Dual Deflector Alignment for Charged Particle Beam Lithography
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Solution Overview
Problem
In charged particle beam lithography, axis deviations and beam misalignment due to consumable electron gun replacement lead to beam defects and blurs, making precise lithography challenging.
Innovation Solution
A charged particle beam lithography apparatus with two alignment deflectors and an imaging unit that calculates and controls the deflection of the beam to compensate for axis deviations, ensuring the beam intersects the optical axis and maintains precision, using a control portion to adjust the first and second deflectors based on image data from a beam detector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the electron gun is replaced as a consumable component, then the device can continue operation, but axis deviations and beam misalignment occur leading to beam defects and blurs
Solution Approach 1:
The patent implements preliminary beam alignment and axis deviation correction by providing multiple alignment deflectors (first alignment deflector, second alignment deflector) that are activated before and during the electron gun replacement process. The control portion calculates appropriate deflection amounts based on detected beam position and applies corrective deflection to prevent beam defects and maintain lithography precision during and after electron gun replacement.
2Manufacturing precision
If multiple alignment deflectors and control mechanisms are added, then beam alignment precision is improved, but device complexity increases
Solution Approach 1:
The patent makes the alignment deflectors serve multiple functions: they are used for initial beam alignment, for correcting axis deviations during electron gun replacement, and for maintaining beam precision during operation. The control portion also performs multiple functions by detecting beam position, calculating deflection amounts, and controlling the deflectors. This multi-functionality reduces the need for separate dedicated components for each function.
3Manufacturing precision
If the beam is repeatedly focused and deflected through multiple lenses and apertures, then the beam is formed precisely on the test piece, but axis deviations accumulate leading to beam defects
Solution Approach 1:
The patent implements a feedback mechanism where the control portion detects the actual beam position and trajectory after it passes through the multiple lenses and apertures, calculates the accumulated axis deviations, and applies corrective deflection through the alignment deflectors. This closed-loop feedback system continuously monitors and corrects beam position, preventing beam defects and maintaining both precision and reliability.
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 effectively compensates for axis deviations, preventing beam defects and blurs, enabling high-precision lithography by ensuring the beam remains aligned and focused on the optical axis.
Implementation Method 1
a first alignment deflector (2) that deflects the charged particle beam emitted from the charged particle beam generation source (1); a second alignment deflector (3) that deflects the charged particle beam deflected by the first alignment deflector (2)
Implementation Method 2
a charged particle beam forming portion, that is, a first illumination lens 4, a beam limitation aperture 5, which is provided so that the center thereof corresponds to the center of the first illumination lens, a second illumination lens 7
Data Source
AI summary
A charged particle beam lithography apparatus includes a charged particle beam generation source; a charged particle beam forming portion through which the charged particle beam is transmitted; a first deflector arranged between the charged particle beam forming portion and the charged particle beam generation source; a second deflector arranged between the first deflector and the charged particle beam forming portion; an imaging unit obtaining image data of the aperture; and a control portion calculating amounts of excitation of the first and second deflector based on the image data. The charged particle beam is deflected by the first deflector to intersect the optical axis. The deflected charged particle beam is deflected by the second deflector to advance on the optical axis. The control portion controls the first and second deflectors based on the calculated amounts of excitation.