SiC MOS Device Interlayer Insulation Dehydration
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Solution Overview
Problem
The existing methods for manufacturing silicon carbide (SiC) semiconductor devices face challenges in achieving higher channel mobility and preventing electrode material corrosion due to moisture absorption by interlayer insulation layers during the heating process.
Innovation Solution
A method involving the formation of a SiC semiconductor device with a metal-oxide semiconductor structure, including steps like forming a channel region, impurity regions, a gate insulation layer, and an interlayer insulation layer, followed by a reflow process in a wet atmosphere and subsequent dehydration in an inert gas atmosphere at 700°C or lower to prevent electrode corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a heating process is performed in the wet atmosphere to form the interlayer insulation layer, then the channel mobility is improved through hydrogen anneal, but the interlayer insulation layer absorbs moisture and corrodes the electrode material
Solution Approach 1:
The patent performs the reflow process in wet atmosphere first to achieve hydrogen anneal and improve channel mobility, then subsequently performs a dehydration process in inert gas atmosphere to remove absorbed moisture from the interlayer insulation layer. This preliminary action sequence ensures that the electrode material is protected from corrosion by removing the harmful moisture after it has been absorbed during the beneficial wet atmosphere treatment.
2Manufacturing precision
If the temperature is maintained high to complete the reflow process, then the interlayer insulation layer is properly formed, but the electrode material becomes susceptible to corrosion from moisture absorption
Solution Approach 1:
The reflow process is completed at high temperature first to ensure proper formation of the interlayer insulation layer, then a dehydration process is performed in inert gas atmosphere to remove absorbed moisture. This sequence of preliminary actions ensures that the interlayer insulation layer is properly formed before addressing the moisture absorption issue that occurs during high-temperature processing.
Solution Approach 2:
The patent uses inert gas atmosphere (such as nitrogen or argon) during the dehydration process to prevent oxidation and corrosion of the electrode material. The inert atmosphere creates a protective environment that eliminates the harmful effects of moisture and oxygen on the electrode material after the high-temperature reflow process.
3Reliability
If hydrogen anneal is performed to improve channel mobility, then the semiconductor device performance is enhanced, but moisture absorption by the interlayer insulation layer leads to electrode corrosion
Solution Approach 1:
The hydrogen anneal process is performed first to improve channel mobility and enhance semiconductor device performance, then a dehydration process is subsequently performed to remove the moisture absorbed during hydrogen anneal. This sequence of preliminary actions ensures that the performance enhancement from hydrogen anneal is achieved while preventing the harmful effect of moisture absorption on the electrode material.
Solution Approach 2:
The patent converts the harmful effect of moisture absorption during hydrogen anneal into a beneficial process by intentionally allowing the interlayer insulation layer to absorb moisture during the hydrogen anneal, then using the subsequent dehydration process in inert gas atmosphere to remove this moisture. The moisture absorption serves as an indicator that the hydrogen anneal has occurred, and the subsequent dehydration eliminates the harmful corrosion effect.
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
This method enhances channel mobility and prevents electrode material corrosion by effectively dehydrating the interlayer insulation layer, ensuring the semiconductor device's reliability and performance.
Implementation Method 1
When a heating process is performed in the wet atmosphere, an interlayer insulation layer made of BPSG (boron phosphorus silicon glass), for example, absorbs moisture
Implementation Method 2
a step of performing a dehydration process in the inert gas atmosphere so that the interlayer insulation layer is dehydrated
Data Source
AI summary
A method of manufacturing a silicon carbide semiconductor device having a MOS structure includes preparing a substrate made of silicon carbide, and forming a channel region, a first impurity region, a second impurity region, a gate insulation layer, and a gate electrode to form a semiconductor element on the substrate. In addition, a film is formed on the semiconductor element to provide a material of an interlayer insulation layer, and a reflow process is performed at a temperature about 700° C. or over in an wet atmosphere so that the interlayer insulation layer is formed from the film. Furthermore, a dehydration process is performed at about 700° C. or lower in an inert gas atmosphere after the reflow process is performed.