Semiconductor Temperature Sensor Integrated in Power Transistor Drift Zone
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Solution Overview
Problem
Power transistors in automotive and industrial electronics require a balance between low on-state resistance and high voltage blocking capability, while also needing effective temperature monitoring, which existing designs struggle to achieve efficiently.
Innovation Solution
A semiconductor device is designed with a temperature sensor integrated into the power transistor, featuring a transistor with a source region, gate electrode, and drift zone in a semiconductor substrate, along with a temperature sensor comprising a pn junction or diode, allowing for temperature measurement and protection by switching off the transistor when a threshold temperature is exceeded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a temperature sensor is integrated into the power transistor, then temperature monitoring capability is improved, but device complexity increases
Solution Approach 1:
The temperature sensor is integrated directly into the power transistor structure by utilizing the drift zone as the temperature sensing region. The sensor contacts are formed within the transistor's existing semiconductor body, merging the temperature monitoring function with the power switching function in a single device structure.
Solution Approach 2:
The drift zone of the power transistor serves dual purposes: it functions as the active region for voltage blocking and current conduction, and simultaneously serves as the temperature sensing element. This multi-functionality allows the same structural region to provide both power device performance and temperature monitoring capability.
2Reliability
If the transistor structure is optimized for low on-state resistance, then conduction performance is improved, but temperature sensing accuracy may deteriorate
Solution Approach 1:
The temperature sensor is positioned specifically within the drift zone, which is the region most sensitive to temperature changes during transistor operation. By placing the sensing element in this specific location rather than uniformly throughout the device, the measurement accuracy is maximized while maintaining the overall low on-state resistance design.
Solution Approach 2:
The drift zone acts as an intermediary element that mediates between the power conduction function and temperature sensing function. It provides a dedicated region where temperature can be accurately measured without interfering with the low on-state resistance characteristics of the channel and contact regions.
3Reliability
If the transistor structure is optimized for high voltage blocking capability, then voltage withstand performance is improved, but temperature sensor integration becomes more difficult
Solution Approach 1:
The temperature sensor is formed by utilizing the existing drift zone structure that is already present in high-voltage power transistors. The sensor contacts are integrated into the drift zone during the same manufacturing process steps used to create the voltage blocking structure, merging the voltage withstand and temperature sensing functions without requiring separate high-voltage processing steps.
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 integration of a temperature sensor within the semiconductor device enables efficient temperature monitoring and protection, maintaining low on-state resistance and high voltage blocking capability, thus enhancing the reliability and performance of power transistors in demanding applications.
Implementation Method 1
A semiconductor device is designed with a temperature sensor integrated into the power transistor, featuring a transistor with a source region, gate electrode, and drift zone in a semiconductor substrate, along with a temperature sensor comprising a pn junction or diode, allowing for temperature measurement
Data Source
AI summary
A semiconductor device includes a transistor in a semiconductor substrate having a first main surface. The transistor includes a source region, a source contact, the source contact including a first and second source contact portion, and a gate electrode in a gate trench in the first main surface adjacent to a body region. The body region and a drift zone are disposed along a first direction parallel to the first main surface between the source region and a drain region. The second source contact portion is disposed at a second main surface of the semiconductor substrate. The first source contact portion includes a source conductive material in direct contact with the source region, the first source contact portion further including a portion of the semiconductor substrate between the source conductive material and the second source contact portion. The semiconductor device further includes a temperature sensor in the semiconductor substrate.