Integrated Alignment Sensor Layout for Multi-Beam Lithography
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Solution Overview
Problem
Current multi-beam charged particle lithography systems face challenges in accurately aligning substrates with charged particle radiation due to the inability to directly measure the relationship between the substrate and the radiation projection system, requiring multiple time-consuming measurements.
Innovation Solution
A multi-beamlet charged particle lithography system incorporating a beamlet measurement sensor and a position mark measurement system with an alignment sensor, where the beamlet measurement sensor surface and position mark are integrated, allowing for simultaneous measurement of beamlet characteristics and substrate alignment, using a converter element and photon receptor to generate and detect photons, and a pattern of blocking structures for precise alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple separate measurements are performed to determine substrate-radiation relationship, then measurement completeness is improved, but measurement time increases
Solution Approach 1:
The patent combines the beamlet measurement sensor and alignment sensor into a single integrated sensor unit. The beamlet measurement sensor measures charged particle beamlet characteristics while the alignment sensor measures substrate position marks, both through a single sensor surface that receives both types of radiation simultaneously. This merging eliminates the need for separate measurement operations, reducing measurement time while maintaining complete measurement capability.
Solution Approach 2:
The integrated sensor serves multiple functions: it acts as both a beamlet measurement sensor for characterizing charged particle beamlets and an alignment sensor for measuring substrate position marks. The single sensor surface can detect both charged particles and light photons, enabling one component to perform what previously required separate specialized sensors and measurement procedures.
2Measurement precision
If separate beamlet measurement and alignment measurement systems are used, then measurement specialization is improved, but system complexity increases
Solution Approach 1:
The patent merges the beamlet measurement sensor and alignment sensor into a single integrated sensor assembly. Instead of having separate measurement systems with separate sensors, readout electronics, and data processing channels, the invention combines both measurement capabilities into one unified sensor that receives both charged particle beamlets and light photons through a common sensor surface, thereby reducing system complexity.
3Device complexity
If conventional alignment methods are used without direct relationship measurement, then system simplicity is maintained, but alignment accuracy deteriorates
Solution Approach 1:
The patent introduces light photons as an intermediary medium to enable direct measurement of the relationship between substrate and radiation. The alignment sensor detects light photons that carry information about substrate position marks, providing a direct optical measurement pathway. This intermediary approach allows for high-precision alignment measurement while maintaining relative system simplicity through a straightforward optical detection mechanism.
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
Enables fast and accurate alignment of substrates with charged particle radiation, improving throughput and precision in transferring patterns to substrates by correlating beamlet and alignment sensor measurements, thereby addressing the limitations of existing systems.
Implementation Method 1
charged-particle beamlets are converted into light beams, using a converter element such as a fluorescent screen or a doped YAG material
Implementation Method 2
a light source for illuminating the position mark and a detector for detecting light that has interacted by reflection with the position mark
Data Source
AI summary
A multi-beamlet charged particle beamlet lithography system for transferring a pattern to a surface of a substrate. The system comprises a projection system (311) for projecting a plurality of charged particle beamlets (7) onto the surface of the substrate; a chuck (313) moveable with respect to the projection system; a beamlet measurement sensor (i.a.i.e., 505, 511) for determining one or more characteristics of one or more of the charged particle beamlets, the beamlet measurement sensor having a surface (501) for receiving one or more of the charged particle beamlets; and a position mark measurement system for measuring a position of a position mark (610, 620, 635), the position mark measurement system comprising an alignment sensor (361, 362). The chuck comprises a substrate support portion for supporting the substrate, a beamlet measurement sensor portion (460) for accommodating the surface of the beamlet measurement sensor, and a position mark portion (470) for accommodating the position mark.