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US 6,787,459 B2Granted
Method for fabricating a semiconductor device
AssigneeRenesas Technology Corp.
InventorsAkemi Moniwa, Takuya Hagiwara, Keitaro Katabuchi, Hiroshi Fukuda, Mineko Adachi
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Abstract
There is provided a method of fabricating a semiconductor device whereby fine patterns are formed with high dimensional accuracy by means of multiple exposures, using a phase shift mask and a trim mask. Phases are periodically assigned to shifter patterns within a given range from patterns generated with the phase shift mask, respectively.
Claims16
A method of fabricating a semiconductor device comprising a step of forming circuit patterns including fine line patterns by:
- preparing a first phase shift mask comprising phase shift apertures with either of two phases substantially opposite to each other, assigned thereto, respectively, and an opaque area, and a second mask comprising apertures, and an opaque area;
- and
- subjecting the first phase shift mask and the second mask, placed at a substantially identical position on a resist film on top of a semiconductor substrate, to multiple exposures including:
- forming latent images of the fine line patterns and one latent image of each of at least one dummy pattern on the resist film with the first phase shift mask, and then removing said latent image of said dummy pattern with the second mask thereby providing resist patterns of the latent images of the fine line patterns on the resist film,
- wherein the respective fine line patterns are generated in respective regions on the resist film, corresponding to respective regions sandwiched between each pair of the phase shift apertures on the first phase shift mask, with mutually opposite phases assigned thereto, respectively, and phases of all the phase shift apertures adjacent to each other within a given distance from the respective fine line patterns, in the direction perpendicular thereto, are substantially opposite to each other.
2 more elements
A method of fabricating a semiconductor device comprising a step of forming circuit patterns including fine line patterns by:
- preparing a first phase shift mask comprising phase shift apertures with either of two phases, substantially opposite to each other, assigned thereto, respectively, and an opaque area, and a second mask comprising apertures, and an opaque area;
- and
- subjecting the first phase shift mask and the second mask, placed at a substantially identical position on a resist film on top of a semiconductor substrate, to multiple exposures including:
- forming latent images of the fine line patterns and one latent image of each of at least one dummy pattern on the resist film with the first phase shift mask, and then removing said latent image of said dummy pattern with the second mask thereby providing resist patterns of the latent images of the fine line patterns on the resist film,
- wherein the respective fine line patterns are generated in respective regions on the resist film, corresponding to respective regions sandwiched between each pair of the phase shift apertures on the first phase shift mask, with mutually opposite phases assigned thereto, respectively, data for the first phase shift mask and the second mask is generated from layout data of the circuit patterns, the data for the second mask is created so as to include protection patterns for protection of the fine line patterns generated in latent image with the first phase shift mask against exposure with the second mask, and circuit other than the fine line patterns, patterns of the first phase shift mask being corrected for proximity effect based on the layout data, and the data for the first phase shift mask and the second mask while patterns of the second mask being corrected for proximity effect based on the data for the second mask.
2 more elements
A method of fabricating a semiconductor device comprising a step of forming circuit patterns including fine line patterns by:
- preparing a first phase shift mask comprising phase shift apertures with either of two phases, substantially opposite to each other, assigned thereto, respectively, and an opaque area, and a second mask comprising apertures, and an opaque area;
- and
- subjecting the first phase shift mask and the second mask, placed at a substantially identical position on a resist film on top of a semiconductor substrate, to multiple exposures including:
- forming latent images of the fine line patterns and one latent image of each of at least one dummy pattern on the resist film with the first phase shift mask, and then removing said latent image of said dummy pattern with the second mask thereby providing resist patterns of the latent images of the fine line patterns on the resist film,
- wherein if a distance between a protection pattern for protection of respective patterns generated with the first phase shift mask created from layout data and a pattern generated in latent image with the second mask is found less than a minimum space dimension permissible for mask inspection from data for the second mask, space between said two patterns is filled up with an opaque pattern provided that a length of a portion of the space, less than the minimum space dimension permissible in width, along which said two patterns are opposed to each other, is not less than a minimum space dimension permissible for the mask inspection, and part of the protection pattern, in contact with the space is deleted to an extent that the minimum space permissible for the mask inspection is secured provided that the length of the portion of the space, along which said two patterns are opposed to each other, is less than the minimum space dimension permissible for the mask inspection.
2 more elements
A method of fabricating a semiconductor device, comprising the steps of:
- (a) preparing a semiconductor substrate formed thereon a film to be worked on;
- (b) coating a photoresist film on said film to be worked on;
- (c) providing a first photomask with an opaque area having at least a first, a second, a third, and a fourth apertures arranged in sequence and isolated by line-shaped opaque portions therebetween, said line-shaped opaque portions corresponding respectively to latent images of at least a first line portion, a second line portion, and a third line portion to be formed on said film, each pair of neighboring apertures of said apertures having mutually opposed phases to each other;
- (d) forming the latent images of the first line portion, the second line portion, and the third line portion on said photoresist film by subjecting said photoresist film to the first photomask with lights passing through edges of the first, second, third, and fourth apertures;
- (e) providing a second photomask with at least one transparent area each corresponding to one of the line portions to be irradiated and at least one opaque area corresponding to the remaining line portions to be shielded;
- (f) forming resist patterns having only said line portion to be shielded by said opaque area on said photoresist film, which has been subjected to the first photomask, by subjecting said photoresist film to the second photomask with lights passing through said transparent area thereon;
- and
- (g) etching said film with the resist patterns thereon.
5 more elements
A method of fabricating a semiconductor device having a first, second, and third layout portion of periodic assignment, and a fourth layout portion of non-periodic assignment located parallel and adjacent thereto comprising the steps of:
- (a) preparing a semiconductor substrate formed thereon a film to be worked on;
- (b) coating a photoresist film on said film to be worked on;
- (c) forming latent images of a first dummy layout portion, a first, a second and a third layout portions, a second dummy layout portion, a fourth layout portion, and a third dummy layout portion by subjecting said photoresist film to a first photomask,
- said first photomask being provided with an opaque area having a first, a second, a third, a fourth, a fifth, a sixth, a seventh, and an eighth apertures which are isolated by line-shaped opaque portions therebetween which correspond respectively to the latent images of the first dummy layout portion, the first, second and third layout portions, the second dummy layout portion, fourth layout portion, and the third dummy layout portion, each pair of the first and second apertures, the third and forth apertures, the fifth and sixth apertures, and the seventh and eighth apertures having mutually opposed phases to each other, while the first, third, fifth and seventh apertures having the same phase with one another and the second, fourth, sixth and eighth apertures having the same phase with one another;
- (d) forming resist patterns having only the first, second, third, and fourth layout portions on said photoresist film, which has been subjected to the first photomask, by subjecting said photoresist film to the second photomask with lights passing through transparent areas thereon,
- the second photomask being provided with opaque areas corresponding to the first, second, third, and fourth layout portions to be shielded and transparent areas corresponding to the first, second, and third dummy layout portions to be irradiated;
- and
- (e) etching said film with the resist patterns thereon.
5 more elements
Dependencies are inferred from the claim text.