Control system for pattern generator in maskless lithography

• US 20080002174A1
• Filed: 06/30/2006
• Published: 01/03/2008
• Est. Priority Date: 06/30/2006
• Status: Abandoned Application

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Tinnemans, Patricius Aloysius Jacobus
• Application Number:
  US11/478,298
• Publication Number:
  US 20080002174A1
• Time in Patent Office: Days
• US Class Current: 355/67
• 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

Abstract

A lithographic apparatus comprises an illumination system, an array of individually controllable elements, a projection system, and a control system. The illumination system is configured to condition a radiation beam. The array of individually controllable elements is capable of modulating the cross-section of the radiation beam. The projection system is configured to project the modulated radiation beam onto a target portion of a substrate. The control system is arranged to send control signals, which control the array of individually controllable elements, such that a desired pattern is projected onto the substrate. The control system calculates the control signals using a bandwidth limited base function or a combination of more than one bandwidth limited base functions.

Claims

1. A lithographic apparatus, comprising:

an illumination system configured to condition a radiation beam;

an array of individually controllable elements capable of patterning the radiation beam;

a projection system configured to project the patterned beam onto a target portion of the substrate; and

a control system arranged to send control signals, which control the array of individually controllable elements, such that a desired pattern is projected onto the substrate, the control system configured to calculate the control signals using a bandwidth limited base function or a combination of more than one bandwidth limited base function.

2. The lithographic apparatus of claim 1, wherein the bandwidth limited base function H(x, y) comprises:

3. The lithographic apparatus of claim 1, wherein the bandwidth limited base function H_i(F,g) comprises:

4. A method of lithography, comprising:

calculating control signals using a bandwidth limited base function or a combination of more than one bandwidth limited base function;

controlling an array of individually controllable elements using the control signals;

patterning a radiation beam using the controlled array of individually controllable elements; and

projecting the patterned radiation beam onto a target portion of a substrate.

5. The method of claim 4, wherein the bandwidth limited base function H(x,y) comprises:

6. The method of claim 4, wherein the bandwidth limited base function H_i(f g) comprises:

7. A computer program product comprising a computer useable medium having computer program logic stored thereon for controlling at least one processor, the computer program logic comprising:

first computer program code means for calculating control signals using a bandwidth limited base function or a combination of more than one bandwidth limited base function;

second computer program code means for controlling an array of individually controllable elements using the control signals;

wherein a radiation beam is patterned using the controlled array of individually controllable elements; and

wherein the patterned beam is projected onto a target portion of a substrate.

8. The computer program product of claim 7, wherein the first computer program code means for calculating control signals uses the bandwidth limited base function H(x,y) comprises:

9. The computer program product of claim 7, wherein the first computer program code means for calculating control signals uses the bandwidth limited base function H_i(f,g) comprises: