Method for Integrated Circuit Patterning
Provided is a method of patterning a substrate. The method includes patterning a resist layer formed over the substrate to result in a resist pattern and treating the resist pattern with an ion beam. The ion beam is generated with a gas, such as CH 4 , SiH 4 , Ar, or He; and is directed towards the resist pattern at a tilt angle at least 10 degrees. In embodiments, the ion beam is directed towards the resist pattern at a uniform twist angle, or at a twist angle having a unimodal or bimodal distribution. The ion beam reduces line edge roughness (LER), line width roughness (LWR), and/or critical dimension of the resist pattern. The method further includes etching the substrate with the treated resist pattern as an etch mask.
1 . A method of patterning a substrate, the method comprising:
patterning a resist layer formed over the substrate, resulting in a resist pattern;
treating the resist pattern with an ion beam, resulting in a treated resist pattern, wherein the ion beam is generated with a first gas and is directed towards the resist pattern at a tilt angle at least 10 degrees; and
etching the substrate with the treated resist pattern as an etch mask.
2 . The method of claim 1 , wherein the ion beam is directed towards the resist pattern at a uniform twist angle.
3 . The method of claim 1 , wherein the ion beam is directed towards the resist pattern at a twist angle having a unimodal distribution from about −50 degrees to about 50 degrees.
4 . The method of claim 1 , wherein the ion beam is directed towards the resist pattern at a twist angle having a bimodal distribution.
5 . The method of claim 4 , wherein the bimodal distribution has one ion energy peak at about 12.5 degrees and another ion energy peak at about −12.5 degrees.
6 . The method of claim 1 , wherein the first gas is Ar and the ion beam is provided with ion energy from about 1.0 kV to about 3.5 kV and ion dose from about 1×e 16 ions/cm 2 to about 10×e 16 ions/cm 2 .
7 . The method of claim 1 , wherein the first gas is He and the ion beam is provided with ion energy from about 1 kV to about 5 kV and ion dose from about 1×e 16 ions/cm 2 to about 10×e 16 ions/cm 2 .
8 . The method of claim 1 , wherein the first gas is SiH 4 and the ion beam is provided with ion energy from about 2 kV to about 5 kV and ion dose from about 0.5×e 16 ions/cm 2 to about 3×e 16 ions/cm 2 .
9 . The method of claim 1 , wherein the first gas is CH 4 and the ion beam is provided with ion energy from about 1 kV to about 5 kV and ion dose from about 1×e 16 ions/cm 2 to about 6×e 16 ions/cm 2 .
10 . The method of claim 1 , wherein the first gas is one of: CH 4 , SiH 4 , Ar, He, O 2 , N 2 , CO 2 , and a combination thereof.
11 . A method of patterning an etch layer over a substrate, the method comprising:
forming a resist layer over the etch layer;
patterning the resist layer, resulting in a patterned resist layer;
performing ion implantation to the patterned resist layer, resulting in a treated patterned resist layer, wherein the performing ion implantation comprises:
providing a treatment gas containing CH 4 , SiH 4 , Ar, or He;
generating an ion beam from the treatment gas; and
directing the ion beam incident upon the substrate at a tilt angle; and
etching the etch layer with the treated patterned resist layer as an etch mask.
12 . The method of claim 11 , wherein the ion beam has an ion dose of at least 0.5×e 16 ions/cm 2 .
13 . The method of claim 11 , wherein the tilt angle is at least 10 degrees.
14 . The method of claim 11 , wherein the ion beam is directed incident upon the substrate with a uniform twist angle.
15 . The method of claim 11 , wherein the ion beam is directed incident upon the substrate at a twist angle having a unimodal distribution.
16 . The method of claim 11 , wherein the ion beam is directed incident upon the substrate at a twist angle having a bimodal distribution.
17 . A method of forming an integrated circuit, the method comprising:
patterning a material layer over a substrate, resulting in a patterned material layer;
treating the patterned material layer with an ion beam generated with one of: CH 4 , SiH 4 , Ar, and He, and directed incident upon the substrate at a tilt angle greater than 10 degrees, resulting in a treated patterned material layer; and
etching the substrate with the treated patterned material layer.
18 . The method of claim 17 , wherein the material layer is a resist layer.
19 . The method of claim 17 , wherein the material layer is a silicon-containing anti-reflection coating (ARC) layer.
20 . The method of claim 17 , wherein the material layer contains silicon, carbon, and oxygen.