Humidity Sensor Metal Oxide Adhesion Layer
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Solution Overview
Problem
Existing humidity sensors face challenges in achieving reliable adhesion between protective films and moisture-sensitive films, particularly at high temperatures and humidity levels, leading to potential film peeling and reduced sensor reliability.
Innovation Solution
Incorporating a metal oxide film, such as alumina (Al2O3), between the protective film and the moisture-sensitive film to enhance adhesion, utilizing its chemical interaction and hydrolysis resistance to maintain bond integrity even under harsh conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a protective film is formed directly on the semiconductor substrate without an adhesion layer, then the device complexity is reduced, but the adhesion between the protective film and moisture sensitive film deteriorates under high temperature and humidity conditions
Solution Approach 1:
A metal oxide film is introduced as an intermediary layer between the protective film and the moisture sensitive film. This intermediate layer acts as a mediator that enhances adhesion between the two films under high temperature and humidity conditions, resolving the contradiction by adding a functional element that improves reliability without significantly complicating the overall device structure.
Solution Approach 2:
The patent employs a composite structure consisting of multiple materials (protective film, metal oxide film, and moisture sensitive film) stacked together. This composite material approach allows each layer to contribute its specific properties, with the metal oxide film providing enhanced adhesion characteristics that neither the protective film nor the moisture sensitive film could achieve alone under harsh environmental conditions.
2Ease of manufacture
If the moisture sensitive film is formed directly on the protective film, then the manufacturing process is simplified, but film peeling occurs under high temperature and humidity conditions
Solution Approach 1:
The metal oxide film serves as a protective intermediary that prevents direct contact between the protective film and moisture sensitive film, thereby eliminating the harmful peeling effect under high temperature and humidity conditions while maintaining a relatively simple manufacturing process through sequential film deposition.
Solution Approach 2:
The metal oxide film is formed beforehand as a cushioning layer that anticipates and prevents the harmful peeling effect before it occurs. This preventive measure ensures that when high temperature and humidity conditions are encountered during operation, the adhesion between films is already protected, avoiding film peeling issues.
3Quantity of substance
If no adhesion enhancement layer is used, then the manufacturing cost is reduced, but the sensor reliability deteriorates due to poor adhesion between films
Solution Approach 1:
A thin metal oxide film is introduced as an intermediary adhesion enhancement layer. Although this adds a small quantity of material, it dramatically improves sensor reliability by preventing film delamination under high temperature and humidity conditions, resolving the contradiction between material quantity and reliability.
Solution Approach 2:
The patent uses a composite material structure with a metal oxide layer that provides specific adhesion properties. This composite approach enhances sensor reliability through the synergistic combination of materials, where the metal oxide film contributes adhesion enhancement without requiring large quantities of material.
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 metal oxide film significantly improves the adhesion between the protective and moisture-sensitive films, ensuring the humidity sensor's reliability and stability at high temperatures and humidity levels, thereby enhancing its operational performance.
Implementation Method 1
utilizing its chemical interaction and hydrolysis resistance to maintain bond integrity even under harsh conditions
Implementation Method 2
utilizing its chemical interaction and hydrolysis resistance to maintain bond integrity even under harsh conditions
Data Source
AI summary
A humidity sensor includes a semiconductor substrate, an insulating film, an interconnect layer formed above the semiconductor substrate via the insulating film, a protective film that covers the interconnect layer, a moisture sensitive film formed above the protective film, and a metal oxide film formed between the protective film and the moisture sensitive film.