Segmented Substrate Cover for Charged-Particle Beam Lithography
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Solution Overview
Problem
Charged-particle beam lithographic systems face productivity issues due to electrostatic charging of substrates, which causes beam deviation, and existing substrate covers are cumbersome, making them difficult to handle and mount, leading to reduced productivity.
Innovation Solution
A charged-particle beam lithographic system with a substrate cover having a frame portion that covers the substrate's outer periphery, featuring a grounded second part that can be easily loaded and unloaded, and conductive pins for grounding the substrate, along with a vibratory portion to reduce residual stress and positional deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a substrate cover with outer size greater than the substrate is used to shield the side surface, then electrostatic charging is suppressed, but the substrate cover becomes difficult to convey and mount by transport devices
Solution Approach 1:
The substrate cover is divided into two functional parts: a first part (frame-like member) that shields the substrate side surface and a second part that can be easily conveyed by transport devices. This segmentation allows each part to have optimized characteristics for its specific function.
Solution Approach 2:
The first part (frame-like member) is positioned to surround and protect the substrate, while the second part is integrated in a way that allows the transport device to access and convey the substrate through the central opening, effectively nesting the substrate and transport device within the cover structure.
2Object-affected harmful factors
If the substrate cover is mounted on the substrate before conveyance, then shielding is effective, but the cover cannot be easily removed after lithography without removing the substrate
Solution Approach 1:
The substrate cover is segmented into a first part mounted on the substrate for shielding and a second part that can be independently removed. This allows the second part to be detached after lithography while the substrate remains mounted, enabling faster substrate reuse.
Solution Approach 2:
The substrate cover transitions from a static fixed structure to a dynamic partially removable structure, where the second part can be selectively removed after lithography to accelerate substrate turnover while maintaining shielding during the process.
3Object-affected harmful factors
If the frame-like member is made large enough to cover the substrate periphery, then shielding effectiveness is improved, but the complexity of mounting and handling increases
Solution Approach 1:
The frame-like member is divided into a first part that provides shielding and a second part that simplifies handling. The second part is designed with features that enable easy conveyance by standard transport devices, reducing mounting complexity.
Solution Approach 2:
The second part acts as an intermediary element that facilitates interaction between the substrate cover and transport devices, enabling easy conveyance and mounting without requiring complex handling procedures for the entire cover structure.
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
The system effectively suppresses electrostatic charging, enhances the ease of handling and mounting of the substrate cover, and improves productivity by allowing faster loading and unloading, reducing substrate flexure and positional deviations.
Implementation Method 1
If a part of the electron beam hits the side surface of the mask blank, then the glass base will be electrostatically charged.
Implementation Method 2
The second part has a conductive pin that makes electrical contact with the substrate and electrically grounds the substrate.
Implementation Method 3
The substrate stage has a vibratory portion that vibrates the substrate in order to reduce residual stress and positional deviation of the substrate
Data Source
AI summary
A charged-particle beam lithographic system (100) delineates a pattern on a substrate (2) by directing a charged-particle beam (L) at the substrate. The system (100) includes a substrate stage (10) on which the substrate (2) is disposed and a substrate cover (20). The cover (20) has a frame portion (22) that covers an outer peripheral portion of the substrate (2) as viewed within a plane. The frame portion (22) has a first part (22a) disposed on the stage (10) and a second part (22b) capable of being loaded and unloaded on and from the stage (10) by a transport portion (40). When the second part (22b) is loaded on the stage (10), it is electrically grounded.