US 6,312,134 B1Granted

Seamless, maskless lithography system using spatial light modulator

AssigneeAnvik Corporation

InventorsKanti Jain, Thomas J. Dunn, Jeffrey M Hoffman

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Abstract

The invention is a seamless projection lithography system that eliminates the need for masks through the use of a programmable Spatial Light Modulator (SLM) with high parallel processing power. Illuminating the SLM with a radiation source (1), which while preferably a pulsed laser may be a shuttered lamp or multiple lasers with alternating synchronization, provides a patterning image of many pixels via a projection system (4) onto a substrate (5). The preferred SLM is a Deformable Micromirror Device (3) for reflective pixel selection using a synchronized pulse laser. An alternative SLM is a Liquid Crystal Light Valve (LCLV) (45) for pass-through pixel selection. Electronic programming enables pixel selection control for error correction of faulty pixel elements. Pixel selection control also provides for negative and positive imaging and for complementary overlapping polygon development for seamless uniform dosage. The invention provides seamless scanning by complementary overlapping scans to equalize radiation dosage, to expose a pattern on a large area substrate (5). The invention is suitable for rapid prototyping, flexible manufacturing, and even mask making.

Claims15

Dependent claims

A maskless lithography system for providing a pattern image on an image field of a large-area substrate (5), consisting of:

a) a radiation source (1) directed onto a selected object plane;
b) a multi-position spatial light modulator, consisting of a set of deformable micromirror devices, one for each pixel position, illuminated by said radiation source (1) at said selected object plane, being capable of selectively relaying radiation toward the substrate (5), for reflecting radiation from said radiation source (1) through projection means (4) to form an image on the substrate (5) of an array assembly of individual pixel modulators, configured as a momentarily selected composite polygonal spatial light pattern image;
c) projection means (4) for imaging said momentarily selected composite polygonal pattern image radiation relayed from said set of deformable micromirror devices (3) onto said substrate (5);
d) a scanning stage (6) upon which said substrate (5) rests, said scanning stage (6) moving at constant velocity so that each momentarily selected composite polygonal pattern image formed by said set of deformable micromirror devices (3) that is projected onto said substrate will illuminate a specific elongated region of the image field of said substrate (5) with composite image intensity varying toward the side edges of said elongated region, until such substrate (5) has been scanned along the length of the image field, at which time said scanning stage (6) moves in a direction orthogonal to the scan direction in order to allow a subsequent partially overlapping polygonal complementary scan along the length of an adjacent elongated region of the image field to take place;
and
e) a control system (7) comprising electronic programming means to provide a data set to configure each said pixel modulator with a selected composite pixel pattern to result in image with intensity varying toward the side edges of said elongated region, and means to synchronize the movement of said scanning stage (6) with the data stream to said spatial light modulator (3);
wherein said radiation source (1) illuminates the entire set of pixel positions of said spatial light modulator (3), and said electronic programming means configures and reconfigures said pixel positions to generate composite elongated region partial images, each of which varies in dosage across its profile to accomplish overlapping complementary polygonal scanning for seamless imaging.

4 more elements

A maskless lithography system for providing a pattern image on an image field of a large-area substrate (5), comprising:

a) a radiation source (1) directed onto a selected object plane;
b) a spatial light modulator array (3), comprising a liquid crystal light valve array for transmitting radiation from said radiation source (1) toward said substrate (5), said liquid crystal light valve being characterized by an array of liquid crystal pixel positions, each of said pixel positions being configured to transmit a selected pixel image onto said substrate (5) configured to form a selected composite polygonal pattern image;
illuminated by said radiation source (1) at said selected object plane, being capable of relaying radiation toward the substrate (5) via said liquid crystal light valve;
c) projection means (4) for imaging said selected composite polygonal pattern image radiation relayed from said spatial light modulator array (3) onto said substrate (5);
d) a scanning stage (6) upon which said substrate (5) rests, said scanning stage (6) moving at constant velocity so that each composite pattern image formed by said spatial light modulator (3) that is projected onto said substrate will illuminate a specific region of said substrate (5), until said substrate (5) has been scanned along the length of the image field, at which time said scanning stage (6) moves in a direction orthogonal to the scan direction in order to allow a subsequent partially overlapping polygonal complementary scan along the length of the image field to take place;
and
e) a control system (7) comprising electronic programming means to provide a data set to configure each said spatial light modulator with a selected composite pattern including light intensity variation toward side edges according to the requirements of complementary overlapping polygonal scanning, and means to synchronize the movement of said scanning stage (6) with the data stream to said liquid crystal light valve.

