Semiconductor Memory Device Internal Stress Films
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Solution Overview
Problem
In stacked memory devices, increasing numbers of electrode layers lead to significant internal stress, causing substrate warping, which complicates manufacturing processes and affects device precision and productivity.
Innovation Solution
The semiconductor memory device incorporates internal stress films with compressive stress, made of silicon nitride, which counteract the tensile stress of metal-based conductive members, reducing overall internal stress and preventing substrate warping by extending in a direction parallel to the conductive members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of electrode layers is increased to achieve higher integration, then memory capacity is improved, but internal stress accumulates causing substrate warping
Solution Approach 1:
The patent introduces internal stress films with compressive stress to counterbalance the tensile stress generated by the stacked electrode layers. These stress compensation films are positioned at strategic locations (such as beneath the substrate or at specific intermediate layers) to provide counteracting forces that prevent substrate warping, enabling higher integration without compromising substrate stability.
Solution Approach 2:
The patent employs composite material structures by combining multiple types of films with different stress characteristics. The internal stress films are integrated into the stack along with insulating films and electrode layers, creating a composite structure where the cumulative stress of tensile and compressive films balances out, thereby maintaining substrate flatness despite increased layer count.
2Quantity of substance
If the number of electrode layers is increased to achieve higher integration, then memory capacity is improved, but manufacturing complexity increases due to substrate warping
Solution Approach 1:
By pre-introducing internal stress films with controlled compressive stress into the stack structure before completing the electrode layer deposition, the patent prevents substrate warping from occurring during manufacturing. This proactive stress compensation simplifies the manufacturing process by eliminating the need for complex warping correction steps that would otherwise be required when handling highly integrated stacks.
3Stability of the object's composition
If internal stress films are added to counteract stress, then substrate stability is improved, but device structure becomes more complex
Solution Approach 1:
The patent applies internal stress films selectively at specific locations within the stack structure rather than uniformly throughout. The stress films are positioned at critical interfaces or beneath the substrate where they provide maximum stress compensation benefit with minimum additional structure, thereby improving substrate stability without proportionally increasing overall device complexity.
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 configuration effectively cancels out internal stress, enhancing shape precision and manufacturing productivity by stabilizing the substrate, making lithography alignment easier and improving handling during processing.
Implementation Method 1
The internal stress films contain material having internal stress having a reverse polarity of internal stress of the metal
Data Source
AI summary
A semiconductor memory device according to an embodiment includes a substrate, a plurality of conductive members containing a metal and provided on the substrate, a stacked body provided in each region between the conductive members, a semiconductor pillar piercing the stacked body, a memory film and internal stress films. The plurality of conductive members extend in a first direction and are separated from each other in a second direction. The internal stress films also extend in the first direction and are separated from each other in the second direction. The first direction and the second direction are parallel to an upper surface of the substrate and intersect each other. The internal stress films contain material having internal stress having the reverse polarity of internal stress of the metal.