Charged Particle Beam Substrate Positioning via Laser Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Charged particle beam processing apparatuses face challenges in maintaining precision and preventing particle defects during mask manufacturing due to positional shifts and contamination, particularly when using image processing techniques with CCD cameras, which can introduce noise and complicate the apparatus.
Innovation Solution
A charged particle beam processing apparatus that utilizes a sample chamber with a movable stage and a Z sensor system to detect the height and position of substrates using laser beams, allowing for precise calculation of the substrate's center of gravity and rotation angle without physical contact, thus minimizing positional shifts and contamination risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If image processing techniques with CCD cameras are used to detect substrate position, then positioning information can be obtained, but optical noise is introduced and apparatus complexity increases
Solution Approach 1:
The patent replaces the optical CCD camera system with a mechanical laser-based measurement system. The laser beam physically measures the distance to the substrate surface by detecting the reflected light, converting an optical imaging problem into a direct distance measurement problem. This substitution eliminates the need for complex image processing algorithms and optical noise filtering while maintaining high positioning precision.
Solution Approach 2:
The patent extracts only the essential measurement function from the complex CCD image processing system. Instead of using the entire optical imaging chain, it isolates the critical distance measurement capability by using a laser beam to directly measure the substrate position, removing unnecessary optical components and processing complexity.
2Manufacturing precision
If substrate is pressed against positional reference on stage, then drawing position can be determined, but particle contamination occurs
Solution Approach 1:
The patent replaces mechanical contact-based positioning (pressing substrate against reference) with a non-contact laser measurement system. The laser beam measures the substrate position from a distance without physical contact, eliminating the source of particle contamination while maintaining positioning accuracy through optical measurement.
Solution Approach 2:
The patent introduces a laser beam as an intermediary between the positioning reference and the substrate. Instead of direct mechanical contact, the laser beam serves as a non-contact mediator that transfers positioning information without causing contamination, allowing position determination while avoiding particle generation.
3Object-affected harmful factors
If substrate is merely placed on substrate holding unit without pressing, then particle contamination is reduced, but position shift occurs
Solution Approach 1:
The patent implements a feedback mechanism where the laser beam continuously measures the substrate position after placement. The measured position information is fed back to the control system, which can then adjust or compensate for any position shifts, ensuring accurate positioning without requiring mechanical pressing that would cause contamination.
Solution Approach 2:
The patent replaces mechanical pressing with non-contact laser measurement and control. The laser-based positioning system provides real-time feedback to maintain substrate position accuracy without physical contact, eliminating the trade-off between contamination and position shift.
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
This solution enables accurate and precise positioning of substrates within the processing apparatus, reducing the likelihood of particle defects and maintaining high drawing precision while simplifying the apparatus by avoiding the complexities associated with image processing and optical noise.
Implementation Method 1
a height and position acquiring unit for acquiring a height of the substrate on the stage by irradiating a laser beam onto the substrate mounted on the stage and using the laser beam reflected from the substrate
Implementation Method 2
using the laser beam reflected from the substrate
Data Source
AI summary
A charged particle beam processing apparatus includes a sample chamber to process a substrate including side faces by a charged particle beam, a movable stage in the sample chamber, the stage including a place on which the substrate is to be mounted, a height and position acquiring unit to acquire a height of the substrate on the stage by irradiating a laser beam onto the substrate on the stage and using the laser beam reflected from the substrate and to acquire positions of at least two adjacent side faces among the side faces based on the acquired height, and a calculating unit to calculate a position of center of gravity of the substrate on the stage and a rotation angle as to a rotary axis vertical to the place on which the substrate is to be mounted based on the positions of the at least two adjacent side faces.