Interlocking Grid Aperture Array for Particle Beam Lithography
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Solution Overview
Problem
Current multi-beam pattern definition devices for particle-beam processing face limitations in achieving sufficient gray scale levels, line edge roughness, and pattern placement accuracy, particularly in nano-scale patterning and lithography applications, due to physical address grid constraints and image distortion issues.
Innovation Solution
The introduction of interlocking grids with fractional offsets for aperture arrangement, allowing for finer resolution and reduced line edge roughness without decreasing aperture size, and enabling gray scale irradiation by interpolating additional exposure spots between basic grid positions, thereby enhancing the address grid and reducing optical performance requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional integer-multiple aperture spacing is used, then device structure is simple, but resolution is insufficient and line edge roughness increases
Solution Approach 1:
The aperture array is divided into multiple domains, where each domain contains apertures arranged according to a basic grid. By segmenting the overall array into distinct domains with different fractional offsets, the system achieves finer resolution without requiring each individual aperture to be more complex.
Solution Approach 2:
Different domains are assigned different fractional offsets (e.g., 0, 1/4, 2/4, 3/4 of the basic pitch) to break the symmetry of traditional integer-multiple spacing. This asymmetric arrangement within domains creates additional addressable positions and reduces line edge roughness while maintaining overall structural organization.
2Manufacturing precision
If aperture size is decreased to improve resolution, then address grid becomes finer, but optical performance requirements increase and critical dimensions are compromised
Solution Approach 1:
Instead of improving resolution by reducing aperture size in one dimension, the invention introduces a new dimension of control through fractional offsets. Apertures are arranged in multiple domains with offsets of 0, 1/4, 2/4, and 3/4 of the basic pitch, creating additional addressable positions without changing aperture dimensions or optical requirements.
3Manufacturing precision
If basic grid arrangement is used, then pattern placement is straightforward, but gray scale levels and pattern placement accuracy are insufficient
Solution Approach 1:
The system dynamically selects which domains to activate based on the required pattern. By controlling the deflection means for different domains, the apparatus can flexibly generate various patterns with high placement accuracy. The fractional offsets enable dynamic adjustment of beam positions to achieve precise gray scale levels and pattern placement.
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 enables a finer resolution on the target surface, downscaling the lithographic node from 45 nm to 32 nm, improving productivity and reducing line edge roughness while maintaining the critical dimensions of the pattern definition device, and allowing for more flexible and accurate pattern placement.
Implementation Method 1
a beam of electrically charged particles is incident on a pattern definition (PD) device
Implementation Method 2
a second state ('switched off') when the deflection means is deflecting particles radiated through the opening off said path
Data Source
AI summary
In a pattern definition device for use in a particle-beam processing apparatus a plurality of apertures (21) are arranged within a pattern definition field (pf) wherein the positions of the apertures (21) in the pattern definition field (pf) taken with respect to a direction (X, Y) perpendicular, or parallel, to the scanning direction are offset to each other by not only multiple integers of the effective width (w) of an aperture taken along said direction, but also multiple integers of an integer fraction of said effective width. The pattern definition field (pf) may be segmented into several domains (D) composed of a many staggered lines (pl) of apertures; along the direction perpendicular to the scanning direction, the apertures of a domain are offset to each other by multiple integers of the effective width (w), whereas the offsets of apertures of different domains are integer fractions of that width.