Method of forming a photoresist underlayer and structure including same

1. A method of forming a structure comprising a photoresist underlayer, the method comprising the steps of:

providing a substrate;

forming a photoresist underlayer overlying a surface of the substrate using a cyclic deposition process;

wherein the photoresist underlayer comprises one or more of an oxide, a nitride, and an oxynitride of a metal;

wherein the metal comprises one or more transition metals;

wherein forming the photoresist underlayer comprises forming a lower underlayer part and an upper underlayer part; and

wherein the lower underlayer part has a laminar structure comprising alternating silicon containing lamellae and metal containing lamellae, wherein forming the lower underlayer part comprises executing a plurality of sub cycles x and sub cycles y, wherein sub cycles x and sub cycles y are carried out alternatingly, wherein sub cycle x comprises exposing the substrate to a silicon precursor in a reaction chamber; purging excess silicon precursor from the reaction chamber; subjecting the substrate to a plasma; and purging excess reactive species from the reaction chamber; and, wherein sub cycle y comprises exposing the substrate to a metal precursor; purging excess metal precursor from the reaction chamber; exposing the substrate to a plasma; and, purging excess reactive species from the reaction chamber.

2. The method of claim 1 , wherein the photoresist underlayer comprises the metal, oxygen, and carbon, and wherein the metal precursor is an alkoxide or alkylamide metal precursor.

3. The method according to claim 2 wherein the metal precursor has a general formula M[R(C x H y ) n ] 4 , wherein M is selected from Ti, Ta, Hf, Zn, and Zr, wherein R is selected from OCH and N, wherein x is 1 or 2, wherein y is 3-6, and wherein n is 2 or 3.

4. The method according to claim 3 wherein M is Ti.

5. The method according to claim 4 wherein the metal precursor is titanium(IV) isopropoxide.

6. The method of claim 3 , wherein a carbon precursor is further provided to the reaction chamber during the step of forming the photoresist underlayer, wherein the carbon precursor comprises one or more of a carboxylic acid anhydrate, toluene, diethylene glycol, triethylene glycol, acetaldehyde, and an organosilicon compound.

7. The method according to claim 3 , wherein the photoresist underlayer is formed using a reactant selected from H 2 O, O 3 , and H 2 O 2 .

8. The method according to claim 1 , wherein the photoresist underlayer is formed using a plasma ALD or a plasma-enhanced pulsed CVD method that employs a plasma selected from the list consisting of H 2 , H 2 /He, H 2 /Ar, Ar, and O 2 plasmas.

9. The method of claim 3 , further comprising a surface treatment step.

10. The method of claim 9 , wherein the surface treatment step comprises exposing the photoresist underlayer to one or more carbon-containing compounds selected from the group consisting of a carboxylic acid anhydrate, toluene, diethylene glycol, triethylene glycol, acetaldehyde, and organosilicon compounds, such as silane and siloxanes.

11. The method of claim 3 , further comprising a step of forming a carbon-containing layer overlying the photoresist underlayer, the carbon-containing layer comprising silicon, oxygen, and carbon.

12. The method of claim 3 , further comprising a step of forming a self-assembled layer overlying the photoresist underlayer, wherein the self-assembled layer is formed of a material selected from the group consisting of-(n,n-dimethylamino)trimethylsilane, hexamethyldisilazane, (3-bromopropyl)trimethoxysilane, (3-iodopropyl)trimethoxysilane, 3-(trimethoxysilyl)propyl acrylate, trimethoxyphenyl silane, trimethoxy (3,3,3-trifluoropropyl)silane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, and tichloro(phenyl)silane, and trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane.

13. The method according to claim 1

wherein the lower underlayer part is formed using a metal halogenide precursor, or wherein the lower underlayer part is formed using a metal-containing precursor having a general formula M[R(C x H y ) n ] 4 , where M is selected from Ti, Ta, Hf, Zn, and Zr, wherein R is selected from OCH and N, wherein x is 1-2, wherein y is 3-6, and wherein n is 2-3; and,

wherein the upper underlayer part is formed using a metal-containing precursor having a general formula M[R(C x H y ) n ] 4 , where M is selected from Ti, Ta, Hf, Zn, and Zr, wherein R is selected from OCH and N, wherein x is 1-2, wherein y is 3-6, and wherein n is 2-3.

14. The method according to claim 13 wherein the upper underlayer part is formed using plasma-enhanced ALD or plasma-enhanced chemical vapor deposition, wherein a noble gas is used as a plasma gas.

15. The method according to claim 3 further comprising a step of exposing the photoresist underlayer to a surface treatment, the surface treatment comprising a step of exposing the photoresist underlayer to an organosilicon compound selected from the list consisting of bis(tripropylsilyl)amine, bis(triethylsilyl)amine, bis(trimethylsilyl)amine, (n,n-dimethylamino)trimethylsilane, (diethylamino)trimethylsilane, (diethylamino)triethylsilane, and (dimethylamino)triethylsilane.