Introduction of metal in hard mask for high aspect ratio device patterning
A method for patterning a boron-containing hard mask includes patterning an oxide hard mask formed on a boron-containing hard mask, and patterning the boron-containing hard mask using the patterned oxide hard mask, wherein the oxide hard mask comprises silicon oxide (SiO 2 ), the boron-containing hard mask is doped with one or more metal elements, and the patterning of the boron-containing hard mask comprises etching the boron-containing hard mask through openings of the patterned oxide hard mask using an etching gas mixture comprising chlorine (Cl 2 ), hydrogen bromide (HBr), and oxygen (O 2 ).
1 . A method for patterning a boron-containing hard mask, comprising:
patterning an oxide hard mask formed on a boron-containing hard mask; and
patterning the boron-containing hard mask using the patterned oxide hard mask, wherein
the oxide hard mask comprises silicon oxide (SiO 2 ),
the boron-containing hard mask is doped with one or more metal elements, and
the patterning of the boron-containing hard mask comprises etching the boron-containing hard mask through openings of the patterned oxide hard mask using an etching gas mixture comprising chlorine (Cl 2 ), hydrogen bromide (HBr), and oxygen (O 2 ).
2 . The method of claim 1 , wherein concentration of boron in the boron-containing hard mask is between 20% and 99.5%.
3 . The method of claim 1 , wherein the one or more metal elements comprise tungsten (W).
4 . The method of claim 1 , wherein concentration of the one or more metal elements is between 0.5% and 80%.
5 . The method of claim 4 , wherein etch selectivity of the boron-containing hard mask to the oxide hard mask is greater than 8.
6 . The method of claim 1 , wherein the oxide hard mask has a thickness of between 100 Å and 3000 Å, and critical dimensions of the openings of the patterned oxide hard mask are between 10 nm and 100 nm.
7 . The method of claim 1 , wherein the boron-containing hard mask has a thickness of between 500 Å and 5000 Å, and openings of the patterned boron-containing hard mask are between 10 nm and 100 nm.
8 . The method of claim 1 , wherein the etching gas mixture further comprises a fluorine-containing gas.
9 . A method for patterning a boron-containing hard mask, comprising:
patterning an oxide hard mask formed on a boron-containing hard mask; and
patterning the boron-containing hard mask using the patterned oxide hard mask, wherein
the oxide hard mask comprises silicon oxide (SiO 2 ), and
the patterning of the boron-containing hard mask comprises etching the boron-containing hard mask through openings of the patterned oxide hard mask using an etching gas mixture comprising chlorine (Cl 2 ), hydrogen bromide (HBr), oxygen (O 2 ), and a metal-containing etchant.
10 . The method of claim 9 , wherein the metal-containing etchant comprises tungsten hexafluoride (WF 6 ) or tin chloride (SnCl 4 ).
11 . The method of claim 9 , wherein concentration of boron in the boron-containing hard mask is between 20% and 100%.
12 . The method of claim 9 , wherein the oxide hard mask has a thickness of between 100 Å and 3000 Å, and critical dimensions of the openings of the patterned oxide hard mask are between 10 nm and 100 nm.
13 . The method of claim 9 , wherein the boron-containing hard mask has a thickness of between 500 Å and 5000 Å, and openings of the patterned boron-containing hard mask are between 10 nm and 100 nm.
14 . The method of claim 9 , wherein the etching gas mixture further comprises a fluorine-containing gas.
15 . A method for patterning a boron-containing hard mask, comprising:
patterning an oxide hard mask formed on a boron-containing hard mask; and
patterning the boron-containing hard mask using the patterned oxide hard mask, wherein
the oxide hard mask comprises silicon oxide (SiO 2 ),
the boron-containing hard mask is doped with one or more metal elements, and
the patterning of the boron-containing hard mask comprises etching the boron-containing hard mask through openings of the patterned oxide hard mask using an etching gas mixture comprising chlorine (Cl 2 ), hydrogen bromide (HBr), oxygen (O 2 ), and a metal-containing etchant.
16 . The method of claim 15 , wherein concentration of boron in the boron-containing hard mask is between 20% and 99.5%.
17 . The method of claim 15 , wherein the one or more metal elements comprise tungsten (W).
18 . The method of claim 15 , wherein concentration of the one or more metal elements is between 0.5% and 80%.
19 . The method of claim 15 , wherein the metal-containing etchant comprises tungsten hexafluoride (WF 6 ) or tin chloride (SnCl 4 ).
20 . The method of claim 15 , wherein the etching gas mixture further comprises a fluorine-containing gas.