Semiconductor Chip Layout for Local Self-Heating Measurement
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Solution Overview
Problem
Existing semiconductor devices, particularly those using FinFET technology, face challenges in accurately measuring local self-heating due to the difficulty in placing temperature sensors near high-power density regions, leading to unreliable reliability life predictions.
Innovation Solution
A semiconductor device with a local sensor and conversion circuit configuration that measures temperature changes in high-power density regions using a leak current from transistors, converting this signal into a digital count value for precise temperature measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a global temperature sensor is used to measure the average temperature of the semiconductor chip, then the measurement coverage is comprehensive, but the measurement precision of local temperature rise is insufficient
Solution Approach 1:
The patent divides the temperature measurement function into multiple segments: a global temperature sensor for overall chip temperature and local temperature sensors (using leak current measurement) for specific high-power density regions. This segmentation allows simultaneous achievement of wide coverage and high local precision.
Solution Approach 2:
The patent introduces an intermediary measurement mechanism - using the leak current of a transistor as an indirect indicator of local temperature. The leak current varies with temperature, serving as a mediator that converts temperature information into a measurable electrical signal without requiring direct thermal contact.
2Measurement precision
If a temperature sensor is placed near the local region to measure transistor-level temperature, then the measurement precision is improved, but the occupied area increases and layout flexibility decreases
Solution Approach 1:
The patent makes the transistor serve multiple functions: it acts as both a functional circuit element and a temperature sensor. By measuring the leak current of the transistor, the same device provides both computational functionality and thermal monitoring, eliminating the need for separate dedicated temperature sensing structures.
Solution Approach 2:
The transistor monitors its own temperature through its inherent leak current characteristic. The device uses itself as the sensing element, eliminating the need for external or separate temperature sensors that would occupy additional area. The leak current naturally varies with the transistor's temperature, providing self-diagnostic capability.
3Adaptability or versatility
If the temperature sensor is added after the clock signal layout design, then the design flexibility is maintained, but the placement difficulty increases due to limited available area
Solution Approach 1:
The patent incorporates the temperature sensing capability into the transistor design from the beginning, rather than adding it as a post-layout modification. The leak current measurement mechanism is built into the transistor structure itself, allowing temperature monitoring to be established during the initial design phase without requiring additional layout iterations.
4Measurement precision
If the Vt measurement type or PN_Junction type temperature sensor is used, then the measurement principle is established, but the device complexity increases due to current-voltage curve conversion requirements
Solution Approach 1:
The patent extracts only the essential temperature-dependent characteristic (leak current) from the transistor, eliminating the need for complex current-voltage curve measurements and conversions. By focusing solely on the leak current parameter that naturally varies with temperature, the system achieves temperature measurement with minimal measurement and processing complexity.
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
Enables accurate measurement of local self-heating, allowing for improved reliability life prediction and control of the semiconductor device's temperature, thereby suppressing reliability deterioration.
Implementation Method 1
a local sensor including a transistor, arranged in proximity to a measurement target region in a semiconductor chip, and outputs a leak current of the transistor as a sensor signal according to a temperature in the measurement target region
Data Source
AI summary
A semiconductor device includes: a local sensor including a transistor, arranged in proximity to a measurement target region in a semiconductor chip, and outputs a leak current of the transistor as a sensor signal according to a temperature in the measurement target region; a conversion circuit arranged on the semiconductor chip, and converting the sensor signal from the local sensor into a digital count value; and a circuit block arranged between the local sensor and the conversion circuit in the semiconductor chip when viewed in a plan view.