Maskless lithography system and method with doubled throughput

• US 6,238,852 B1
• Filed: 01/04/1999
• Issued: 05/29/2001
• Est. Priority Date: 01/04/1999
• Status: Expired due to Fees

• Current Assignee: Anvik Corporation
• Original Assignee: Anvik Corporation
• Inventors: Klosner, Marc A.
• Primary Examiner(s): McPherson, John A.
• Application Number:
  US09/225,385
• Time in Patent Office: 876 Days
• Field of Search: 430/322, 430/396, 355/46, 355/53, 355/77
• US Class Current: 430/396
• CPC Class Codes: G03F 7/2002 with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/704 Scanned exposure beam, e.g. raster-, rotary- and vector scanning mask projection exposure involving relative movement of patterned beam and workpiece during imaging G03F7/70358

Abstract

A maskless lithography system that provides large-area, seamless patterning using a reflective spatial light modulator such as a Deformable Micromirror Device (DMD) directly addressed by a control system so as to provide a first pattern, via a first projection subsystem, on a first photoresist-coated substrate panel, while simultaneously providing a duplicate pattern, which is a negative of the pattern on the first substrate panel, via a second projection subsystem, onto a second photosensitive substrate panel, thus using the normally-rejected non-pattern “off” pixel radiation reflected by the “off” pixel micromirrors of the DMD, to pattern a second substrate panel. Since the “off” pixel reflections create a pattern which is complementary to the “on” pixel pattern, using a complementary photoresist coating on the second substrate panel provides for a duplicate pattern, as is usually desired. Since both the “on” and “off” reflections are used from each pixel position, using the same selection, the result is the doubling of throughput.

Claims

1. A microlithographic system using a writable DMD spatial light modulator to provide the selected pattern over a number of partially overlapping scans to provide a seamless composite pattern on a photosensitive substrate, having a radiation source (1) providing a radiation beam (2) to a DMD (3) to provide via a projection subsystem (4) a dynamic partial pattern of selected ‘

on’

pixels under control of control means (7) as a stage (6), also under control of control means (7), provides a relative motion for scanning said selected partial pattern of selected ‘

on’

pixels onto a photosensitive layer (5) on a substrate panel (8)

characterized by

second projection subsystem (4-c) arranged to accept a dynamic partial pattern of selected ‘

c-on’

pixels, which is a negative of said dynamic partial pattern of selected ‘

on’

pixels;

a second substrate panel (8-c), having a second photosensitive layer (5-c), mounted for common scanning motion with said substrate panel (8) on said stage (6);

whereby a first pattern is imaged onto said first substrate panel (8) and a second pattern related to said first pattern is simultaneously imaged on said second substrate panel (8-c), utilizing all the radiation output of said radiation source (1).

2. A microlithographic system according to claim 1, in which said photosensitive layer (5) is complementary in polarity to said second photosensitive layer (5-c), resulting in simultaneous patterning of identical patterns on both first and second substrate panels.

3. A microlithographic system according to claim 1, in which said photosensitive layer (5) is identical in polarity to said second photosensitive layer (5-c), resulting in simultaneous patterning of a positive pattern on said first substrate panel (8) and a negative pattern on said second substrate panel (8-c).

4. A method of simultaneously patterning a plurality of large-area substrate panels with high processing throughput and high resolution, comprising the steps of:

a) sending a focused beam (2) from a radiation source (1);

b) treating the beam from said radiation source (1) for desired numerical aperture in an illumination system;

c) illuminating a DMD (3) by said radiation source (1), whereby said DMD is configured to present an ‘

on’

pixel image and a simultaneous ‘

off’

pixel image which is the complement of the ‘

on’

pixel image, of a desired portion of the pattern to be placed on the substrate panels, in response to a data stream from a control system (7) which is characterized by electronic programming means to provide the data stream to said DMD (3), said ‘

on’

pixel image and said ‘

off’

pixel image being reflected in respective ‘

on’

radiation and ‘

c-on’

radiation along separate pathways;

d) imaging the ‘

on’

radiation from said spatial light modulator (3) through a first projection subassembly onto a first substrate panel, and simultaneously imaging the ‘

c-on’

radiation from said spatial light modulator (3) through a second projection subassembly onto a second substrate panel, on a scanning stage (6) that moves at a controlled velocity in the scan direction;

e) reconfiguring said spatial light modulator (3) with another set of data from said electronic programming means;

f) repeating steps (a) through (e) above for the next pulse from said radiation source (1), whereby the repetition rate of said radiation source (1) is synchronized by said control system (7) to the data stream that configures said DMD (3) and to the motion of the scanning stage (6), until both said first substrate panel (5) and said second substrate panel (5-c) have been scanned along the length of their respective image fields;

g) moving the scanning stage (6) in a direction orthogonal to the scan direction upon completion of a scan through a distance which enables seamless scanning to be achieved when an adjacent scan is generated, in the same manner as described in steps (a) through (f) above, until both said first substrate panel (5) and said second substrate panel (5-c) have been scanned seamlessly over an imaging area.

5. A method according to claim 4, in which said substrate panels are coated with different polarity photoresists respectively for activation by ‘

on’

radiation and ‘

c-on’

on radiation, which results in identical patterning of each of the plural substrate panels.