Power Device Schottky Diode Segmentation for Fast Switching
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Solution Overview
Problem
Conventional power devices experience long switching times and unwanted current generation due to parasitic body diodes when switching between conduction and non-conduction states, especially in synchronous switching regulators with minority carriers.
Innovation Solution
A power device design featuring a Schottky diode formed by a second conduction portion and a drift region, with a continuous depletion region and strategically placed gate openings, allowing minority carriers to flow back to the source without affecting operation, thereby reducing unwanted currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional power device uses a parasitic body diode for switching between conduction and non-conduction states, then the device structure is simple, but the switching time is long and power consumption increases
Solution Approach 1:
The power device is segmented into distinct functional regions: a body region, a drift region, and a Schottky diode region. The Schottky diode is formed by a separate conduction portion and second conduction portion structure, dividing the device into specialized zones that perform switching and current blocking functions independently, enabling faster switching without requiring a complex overall structure
Solution Approach 2:
The gate structure acts as an intermediary element positioned between the body region and drift region. The gate controls the formation of a depletion region that mediates the switching action, allowing rapid transition between conduction and non-conduction states by controlling carrier flow without requiring complex external circuitry
2Device complexity
If a conventional power device uses a parasitic body diode, then the device structure is simple, but power consumption increases
Solution Approach 1:
The device is divided into specialized regions including a Schottky diode formed by distinct conduction portions. This segmentation allows the Schottky diode to handle reverse recovery current efficiently with low loss, while the main power device handles forward conduction, optimizing energy usage without increasing overall structural complexity
Solution Approach 2:
The invention changes the electrical parameters of the switching mechanism by using a Schottky diode with a metal-semiconductor junction instead of a conventional PN junction body diode. This parameter change reduces reverse recovery charge and switching losses, decreasing power consumption while maintaining a relatively simple device structure
3Adaptability or versatility
If a conventional power device with minority carriers is used in a synchronous switching regulator, then the device can function as a bridge switch, but unwanted current is generated causing operation problems
Solution Approach 1:
The harmful minority carrier effects are extracted and isolated to the body region, while the Schottky diode region handles the main switching current. The gate-depletion region structure extracts and controls carrier flow, preventing unwanted current generation in the drift region that would otherwise cause operation problems in synchronous switching regulators
Solution Approach 2:
The invention converts the potential harm of minority carriers by using them beneficially in the body region while the Schottky diode structure prevents their harmful effects in the drift region. The gate-controlled depletion region transforms what would be harmful leakage current into a controlled switching mechanism, eliminating unwanted current in synchronous switching applications
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 design enables faster switching and reduced power consumption by ensuring continuous depletion regions and efficient carrier management, preventing operation issues in synchronous switching regulators.
Implementation Method 1
A Schottky diode is formed by the second conduction portion and the drift region
Implementation Method 2
a depletion region is continuously formed without break in the drift region, to encompass a junction between the drift region and the second conduction portion under the top surface
Data Source
AI summary
The invention provides a power device, which includes: an operation layer, including a top surface, a body region and a drift region, the body region and the drift region being connected in a lateral direction, to form a PN junction along a channel width direction between the body region and the drift region; a gate, formed on the top surface, and the PN junction is located under the gate; a source, formed in a portion of the operation layer between the body region and the top surface; a drain, formed in another portion of the operation layer between the drift region and the top surface; a first conduction portion, formed on the top surface for electrically connecting the source; a conduction layer, formed on the first conduction portion and electrically connected to the source via the first conduction portion; and a second conduction portion, formed on the top surface and between the conduction layer and the drift region in a thickness direction, for electrically connecting the drift region and the conduction layer, wherein a Schottky diode is formed by the second conduction portion and the drift region.