Semiconductor Nodule Defect Removal via Selective Plasma Etching
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Solution Overview
Problem
In semiconductor manufacturing, selective epitaxial growth processes often result in ball-like nodule defects on non-selected regions like spacers or dielectric materials, which can obstruct subsequent processes and reduce yield.
Innovation Solution
A method involving the use of a plasma with high etching selectivity to remove nodule defects formed on dielectric portions during the semiconductor structure manufacturing, specifically using hydrogen plasma to selectively remove amorphous or polycrystalline nodule defects from crystalline source-drain regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If selective epitaxial growth process is used to re-grow source/drain regions, then source/drain regions are successfully formed in recesses, but ball-like nodule defects grow on non-selected regions such as spacers or dielectric materials
Solution Approach 1:
The patent extracts and removes the harmful nodule defects from the semiconductor structure using a plasma etching process. The plasma selectively removes the amorphous or polycrystalline nodule defects from dielectric portions while preserving the crystalline source-drain regions, thereby separating the harmful elements from the functional structure.
Solution Approach 2:
The patent changes the physical and chemical parameters of the material structure by controlling the crystalline structure during epitaxial growth. The source-drain regions are grown as crystalline material, while the nodule defects form as amorphous or polycrystalline material on dielectric portions. This parameter change in crystalline structure enables selective removal of defects in subsequent plasma processing.
2Productivity
If nodule defects are present on non-selected regions, then subsequent processing steps are blocked, but removing defects requires additional process steps
Solution Approach 1:
The patent converts the harmful nodule defects into a beneficial situation by utilizing their distinct material properties (amorphous or polycrystalline structure) to enable selective removal. The plasma etching process exploits the difference in etch selectivity between the crystalline source-drain regions and the amorphous/polycrystalline nodule defects, transforming a manufacturing obstacle into a removable contaminant that can be selectively eliminated without damaging the functional structure.
3Reliability
If plasma etching is used to remove nodule defects, then nodule defects are selectively removed, but etching selectivity must be precisely controlled to avoid damaging source-drain regions
Solution Approach 1:
The patent applies local quality by creating distinct material properties in different regions of the semiconductor structure. The source-drain regions are grown as crystalline material with specific etch resistance, while the nodule defects on dielectric portions are formed as amorphous or polycrystalline material with different etch characteristics. This local differentiation in material quality enables the plasma etching process to selectively remove defects from specific locations without affecting the crystalline source-drain regions.
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 effectively reduces nodule defects, enhancing the yield of semiconductor devices by ensuring clear access for subsequent processing steps and improving the integrity of the semiconductor structure.
Implementation Method 1
applying a plasma which has a higher selectivity to etch the nodule defects relative to the crystalline source-drain regions to thereby eliminate the nodule defects
Implementation Method 2
a selective epitaxial growth process may be used for, e.g., re-growing source/drain regions in recesses
Data Source
AI summary
A method for removing nodule defects is disclosed. The nodule defects may be formed on a non-selected portion of a semiconductor structure during formation of a semiconductor region on a selected portion of the semiconductor structure. A plasma having a higher selectivity to etch the nodule defects relative to the semiconductor region may be used to selectively remove the nodule defects on the non-selected portion.