Metal Resist Mask Shaping With Angled Reactive Ion Beams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices scale to smaller dimensions, traditional lithographic techniques struggle to achieve precise patterning of features with correct shape, packing density, and overlay, particularly in arrays with small tip-to-tip spacing, and current photoresist materials are less effective for pitches below 30 nm.
Innovation Solution
A method involving angled ion beam etching with reactive species is used to selectively alter dimensions of patterning features in a metal resist mask, employing gas mixtures like CH4, CxHy, CxHyOH, HCl, and HBr to form volatile etch products, preserving certain dimensions while modifying others.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional lithographic techniques are used for patterning, then the process is simple and well-established, but the manufacturing precision and ability to achieve correct feature shape and packing density deteriorates as pitch scales below 50 nm
Solution Approach 1:
The patent applies preliminary action by performing angled ion beam etching on the metal resist mask before the main lithographic patterning step. This pre-shaping of the mask features enables subsequent lithographic processes to achieve the desired final pattern geometry, effectively preparing the structure in advance to overcome the limitations of traditional lithography at small pitches
Solution Approach 2:
The patent introduces a new dimensional approach by using angled ion beam etching that selectively modifies features in specific directions. The angled beam approach allows differential etching along different dimensions of the patterned features, enabling precise control over feature shape and packing density that cannot be achieved with conventional planar lithographic methods
2Manufacturing precision
If photoresist materials are used for patterning, then the material is easy to process, but the patterning effectiveness deteriorates for pitches below 30 nm
Solution Approach 1:
The patent changes the material parameter by replacing traditional photoresist with metal resist materials such as HfO2, TiO2, or Ta2O5. These metal resists exhibit different etch selectivity and pattern fidelity characteristics that enable effective patterning at pitches below 30 nm, overcoming the fundamental limitations of organic photoresist materials while maintaining processability through established deposition and etching techniques
3Manufacturing precision
If angled ion beam etching is applied to selectively alter dimensions, then the patterning precision is improved, but the process complexity increases
Solution Approach 1:
The patent applies local quality by using angled ion beam etching to selectively modify specific dimensions of the patterned features while leaving other dimensions substantially unchanged. The angled beam configuration enables targeted material removal from specific surfaces or sidewalls of the features, achieving local dimensional control that precisely shapes the pattern geometry without requiring multiple complex processing steps
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 enhances patterning precision by reducing linewidth or increasing trench length selectively, improving device density and performance without metal contamination, and addressing the limitations of EUV lithography for small pitches.
Implementation Method 1
The angled ion beam may comprise reactive species to etch the at least one patterning feature by forming volatile etch products
Implementation Method 2
The angled ion beam may comprise reactive species to etch the at least one patterning feature by forming volatile etch products
Implementation Method 3
a plasma chamber to generate a plasma therein
Data Source
AI summary
A method of enhancing patterning of a substrate. The method may include providing a metal resist mask on a substrate stack of the substrate, wherein the metal resist mask comprises at least one patterning feature. The method may include subjecting the metal resist mask to a directional etch, by directing an angled ion beam to the at least one patterning feature. The angled ion beam may comprise reactive species to etch the at least one patterning feature by forming volatile etch products, wherein a first dimension of the at least patterning feature is selectively altered with respect to a second dimension of the at least one patterning feature.