4 more elements

A maskless lithography system for providing a pattern image on an image field of a large-area substrate (5), characterized by:

a) a radiation source (1) directed onto a selected object plane;
b) a spatial light modulator array (3), comprising a liquid crystal light valve array for transmitting radiation from said radiation source (1) toward said substrate (5), said liquid crystal light valve being characterized by an array of liquid crystal pixel positions, each of said pixel positions being configured to transmit a selected pixel image onto said substrate (5) configured to form a selected composite polygonal pattern image illuminated by said radiation source (1) at said selected object plane, being capable of relaying radiation toward the substrate (5) wherein said radiation source (1) illuminates the entire set of pixel positions of said spatial light modulator (3);
c) projection means (4) for imaging said selected composite polygonal pattern image radiation relayed from said spatial light modulator array (3) onto said substrate (5);
d) a scanning stage (6) upon which said substrate (5) rests, said scanning stage (6) moving at constant velocity so that each composite pattern image formed by said spatial light modulator (3) that is projected onto said substrate will illuminate a specific region of said substrate (5), until an elongated region of such substrate (5) has been scanned along the length of the image field with cumulative exposure intensity varying toward the sides of said elongated region, at which time said scanning stage (6) moves in a direction orthogonal to the scan direction in order to allow a subsequent partially overlapping polygonal complementary scan of an adjacent elongated region along the length of the image field to take place;
and
e) a control system (7) comprising electronic programming means to provide a data set to configure each said spatial light modulator with a selected composite pattern, and means to synchronize to movement of said scanning stage (6) with the data stream to said spatial light modulator (3) to configure said pixel positions to generate a sequence of said selected composite polygonal pattern partial images which varies in illumination dosage across its profile for overlapping complementary polygonal scanning for seamless imaging.

3 more elements

A maskless lithography system for providing a pattern image on an image field of a large-area substrate (5), characterized by:

a) a radiation source (1) directed onto a selected object plane;
b) a spatial light modulator array (3) comprising a liquid crystal light valve array for transmitting radiation from said radiation source (1) toward said substrate (5), said liquid crystal light valve being characterized by an array of liquid crystal pixel positions, each of said pixel positions being configured to transmit a selected pixel image onto said substrate (5) configured to form a selected composite polygonal pattern image illuminated by said radiation source (1) at said selected object plane, being capable of relaying radiation toward the substrate (5) wherein said radiation source (1) illuminates an entire set of pixel positions of said spatial light modulator (3);
c) projection means (4) for imaging said selected composite polygonal pattern image radiation relayed from said spatial light modulator array (3) onto said substrate (5);
d) a scanning stage (6) upon which said substrate (5) rests, said scanning stage (6) moving at constant velocity so that each selected composite pattern image formed by said spatial light modulator (3) that is projected onto said substrate will illuminate a specific region of said substrate (5), until such substrate (5) has been scanned along an elongated region of the image field, at which time said scanning stage (6) moves in a direction orthogonal to the scan direction in order to allow a subsequent partially overlapping polygonal complementary scan along the length of the image field to take place;
and
e) a control system (7) comprising electronic programming means to provide a data set to configure said spatial light modulator array with such selected composite pattern, and means to synchronize the movement of said scanning stage (6) with the data stream to said spatial light modulator array (3) to configure said pixel positions to generate a partial image which varies in illumination dosage across its profile;
wherein said electronic programming means furthermore configures said spatial light modulator (3) to produce an image whose dosage profile tapers off towards its lateral edges, and said scanning stage, upon completion of one scan, is capable of moving in a direction orthogonal to the scan direction in order to be positioned for a subsequent scan, so that said subsequent scan elongated region partially overlaps the prior scan elongated region by an amount which enables seamlessness and uniformity in intensity of the image on the substrate with respect to each prior scan.

4 more elements

A maskless lithography system for providing a pattern image on an image field of a large-area substrate (5), characterized by;

a) a radiation source (1) directed onto a selected object plane;
b) a spatial light modulator array (3) having a multiplicity of pixel positions, each of said pixel positions being configured to transmit a selected pixel image onto said substrate (5) configured to form a selected composite polygonal pattern image illuminated by said radiation source (1) at said selected object plane, being capable of relaying radiation toward the substrate (5) wherein said radiation source (1) illuminates an entire set of pixel positions of said spatial light modulator (3);
c) projection means (4) for imaging said selected composite polygonal pattern image radiation relayed from said spatial light modulator array (3) onto said substrate (5);
d) a scanning stage (6) upon which said substrate (5) rests, said scanning stage (6) moving at constant velocity to that each selected composite pattern image formed by said spatial light modulator (3) that is projected onto said substrate will illuminate a specific region of said substrate (5), until such substrate (5) has been scanned along an elongated region of the image field, at which time said scanning stage (6) moves in a direction orthogonal to the scan direction in order to allow a subsequent partially overlapping polygonal complementary scan along the length of the image field to take place;
and
e) a control system (7) comprising electronic programming means to provide a data set to configure said spatial light modulator array with such selected composite pattern, and means to synchronize the movement of said scanning stage (6) with the data stream to said spatial light modulator array (3) to configure said pixel positions to generate a partial image which varies in illumination dosage across its profile;
wherein said electronic programming means furthermore configures said spatial light modulator (3) to produce an image whose dosage profile tapers off towards its lateral edges, and said scanning stage, upon completion of one scan, is capable of moving in a direction orthogonal to the scan direction in order to be positioned for a subsequent scan, so that said subsequent scan elongated region partially overlaps the prior scan elongated region by an amount which enables seamlessness and uniformity in intensity of the image on the substrate with respect to each prior scan.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/230,438Filed 23 Jan 1999 · continuation
Priority: 25 Jul 1996
Granted: 6 Nov 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G03F 7/70475
Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating…
G03F 7/70291
Mask effects on the imaging process: addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid…
G03F 7/70358
Mask projection systems: scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
G03F
Photomechanical production of textured or patterned surfaces