Doped Oxide Capacitor Structure Without Interface Oxide Layers
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Solution Overview
Problem
Natural oxide layers formed between electrodes and dielectric patterns in DRAM capacitors can deteriorate electric characteristics, leading to performance issues.
Innovation Solution
A capacitor structure is developed with a lower electrode structure on a substrate, doped with specific metals, and a dielectric pattern on its sidewall, eliminating the formation of interface oxide layers to enhance electric characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If natural oxide layers are formed between electrodes and dielectric patterns, then the capacitor structure is simple to manufacture, but the electric characteristics deteriorate due to interface oxide layers
Solution Approach 1:
A lower electrode structure is formed before the dielectric pattern, comprising an oxide of a first metal (4 valence electrons) doped with a second metal (3, 5, 6, or 7 valence electrons). This preliminary doping prevents natural oxide formation at the interface, eliminating depletion layers and improving electric characteristics before the dielectric is deposited
Solution Approach 2:
The oxide of the first metal is doped with the second metal to change its electrical parameters, specifically to reduce resistivity and prevent natural oxide formation. The doping concentration and metal selection (3, 5, 6, or 7 valence electrons) are optimized to eliminate interface oxide layers while maintaining structural integrity
2Reliability
If interface oxide layers are eliminated through doping, then electric characteristics improve, but the manufacturing process becomes more complex
Solution Approach 1:
The doping of the second metal into the first metal oxide is combined with the oxide formation process itself, rather than being a separate subsequent step. This integration occurs during the lower electrode structure formation, reducing overall process complexity while achieving the goal of eliminating interface oxide layers
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 prevents the formation of depletion layers, thereby improving the electric characteristics and performance of the capacitors by eliminating interface oxide layers.
Implementation Method 1
A natural oxide layer may be formed between the dielectric pattern and each of the upper and lower electrodes, and may deteriorate the electric characteristics of the capacitor
Data Source
AI summary
A capacitor structure includes a lower electrode structure disposed on a substrate, including an oxide of a first metal having 4 valence electrons, and being doped with a second metal having 3, 5, 6, or 7 valence electrons, a dielectric pattern disposed on a sidewall of the lower electrode structure, and an upper electrode disposed on a sidewall of the dielectric pattern.