Semiconductor Electrode Oxide Layer Prevents Organic Contamination
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Solution Overview
Problem
The exposure of metal films to the atmosphere during film formation processes in semiconductor devices leads to contamination by organic matter in clean room environments, affecting the electrical characteristics and reliability of the semiconductor device.
Innovation Solution
A semiconductor device with a laminated electrode structure that includes a first metal layer in contact with the semiconductor substrate, an oxide layer containing a metal and oxygen with specific oxygen concentration ranges, and a second metal layer, which prevents organic contamination and maintains low electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If metal films are formed by different film forming apparatuses or through different film formation processes, then the electrode structure can be flexibly manufactured, but the metal films are exposed to the atmosphere causing organic contamination
Solution Approach 1:
An oxide layer is introduced as an intermediary between the first metal layer and the second metal layer. This oxide layer acts as a protective barrier that prevents organic matter from contaminating the metal films while allowing the electrode to be formed using different film forming apparatuses and processes. The oxide layer is formed by oxidizing the surface of the first metal layer, creating a stable interface that blocks atmospheric exposure.
Solution Approach 2:
The oxide layer is formed in advance before the second metal layer is deposited. This preliminary oxidation step creates a protective barrier on the surface of the first metal layer, ensuring that subsequent metal layers are not contaminated by atmospheric exposure during the film formation process. The oxide layer is prepared beforehand to prevent contamination rather than removing contamination after it occurs.
2Object-affected harmful factors
If an oxide layer is formed on the first metal layer to prevent contamination, then organic contamination is reduced, but the electrical resistance may increase
Solution Approach 1:
The concentration of oxygen in the oxide layer is precisely controlled within the range of 8.0×10^21 to 4.0×10^22 atoms/cm³. By optimizing this parameter, the oxide layer provides sufficient protection against organic contamination while maintaining low electrical resistance. The controlled oxygen concentration ensures the oxide layer is not too thick or dense, which would increase resistance, nor too thin to be ineffective.
Solution Approach 2:
The oxide layer is formed only on the surface of the first metal layer where it is needed for protection, rather than throughout the entire electrode structure. This localized oxidation provides contamination protection at the interface where atmospheric exposure occurs, while the bulk metal layers maintain their excellent electrical conductivity properties.
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 proposed solution effectively prevents organic contamination and maintains the electrical integrity of the semiconductor device by forming an oxide layer with controlled oxygen concentrations, reducing carbon contamination and avoiding alloying reactions that increase electrical resistance.
Implementation Method 1
an oxide layer which contains a metal and oxygen and is formed on a surface of the first metal layer
Data Source
AI summary
An object is to provide a semiconductor device that can prevent organic contamination of an electrode including a plurality of laminated metal layers. A semiconductor device includes: a semiconductor substrate; and an electrode including a plurality of layers laminated on a principal surface of the semiconductor substrate. The electrode includes: a first metal layer in contact with the principal surface of the semiconductor substrate, the first metal layer containing Al; an oxide layer formed on a surface of the first metal layer, the oxide layer containing a metal and oxygen; and a second metal layer formed on a surface of the oxide layer. Concentrations of the oxygen in the oxide layer are higher than or equal to 8.0×1021/cm3 and lower than or equal to 4.0×1022/cm3.