Polycrystalline SiC Electrode Surface Waviness for Uniform Plasma Etching
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Solution Overview
Problem
The increasing wafer area and circuit density in semiconductor devices demand more uniform plasma etching techniques, which are affected by the uniformity of electrical resistivity, thermal conductivity, and surface evenness of electrodes.
Innovation Solution
A polycrystalline SiC compact with controlled arithmetic mean waviness in specific wavelength ranges (0 to 10 mm, 10 to 20 mm, and 20 to 30 mm) achieved through a multi-stage grinding process using abrasives of progressively finer grain sizes, along with controlled nitrogen doping for uniform plasma etching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single-stage grinding process is used, then manufacturing complexity is reduced, but surface evenness and waviness control are insufficient
Solution Approach 1:
The grinding process is divided into three sequential stages, each using abrasives with different grain sizes (first abrasive with coarser grains, second abrasive with intermediate grains, third abrasive with finest grains). This segmentation allows progressive removal of surface irregularities at different scales, achieving superior surface evenness and waviness control that cannot be obtained with a single-stage process.
2Productivity
If wafer area and circuit density are increased, then device performance is improved, but plasma etching uniformity becomes more difficult to achieve
Solution Approach 1:
The invention precisely controls the waviness parameters of the electrode surface by specifying arithmetic mean waviness values for three different wavelength ranges (0.05 μm or less for 0-10 mm, 0.13 μm or less for 10-20 mm, and 0.20 μm or less for 20-30 mm). This parameter control ensures uniform plasma distribution and etching uniformity across larger wafers with higher circuit density.
3Manufacturing precision
If electrode surface waviness is not controlled, then manufacturing is simpler, but plasma etching uniformity deteriorates
Solution Approach 1:
The electrode surface is prepared in advance through a systematic three-stage grinding process that pre-establishes the required waviness characteristics before the electrode is put into service. This preliminary action ensures that the surface geometry is optimized for uniform plasma etching from the start, eliminating the need for complex adjustments during actual manufacturing operations.
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 uniform plasma etching with reduced unevenness and ensures consistent etching rates across semiconductor wafers, enhancing the effectiveness of plasma etching processes.
Implementation Method 1
grinding the major surfaces with a first abrasive, grinding the major surfaces with a second abrasive after the step of grinding with the first abrasive, and grinding the major surfaces with a third abrasive after the step of grinding with the second abrasive
Data Source
AI summary
Provided are a polycrystalline SiC compact capable of achieving uniform plasma etching when used as electrodes and a method for manufacturing the same. A polycrystalline SiC compact has a major surface in which Wa (0 to 10 mm) is 0.00 to 0.05 μm or less, Wa (10 to 20 mm) is 0.13 μm or less, and Wa (20 to 30 mm) is 0.20 μm or less.