Multi-beam blanking control for semiconductor lithography
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Solution Overview
Problem
In multi-beam writing systems for semiconductor manufacturing, the existing blanking control methods face challenges in achieving high-speed and high-precision beam ON/OFF control due to space and current restrictions on the blanking plate, leading to decreased writing precision and increased crosstalk when control circuits are placed outside the plate.
Innovation Solution
Implementing a multi-charged particle beam writing method that uses individual blanking systems for each beam and a common blanking system to collectively control all beams, with a logic circuit converting irradiation time into binary numbers and dividing it into multiple irradiation steps, allowing for precise control of beam ON/OFF states during irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a blanking control circuit for each beam is placed on a blanking plate, then beam ON/OFF control can be performed, but the installation space is restricted and the pitch of multiple beams is narrowed
Solution Approach 1:
The invention extracts the control circuit from the blanking plate and places it outside. The blanking plate retains only the blanking electrodes, while the control circuits are relocated to external positions, connected via wiring. This resolves the space conflict by separating the control function from the blanking structure.
Solution Approach 2:
The system is segmented into distinct functional modules: the blanking plate with electrodes, external control circuits, and connecting wiring. This segmentation allows each component to be optimized independently, with the blanking plate focusing on beam control and external circuits handling logic operations.
2Area of stationary object
If control circuits are placed outside the blanking plate to secure installation space, then more space is available, but wiring becomes long and crosstalk increases
Solution Approach 1:
The invention introduces an intermediary structure (the blanking plate with integrated electrodes) that mediates between the external control circuits and the beams. This allows control signals to be transmitted with minimized crosstalk while maintaining external circuit placement for space efficiency.
3Ease of manufacture
If an uncomplicated circuit is used on the blanking plate due to space restrictions, then installation is simpler, but high-speed and high-precision operation becomes difficult
Solution Approach 1:
Complex control circuits requiring high-speed operation are extracted from the blanking plate and placed externally, where they can be designed with higher complexity without space constraints. The blanking plate retains only simple electrode structures, while precision control is achieved through external circuitry.
4Productivity
If multiple beams are arranged with narrow pitch to increase throughput, then more beams can be processed simultaneously, but the required installation space decreases
Solution Approach 1:
The invention resolves the space-throughput tradeoff by moving the control circuitry to an external dimension, away from the blanking plate plane. This allows beams to be arranged with narrow pitch on the plate without requiring additional space for control circuits, thereby increasing throughput while maintaining compact beam spacing.
Data Source
AI summary
A multi charged particle beam writing method includes performing ON/OFF switching of a beam by an individual blanking system for the beam concerned, for each beam in multi-beams of charged particle beam, with respect to each time irradiation of irradiation of a plurality of times, by using a plurality of individual blanking systems that respectively perform beam ON/OFF control of a corresponding beam in the multi-beams, and performing blanking control, in addition to the performing ON/OFF switching of the beam for the each beam by the individual blanking system, with respect to the each time irradiation of the irradiation of the plurality of times, so that the beam is in an ON state during an irradiation time corresponding to irradiation concerned, by using a common blanking system that collectively performs beam ON/OFF control for a whole of the multi-beams.