Pattern forming method, semiconductor device manufacturing method and semiconductor device manufacturing apparatus

A pattern forming method for forming a pattern of a predetermined shape which serves as a mask for etching an etching target layer on a substrate, the method comprising:

• a first pattern forming process for forming a first pattern on the etching target layer by patterning a first mask material layer made of a photoresist;
• a boundary layer forming process for forming a boundary layer, which is made of a material selectively removable with respect to the photoresist, at sidewall portions, top portions of the first pattern and an exposed surface of the etching target layer;
• a second mask material layer forming process for forming a second mask material layer, which is made of a material selectively removable with respect to the boundary layer, while top portions of the boundary layer are exposed;
• a second boundary layer forming process for forming a second boundary layer, which is made of a material selectively removable with respect to the photoresist, on the second mask material layer and the boundary layer;
• a third mask material layer forming process for forming a third mask material layer, which is made of a photoresist and formed in a predetermined pattern, on the second boundary layer;
• an etching process for etching the second boundary layer into the predetermined pattern by using the third mask material layer as a mask and etching the second mask material layer by using the second boundary layer of the predetermined pattern as a mask;
• a boundary layer etching process for forming a second pattern made of the second mask material layer on the boundary layer by etching and removing the boundary layer and forming a void between the sidewall portions of the first pattern and the second mask material layer;
• and
• a trimming process for reducing a width of the first pattern and a width of the second pattern to predetermined widths.

A semiconductor device manufacturing method comprising:

• a process for etching an etching target layer on a substrate through a mask,
• wherein the mask is formed by a pattern forming method including:
• a first pattern forming process for forming a first pattern on the etching target layer by patterning a first mask material layer made of a photoresist;
• a boundary layer forming process for forming a boundary layer, which is made of a material selectively removable with respect to the photoresist, at sidewall portions, and top portions of the first pattern and an exposed surface of the etching target layer;
• a second mask material layer forming process for forming a second mask material layer, which is made of a material selectively removable with respect to the boundary layer, so as to cover a surface of the boundary layer;
• a second mask material removing process for removing a part of the second mask material layer to expose top portions of the boundary layer;
• a second boundary layer forming process for forming a second boundary layer, which is made of a material selectively removable with respect to the photoresist, on the second mask material layer and the boundary layer;
• a third mask material layer forming process for forming a third mask material layer, which is made of a photoresist and formed in a predetermined pattern, on the second boundary layer;
• an etching process for etching the second boundary layer into the predetermined pattern by using the third mask material layer as a mask and etching the second mask material layer by using the second boundary layer of the predetermined pattern as a mask;
• a boundary layer etching process for forming a second pattern made of the second mask material layer on the boundary layer by etching and removing the boundary layer and forming a void between the sidewall portions of the first pattern and the second mask material layer;
• and
• a trimming process for reducing a width of the first pattern and a width of the second pattern to predetermined widths.

A semiconductor device manufacturing method comprising:

• a process for etching an etching target layer on a substrate through a mask,
• wherein the mask is formed by a pattern forming method including:
• a first pattern forming process for forming a first pattern on the etching target layer by patterning a first mask material layer made of a photoresist;
• a boundary layer forming process for forming a boundary layer, which is made of a material selectively removable with respect to the photoresist, at sidewall portions, top portions of the first pattern and an exposed surface of the etching target layer;
• a second mask material layer forming process for forming a second mask material layer, which is made of a material selectively removable with respect to the boundary layer, while top portions of the boundary layer are exposed;
• a second boundary layer forming process for forming a second boundary layer, which is made of a material selectively removable with respect to the photoresist, on the second mask material layer and the boundary layer;
• a third mask material layer forming process for forming a third mask material layer, which is made of a photoresist and formed in a predetermined pattern, on the second boundary layer;
• an etching process for etching the second boundary layer into the predetermined pattern by using the third mask material layer as a mask and etching the second mask material layer by using the second boundary layer of the predetermined pattern as a mask;
• a boundary layer etching process for forming a second pattern made of the second mask material layer on the boundary layer by etching and removing the boundary layer and forming a void between the sidewall portions of the first pattern and the second mask material layer;
• and
• a trimming process for reducing a width of the first pattern and a width of the second pattern to predetermined widths.