Semiconductor Power Switch with Schottky Gate Junctions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor structures for electronic power switches suffer from parasitic bipolar current issues due to the presence of a second p-n junction, leading to limited current flow between the drain and source, and potential damage from high current between the gate and source when the bias voltage is negative.
Innovation Solution
The semiconductor structure eliminates the second p-n junction by incorporating Schottky-type diodes formed between the gate, source, and semiconductor regions, allowing for unipolar current flow and reducing the risk of damage, while also increasing the current flow between the drain and source for improved electrical conduction, and utilizing two gates for enhanced switching speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a second p-n junction is present in the semiconductor structure, then the device can function as a power switch, but parasitic bipolar current flows when VDs is negative, limiting IDS and potentially damaging the gate
Solution Approach 1:
The patent removes the second p-n junction from the semiconductor structure, extracting the source of parasitic bipolar current. By eliminating this junction, the device prevents the harmful parasitic current flow that occurs when VDs is negative, while maintaining the essential power switch functionality through the remaining p-n junction and Schottky gate configuration.
Solution Approach 2:
The patent changes the gate junction type from p-n to Schottky, fundamentally altering the electrical characteristics of the gate region. This parameter change eliminates the parasitic bipolar current path while maintaining gate control functionality, as the Schottky junction does not support the same parasitic bipolar conduction mechanisms as a p-n junction.
2Device complexity
If a second p-n junction is used to control conduction channels, then the device structure is established, but IDS is strongly limited while IGS becomes high enough to damage the structure
Solution Approach 1:
The patent extracts the second p-n junction that causes high IGS, replacing it with a Schottky gate configuration. This removal eliminates the parasitic bipolar current path that leads to damaging gate currents, while the conduction channel control function is maintained through the Schottky gate's field effect on the underlying p-n junction.
Solution Approach 2:
The patent substitutes the p-n junction gate control mechanism with a Schottky gate mechanism. The Schottky gate uses a metal-semiconductor junction with different electrical characteristics that prevent parasitic bipolar conduction, replacing the problematic p-n junction-based gate control while maintaining the essential function of controlling conduction channels between drain and source.
3Object-generated harmful factors
If Schottky-type diodes are used instead of p-n junctions, then unipolar current flow is achieved and gate current is reduced, but the device structure becomes more complex
Solution Approach 1:
The patent changes the junction type from p-n to Schottky at the gate, fundamentally altering the electrical parameters of the gate region. This parameter change achieves unipolar current flow and reduces parasitic bipolar current, while the structural complexity increase is offset by the elimination of the second p-n junction, resulting in a net simplification of the overall device structure.
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 solution effectively reduces the current between the gate and source, protects the semiconductor structure, and enhances the switching speed and electrical conduction performance by utilizing Schottky-type diodes and ohmic contacts, thereby improving the overall performance and reliability of the semiconductor structure.
Implementation Method 1
a first gate electrode G1 having first portions 70 in contact with the second semiconductor region 3 and a second portion 71 in contact with the first semiconductor region 2 so as to form a first junction of the Schottky type
Implementation Method 2
a contact zone 210, of n-type conductivity, formed on the upper surface 21 of the first semiconductor region 2... a source electrode S in contact with the contact zone 210 of the first semiconductor region 2
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a structure comprising an n-type substrate (1) having a bottom surface (10) and a top surface (11), a drain (D) contacting the bottom surface (10) of the substrate (1), a first n-type semiconductor region (2) having a top surface (21) provided with a contact area (210), a source (S) contacting the contact area (210), and a second p-type semiconductor region (3) arranged inside the first semiconductor region (2) and defining first and second conduction channels (C1, C2) between the drain and the source, characterized in that said structure comprises first and second metal gratings (G1, G2), each of which has a portion (40, 71) contacting the first semiconductor region (2) so as to form a Schottky junction.