SiC Epitaxial Substrate Layout for Defect-Free Chip Yield
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing silicon carbide epitaxial substrates face challenges in managing macroscopic defects, which affect the yield and quality of silicon carbide semiconductor devices, as these defects are not effectively distributed to minimize their impact on the substrate's surface.
Innovation Solution
A silicon carbide epitaxial substrate with a specific configuration where the central region is divided into square regions of varying sizes, with defect-free areas calculated to ensure that macroscopic defects are locally concentrated, thereby maximizing the number of defect-free chips produced, using a controlled pressure reduction method during the manufacturing process to minimize defect formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If macroscopic defects are uniformly distributed across the substrate surface, then the defect density is reduced, but the number of defect-free chips that can be produced is limited
Solution Approach 1:
The patent applies local quality by creating non-uniform defect distribution where the central region has higher defect density while the outer peripheral region maintains lower defect density. This is achieved through controlled pressure reduction during epitaxial growth, which causes defects to concentrate in specific areas. By making different regions have different defect characteristics, the patent maximizes the usable defect-free area for chip production while maintaining overall quality control.
2Area of stationary object
If the substrate area is increased to produce more chips, then the total number of chips increases, but the proportion of defective areas may increase
Solution Approach 1:
The patent segments the substrate surface into two distinct regions: a central region with higher defect density and an outer peripheral region with lower defect density. This segmentation allows the larger substrate area to be utilized effectively, with the outer peripheral region providing abundant defect-free areas for chip production. The segmentation strategy ensures that increased substrate area translates to increased yield without compromising the reliability of produced chips.
3Reliability
If the defect density is reduced across the entire substrate, then the quality of semiconductor devices is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent changes the pressure parameter during the epitaxial growth process to control defect distribution. By implementing a controlled pressure reduction strategy, the manufacturing process achieves non-uniform defect distribution with higher defects in the central region and lower defects in the outer peripheral region. This parameter change approach simplifies the overall manufacturing complexity compared to attempting to reduce defects uniformly across the entire substrate, while still ensuring high quality devices are produced from the defect-free outer regions.
Data Source
AI summary
When a value obtained by dividing the number of the one or more second regions by a total of the number of the one or more first regions and the number of the one or more second regions is defined as a first defect free area ratio, a value obtained by dividing the number of the one or more fourth regions by a total of the number of the one or more third regions and the number of the one or more fourth regions is defined as a second defect free area ratio, and a value obtained by dividing the number of the one or more macroscopic defects by an area of the central region is defined as X cm−2, A is smaller than B, B is less than or equal to 4, X is more than 0 and less than 4, and a Formula 1 is satisfied.