EUV Patterning Stack with Adhesion Layer for Dose Reduction
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Solution Overview
Problem
Existing Extreme Ultraviolet Lithography (EUV) underlying layers face issues such as poor etch contrasts, adhesion problems with resists, and scumming, necessitating improved patterning stacks.
Innovation Solution
A structure comprising a dose reducing layer with an EUV radiation-absorbing element, an adhesion layer made of amorphous carbon or organic compounds, and a resist, where the adhesion layer is positioned between the dose reducing layer and the resist, along with a hard mask, to enhance adhesion and etch contrast, formed using plasma-enhanced atomic layer deposition and molecular layer deposition techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a dose reducing layer with EUV-absorbing elements is used to reduce EUV dose, then throughput increases, but adhesion with resist deteriorates and scumming occurs
Solution Approach 1:
An adhesion layer comprising amorphous carbon or organic compound is introduced between the dose reducing layer and the resist. This intermediary layer resolves the adhesion problem by providing a surface that bonds well to both the dose reducing layer above and the resist below, eliminating scumming while preserving the dose reduction benefit for improved throughput
2Productivity
If a dose reducing layer with EUV-absorbing elements is used to reduce EUV dose, then throughput increases, but etch contrast deteriorates
Solution Approach 1:
The underlying layer is segmented into multiple functional layers: a dose reducing layer for EUV absorption and an adhesion layer for proper etch contrast. This segmentation allows each layer to specialize in its function, with the adhesion layer providing the necessary etch contrast properties that the dose reducing layer alone cannot provide
Solution Approach 2:
The adhesion layer acts as an intermediary between the dose reducing layer and the resist, providing the necessary etch contrast properties. This intermediate layer enables selective etching processes to work effectively while the dose reducing layer continues to absorb EUV radiation for reduced dose requirements
3Reliability
If an adhesion layer comprising amorphous carbon or organic compound is introduced, then adhesion with resist improves, but device complexity increases
Solution Approach 1:
The adhesion layer is designed with specific parameter ranges: thickness of 1-10 nm and controlled composition (amorphous carbon or organic compound). By optimizing these parameters, the layer provides necessary adhesion improvement while keeping the added complexity minimal and manageable within existing fabrication capabilities
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 solution provides good pattern fidelity, minimizes patterning defects, and reduces the EUV dose required, achieving effective pattern transfer with improved adhesion and etch contrast.
Implementation Method 1
extreme ultraviolet radiation (EUV)-absorbing elements can be used in resists or in underlying layers to limit the EUV dose needed for full exposure
Implementation Method 2
an adhesion layer, the adhesion layer being positioned between the dose reducing layer and the resist, the adhesion layer comprising amorphous carbon or an organic compound
Implementation Method 3
the dose reducing layer is formed by means of plasma-enhanced atomic layer deposition
Implementation Method 4
the resist is formed by means of molecular layer deposition
Data Source
AI summary
Structures and related systems and methods for dose reduction in extreme ultraviolet (EUV) lithography. The structures can comprise a dose reducing layer, an adhesion layer, and a resist.