Techniques to engineer nanoscale patterned features using ions

Patent metadata

Field	Value
Publication number	US-10008384-B2
Application number	US-201514749822-A
Country	US
Kind code	B2
Filing date	Jun 25, 2015
Priority date	Jun 25, 2015
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A method of patterning a substrate. The method may include providing a surface feature on the substrate, the surface feature having a first dimension along a first direction within a substrate plane, and a second dimension along a second direction within the substrate plane, wherein the second direction is perpendicular to the first direction; and directing first ions in a first exposure to the surface feature along the first direction at a non-zero angle of incidence with respect to a perpendicular to the substrate plane, in a presence of a reactive ambient containing a reactive species; wherein the first exposure etches the surface feature along the first direction, wherein after the directing, the surface feature retains the second dimension along the second direction, and wherein the surface feature has a third dimension along the first direction different than the first dimension.

First claim

What is claimed is:

1. A method of patterning a substrate, comprising:
providing a surface feature in a first layer, the first layer disposed directly on a second layer in the substrate, the second layer being a continuous layer, the surface feature having a first dimension along a first direction within a substrate plane, and a second dimension along a second direction within the substrate plane, wherein the second direction is perpendicular to the first direction; and
directing first ions in a first exposure to the surface feature along a trajectory, wherein a projection of the trajectory in the substrate plane is parallel the first direction, wherein the trajectory forms a non-zero angle of incidence with respect to a perpendicular to the substrate plane, and wherein the trajectory forms a second non-zero angle of incidence with respect to the first direction, wherein the first exposure comprises a reactive ion etch including the first ions in a presence of a reactive ambient containing a reactive species, the reactive ion etch configured to selectively etch the first layer with respect to the second layer;
wherein the first exposure etches the surface feature along the first direction, wherein after the directing, the surface feature retains the second dimension along the second direction, wherein the second dimension along the second direction is not reduced, wherein the surface feature has a third dimension along the first direction different than the first dimension, and wherein the first exposure does not etch the second layer.

2. The method of claim 1 , wherein the surface feature comprises a hole within a layer disposed on the substrate, the first dimension being a first hole dimension and second dimension being a second hole dimension, wherein the first exposure increases the first hole dimension to a third hole dimension using the first ions and reactive ambient, while not increasing the second hole dimension.

3. The method of claim 1 , wherein the surface feature comprises a pillar structure or a line structure, wherein the third dimension is less than the first dimension.

4. The method of claim 1 , wherein first layer comprising a first material, wherein the second layer comprising a second material.

5. The method of claim 1 , wherein the ions form a ribbon beam having a long axis parallel to the second direction and a short axis parallel to the first direction.

6. The method of claim 1 , the method further comprising:
after the first exposure, forming a lower feature in the second layer in a region defined by the surface feature.

7. The method of claim 6 , wherein the etching the second layer takes place in a vertical direction along the perpendicular to the plane of the substrate.

8. The method of claim 3 , wherein the feature is a line arranged in a first array of lines, wherein before the first exposure the array of lines is characterized by a first spacing between adjacent lines along a first axis, the first axis being parallel to the first direction, wherein after the first exposure, a second array of lines is generated, and characterized by a second spacing between adjacent lines along the first axis greater than the first spacing.

9. The method of claim 8 , wherein the first ions have a first set of trajectories, wherein a projection of the first set of trajectories within the substrate plane lie parallel to the first direction, wherein the first exposure further comprises directing second ions to the surface feature along a second set of trajectories opposite the first set of trajectories at a non-zero angle of incidence with respect to the perpendicular, in a presence of a reactive ambient containing a reactive species, wherein the second array of lines is displaced symmetrically with respect to the first array of line.

10. A method of patterning a substrate, comprising:
providing a first layer directly on a second layer in the substrate, the first layer having at least one hole, the second layer comprising a continuous layer; and
directing first ions in a first exposure to the first layer along a trajectory, wherein a projection of the trajectory in a substrate plane is parallel to a first direction, the trajectory forming a non-zero angle of incidence with respect to a perpendicular to the substrate plane, and wherein the trajectory forms a second non-zero angle of incidence with respect to the first direction, wherein the first exposure comprises a reactive ion etch including the first ions in a presence of a reactive ambient containing a reactive species, the reactive ion etch configured to selectively etch the first layer with respect to the second layer,
wherein the first exposure increases a first hole dimension of the hole by etching the hole along the first direction using the first ions and reactive ambient, while not increasing a second hole dimension of the hole along a second direction perpendicular to the first direction, and wherein the first exposure does not etch the second layer.

11. The method of claim 10 , wherein the at least one hole comprises an array of holes characterized by a first separation along the first direction between adjacent holes before the directing, and wherein the array of holes is characterized by a second separation along the first direction less than the first separation after the directing.

12. The method of claim 11 , wherein the array of holes are formed by a proximity correction mask.

13. The method of claim 10 , further comprising:
after the first exposure, forming a lower hole in the substrate layer by etching the at least one additional layer in a region defined by the at least one hole, wherein the etching takes place along the perpendicular to the plane of the substrate.

14. The method of claim 10 , wherein the first layer comprises silicon oxide, silicon nitride, silicon, carbon, photoresist, TiN, or an ARC layer.

15. A method of patterning a substrate, comprising:
providing a first layer directly on a second layer in the substrate, the second layer comprising a continuous layer;
forming a first set of holes in the first layer using a first lithography mask having a first spacing between adjacent features;
directing first ions in a first exposure to the first layer along a trajectory, wherein a projection of the trajectory in a substrate plane is parallel to a first direction, the trajectory forming a non-zero angle of incidence with respect to a perpendicular to a substrate plane, and wherein the trajectory forms a second non-zero angle of incidence with respect to the first direction, the first exposure comprises a reactive ion etch including the first ions in a presence of a reactive ambient containing a reactive species, the reactive ion etch configured to selectively etch the first layer with respect to the second layer,
wherein at least two holes of the first set of holes are etched along the first direction and are characterized by a final hole separation along the first direction less than the first spacing after the first exposure, wherein the first exposure does not etch the substrate layer, and wherein the at least two holes are not etched along a second direction perpendicular to the first direction.

16. The method of claim 15 , further comprising forming a second set of holes in the first layer using a second lithography exposure employing a second lithography mask having a second spacing between adjacent features no less than the first spacing, wherein the second set of holes is characterized by a second final hole separation less than the first spacing, and wherein the second set of holes is interspersed amon

Assignees

• Varian Semiconductor Equipment Ass Inc

Inventors

• Ruffell Simon
• Hautala John
• Brand Adam
• Dai Huixiong

Classifications

• H10P76/4085

  characterised by the processes involved to create the masks · CPC title

• H10P50/695

  characterised by the process involved to create the mask, e.g. lift-off masks or sidewalls or to modify the mask · CPC title

• H10W20/089

  using processes for implementing desired shapes or dispositions of the openings, e.g. double patterning · CPC title

• H10P76/204 Primary

  of organic photoresist masks · CPC title

• H10P50/283

  by chemical means · CPC title