Dynamic RON Measurement Circuit for High Voltage HEMTs
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Solution Overview
Problem
Testing high voltage transistors for dynamic on-state resistance (dRON) is challenging due to the high off-state voltage and dynamic range requirements, especially in manufacturing, where transistors with defects can lead to increased resistance and overheating, and existing methods struggle with high speed switching transitions and varying resistance values across different transistors.
Innovation Solution
A test system and method involving a voltage source, switch circuit, capacitor, resistor, gate drive circuit, and signal processing circuit that charges a capacitor to a non-zero DC voltage while the transistor is off, then disconnects the voltage source and measures the voltage signal across the resistor when the transistor is turned on, determining the dynamic on-state resistance based on this signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two different power supplies are used to provide high voltage in off state and high current in on state, then the transistor can be tested under realistic operating conditions, but the system complexity increases and high speed switching transitions become difficult to achieve
Solution Approach 1:
The patent combines the high voltage source and high current capability into a single power supply system. The power supply operates in two modes: providing high voltage (e.g., 100V) for off-state testing and high current (e.g., 1A) for on-state testing, eliminating the need for two separate power supplies and their complex transition control.
Solution Approach 2:
The power supply dynamically switches between high voltage/low current mode and low voltage/high current mode based on the transistor state being tested. This dynamic operation allows the single power supply to provide both high voltage for off-state and high current for on-state testing without requiring complex transition control between separate supplies.
2Device complexity
If a single power supply is used to provide both high voltage and high current, then the system complexity is reduced, but achieving both high voltage and high current simultaneously becomes challenging
Solution Approach 1:
The power supply operates periodically, alternating between high voltage mode (for off-state testing) and high current mode (for on-state testing). The control circuit switches the power supply between these modes based on the testing requirements, allowing the single supply to achieve both high voltage and high current capabilities at different time periods.
3Measurement precision
If high speed switching transitions are implemented, then dynamic on-state resistance measurement accuracy is improved, but the difficulty of controlling power supply transitions increases
Solution Approach 1:
The control circuit uses feedback from the transistor state to automatically adjust the power supply mode. When the transistor is in off-state, the control circuit detects this and switches the power supply to high voltage mode. When the transistor turns on, the control circuit detects the change and switches to high current mode, achieving high speed transitions without complex manual control.
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
This approach allows for accurate and efficient testing of transistors for acceptable dynamic on-state resistance, enabling effective screening of transistors during manufacturing and reducing manufacturing costs by identifying and discarding defective units early.
Implementation Method 1
A first terminal of the capacitor is coupled to the second contact terminal, and a second terminal of the capacitor is coupled to the reference voltage node
Implementation Method 2
A first terminal of the resistor is adapted to be coupled to a second terminal of the DUT transistor, and a second terminal of the resistor is coupled to the reference voltage node
Data Source
AI summary
A test system, a method for manufacturing an electronic device, and a method for testing a wafer or electronic device that includes coupling a transistor in a series circuit with a capacitor and a resistor, coupling a voltage source to the capacitor to charge the capacitor to a non-zero DC voltage while the transistor is turned off, disconnecting the voltage source from the capacitor while the transistor is turned off, turning the transistor on while the voltage source is disconnected from the capacitor, measuring a voltage signal across the resistor while the transistor is turned on, and determining a test result indicating whether the transistor has an acceptable dynamic on-state resistance according to the voltage signal across the resistor.