Tunable Bottom Shadow Ring for Vertical Plasma Etching
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Solution Overview
Problem
Plasma etch tools face defects in semiconductor substrates due to discontinuities in the plasma sheath's electromagnetic profile, leading to etch defects and contamination during dicing operations.
Innovation Solution
A combination bottom shadow ring component with a moveable inner ring and a fixed outer ring is used to adjust the electromagnetic profile of the plasma sheath, ensuring vertical ion bombardment and protecting beveled regions, thereby reducing etch defects and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plasma etch tool uses a conventional plasma sheath configuration, then the etching process can proceed, but discontinuities in the electromagnetic profile cause etch defects and contamination
Solution Approach 1:
The patent applies parameter changes by adjusting the electromagnetic profile parameters of the plasma sheath through a tunable configuration. The system modifies the electromagnetic field distribution to eliminate discontinuities, thereby preventing etch defects and contamination while maintaining reliable etching processes
Solution Approach 2:
The patent introduces an intermediary electromagnetic profile adjustment mechanism that mediates between the plasma source and the semiconductor substrate. This intermediary system modifies the electromagnetic field distribution to ensure uniform plasma sheath characteristics, eliminating harmful discontinuities that cause etch defects
2Manufacturing precision
If the electromagnetic profile of the plasma sheath is not adjusted, then the system operation is simple, but ion bombardment is not vertical causing etch profile defects
Solution Approach 1:
The patent changes the electromagnetic profile parameters to achieve vertical ion bombardment. By adjusting the electromagnetic field distribution through the tunable plasma sheath system, the patent ensures uniform ion directionality and vertical etch profiles, accepting the necessary device complexity to achieve this precision
Solution Approach 2:
The patent implements a dynamic electromagnetic profile adjustment capability that allows real-time optimization of the plasma sheath characteristics. This dynamic system can adapt the electromagnetic field distribution to maintain vertical ion bombardment and precise etch profiles under varying process conditions
3Reliability
If beveled regions are not protected during etching, then the process is simpler, but etch defects occur on beveled regions leading to lower yield
Solution Approach 1:
The patent applies local quality by creating a localized protective effect on beveled regions through the tuned electromagnetic profile. The system selectively modifies the plasma sheath characteristics in specific areas to protect beveled regions from etch defects, applying different effective properties to different locations on the substrate surface
Solution Approach 2:
The patent introduces an intermediary protective mechanism through the electromagnetic profile adjustment that specifically shields beveled regions during etching. This intermediary system creates a favorable electromagnetic environment that prevents direct harmful plasma interaction with sensitive beveled areas, reducing etch defects and improving yield
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 solution increases productivity and yield of semiconductor products by minimizing downtime and resource requirements, reducing particulates and contamination during dicing operations.
Implementation Method 1
adjust an electromagnetic profile of the plasma sheath
Data Source
AI summary
Some implementations described herein include an etch tool including a combination bottom shadow ring component including a moveable inner ring component and a fixed inner ring component. The moveable inner ring component provides for an adjustability of an effective thickness of the combination bottom shadow ring component during an etching operation. The adjustability (e.g., “tunability”) of the effective thickness of the combination bottom shadow ring component enables flexibility and is conducive to changes in one or more parameters related to different etch recipes for a semiconductor substrate. Additionally, the fixed inner ring component shadows beveled regions of the semiconductor substrate during the etching operation to reduce a likelihood of damage to the beveled regions.