Heterojunction Diode Using Non-Noble Metal Electrodes
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Solution Overview
Problem
Resistive memory devices using nickel oxide layers and noble metal electrodes require high-temperature processes and are costly, making them inefficient in manufacturing and resource-intensive.
Innovation Solution
A heterojunction diode is developed with a non-oxide layer, such as a highly doped Si layer, bonded to an oxide layer, using non-noble metal electrodes, which reduces manufacturing costs and allows for a lower temperature process, enabling efficient rectification characteristics without the need for expensive noble metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If noble metal electrodes (e.g., platinum) are used in resistive memory devices, then reliable rectification characteristics are achieved, but manufacturing cost increases significantly
Solution Approach 1:
The patent replaces expensive noble metal electrodes with non-noble metal electrodes (such as titanium, tungsten, or molybdenum) that are cheaper and more suitable for mass production. The non-noble metal electrodes form a heterojunction with the oxide layer that provides the necessary rectification characteristics without requiring precious metals, thereby reducing manufacturing cost while maintaining functional reliability
Solution Approach 2:
The patent modifies the work function parameter of the electrode material by using non-noble metals with appropriately tuned work functions (greater than 4.5 eV) and controls the doping concentration of the oxide layer to achieve the desired rectification characteristics. This parameter optimization allows the system to function reliably without expensive noble metals
2Reliability
If high-temperature processes are used to manufacture resistive memory devices with nickel oxide layers, then proper material formation and bonding are achieved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent reduces the manufacturing temperature by optimizing the doping concentration of the oxide layer to 10^19 to 10^21 atoms/cm³ and selecting non-noble metal electrodes with appropriate work functions. These parameter changes enable proper material formation and bonding at lower temperatures, simplifying the manufacturing process while maintaining bonding quality
Solution Approach 2:
The patent creates a composite heterojunction structure consisting of non-noble metal electrodes and doped oxide layers that can be formed at lower temperatures. This composite material approach allows the system to achieve proper bonding and functionality without requiring high-temperature processing, thereby reducing manufacturing complexity
3Ease of manufacture
If non-noble metal electrodes are used in heterojunction diodes, then manufacturing cost decreases, but achieving desired rectification characteristics becomes more difficult
Solution Approach 1:
The patent achieves the desired rectification characteristics with non-noble metal electrodes by precisely controlling the work function of the electrode material (selecting metals with work functions greater than 4.5 eV) and optimizing the doping concentration of the oxide layer. These parameter adjustments ensure that the heterojunction forms an appropriate potential barrier that enables reliable rectification without requiring expensive noble metals
4Device complexity
If oxide layers with high doping concentration are used in heterojunction diodes, then lower temperature processing is enabled, but material stability may be compromised
Solution Approach 1:
The patent optimizes the doping concentration of the oxide layer within the range of 10^19 to 10^21 atoms/cm³, which is high enough to enable lower temperature processing but controlled to maintain material stability. This optimized doping level provides sufficient charge carriers for low-temperature formation while avoiding excessive doping that could compromise the structural and electrical stability of the oxide layer
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 heterojunction diode achieves desired rectification characteristics and efficient operation in a resistive memory device with a lower temperature process, reducing manufacturing costs and improving integration density.
Implementation Method 1
A work function of the non-oxide layer may be greater than a work function of the oxide layer by about 0.8-1.2 eV
Data Source
AI summary
Example embodiments relate to a heterojunction diode, a method of manufacturing the heterojunction diode, and an electronic device including the heterojunction diode. The heterojunction diode may include a first conductive type non-oxide layer and a second conductive type oxide layer bonded to the non-oxide layer. The non-oxide layer may be a Si layer. The Si layer may be a p++ Si layer or an n++ Si layer. A difference in work functions of the non-oxide layer and the oxide layer may be about 0.8-1.2 eV. Accordingly, when a forward voltage is applied to the heterojunction diode, rectification may occur. The heterojunction diode may be applied to an electronic device, e.g., a memory device.