Method of forming a semiconductor device including a pitch multiplication

1. A method comprising:

forming first and second layers over an underlying material such that the first layer is between the underlying material and the second layer;

forming a third layer over the second layer;

forming first and second core portions apart from each other over the third layer;

forming a gap portion between the first and the second core portions;

removing the second and the third layers by using the first and the second core portions and the gap portion as a mask to expose a part of the first layer;

the forming the gap portion comprising:

forming a sacrifice film covering each side surface of the first and the second core portions and an upper surface of the third layer so as to form a concave portion between the first and the second core portions;

forming an organic material to fill the concave portion; and

removing the sacrifice film between the organic material and each of the first and the second core portions to expose the third layer, wherein the gap portion is formed as a stacked layer including the organic material on the sacrifice film;

after the removing the second and the third layers:

removing the first and the second core portions to expose a first part of the third layer and removing the organic material of the gap portion; and

removing the sacrifice film of the gap portion to expose a second part of the third layer; and

after the removing the sacrifice film of the gap portion:

forming a feature including an opening that intersects the first and the second parts of the third layer;

removing, through the opening, the second and the third layers to expose a second part of the first layer;

removing the feature; and

removing the first and the second parts of the first layer to expose the underlying material, wherein each of the first and the second parts of the third layer is removed to expose the second layer.

2. The method according to claim 1 , further comprising:

removing the exposed underlying material by using the second layer as a mask.

3. The method according to claim 1 , wherein a thickness of the first part of the first layer is decreased during the removing the third layer.

4. A method comprising:

forming first and second layers over an underlying material such that the first layer is between the underlying material and the second layer;

forming a third layer over the second layer;

forming first and second core portions apart from each other over the third layer;

forming a gap portion between the first and the second core portions;

removing the second and the third layers by using the first and the second core portions and the gap portion as a mask to expose a part of the first layer;

the forming the gap portion comprising:

forming a sacrifice film covering each side surface of the first and the second core portions and an upper surface of the third layer so as to form a concave portion between the first and the second core portions;

forming an organic material to fill the concave portion; and

removing the sacrifice film between the organic material and each of the first and the second core portions to expose the third layer, wherein the gap portion is formed as a stacked layer including the organic material on the sacrifice film; and

wherein the sacrifice film has a different etching rate from the third layer for a given etchant.

5. A method comprising:

forming first and second layers over an underlying material such that the first layer is between the underlying material and the second layer;

forming a third layer over the second layer;

forming first and second core portions apart from each other over the third layer;

forming a gap portion between the first and the second core portions;

removing the second and the third layers by using the first and the second core portions and the gap portion as a mask to expose a part of the first layer;

wherein the third layer has a different etching rate from the second layer for a given etchant; and

wherein each of the first and the third layers comprises at least one of silicon nitride and silicon oxy-nitride, wherein the second layer comprises silicon oxide.

6. A method comprising:

forming first and second layers over an underlying material such that the first layer is between the underlying material and the second layer;

forming a third layer over the second layer;

forming first and second core portions apart from each other over the third layer;

forming a gap portion between the first and the second core portions;

removing the second and the third layers by using the first and the second core portions and the gap portion as a mask to expose a part of the first layer; and

wherein the first and second core portions are formed by using a triple layer comprising an organic coating.

7. A method comprising:

forming first and second layers over an underlying material such that the first layer is between the underlying material and the second layer;

forming a third layer over the second layer;

forming first and second features respectively including side surfaces facing each other over the third layer;

forming a sacrifice film that covers the respective side surfaces of the first and the second features so as to form a concave portion therebetween over the third layer;

forming a third feature in the concave portion of the sacrifice film;

removing the sacrifice film between the third feature and each of the first and the second features to expose the third layer;

removing the second and the third layers in a region of the exposed part of the third layer to expose a first part of the first layer;

after the removing the second and the third layers:

removing the first and the second features to expose a first part of the third layer, wherein the third feature is removed to expose a residual sacrifice film; and

removing the residual sacrifice film to expose a second part of the third layer;

further comprising:

forming a fourth feature including an opening intersecting the first and the second parts of the third layer and the first part of the first layer; and

removing, through the opening, the second and the third layers to expose a second part of the first layer; and

wherein the removing, through the opening, the second and the third layers comprises:

decreasing a thickness of the first part of the first layer during removing the second and the third layers.

8. A method comprising:

forming first and second layers over an underlying material of a substrate such that the first layer is between the underlying material and the second layer;

forming a third layer over the second layer;

forming first and second features respectively including side surfaces facing each other over the third layer;

forming a sacrifice film that covers the respective side surfaces of the first and the second features so as to form a concave portion therebetween over the third layer;

forming a third feature in the concave portion of the sacrifice film,

wherein the third feature is spaced further from the second layer than the first and second features;

removing the sacrifice film between the third feature and each of the first and the second features to expose the third layer;

removing the second and the third layers in a region of the exposed part of the third layer to expose a first part of the first layer;

further comprising after the removing the second and the third layers:

removing the first and the second features to expose a first part of the third layer, wherein the third feature is removed to expose a residual sacrifice film; and

removing the residual sacrifice film to expose a second part of the third layer;

further comprising:

forming a fourth feature including an opening intersecting the first and the second parts of the third layer and the first part of the first layer; and

removing, through the opening, the second and the third layers to expose a second part of the first layer; and

further comprising after the removing, through the opening, the second and the third layers:

removing the fourth feature; and

removing the first and the second parts of the first layer to expose the underlying material, wherein the first and the second parts of the third layer is removed therewith to expose a residual second layer.

9. The method according to claim 8 , further comprising after the removing the first and the second parts of the first layer:

removing the underlying material by using the residual second layer as a mask.

10. A method comprising:

forming first and second layers over an underlying material such that the first layer is between the underlying material and the second layer;

forming a third layer over the second layer;

coating a first triple-layer including a first organic material over the third layer;

forming first and second features each including the organic material by patterning the first triple-layer to expose a part of the third layer;

forming a spacer covering the exposed part of the third layer and respective sidewall portions of the first and the second features so as to form a concave portion between the first and the second features;

coating a second organic material on the spacer;

removing a part of the second organic material so as to remain the second organic material in the concave portion of the spacer as a third feature;

removing selectively each sidewall portion of the spacer between the third feature and each of the first and the second features to expose a first part of the third layer;

removing the second and the third layers in the first part of the third layer to expose a part of the first layer;

removing the first and the second features to expose a second part of the third layer and the third feature to expose a residual spacer;

removing the residual spacer; coating a second triple-layer;

forming a fourth feature including an opening intersecting the second part of the third layer and the exposed part of the first layer by patterning the second triple-layer;

removing selectively the second and the third layers in the opening of the fourth feature to expose another part of the first layer;

removing the fourth feature;

removing the exposed part of the first layer and the another exposed part of the first layer with a residual third layer; and

etching the underlying material by using the second layers as a mask.