GeCTe Selector Layers for Thermally Stable Cross-Point Memory
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Solution Overview
Problem
Current semiconductor devices face challenges in achieving miniaturization, higher speed, and reduced power consumption due to limitations in materials and structures used in memory devices, particularly in selector layers and memory elements.
Innovation Solution
The use of a ternary GeCTe material comprising carbon, germanium, and tellurium, with specific atomic percentages, is introduced as a switch layer in memory devices, enhancing optical bandgap, thermal stability, and endurance, thereby improving the performance of ovonic threshold switches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials are used in selector layers and memory elements, then device structure and materials can be kept simple, but miniaturization, speed, and power consumption performance cannot be improved
Solution Approach 1:
The patent employs a composite material system consisting of a GeCTe selector layer combined with a chalcogenide memory layer (GST or GSST). This composite structure leverages the complementary properties of each material: GeCTe provides superior carrier blocking capability and thermal stability, while the chalcogenide layer enables phase-change memory functionality. The synergistic combination achieves enhanced electrical performance, faster switching speeds, and lower power consumption compared to conventional single-material systems.
Solution Approach 2:
The patent optimizes the compositional parameters of the GeCTe material by varying the ratios of germanium, carbon, and tellurium to achieve the desired optical bandgap and electrical properties. By adjusting the material composition parameters, the device achieves improved selector characteristics including higher breakdown voltage and lower leakage current, directly addressing the electrical performance requirements without increasing structural complexity.
2Stability of the object's composition
If material composition is optimized for thermal stability, then thermal resistance increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent systematically varies the compositional parameters of GeCTe (germanium content, carbon content, tellurium content) to optimize the balance between thermal stability and manufacturability. By adjusting the Ge/Te ratio and carbon concentration, the material achieves sufficient thermal resistance for non-volatile memory operation while remaining compatible with existing sputtering and deposition processes, avoiding excessive manufacturing precision requirements.
Solution Approach 2:
The patent applies local quality optimization by ensuring uniform composition distribution within the GeCTe layer while allowing composition gradients or variations in adjacent layers. The GeCTe selector layer maintains consistent stoichiometry to ensure reliable thermal stability, while the interface regions with electrodes and memory layers are optimized for specific electrical characteristics, achieving localized property optimization without compromising overall manufacturability.
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 ternary GeCTe material demonstrates superior thermal resistance, lower leakage currents, and increased endurance, making it suitable for non-volatile memories, while maintaining power efficiency and reliability.
Implementation Method 1
The ternary GeCTe material demonstrates superior thermal resistance
Implementation Method 2
lower leakage currents
Data Source
AI summary
A semiconductor device includes a semiconductor substrate and an interconnection structure. The interconnection structure is disposed over the semiconductor substrate. The interconnection structure includes first conductive lines, second conductive lines, and ovonic threshold switches. The first conductive lines extend parallel to each other in a first direction. The second conductive lines are stacked over the first conductive lines and extend parallel to each other in a second direction perpendicular to the first direction. The ovonic threshold switches are disposed between the first conductive lines and the second conductive lines. The ovonic threshold switches include a ternary GeCTe material. The ternary GeCTe material consists substantially of carbon, germanium, and tellurium. In the ternary GeCTe material, a content of carbon is in a range from 10 to 30 atomic percent and a content of germanium is in a range from 10 to 65 atomic percent.