TMD Thin Film Atomic Layer Etching for Precise Layer Control
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Solution Overview
Problem
Existing methods for forming transition-metal dichalcogenide (TMD) thin-films with varying numbers of molecular layers are prone to damage and fail to accurately control layer thickness, leading to unintended hetero-junction formation and pattern issues.
Innovation Solution
A semiconductor and photoelectronic device comprising a TMD thin-film with regions of different molecular layers, achieved through selective etching using atomic layer etching (ALE) processes, allowing precise control of layer numbers and patterns without damaging the material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical peeling method is used to separate TMD molecular layers, then layer separation is achieved, but layer thickness control is lost and hetero-junctions cannot be formed with target number and pattern
Solution Approach 1:
The invention segments the TMD thin-film into multiple regions with different numbers of molecular layers through selective removal. By dividing the film into first, second, and third regions with controlled layer counts, the patent achieves both layer separation and precise thickness control that mechanical peeling cannot provide.
Solution Approach 2:
The patent applies local quality by creating regions with different molecular layer configurations in specific locations. The first region retains N+M layers, the second region has N layers, and the third region has Z layers, allowing each region to have optimized properties for its specific function while forming controlled hetero-junctions.
2Manufacturing precision
If conventional etching is used to control TMD layer thickness, then layer number control is improved, but material damage occurs
Solution Approach 1:
The patent replaces conventional mechanical/chemical etching methods with atomic layer etching (ALE), which uses controlled atomic-scale removal processes. This substitution enables precise layer number control through atom-by-atom removal while minimizing material damage and maintaining the integrity of the TMD crystal structure.
Solution Approach 2:
The invention changes the etching parameters to atomic-scale precision, controlling the removal process at the level of individual molecular layers. By adjusting the ALE process parameters, the patent achieves exact layer thickness control without the uncontrolled damage associated with conventional etching methods.
3Reliability
If TMD thin-film with varying molecular layers is formed, then hetero-junctions are created with improved optical properties, but device complexity increases
Solution Approach 1:
The patent introduces vertical dimensionality control by stacking different numbers of molecular layers in different regions. This vertical variation in layer count creates hetero-junctions with improved optical and electrical properties while maintaining a relatively simple planar device structure, thus managing complexity effectively.
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 enables the formation of TMD thin-films with defined hetero-junctions between regions of varying thickness, enhancing photocurrent and optical properties such as photoresponsivity, resulting in improved device performance.
Implementation Method 1
selective etching using atomic layer etching (ALE) processes
Implementation Method 2
a two-dimensional material with a layered structure in which molecular layers is combined to each other via weak van der Waals force
Data Source
AI summary
The present disclosure relates to a semiconductor device and a photoelectronic device, both including a transition-metal dichalcogenide thin-film, and to a method for producing a transition-metal dichalcogenide thin-film. The transition-metal dichalcogenide thin-film includes: a first region including a stack of N+M transition-metal dichalcogenide molecular layers; and a second region including a stack of N transition-metal dichalcogenide molecular layers, wherein the second region is horizontally adjacent to the first region, wherein the N transition-metal dichalcogenide molecular layers of the second region respectively horizontally extend from the N transition-metal dichalcogenide molecular layers of the first region.