Conductive Damascene Structures for Memory Device Reliability
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Solution Overview
Problem
Conventional memory device manufacturing processes face issues with polysilicon stringers causing short-circuits due to incomplete etching, leading to reduced reliability and efficiency of memory devices as feature sizes decrease.
Innovation Solution
The implementation of conductive damascene structures formed through a damascene process, with dielectric structures ensuring precise insulation between word lines, reducing the likelihood of short-circuits and enhancing the uniformity and reliability of memory devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional etching processes are used to form word lines, then the manufacturing process is simple, but polysilicon stringers cause short-circuits due to incomplete etching
Solution Approach 1:
The patent divides the word line formation process into separate stages: first forming isolated trenches between bit lines, then filling with conductive material, and finally forming the complete word line structure. This segmentation ensures complete separation between adjacent word lines, eliminating polysilicon stringers and preventing short-circuits while maintaining manufacturing feasibility
Solution Approach 2:
The patent performs preliminary trench formation and dielectric filling before depositing the conductive word line material. By pre-establishing the trench structure and insulation layer, the process ensures that subsequent conductive material deposition occurs in well-defined, isolated regions, preventing residual polysilicon from causing short-circuits
2Productivity
If feature sizes are reduced to increase device density, then device capacity increases, but the probability of short-circuits increases
Solution Approach 1:
The patent segments the word line formation into distinct steps with dielectric material filling between bit lines before conductive material deposition. This segmentation creates physical isolation barriers that remain effective even as feature sizes shrink, preventing short-circuits while enabling higher device density through reduced dimensions
Solution Approach 2:
The patent introduces dielectric material as an intermediary substance between adjacent bit lines and word lines. This dielectric layer acts as a reliable insulation barrier that maintains electrical isolation even at reduced feature sizes, enabling higher density without increasing short-circuit probability
3Reliability
If conventional polysilicon word lines are used, then the process is established, but residual polysilicon causes short-circuits
Solution Approach 1:
The patent segments the word line formation process into discrete steps: trench formation, dielectric filling, and conductive material deposition. This segmented approach replaces the single-step conventional process, ensuring complete isolation between word lines and eliminating residual polysilicon issues, though it increases process complexity
Solution Approach 2:
The patent changes the material parameter from conventional polysilicon to alternative conductive materials deposited through physical vapor deposition or chemical vapor deposition. This parameter change, combined with the segmented process, ensures complete removal of residual conductive material and prevents short-circuits
Data Source
AI summary
A semiconductor element and a manufacturing method of the same are provided. The semiconductor element includes a substrate, a plurality of doping strips, a memory material layer, a plurality of conductive damascene structures, and a dielectric structure. The doping strips are formed in the substrate. The memory material layer is formed on the substrate, and the memory material layer comprises a memory area located on two sides of the doping strips. The conductive damascene structures are formed on the memory material layer. The dielectric structure is formed on the doping strips and between the conductive damascene structures. The conductive damascene structures are extended in a direction perpendicular to a direction which the doping strips are extended in.