SiC Substrate Alignment Marks That Resist Epitaxial Facet Blur
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Solution Overview
Problem
The formation of facets on SiC epitaxial layers during the growth of semiconductor elements on SiC substrates leads to blurred alignment marks, making it difficult for semiconductor manufacturing apparatuses to recognize and align patterns accurately.
Innovation Solution
The formation of concave marks on the SiC substrate with recessed patterns along specific directions suppresses the formation of facets on the SiC epitaxial layer, ensuring clear recognition of alignment marks by manufacturing apparatuses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mark is formed on the SiC substrate for alignment purposes, then alignment is enabled, but the mark becomes blurred and deformed due to facet formation on the SiC epitaxial layer
Solution Approach 1:
The mark is divided into multiple segments or portions along the extension direction. Each segment is separated by a predetermined interval, creating a discontinuous pattern. This segmentation prevents the continuous growth of facets that would otherwise blur the mark image, while still maintaining sufficient features for alignment recognition by the semiconductor manufacturing apparatus
Solution Approach 2:
The invention introduces a new dimensional characteristic to the mark by creating recessed patterns that extend in a direction different from the primary mark extension direction. These recessed patterns are formed at specific intervals and orientations to suppress facet formation in critical directions, thereby preventing image blurring while maintaining alignment functionality
2Productivity
If SiC epitaxial layer is grown on the SiC substrate with marks, then semiconductor elements are formed, but facets appear on the epitaxial layer causing mark image distortion
Solution Approach 1:
The mark structure is designed in advance with specific geometric features (segmentation and recessed patterns) that actively counteract the facet formation mechanism during epitaxial growth. By pre-configuring the mark with discontinuous segments and strategically placed recesses, the invention prevents the harmful facet growth before it can blur the mark image, ensuring clear mark recognition throughout the semiconductor manufacturing process
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 clear and automatic recognition of alignment marks, facilitating precise pattern alignment and reducing manufacturing defects in semiconductor devices.
Implementation Method 1
An SiC epitaxial layer may be grown on a surface of an SiC substrate after a mark is formed on the SiC substrate
Data Source
AI summary
In a manufacturing method of a semiconductor device according to the present embodiment, there is formed a first mark that is concave from a first direction substantially perpendicular to a first face of an SiC substrate and surrounded by first and third sides extending in a second direction orthogonal to the first direction on the first face and second and fourth sides extending in a third direction orthogonal to the first and second directions, and includes at least one recessed pattern recessed in the third direction from the first side toward the third side opposite to the first side on the first side. An SiC layer is epitaxially grown on the first mark of the SiC substrate.