Support Pin Voltage Equalization in Electron Beam Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The occurrence of discharge between the substrate with a retarding voltage and support pins in electron beam inspection apparatuses degrades inspection accuracy and can damage the equipment, due to the concentration of electric fields.
Innovation Solution
The use of support pins with a columnar insulator and a metal film, where a second voltage is applied to the metal film to equalize its potential with the substrate, reducing electric field concentration and preventing discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a retarding voltage is applied to the substrate to decelerate the electron beam, then the resolution is improved, but discharge occurs between the substrate and support pins
Solution Approach 1:
A voltage-adjusting unit is introduced as an intermediary component between the substrate and support pins. This unit actively adjusts the potential of support pins to match the substrate potential, preventing discharge while maintaining the retarding voltage for high-resolution inspection.
Solution Approach 2:
The potential of the support pins is dynamically changed to match the substrate potential. By adjusting the voltage parameter of the support pins based on the substrate potential, the system prevents discharge while maintaining the necessary retarding voltage for high-resolution electron beam inspection.
2Measurement precision
If the electron beam acceleration voltage is raised to improve resolution, then the inspection accuracy is improved, but the electron beam path changes due to discharge
Solution Approach 1:
The voltage-adjusting unit acts as a mediator that prevents discharge by matching support pin potentials to substrate potentials. This eliminates the harmful electric field concentration that would otherwise cause electron beam path deviations, ensuring reliable and stable inspection.
Solution Approach 2:
The system applies preliminary anti-action by pre-adjusting the support pin potentials to match the substrate potential before discharge can occur. This preventive measure eliminates the cause of electron beam path changes, ensuring stable and reliable inspection results.
3Ease of operation
If support pins are used to hold the substrate, then the substrate positioning is enabled, but electric field concentration occurs between the substrate and support pins
Solution Approach 1:
The potential parameter of the support pins is changed to match the substrate potential. This eliminates electric field concentration at the interface between substrate and support pins, while maintaining the mechanical positioning function of the support pins.
Solution Approach 2:
The voltage-adjusting unit serves as an intermediary that equalizes potentials between substrate and support pins. This eliminates harmful electric field concentration while preserving the essential substrate positioning function provided by the support pins.
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 configuration ensures accurate and reliable electron beam inspection by preventing discharge and maintaining the integrity of the inspection apparatus.
Implementation Method 1
concentration of electric field in the space between the substrate to which a retarding voltage is applied and the support pins
Implementation Method 2
Discharge may be induced by concentration of electric field in the space between the substrate to which a retarding voltage is applied and the support pins
Data Source
AI summary
In one embodiment, an electron beam inspection apparatus includes an optical system irradiating a substrate with primary electron beams, a beam separator separating, from the primary electron beams, secondary electron beams emitted as a result of irradiating the substrate with the primary electron beams, a detector detecting the secondary electron beams separated, a movable stage on which the substrate is placed, a support base supporting the substrate on the stage, and an applying unit applying a first voltage to the substrate. The support base includes a plurality of support pins that support the substrate from below. The support pins each include a columnar insulator and a metal film disposed in the insulator. A second voltage is applied to the metal film.