emitting material paste to form an electron emitting material layer on the cathode:

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms;

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and the joining of R 1 and R 2 , or R 1 and either R 3 or R 4 , or R 2 and either R 3 or R 4 forms a 5-, 6-, or 7-membered ring; and

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and the joining of R 1 and R 2 , or R 1 and either R 3 or R 4 , or R 2 and either R 3 or R 4 forms a 5-, 6-, or 7-membered ring.

9. The method of claim 8 , wherein the polymer in the photoresist is selected from the group consisting of 1-ehtoxyethyl methacrylate, 1-ehtoxyethyl acrylate, 1-butoxyethyl methacrylate, 1-butoxyethyl acrylate, 1-ethoxy-1-propyl methacrylate, 1-ethoxy-1-propyl acrylate, tetrahydropyranyl methacrylate, tetrahydropyranyl acrylate, tetrahydropyranyl p-vinylbenzoate, 1-ethoxy-1-propyl p-vinylbenzoate, 4-(2-tetrahydropyranyloxy)benzyl methacrylate, 4-(2-tetrahydropyranyloxy)benzyl acrylate, 4-(1-butoxyethoxy)benzyl methacrylate, 4-(1-butoxyethoxy)benzyl acrylate, t-butyl methacrylate, t-butyl acrylate, neopentyl methacrylate, neopentyl acrylate, 1-Bicyclo{2,2,2}octyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{2,2,1}heptyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{2,1,1}hexyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{1,1,1}pentyl methacrylate (or acrylate) and their derivatives, and 1-adamantyl methacrylate (or acrylate) and their derivatives.

10. The method of claim 8 , wherein the polymer has a molecular weight of 7,000 to 1,000,000.

11. The method of claim 8 , wherein the first temperature range is from 70 to 100° C.

12. The method of claim 8 , wherein the second temperature range is from 100 to 130° C.

13. The method of claim 8 , wherein the electronic device is a field emission device, the second layer is a gate electrode, the first layer is a gate insulation layer, the second hole is a through-hole, and the first hole is a gate hole.

14. The method of claim 8 , wherein the first hole is trapezoidal-shaped in a sectional view, and an upper portion of the first hole is wider than a lower portion of the first hole, and the upper portion of the first hole has a larger diameter than the second hole.

15. The method of claim 8 , wherein the electron emitting material paste is a carbon nanotube paste.

16. A method of forming a field emission device, comprising:

preparing a precursor of the field emission device, the precursor comprising a substrate, a cathode on the substrate, a gate electrode having a through-hole, and a gate insulation layer disposed between the cathode and the gate electrode and having a gate hole corresponding to the through-hole, the gate hole having a trapezoidal-shape in a sectional view, a top portion of the gate hole being wider than a bottom portion of the gate hole, the upper portion of the gate hole having a larger diameter than the through-hole;

forming a sacrificial layer to cover the gate electrode and fill the gate hole and the through-hole, the sacrificial layer comprising polymers on the precursor, the polymers comprising at least 50 mole % of monomers having structures selected from the group consisting of Formulae 1 through 3;

soft-baking the sacrificial layer at a first temperature range;

positioning a photomask on a position of the sacrificial layer corresponding to the bottom of the gate hole;

exposing a portion of the sacrificial layer uncovered by the photomask to light;

hard-baking the sacrificial layer at a second temperature range;

developing the unexposed portion of the sacrificial layer covered by the photomask using one of TCE and CH 2 Cl 2 solvents to form a well in the sacrificial layer;

filling the well by applying an electron emitting material paste including a light-hardened photoresist to the sacrificial layer;

hardening a lower portion of the electron emitting material paste filled in the well by radiating light from the bottom of the substrate; and

removing the sacrificial layer and the unexposed electron emitting material paste to form an electron emitting material layer on the cathode:

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms;

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and the joining of R 1 and R 2 , or R 1 and either R 3 or R 4 , or R 2 and either R 3 or R 4 forms a 5-, 6-, or 7-membered ring; and

where R 1 is hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, R 2 is an alkyl group having 1 to 6 linear or cyclic carbon atoms, and R 3 and R 4 are independently hydrogen or an alkyl group having 1 to 6 linear or cyclic carbon atoms, and the joining of R 1 and R 2 , or R 1 and either R 3 or R 4 , or R 2 and either R 3 or R 4 forms a 5-, 6-, or 7-membered ring.

17. The method of claim 16 , wherein the polymer in the photoresist is selected from the group consisting of 1-ehtoxyethyl methacrylate, 1-ehtoxyethyl acrylate, 1-butoxyethyl methacrylate, 1-butoxyethyl acrylate, 1-ethoxy-1-propyl methacrylate, 1-ethoxy-1-propyl acrylate, tetrahydropyranyl methacrylate, tetrahydropyranyl acrylate, tetrahydropyranyl p-vinylbenzoate, 1-ethoxy-1-propyl p-vinylbenzoate, 4-(2-tetrahydropyranyloxy)benzyl methacrylate, 4-(2-tetrahydropyranyloxy)benzyl acrylate, 4-(1-butoxyethoxy)benzyl methacrylate, 4-(1-butoxyethoxy)benzyl acrylate, t-butyl methacrylate, t-butyl acrylate, neopentyl methacrylate, neopentyl acrylate, 1-Bicyclo{2,2,2}octyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{2,2,1}heptyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{2,1,1}hexyl methacrylate (or acrylate) and their derivatives, 1-Bicyclo{1,1,1}pentyl methacrylate (or acrylate) and their derivatives, and 1-adamantyl methacrylate (or acrylate) and their derivatives.

18. The method of claim 16 , wherein the polymer has a molecular weight of 7,000 to 1,000,000.

19. The method of claim 16 , wherein the first temperature range is from 70 to 100° C., and the second temperature range is from 100 to 130° C.

20. The method of claim 16 , wherein the electron emitting material paste is a carbon nanotube paste.