Corrugated Tier Support Structure for Reliable Vertical Memory Contacts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing aspect ratios of openings and the number of alternating dielectric and nitride layers in vertical memory arrays make precise control of the etch process difficult, leading to challenges in forming reliable electrical connections to the dies and support layers.
Innovation Solution
A corrugated support structure is introduced, featuring a planar surface with vias that terminate in voids between flutes, allowing for the formation of electrical connections between channel poly layers and interconnect structures in the substrate, enhancing structural integrity and connection reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the aspect ratio of openings and the number of alternating dielectric and nitride layers are increased to improve memory density, then the memory capacity increases, but the etch process control difficulty and connection reliability deteriorate
Solution Approach 1:
The support structure is segmented into multiple functional regions including a planar region for stable connection formation, a corrugated region for mechanical strength, and void regions for stress relief. This segmentation allows each region to optimize its function independently, enabling high aspect ratio openings to be formed with better control while maintaining connection reliability.
Solution Approach 2:
The invention transitions from a conventional planar support structure to a three-dimensional corrugated structure with varying heights and void spaces. This dimensional change provides additional degrees of freedom for process control, allowing the etch process to be better managed while maintaining structural integrity and connection reliability in high-density memory arrays.
2Quantity of substance
If the aspect ratio of openings and the number of alternating dielectric and nitride layers are increased to improve memory density, then the memory capacity increases, but the reliability of electrical connections deteriorates
Solution Approach 1:
The support structure is segmented into multiple functional regions including a planar region for stable connection formation, a corrugated region for mechanical strength, and void regions for stress relief. This segmentation allows each region to optimize its function independently, enabling high aspect ratio openings to be formed with better control while maintaining connection reliability.
Solution Approach 2:
The corrugated structure with void regions provides beforehand cushioning by absorbing mechanical stress and thermal expansion forces before they can affect the electrical connections. This pre-cushioning effect protects the fragile connections in high aspect ratio openings from failure during downstream processing steps.
3Ease of manufacture
If a conventional planar support structure is used, then the manufacturing process is simple, but the structural strength and connection reliability are insufficient
Solution Approach 1:
The support structure incorporates corrugated regions with curved surfaces instead of flat planes. This curvature provides mechanical strength and stress distribution benefits while still being compatible with standard semiconductor fabrication processes. The corrugated geometry naturally resists bending and breaking forces that would affect planar structures.
Solution Approach 2:
The support structure functions as a composite system combining planar regions, corrugated regions, and void spaces into a unified structure. Each region contributes different properties - the planar regions provide stable connection surfaces, the corrugated regions provide mechanical strength, and the void regions provide stress relief - creating a composite structure that achieves both strength and manufacturability.
Data Source
AI summary
A semiconductor device, such as comprising NAND memory structures, can include a substrate with an arrangement of conductive interconnects. A corrugated support can be provided on the substrate, wherein the support comprises a planar first major surface and an opposed second major surface proximal to the substrate, the first major surface including a plurality of vias extending along a first direction, wherein the vias have an inlet at a first major surface of the support and an outlet at the second major surface of the support. An arrangement of flutes can be provided on the second major surface of the support. The flutes can extend along a second direction normal to the first direction. The flutes are separated by voids, and the vias terminate in the voids.