Method for fabricating large-area nanoscale pattern
A method for fabricating a large-area nanoscale pattern includes: forming multilayer main thin films isolated by passivation layers; patterning a first main thin film to form a first main pattern; forming a first spacer pattern with respect to the first main pattern; and forming a second main pattern by transferring the first spacer pattern onto a second main thin film. By using multilayer main thin films isolated by different passivation films, spacer lithography capable of reducing a pattern pitch can be repetitively performed, and the pattern pitch is repetitively reduced without shape distortion after formation of micrometer-scale patterns, thereby forming nanometer-scale fine patterns uniformly over a wide area.
1. A method for fabricating large-area nanoscale patterns, comprising:
forming multilayer main thin films isolated by passivation layers;
etching a first main thin film using a first passivation layer on an upper portion of the first main thin film and
removing the first passivation layer to form a first main pattern;
forming a spacer layer covering the first main pattern and
etching an upper surface of the spacer layer
to form a first spacer pattern
to expose an upper portion of the first main pattern,
removing the first main pattern, and
thereafter etching a second passivation layer
under the first spacer pattern
using the first spacer pattern;
vertically etching a second main thin film
under the second passivation layer
using the first spacer pattern and the second passivation layer and
removing the first spacer pattern and the second passivation layer to form a second main pattern;
depositing a spacer material on the second main pattern and
vertically etching the deposited spacer material on the second main pattern to form a second spacer pattern, and
thereafter removing the second main pattern;
etching a third passivation layer under a second main film
using the second spacer pattern, and
thereafter removing the second spacer pattern; and
etching a third main thin film using the third passivation layer and
removing the third passivation layer to form a third main pattern.
2. The method of claim 1 , wherein the passivation layers are formed using a silicon nitride film or a silicon oxide film.
3. The method of claim 2 , wherein the main thin films are formed of any one of single-crystalline silicon, polycrystalline silicon, and amorphous silicon.
4. The method of claim 1 , wherein the process of forming the spacer layer on the first main pattern is performed by a deposition process.
5. The method of claim 1 , wherein the spacer layer is formed of the same material as the passivation layers.
6. The method of claim 1 , wherein the period of the first main pattern of the upper part is two times the period of the second main pattern to be formed at the lower part.
7. The method of claim 6 , wherein the line width of the first main pattern is equal to the distance between the second main patterns.
8. The method of claim 6 , wherein the distance between the first main patterns is two or more times the line width of the second main pattern.