Plasma Processing Cover with Window for Holding Sheet Protection
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Solution Overview
Problem
In plasma processing of wafers held in carriers with annular frames and holding sheets, the existing technologies expose the holding sheets to plasma, causing damage due to direct exposure and heat effects, as the covering's inner diameter is larger than the wafer's outer diameter.
Innovation Solution
A plasma processing apparatus with a chamber, plasma source, stage, and a cover that moves to cover the holding sheet and frame, featuring a window to limit the exposed substrate area, preventing plasma exposure to the holding sheet by positioning the cover to cover the outer edge area of the substrate, thus protecting it from plasma and heat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the covering's inner diameter is made larger than the wafer's outer diameter to allow wafer processing, then the wafer can be processed by plasma, but the holding sheet becomes exposed to plasma and gets damaged
Solution Approach 1:
The cover is divided into a plasma-shielding portion and a window portion, creating distinct functional zones. The window portion has a specific size that exposes only the necessary wafer area while the shielding portion protects the holding sheet, segmenting the cover's function to resolve the contradiction between processing access and protection.
Solution Approach 2:
Different parts of the cover have different properties: the window portion allows plasma passage for wafer processing, while the surrounding shielding portion blocks plasma to protect the holding sheet. This local differentiation of quality (permeable vs. impermeable regions) enables simultaneous achievement of processing and protection.
2Power
If the covering temperature increases during plasma processing, then plasma generation is maintained, but the holding sheet is damaged by heat
Solution Approach 1:
The cover structure segments the thermal environment: the window portion allows plasma and heat to reach the wafer for processing, while the shielding portion acts as a thermal barrier protecting the holding sheet from excessive heat, enabling power maintenance without heat damage.
Solution Approach 2:
The shielding portion of the cover acts as an intermediary between the hot plasma environment and the holding sheet. It mediates the thermal interaction by blocking direct heat transfer to the holding sheet while still allowing the plasma processing to occur through the window portion.
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 effectively prevents deformation and damage to the holding sheet by limiting plasma exposure and managing heat effects, ensuring the holding sheet remains intact during plasma processing.
Implementation Method 1
a plasma source generating plasma inside the chamber
Data Source
AI summary
The plasma processing apparatus is provided with a chamber 11, a plasma source 13 which generates plasma inside the chamber 11, a stage 16 which is provided inside the chamber 11 and places a carrier 5 thereon, a cover 31 which is arranged above the stage 16 to cover a holding sheet 6 and a frame 7 and has a window 33 which is formed on a central part thereof to penetrate the cover 31 in the thickness direction, and a drive mechanism 38 which changes the position of the cover 31 relative to the stage 16 between a first position which is away from the stage 16 and allows the carrier 5 to be placed on and removed from the stage 16 and a second position which allows the cover 31 to cover the holding sheet 6 and the frame 7 of the carrier 5 placed on the stage 16 and a substrate 2 held on the holding sheet 6 to be exposed through the window 33. The window 33 of the cover 31 allows an area of the substrate 2, the area being located on the inner side with respect to an outer edge area of the substrate 2, to be exposed therefrom.