SiC Trench Power Device Interlayer Dielectric for Gate Heat Dissipation
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Solution Overview
Problem
Vertical power semiconductor devices face challenges in effectively dissipating heat during high temperature transients and over-voltage events, which can lead to damage to the gate oxide of SiC power transistors and reduce device reliability.
Innovation Solution
A vertical power semiconductor device with a trench structure and an interlayer dielectric structure comprising aluminum nitride, silicon nitride, aluminum oxide, or boron nitride layers is used, which enhances heat dissipation and protects the gate dielectric from overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device geometries are shrunk to reduce costs and increase device functionalities per unit area, then productivity and area utilization are improved, but heat dissipation capability deteriorates leading to higher temperatures and potential gate oxide damage
Solution Approach 1:
The patent employs a composite interlayer dielectric structure consisting of multiple materials with different thermal properties. Specifically, it uses a first interlayer dielectric material (such as SiO2 or Si3N4) combined with a second interlayer dielectric material having higher thermal conductivity (such as AlN, BN, or diamond). This composite structure enables effective heat dissipation from the shrunk device geometries while maintaining the high device functionalities per unit area, thus resolving the contradiction between productivity and temperature control.
2Reliability
If device geometries are shrunk to improve reliability under high temperature conditions, then temperature resistance is improved, but heat dissipation path length increases reducing effectiveness
Solution Approach 1:
The patent introduces an interlayer dielectric structure as an intermediary heat dissipation pathway between the gate electrode and the substrate. This intermediary structure, particularly when incorporating materials like AlN or BN with high thermal conductivity, provides an efficient thermal conduction path that bypasses the limitations of increased heat dissipation path length caused by shrunk geometries. The intermediary layer directly contacts the gate electrode and conducts heat away effectively, thus improving reliability without being constrained by the increased path length.
3Ease of manufacture
If conventional interlayer dielectric materials are used to simplify manufacturing, then ease of manufacture is improved, but thermal conductivity is insufficient leading to poor heat dissipation
Solution Approach 1:
The patent changes the thermal conductivity parameter of the interlayer dielectric materials by selecting materials with fundamentally different thermal properties. Instead of using conventional low thermal conductivity materials like pure SiO2, the patent employs materials such as AlN, BN, or diamond that possess high thermal conductivity. This parameter change enables effective heat dissipation while maintaining compatibility with existing semiconductor manufacturing processes, thus improving energy loss characteristics without significantly compromising ease of manufacture.
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 interlayer dielectric structure effectively dissipates heat, improving the reliability and preventing damage to the gate dielectric, thereby enhancing the overall performance and longevity of the vertical power semiconductor devices.
Implementation Method 1
The interlayer dielectric structure effectively dissipates heat, improving the reliability and preventing damage to the gate dielectric
Data Source
AI summary
A vertical power semiconductor device is proposed. The vertical power semiconductor device includes a silicon carbide (SIC) semiconductor body including a trench structure. The trench structure extends into the SiC semiconductor body at a first surface of the SiC semiconductor body. The trench structure includes a gate electrode and a gate dielectric arranged between the gate electrode and the SiC semiconductor body. An interlayer dielectric structure is arranged on the trench structure. The interlayer dielectric structure includes at least one of an aluminum nitride layer, a silicon nitride layer, an aluminum oxide layer, or a boron nitride layer. The vertical power semiconductor device further includes a source or emitter electrode on the interlayer dielectric structure.