Space-Charge Control Electrodes for High-Voltage Breakdown
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Solution Overview
Problem
Current high-voltage field-effect transistors (FETs) face limitations in achieving breakdown voltages due to non-uniform electric fields and premature breakdown, especially at high voltages, which restricts their performance and design for kilovolt switching applications.
Innovation Solution
A semiconductor device with a set of space-charge control electrodes located between a gate and a drain, equipped with a biasing network that supplies individual bias voltages to each electrode based on the terminal voltages and location, configured to deplete the channel region and optimize the electric field distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the gate-drain spacing distance is increased to increase breakdown voltage, then the breakdown voltage should increase, but the peak electric field near the gate edge remains strong and breakdown voltage saturation occurs
Solution Approach 1:
The gate-drain spacing is segmented into multiple regions by introducing field plates at different positions and potentials. This divides the single peak electric field into multiple smaller peaks, preventing any single location from having an excessively strong field that would cause premature breakdown.
Solution Approach 2:
Different regions of the gate-drain spacing are given different electric field characteristics through the field plates. The field plates create localized field modulation, with stronger field control near the gate edge and gradual field distribution toward the drain, optimizing breakdown characteristics throughout the spacing.
2Strength
If field plates are used to reduce peak electric field, then breakdown voltage increases, but device complexity and manufacturing precision requirements increase
Solution Approach 1:
The field plates are designed to serve multiple functions simultaneously: they modulate the electric field to prevent premature breakdown, provide gradual field distribution, and can be integrated with existing gate or drain structures. This multi-functionality reduces the need for additional separate components.
Solution Approach 2:
The field plates are merged with existing device structures such as the gate electrode extension or drain contact regions. By combining the field plate function with existing structural elements, the device complexity is minimized while still achieving the desired electric field distribution.
3Strength
If field plates are used to control electric field distribution, then breakdown voltage improves, but inter-electrode capacitance increases and maximum operating frequency decreases
Solution Approach 1:
The field plates are designed with optimized dimensions, spacing, and potential values to achieve the desired electric field distribution while minimizing capacitance. By carefully controlling the geometric parameters and electrical parameters of the field plates, a balance is struck between breakdown voltage enhancement and frequency response preservation.
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 solution enhances the breakdown voltage and operating power of the semiconductor device by achieving a more uniform electric field and reducing premature breakdown, thereby improving device performance and design capabilities for high-voltage applications.
Implementation Method 1
the electric field profile in the gate-drain spacing having a distance, LGD
Implementation Method 2
configured to deplete a region of the channel under the corresponding space-charge control electrode
Data Source
AI summary
A circuit including a semiconductor device having a set of space-charge control electrodes is provided. The set of space-charge control electrodes is located between a first terminal, such as a gate or a cathode, and a second terminal, such as a drain or an anode, of the device. The circuit includes a biasing network, which supplies an individual bias voltage to each of the set of space-charge control electrodes. The bias voltage for each space-charge control electrode can be: selected based on the bias voltages of each of the terminals and a location of the space-charge control electrode relative to the terminals and/or configured to deplete a region of the channel under the corresponding space-charge control electrode at an operating voltage applied to the second terminal.