Projection Drawing Head Pattern Correction for Uneven Substrates

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Solution Overview

Problem

Existing drawing apparatuses struggle to accurately draw patterns on surfaces with complex shapes, such as inclined surfaces, beyond the focal depth of the optical system, leading to defocus and increased differences between the drawing and design patterns, especially when the height exceeds 100 μm.

Innovation Solution

A drawing apparatus and method that utilizes a spatial light modulator and projection optical system to generate modulated light, controlled by correction pattern data generated from substrate surface profile data, allowing precise focusing and exposure without complex optical adjustments, even on surfaces with heights exceeding the focal depth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the height of the substrate surface greatly exceeds the focal depth, then the drawing apparatus can handle complex surface shapes, but the difference between the drawing pattern and the design pattern increases due to defocus

Engineering Contradiction:

Improveability to handle complex surface shapesVSAvoidpattern accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention performs preliminary actions by generating correction pattern data based on surface profile data before the actual drawing process. The correction pattern data pre-compensates for the height differences and defocus effects that would occur on complex surfaces, allowing the drawing apparatus to maintain pattern accuracy without real-time focus adjustment.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention changes parameters by modifying the pattern data according to the surface profile. The correction pattern data adjusts geometric parameters (pattern dimensions, positions) based on the measured surface height variations, compensating for defocus effects through parameter transformation rather than physical focus adjustment.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If one inclined surface is divided into a plurality of exposure regions to expose fine patterns, then the pattern accuracy can be maintained, but the control of the drawing apparatus becomes complicated

Engineering Contradiction:

Improvepattern accuracyVSAvoidcontrol complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention merges the correction of focus errors into a single correction pattern data generation step rather than requiring separate focus adjustments for multiple exposure regions. The controller integrates surface profile information and generates comprehensive correction data that handles the entire inclined surface in one process, simplifying control while maintaining accuracy.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If the height exceeds 100 μm, then the drawing apparatus can handle taller structures, but it is difficult to follow the change in height with a typical autofocus mechanism

Engineering Contradiction:

Improveability to handle tall structuresVSAvoidfocus adjustment difficulty

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The invention replaces the mechanical autofocus system with a computational approach. Instead of using mechanical lenses or mirrors to physically adjust focus for height changes exceeding 100 μm, the system uses correction pattern data generated from surface profile measurements to computationally compensate for the height variations, eliminating the need for complex mechanical focus adjustment mechanisms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables high-accuracy drawing on surfaces with heights up to 100 μm or more by correcting design patterns based on surface profiles, maintaining focus and exposure density, thus reducing defocus-related errors.

Implementation Method 1

a spatial light modulator that modulates light from a light source to generate modulated light

Methodology Applied

Scientific EffectLight modulation:

Implementation Method 2

a projection optical system that focuses the modulated light on a focus position in a height direction over the stage

Methodology Applied

Scientific EffectOptical focusing: Focusing

Data Source

PatentUS12504691B2Drawing apparatus, drawing system, and drawing method

Publication Date: 2025.12.23 SCREEN HOLDINGS CO LTD

AI summary

Provided is a drawing apparatus capable of drawing with high accuracy on a surface having a shape whose height exceeds a focal depth without complicatedly adjusting focus of an optical system. A substrate can be placed on a stage. A drawing head includes a spatial light modulator that generates modulated light, and a projection optical system that focuses the modulated light on a focus position in a height direction over the stage. A mover relatively moves the stage and the drawing head in the horizontal direction. A controller controls the mover and the drawing head. The controller controls the spatial light modulator based on correction pattern data representing a correction pattern, and the correction pattern data is generated by correcting design pattern data representing a design pattern based on surface profile data representing a surface profile of the substrate.