TaSiN Resistive Element for Low TCR Battery Monitoring
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Solution Overview
Problem
Lithium-ion battery multi-cell systems require accurate charge monitoring, necessitating a sense resistor with a minimized temperature coefficient of resistance to function effectively across a wide range of operating temperatures, especially in car-mounted applications, while also needing to be integrated into multilayer wiring with a reduced element area.
Innovation Solution
A semiconductor device with a resistive element having a TaSiN layer over a first insulating layer, coupled with via plugs in an interlayer insulating layer, where the TaSiN layer is formed by modifying a TaN layer with a Si-containing gas, achieving high resistivity and a small temperature coefficient of resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional resistive element is used, then the element area can be larger, but the temperature coefficient of resistance increases and resistivity decreases
Solution Approach 1:
The patent changes the material composition parameters by forming a TaSiN layer with specific silicon content (5-30 at%) and nitrogen content (70-45 at% TaSi). This compositional parameter change achieves high resistivity (500 μΩ·cm or more) and low temperature coefficient of resistance (50 ppm/°C or less) simultaneously, resolving the contradiction between reliability and element area.
Solution Approach 2:
The patent uses a composite material approach by creating a TaSiN layer that combines tantalum, silicon, and nitrogen in specific ratios. This composite material structure provides both high resistivity and thermal stability, allowing the resistive element to maintain small area while achieving excellent temperature characteristics.
2Productivity
If the resistive element area is reduced for compact integration, then device integration improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent replaces mechanical sputtering methods with plasma CVD (chemical vapor deposition) for forming the TaSiN layer. This substitution enables better control over film thickness and composition uniformity, achieving precise resistivity control (500 μΩ·cm or more) even in small-area elements, thus improving integration efficiency without compromising manufacturing precision.
3Reliability
If high resistivity is achieved through material composition, then element area can be reduced, but manufacturing complexity increases
Solution Approach 1:
The patent merges the resistive layer formation with the existing interlayer insulating layer structure. The TaSiN layer is formed as part of the interlayer insulating layer 360, combining insulation and resistance functions in a single structural element. This integration reduces manufacturing process complexity while achieving high resistivity (500 μΩ·cm or more) and compact area.
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 solution provides a semiconductor device with a resistive element that maintains high resistivity and a low temperature coefficient of resistance, enabling accurate charge monitoring in lithium-ion batteries and efficient integration into multilayer wiring with a reduced area.
Implementation Method 1
a silane application step of modifying at least a surface layer of the TaN layer to a TaSiN layer by applying a Si-containing gas
Data Source
AI summary
A semiconductor device includes a first insulating layer (interlayer insulating layer), a resistive element that is disposed over the first insulating layer (interlayer insulating layer) and at least a surface layer of which is a TaSiN layer, and an interlayer insulating layer disposed over the first insulating layer (interlayer insulating layer) and the resistive element. Multiple via plugs having ends coupled to the TaSiN layer are disposed in the interlayer insulating layer.