2D Semiconductor Etching via Layered Plasma and Re-sulfurization Repair
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in the difficulty of etching two-dimensional (2D) materials like transition metal dichalcogenides without damaging the remaining unetched portions, which limits the performance of 2D semiconductor devices due to their thinness and the resulting damage from etching processes.
Innovation Solution
A method involving layer-by-layer etching using low-power oxygen plasma followed by re-sulfurization to repair any damage, allowing for selective and precise etching of 2D metal dichalcogenide films, such as MoS2, while maintaining the material's characteristics by converting oxidized layers back to their original form.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching methods are used on 2D materials, then etching can be performed, but the remaining unetched portions are damaged due to the thinness of the material
Solution Approach 1:
The etching process is divided into multiple sequential steps (first etching step, second etching step) with intermediate treatments. Each step removes a portion of the 2D material layer, allowing controlled removal while monitoring and preventing damage to remaining portions. This segmentation enables precise etching depth control without compromising material integrity.
Solution Approach 2:
A metal layer is deposited on the 2D material layer before etching begins. This metal layer serves as a protective preliminary structure that prevents direct damage to the 2D material during etching. The metal layer can be selectively removed later, having served its protective function throughout the etching process.
2Productivity
If etching is performed to pattern 2D materials, then device fabrication can proceed, but damaged portions limit device performance
Solution Approach 1:
The etching process intentionally creates controlled damage to the 2D material layer, and then a subsequent treatment step converts this damage into a beneficial structure. The damaged portions are transformed into a desired patterned structure that enhances device performance, turning the harmful etching damage into a useful feature.
Solution Approach 2:
The metal layer is deposited, serves its protective function during etching, and is then selectively removed. The temporary metal structure is discarded after fulfilling its purpose, having protected the 2D material and enabled precise patterning without permanent damage to the functional layers.
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 selective etching of 2D semiconductor layers with minimal damage, preserving the material's properties and achieving improved electrical performance in 2D crystal hetero-structure devices, such as increased drain current and field-effect mobility, without the need for film transferring operations.
Implementation Method 1
plasma etching a portion of a plurality of metal dichalcogenide films
Implementation Method 2
converting oxidized layers back to their original form
Implementation Method 3
re-sulfurization to repair any damage, allowing for selective and precise etching of 2D metal dichalcogenide films
Data Source
AI summary
A method of fabricating a semiconductor device includes plasma etching a portion of a plurality of metal dichalcogenide films comprising a compound of a metal and a chalcogen disposed on a substrate by applying a plasma to the plurality of metal dichalcogenide films. After plasma etching, a chalcogen is applied to remaining portions of the plurality of metal dichalcogenide films to repair damage to the remaining portions of the plurality of metal dichalcogenide films from the plasma etching. The chalcogen is S, Se, or Te.