Charged particle beam transfer method
AssigneeMamoru Nakasuji
InventorsMamoru Nakasuji, Shintaro Kawata
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Abstract
This invention provides the charged particle beam transfer method, which can control adverse effect of distortion or blur that arises from the space charge effect due to the non-uniform pattern density to a minimum. A pattern formed on reticle is raster or step-and-repeat scanned with a charged particle beam and is illuminated in consecutive order, and a pattern image of a sub-field, which is illuminated, is to be formed on a certain position of a radiation sensitive substrate. On the radiation sensitive substrate whole pattern is projected through stitching the said pattern image. The pattern is to be divided into plural areas A and B which differ in pattern density one another, and the above-described scan boundary is made to coincide with the boundary of these plural areas.
Claims20
A charged particle beam transfer method, comprising the steps of:
- (a) forming a pattern to be projected on a magnified reticle, the reticle is divided into plural stripes which have a longer side and a shorter side and where a reticle stage and a substrate stage are moving continuously along the longer side dimension during projection, each stripe is further divided into plural main fields of the charged particle beam optical system, and the longer side of the main field is the same as the shorter side of the stripe, each main field includes plural sub-fields,
- (b) scanning the pattern formed on the reticle in raster or step-and-repeat manner with the charged particle beam being to illuminate each sub-field one by one, wherein a pattern image of the illuminated sub-field is formed on a certain position of a radiation sensitive substrate,
- (c) thus projecting the whole pattern through stitching the pattern images of the sub-fields on the radiation sensitive substrate,
- wherein the above-described pattern is divided into plural areas whose pattern density differs one another;
- and the boundary of those areas coincide with that of the above-described scanning or of the sub field.
A charged particle beam transfer method, comprising the steps of:
- (a) forming a pattern to be projected on a magnified reticle, the reticle is divided into plural stripes which have a longer side and a shorter side and where a reticle stage and a substrate stage are moving continuously along the longer side dimension during projection, each stripe is further divided into plural main fields of the charged particle beam optical system, and the longer side of the main field is the same as the shorter side of the stripe, each main field includes plural sub-fields,
- (b) scanning the pattern formed on the reticle in raster or step-and-repeat manner with the charged particle beam being to illuminate each sub-field one by one, wherein a pattern image of the illuminated sub-field is formed on a certain position of a radiation sensitive substrate,
- (c) thus projecting the whole pattern through stitching the pattern images of the sub-fields on the radiation sensitive substrate, wherein
- the method levels the difference of pattern density in scanning direction, or converts the projected image distortion into blur that arises from the pattern density non-uniform in the X-direction.
A charged particle beam transfer method, comprising the steps of:
- (a) forming a pattern to be projected on a magnified reticle, the reticle is divided into plural stripes which have a longer side and a shorter side and where a reticle stage and a substrate stage are moving continuously along the longer side dimension during projection, each stripe is further divided into plural main fields of the charged particle beam optical system, and the longer side of the main field is the same as the shorter side of the stripe, each main field includes plural sub-fields,
- (b) scanning the pattern formed on the reticle in raster or step-and-repeat manner with the charged particle beam being to illuminate each sub-field one by one, wherein a pattern image of the illuminated sub-field is formed on a certain position of a radiation sensitive substrate,
- (c) thus projecting the whole pattern through stitching the pattern images of the sub-fields on the radiation sensitive substrate, wherein
- the main field X-dimension size is determined as follows the X-direction length of the chip is divided by integer and is to be selected from the size which is smaller than the size of the maximum optical main field and closest to it.
Dependencies are inferred from the claim text.