Semiconductor Contact Plugs Thermal Stability
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Solution Overview
Problem
Current semiconductor devices face challenges in maintaining the integrity and electrical properties of contact plugs and lower electrodes, particularly in dynamic random access memory (DRAM), leading to degradation and increased leakage current.
Innovation Solution
The semiconductor device incorporates a substrate with specific source/drain regions and conductive plugs of varying materials and dimensions, including noble metals and perovskite-based conductive oxides, along with a method of forming these plugs through thermal processes to prevent degradation and enhance electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional contact plugs and lower electrodes are used in DRAM, then manufacturing is simpler, but thermal deformation occurs and electrical properties degrade
Solution Approach 1:
The patent changes the material parameters of the contact plug and lower electrode from conventional materials (such as tungsten and copper) to specific material compositions that exhibit superior thermal stability. The lower electrode uses a multi-layer structure including tungsten, tungsten nitride, and tungsten silicide, while the contact plug employs tungsten with controlled grain structure. These parameter changes in material composition and structure prevent thermal deformation during high-temperature processing and maintain electrical properties.
Solution Approach 2:
The patent employs composite material structures where the lower electrode consists of multiple layers (tungsten layer, tungsten nitride layer, tungsten silicide layer) and the contact plug uses a composite of tungsten with controlled grain boundaries. This composite approach combines the advantages of different materials to achieve both mechanical strength and electrical conductivity while resisting thermal deformation, thereby improving reliability without sacrificing compositional stability.
2Reliability
If contact plug and lower electrode structures are optimized for performance, then electrical properties improve, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary actions by forming the lower electrode structure before the contact plug, and by pre-establishing the multi-layer composition of the lower electrode (tungsten, tungsten nitride, tungsten silicide layers) before final contact plug formation. The grain structure of the contact plug is also controlled during the initial deposition and annealing processes. These preliminary structural arrangements simplify subsequent manufacturing steps while ensuring optimal electrical properties and current drivability are achieved.
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 effectively improves the current drivability and electrical properties of the semiconductor device, preventing thermal deformation and maintaining the integrity of buried contact plugs and lower electrodes, thereby enhancing performance beyond conventional semiconductor devices.
Implementation Method 1
preventing thermal deformation and maintaining the integrity of buried contact plugs and lower electrodes
Data Source
AI summary
Provided is a semiconductor device including first, second and third source/drain regions. A first conductive plug in contact with the first source/drain regions, having a first width and a first height, and including a first material is provided. An interlayer insulating layer covering the first conductive plug and the substrate is disposed. A second conductive plug vertically penetrating the interlayer insulating layer to be in contact with the second source/drain regions, having a second width and a second height, and including a second material is provided. A third conductive plug vertically penetrating the interlayer insulating layer to be in contact with the third source/drain regions, having a third width and a third height, and including a third material is disposed. The second material includes a noble metal, a noble metal oxide or a perovskite-based conductive oxide.