Semiconductor Device Side-Wall Epitaxial Growth Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High aspect ratio holes in semiconductor manufacturing lead to fluctuations in the depth of semiconductor material growth, affecting device characteristics and yield due to uneven upper surface heights of the grown material.
Innovation Solution
The semiconductor device employs a substrate with columnar protrusions and voids, where silicon is epitaxially grown from the side walls of memory holes, with the upper end of the protrusions positioned between electrode layers, and a method involving alternating sacrificial and insulating layers to control silicon growth, promoting growth from the side walls over the bottom surfaces to minimize depth fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the aspect ratio of holes is increased to achieve higher integration density, then the number of memory cells per unit area increases, but the depth fluctuation of epitaxial growth increases causing device characteristic degradation
Solution Approach 1:
The invention transitions from bottom-up growth (0D/1D) to side-wall growth (2D surface growth). By forming protrusions at the bottom of holes and controlling silicon epitaxial growth to occur primarily on the side walls rather than from the bottom surfaces, the method achieves uniform upper surface heights even in high aspect ratio holes, thereby increasing integration density without sacrificing depth uniformity
Solution Approach 2:
The invention creates different growth conditions in different regions of the hole structure. Protrusions are formed at the bottom to serve as nucleation sites, but the epitaxial growth is controlled to occur preferentially on the side walls. This local differentiation of growth locations ensures that the upper surface height is determined by side-wall growth rather than bottom growth, achieving both high integration density and uniform depth control
2Quantity of substance
If the aspect ratio of holes is increased to achieve higher integration density, then the number of memory cells per unit area increases, but the upper surface height uniformity of grown semiconductor material deteriorates
Solution Approach 1:
The invention transitions from bottom-up growth (0D/1D) to side-wall growth (2D surface growth). By forming protrusions at the bottom of holes and controlling silicon epitaxial growth to occur primarily on the side walls rather than from the bottom surfaces, the method achieves uniform upper surface heights even in high aspect ratio holes, thereby increasing integration density without sacrificing depth uniformity
Solution Approach 2:
The invention creates different growth conditions in different regions of the hole structure. Protrusions are formed at the bottom to serve as nucleation sites, but the epitaxial growth is controlled to occur preferentially on the side walls. This local differentiation of growth locations ensures that the upper surface height is determined by side-wall growth rather than bottom growth, achieving both high integration density and uniform depth control
3Ease of manufacture
If conventional epitaxial growth from bottom surfaces is used, then the manufacturing process is simple, but device characteristics and yield are affected due to depth fluctuation
Solution Approach 1:
The invention performs preliminary actions before the main epitaxial growth process: forming protrusions at the bottom of holes, creating sacrificial layers, and forming insulating layers with specific patterns. These preliminary structures control the subsequent silicon growth to occur on side walls rather than from bottom surfaces, ensuring uniform upper surface heights and consistent device characteristics while maintaining manufacturing feasibility
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 approach reduces the fluctuation of the upper end positions of the semiconductor bodies, enhances uniformity, prevents leaks between electrode layers, and increases the yield by selectively promoting silicon growth from the side walls, thus stabilizing device performance.
Implementation Method 1
silicon is epitaxially grown from the side walls of memory holes
Data Source
AI summary
According to one embodiment, the substrate includes a plurality of protrusions having columnar configurations, and a void being formed below the protrusions. The stacked body is provided on the substrate. The stacked body includes a plurality of electrode layers stacked with an insulator interposed. The semiconductor body contacts the protrusion and extends through the stacked body in a stacking direction of the stacked body. Upper ends of the protrusions are positioned at a height between a lowermost electrode layer and an electrode layer of a second layer from a bottom of the electrode layers.