Semiconductor Refresh Circuit for Radiation-Induced Threshold Shift
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Solution Overview
Problem
Semiconductor devices with field-effect transistors suffer from operation failures due to radiation exposure, which causes threshold voltage shifts and decreases in ON current, leading to deterioration of transistor performance.
Innovation Solution
A semiconductor device with an electronic circuit, power supply circuit, and correction circuit that switches between normal and refresh operation modes, utilizing P-channel and N-channel field-effect transistors to apply specific voltage operations to remove radiation-induced protons and holes, thereby maintaining transistor performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If field-effect transistors are used in semiconductor devices, then device functionality and integration are improved, but radiation exposure causes threshold voltage shifts and ON current decrease leading to operation failures
Solution Approach 1:
The patent applies preliminary action by performing a refresh operation before the radiation-induced damage becomes critical. The system detects threshold voltage shifts and proactively applies correction voltages to neutralize trapped charges in the gate insulating film, preventing operation failures before they occur. This is evident in the refresh operation mode where correction voltages are applied based on detected threshold voltage changes.
Solution Approach 2:
The patent converts the harmful radiation-induced charge trapping into a beneficial correction mechanism. By detecting threshold voltage shifts caused by radiation and applying opposite polarity correction voltages, the system neutralizes the harmful effects. The refresh operation uses the detected threshold voltage information to apply corrective action, turning the radiation damage signal into a self-correcting mechanism.
2Stability of the object's composition
If refresh operation mode is activated to correct radiation damage, then threshold voltage stability is improved, but additional power supply voltage operations and circuit complexity are required
Solution Approach 1:
The power supply circuit is designed with multi-functionality to serve both normal operation and refresh operation modes. The same power supply circuit generates different voltage levels (VDD1, VDD2, VDD3) that are used in both normal transistor operation and in the correction process during refresh mode. This eliminates the need for separate correction circuitry and reduces overall device complexity.
Solution Approach 2:
The patent changes operational parameters by switching between different power supply voltage levels depending on the operation mode. During normal operation, standard voltage levels are used, while during refresh operation, adjusted voltage levels are applied to the gate and drain/source terminals to perform the correction. This parameter switching approach allows a single circuit to handle both modes without additional complexity.
3Reliability
If correction voltages are applied to neutralize radiation-induced charges, then ON current is restored, but additional power supply operations and control mechanisms are needed
Solution Approach 1:
The patent merges the correction function with the existing power supply circuit rather than adding a separate correction circuit. The power supply circuit is controlled to output different voltage levels based on the operation mode, combining the normal operation function and the correction function into a single integrated system. This reduces control circuit complexity by using one control mechanism for both functions.
Solution Approach 2:
The system performs self-service by automatically detecting threshold voltage shifts and initiating the refresh operation without external intervention. The correction circuit monitors the transistor parameters and autonomously applies the necessary correction voltages to restore ON current, eliminating the need for complex external control mechanisms.
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 refresh operation mode effectively improves threshold voltage stability and ON current, preventing device operation failures by neutralizing radiation-induced damage.
Implementation Method 1
a negative voltage is applied between the gate and at least one selected from the group consisting of a source and a drain so that the gate is lower in potential than the at least one selected from the group consisting of the source and the drain
Implementation Method 2
a positive voltage is applied between the gate and at least one selected from the group consisting of a source and a drain so that the gate is higher in potential than the at least one selected from the group consisting of the source and the drain
Data Source
AI summary
A semiconductor device includes: an electronic circuit to receive a first signal and transmit a second signal; a power supply circuit to supply a power supply voltage to the electronic circuit; and a correction circuit to change a value of the power supply voltage to switch between a normal and a refresh operation mode. The electronic circuit includes: a first Pch transistor in which a potential of a first gate changes according to the first signal, and a potential of one of the first source and drain changes in response to the power supply voltage; and a first Nch transistor in which the second gate is electrically connected to the first gate, a potential of one of the second source and drain is equal to or lower than a ground potential, and another of the second source and drain is electrically connected to another of the first source and drain.