Double patterning by PTD and NTD process
A method of manufacturing using a double patterning method is provided. The double patterning method uses a first developer and a second developer that are different. For example, the first developer may be a positive tone developer for a positive photoresist while the second developer may be a negative tone developer for the positive photoresist. Photoresists having a photoactive compound are also provided that may be useful in double patterning methods.
1. A method of making a photoresist pattern comprising:
providing a photoresist layer;
exposing the photoresist layer to a first light passing through a first mask;
developing the photoresist layer using a positive tone developer (PTD);
exposing the photoresist layer to a second light passing through a second mask, wherein an approximately opaque region of the second mask is positioned substantially at the center of an approximately transparent region of the first mask; and
developing the photoresist layer using a negative tone developer (NTD).
2. The method of claim 1 , wherein the photoresist layer comprises a positive photoresist.
3. The method of claim 2 , wherein the photoresist layer comprises a photoactive compound having a first transition range defined by a first range of exposure to energy and the positive photoresist transitions over the first transition range to a first compound that dissolves in the positive tone developer.
4. The method of claim 3 , wherein the photoactive compound having a second transition range defined by a second range of exposure to energy and the positive photoresist transitions over the second transition range to a second compound that does not dissolve in the negative tone developer.
5. The method of claim 4 , wherein the first transition range and the second transition range are about the same.
6. A method of making a photoresist pattern comprising:
providing a photoresist layer;
exposing the photoresist layer to a first light passing through a first mask having a first line/space ratio;
developing the photoresist layer using a positive tone developer (PTD);
exposing the photoresist layer to a second light passing through a second mask having a second line/space ratio, wherein an approximately opaque region of the second mask is positioned substantially at the center of an approximately transparent region of the first mask; and
developing the photoresist layer using a negative tone developer (NTD),
wherein the first line/space ratio is larger than the second line/space ratio.
7. The method of claim 6 , wherein the photoresist layer comprises a positive photoresist.
8. The method of claim 6 , wherein the first line/space ratio is from about 1 to about 9.
9. The method of claim 6 , wherein the second line/space ratio is from about 1/9 to about 1.
10. A method of making a photoresist pattern comprising:
exposing a photoresist with a first mask having a first dense pattern and a periphery pattern;
developing the photoresist with a positive tone developer (PTD);
exposing the photoresist with a second mask having a second dense pattern, wherein an opaque region of the second mask is positioned substantially at the center of an transparent region of the first mask; and
developing the photoresist with a negative tone developer (NTD).
11. The method of claim 10 , wherein the photoresist comprises a positive photoresist.
12. The method of claim 10 , wherein a dimension of the first dense pattern is larger than a dimension of the second dense pattern.
13. The method of claim 10 , wherein:
the first mask comprising a first opaque region and a first substantially translucent region surrounding the first opaque region.
14. The method of claim 13 , wherein the first opaque region defines a corresponding pad and the opaque region of the second mask defines a separation region to divide the corresponding pad into at least two portions.