Multi-Layer Mask for Rapid Electron Area Masking Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mask-based electron beam lithography techniques face challenges in achieving small feature sizes due to thick masks limiting patterned features and low-energy techniques restricting material usage and exposure times.
Innovation Solution
A multi-layer mask is fabricated with a first mask layer from silicon nitride defining feature apertures and coated with an electron-energy-reducing material like gold, optionally with a scaffolding silicon layer for structural integrity, allowing for smaller feature sizes and higher electron energies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a thick mask is used to prevent electron penetration, then electron exposure control is improved, but the minimum feature size increases
Solution Approach 1:
The mask is divided into multiple layers with distinct functions: a thin first mask layer (100-500 nm) for defining features, a thick second mask layer (1-10 μm) for stopping electrons, and an optional third scaffolding layer for structural support. This segmentation allows each layer to optimize for its specific function, enabling small features while preventing penetration.
Solution Approach 2:
Different regions of the mask structure have different properties optimized for their local function. The first mask layer is thin and patterned for high-resolution feature definition, while the second mask layer is thick and uniform for electron stopping, and the third layer provides mechanical strength where needed.
2Manufacturing precision
If a thin mask is used to achieve smaller feature sizes, then manufacturing precision is improved, but electron penetration increases
Solution Approach 1:
The mask is divided into multiple layers with distinct functions: a thin first mask layer (100-500 nm) for defining features, a thick second mask layer (1-10 μm) for stopping electrons, and an optional third scaffolding layer for structural support. This segmentation allows each layer to optimize for its specific function, enabling small features while preventing penetration.
3Manufacturing precision
If low electron energy is used with thin masks, then feature size is reduced, but material selection and exposure efficiency are limited
Solution Approach 1:
The multi-layer mask structure changes the energy parameter profile through the mask depth. Low-energy electrons (1-5 keV) are stopped by the thin first layer, while higher-energy electrons (10-100 keV) can penetrate the first layer and be stopped by the second layer, enabling versatile material selection and exposure conditions.
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 the patterning of smaller features while maintaining structural integrity and reducing electron exposure where not desired, improving the efficiency and resolution of electron beam lithography.
Implementation Method 1
capable of at least one of: scattering electrons and absorbing electrons
Implementation Method 2
capable of at least one of: scattering electrons and absorbing electrons
Data Source
AI summary
A method for electron beam lithography. The method may comprise fabricating a multi-layer mask and interposing the multi-layer mask between an electron beam and an energy-sensitive layer to thereby expose the energy-sensitive layer to the electron beam through the mask. Fabricating the multi-layer mask may comprises providing a first mask layer fabricated from a first mask material (e.g. silicon nitride) which defines one or more feature apertures corresponding to features of interest and coating an electron-energy-reducing material (e.g. gold) onto the first mask layer to thereby provide a second mask layer.