Method and system for forming a diagonal pattern using charged particle beam lithography

A method for forming a semiconductor device layout pattern on a reticle, the layout pattern to be formed on a wafer using a lithographic process with the reticle, the layout pattern comprising a diagonal pattern, wherein a portion of the diagonal pattern comprises a constant-width or nearly constant-width track on the wafer, and wherein an inner transition region of the diagonal pattern is adjoined on one side by an outer transition region and on the other side by a central core region, the method comprising the steps of:

• determining a set of at least three non-overlapping variable-shaped beam (VSB) outer transition shots which is capable of forming on the reticle the portion of the diagonal pattern in the outer transition region;
• determining a set of VSB core shots which is capable of forming on the reticle the portion of the diagonal pattern in the central core region, wherein each shot in the set of core shots overlaps another shot in the set of core shots;
• determining a series of at least three VSB inner transition shots which is capable of forming an inner transition pattern on the reticle, wherein an inner transition pattern characteristic smoothly transitions between the pattern defined by the outer transition shots and the pattern defined by the core shots;
• and
• forming the layout pattern on the reticle with the set of outer transition shots, the set of core shots and the series of inner transition shots.

A method for forming a semiconductor device layout pattern on a substrate, the layout pattern comprising a diagonal pattern, wherein a portion of the diagonal pattern comprises a constant-width or nearly constant-width track on the wafer, the method comprising the steps of:

• using a reticle, where the reticle pattern has been created using a method comprising the steps of:
• forming an outer region of the diagonal pattern using a set of non-overlapping variable-shaped beam (VSB) shots;
• forming a central core region of the diagonal pattern using a plurality of overlapping VSB shots;
• and
• forming an inner transition region of the diagonal pattern using a plurality of VSB shots, wherein the inner transition region adjoins the central core region on one side and the outer region on the opposite side, and wherein the characteristics of the diagonal pattern transition smoothly from the boundary with the central core region to the boundary with the outer region, wherein the characteristics are selected from the group consisting of line edge roughness (LER) and period of waviness;
• and
• forming the layout pattern on the substrate using an optical lithographic process and the reticle.

A method for fracturing or mask data preparation of a semiconductor device layout design comprising a diagonal pattern, the method comprising the steps of:

• determining a first set of non-overlapping variable-shaped beam shots that is capable of forming a first pattern portion of the diagonal pattern on a surface, wherein the first pattern portion comprises a first boundary;
• determining a second set of charged particle beam shots that is capable of forming a second pattern portion of the diagonal pattern on the surface, wherein the second pattern portion comprises a second boundary;
• and
• determining a series of charged particle beam shots which is capable of forming on the surface a third pattern portion of the diagonal pattern which is interposed between the first pattern portion and the second pattern portion and which is adjacent to both the first boundary and the second boundary, wherein the third pattern portion smoothly transitions between the first pattern portion and the second pattern portion.

A system for fracturing or mask data preparation of a semiconductor device layout design to be formed on a wafer using a lithographic process with a reticle, the layout design comprising a diagonal pattern, wherein a portion of the diagonal pattern comprises a constant-width or nearly constant-width track on the wafer, and wherein an inner transition region of the diagonal pattern is adjoined on one side by an outer transition region and on the other side by a central core region, the system comprising:

• a device configured to determine a set of at least three non-overlapping variable-shaped beam (VSB) outer transition shots which is capable of forming on the reticle the portion of the diagonal pattern in the outer transition region;
• a device configured to determine a set of VSB core shots which is capable of forming on the reticle the portion of the diagonal pattern in the central core region, wherein each shot in the set of core shots overlaps another shot in the set of core shots;
• a device configured to determine a series of at least three VSB inner transition shots which is capable of forming an inner transition pattern on the reticle, wherein the inner transition pattern smoothly transitions between the pattern defined by the outer transition shots and the pattern defined by the core shots;
• and
• a device configured to output the set of outer transition shots, the set of core shots and the series of inner transition shots.