Method for forming fine pattern of semiconductor device using double spacer patterning technology
A method of forming a fine pattern of a semiconductor device using double SPT process, which is capable of implementing a line and space pattern having a uniform fine line width by applying a double SPT process including a negative SPT process, is provided. The method includes a first SPT process and a second SPT process and the second SPT process includes a Negative SPT process.
1. A method of forming a fine pattern of a semiconductor device, the method comprising:
forming a second layer over a first layer;
forming a partition pattern over the second layer;
forming first spacers over sidewalls of the partition pattern;
forming a first gap-fill layer filling between the first spacers;
removing the first spacers;
etching the second layer using the partition pattern and the first gap-fill layer as an etch mask to form a first pattern;
forming second spacers over sidewalls of the first pattern;
forming a second gap-fill layer filling between the second spacers;
removing the second spacers; and
etching the first layer using the first pattern and the second gap-fill layer as an etch mask to form a second pattern,
wherein the first layer and the second gap-fill layer are formed of the same material.
2. The method of claim 1 , wherein the forming the partition pattern includes:
forming a hard mask layer over the second layer;
forming a photoresist pattern over the hard mask layer; and
etching the hard mask layer using the photoresist pattern as an etch mask.
3. The method of claim 2 , wherein the photoresist pattern has a line-to-space width ratio of 1:7.
4. The method of claim 3 , wherein a width of the space of the photoresist pattern is four times larger than a width of the second pattern.
5. The method of claim 1 , wherein the first spacers are formed so that a width between the first spacers is substantially the same as a width of the partition pattern.
6. The method of claim 1 , wherein the partition pattern and the first gap-fill layer are formed of the same material.
7. The method of claim 1 , wherein the partition pattern, the first gap-fill layer, the first layer, and the second gap-fill layer are formed of the same material.
8. The method of claim 1 , wherein the forming the second pattern includes cutting a U-shaped edge of the first pattern to form the first pattern in a line shape.