Multi-Beam Electron Writing Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multi-beam electron beam writing, leaked beams occur due to incomplete blocking by the limiting aperture, affecting writing accuracy, and existing methods struggle to completely control beam emission.
Innovation Solution
A multiple electron beam writing apparatus and method that utilize an excitation light source, multi-lens array, photoemissive surface, blanking aperture array mechanism, and electron optical system, with a control circuit to synchronize the timing of excitation light emission and beam switching between ON and OFF states, ensuring precise blanking control of each beam.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a limiting aperture is used to block electron beams in the blanking mechanism, then beam switching control is achieved, but leaked beams cannot be completely suppressed
Solution Approach 1:
The patent applies preliminary action by stopping the excitation light before switching the beam to OFF state. The control circuit generates a light stop signal that precedes the beam blanking signal, ensuring that photoelectron generation ceases before the beam is deflected away from the target. This temporal sequencing prevents leaked beams from reaching the target object during beam switching transitions.
Solution Approach 2:
The patent implements periodic action through synchronized timing of light emission and beam switching. The control circuit coordinates the periodic generation of light stop signals with the periodic beam blanking signals, creating a rhythmic pattern where light is stopped and restarted in sync with beam ON/OFF transitions. This periodic coordination ensures consistent suppression of leaked beams across multiple writing cycles.
2Productivity
If multiple beams are used simultaneously for writing, then writing throughput is greatly increased, but control complexity for individual beam switching increases
Solution Approach 1:
The patent applies segmentation by dividing the control of multiple beams into independent, individually addressable units. Each beam has its own blanking signal line and corresponding control logic in the control circuit, allowing independent ON/OFF switching of each beam. This segmented control approach enables precise dosing for each beam position while maintaining multi-beam parallel operation, thus achieving high throughput without sacrificing control precision.
Solution Approach 2:
The patent introduces an intermediary control circuit that mediates between the beam generation system and the beam deflection system. This control circuit receives writing pattern data and generates coordinated blanking signals for multiple beams simultaneously, acting as an intermediary that simplifies the overall control architecture. The control circuit processes beam control signals and light stop signals in coordination, reducing the complexity that would otherwise exist in directly controlling multiple beams without centralized coordination.
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 approach effectively reduces leaked beams, improving writing accuracy by ensuring each beam is accurately controlled between ON and OFF states, thereby enhancing the precision of pattern writing on semiconductor devices.
Implementation Method 1
a photoemissive surface configured on the multi-lens array to receive the plurality of lights incident through its upper side, and emit multiple photoelectron beams from its back side
Data Source
AI summary
A multiple electron beam writing apparatus includes an excitation light source to emit an excitation light, a multi-lens array to divide the excitation light into a plurality of lights, a photoemissive surface to receive the plurality of lights incident through its upper side, and emit multiple photoelectron beams from its back side, a blanking aperture array mechanism to provide, by deflecting each beam of the multiple photoelectron beams, an individual blanking control which individually switches each beam between ON and OFF, an electron optical system to include an electron lens, and to irradiate, using the electron lens, a target object with the multiple photoelectron beams having been controlled to be beam ON, and a control circuit to interconnect, for each shot of the multiple photoelectron beams, a timing of switching the excitation light between emission and non-emission with a timing of switching the each beam between ON and OFF.