Complementary BJT Thermal Sensor for IC Hot Spot Sensing
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Solution Overview
Problem
Conventional thermal sensors in semiconductor ICs are not adequately positioned to measure heat at hot spots, leading to performance deterioration due to increased device packing density, and require additional fabrication processes, which complicates their integration with active components.
Innovation Solution
A complementary bipolar junction transistor (CBJT) thermal sensor is fabricated using similar processes as multi-bridge-channel transistors, with a unique structure that includes PNP and NPN BJTs, allowing accurate temperature sensing by coupling base and collector regions to different potentials, thereby canceling out dopant non-uniformity and improving measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional thermal sensors are used, then thermal sensing function is provided, but additional fabrication process steps are required and sensors cannot be placed sufficiently adjacent to hot spots
Solution Approach 1:
The patent combines the thermal sensor fabrication with the existing MBC transistor fabrication process. The CBJT structures are formed using the same fin-shaped structure formation, doping, and gate electrode deposition steps as the MBC transistors, eliminating separate sensor fabrication processes and reducing overall device complexity.
Solution Approach 2:
The CBJT structures serve dual purposes: they function as active electronic components (transistors) and as thermal sensors. By configuring some CBJTs with specific doping patterns and electrical connections, they can monitor temperature while simultaneously contributing to the circuit's active functionality, reducing the need for dedicated sensor structures.
2Productivity
If device packing density is increased to improve production efficiency, then more functions are supported, but heat generation increases causing performance deterioration
Solution Approach 1:
The patent implements thermal feedback by using CBJT-based thermal sensors to monitor temperature in real-time near heat-generating MBC transistors. The sensor outputs temperature information that can be used to adjust operating conditions, activate cooling mechanisms, or throttle performance to prevent thermal runaway and maintain stable operation at high packing densities.
Solution Approach 2:
The CBJT structures act as intermediary elements between the heat-generating MBC transistors and the thermal management system. They are positioned adjacent to hot spots and provide localized temperature monitoring, enabling precise thermal control without requiring direct intervention in the high-density transistor array.
3Ease of manufacture
If conventional thermal sensors are placed away from hot spots, then fabrication is simplified, but temperature measurement accuracy deteriorates
Solution Approach 1:
The thermal sensors are merged with the active CBJT structures that are already positioned adjacent to heat-generating MBC transistors. This integration allows the sensors to be located precisely at hot spots without requiring separate placement processes, maintaining measurement accuracy while simplifying manufacturing.
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 CBJT thermal sensor provides stable and accurate thermal measurements by being fabricated alongside MBC transistors, reducing the need for additional processes and allowing closer proximity to heat sources, thus enhancing the monitoring and control of heat generation in IC devices.
Implementation Method 1
The voltage difference between the first potential and the second potential correlates to change of temperature and allows the thermal sensor of the present disclosure to sense temperature
Implementation Method 2
The complementary nature of the CBJT cancels out uneven concentration distribution of n-type and p-type dopants
Data Source
AI summary
The present disclosure provides embodiments of semiconductor devices. In one embodiment, the semiconductor device includes a dielectric layer and a fin-shaped structure disposed over the dielectric layer. The fin-shaped structure includes a first p-type doped region, a second p-type doped region, and a third p-type doped region, and a first n-type doped region, a second n-type doped region, and a third n-type doped region interleaving the first p-type doped region, the second p-type doped region, and the third p-type doped region. The first p-type doped region, the third p-type doped region and the third n-type doped region are electrically coupled to a first potential. The second p-type doped region, the first n-type doped region and the second n-type doped region are electrically coupled to a second potential different from the first potential.