TiN Field Plate for Power Semiconductor Breakdown Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power semiconductor devices face challenges in achieving high breakdown voltage with low leakage current, particularly due to contamination issues during the deposition of amorphous silicon field plates.
Innovation Solution
The use of a titanium nitride (TiN) field plate with ultra-low thickness, deposited post-metallization, which is semi-insulating and has low resistivity, effectively forming a linear voltage drop to enhance breakdown voltage and reduce leakage current, while avoiding high-temperature deposition that can contaminate the device wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If amorphous silicon field plate is deposited using conventional methods, then the field plate can be formed, but furnace contamination occurs and breakdown voltage is compromised
Solution Approach 1:
The patent changes the material parameter from amorphous silicon to titanium nitride (TiN) and adjusts the deposition temperature parameter to below the melting temperature of aluminum. This parameter change eliminates furnace contamination while maintaining field plate functionality and improving breakdown voltage characteristics.
Solution Approach 2:
The patent uses titanium nitride as a composite material that combines semi-insulating properties with low resistivity. This composite material approach allows the field plate to achieve both contamination-free deposition and enhanced electrical performance for high breakdown voltage applications.
2Reliability
If TiN film thickness is reduced to achieve semi-insulating properties, then leakage current decreases, but deposition temperature must be kept low to avoid contamination
Solution Approach 1:
The patent optimizes the TiN film thickness parameter to ultra-low values (e.g., 10 nm or below) to achieve semi-insulating properties and minimize leakage current. Simultaneously, the deposition temperature is controlled to remain below the melting temperature of aluminum, preventing furnace contamination while enabling low-temperature processing.
3Reliability
If conventional field plate materials are used, then manufacturing process is established, but off-state leakage current is high
Solution Approach 1:
The patent employs titanium nitride as a composite material that provides semi-insulating properties to reduce off-state leakage current. The material can be deposited using established semiconductor fabrication techniques, maintaining ease of manufacture while significantly improving electrical performance.
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 TiN field plate improves breakdown voltage performance and minimizes leakage current, maintaining low resistivity and reducing contamination risks, thus addressing the limitations of traditional semiconductor devices.
Implementation Method 1
TiN has a relatively low resistivity of around 10−4 ohm-cm... By forming a field plate having a TiN film with an ultra-low thickness (e.g., 10 nm or below), the field plate is semi-insulating. As leakage current is approximately proportional to the thickness of the TiN film
Implementation Method 2
The TiN field plate may be fabricated by deposition after metallization of the power semiconductor device. After TiN deposition, the TiN layer thus formed is on top of both the silicon oxide layer and the metal electrodes.
Data Source
AI summary
A power semiconductor device comprising a first metal electrode and a second metal electrode formed on a first substrate surface of a semiconductor substrate, a semi-insulating field plate interconnecting said first and second metal electrodes, and an insulating oxide layer extending between said first and second metal electrodes and between said field plate and said semiconductor substrate, wherein said semi-insulating field plate is a titanium nitride (TiN) field plate.