Vertical Semiconductor Sampling Structure for Short-Circuit Detection
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Solution Overview
Problem
Current short-circuit protection methods for vertical semiconductor structures, such as IGBTs, are hindered by the high cost and delay associated with Hall current sensors and desaturation detection, which require complex peripheral circuits to handle high voltages.
Innovation Solution
An integrated sampling structure within the vertical semiconductor structure, comprising a vertical-semiconductor-structure unit cell and a sampling unit cell, with a sampling electrode that samples voltage differences and uses PN junctions to block electron emission, reducing the need for direct high-voltage sampling and simplifying peripheral circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Hall current sensors are used to monitor channel current for short-circuit protection, then detection accuracy is improved, but device size and delay increase
Solution Approach 1:
The sampling structure is integrated directly into the semiconductor device structure, merging the protection function with the main device. The sampling electrode is formed within the existing device layers (N-type base region, P-type well region, N-type source regions), eliminating the need for separate external Hall sensors and reducing overall device size while maintaining detection capability.
Solution Approach 2:
Instead of using complex Hall current sensors, the patent creates a simplified sampling structure that copies only the essential detection function. The sampling electrode monitors voltage differences between the N-type base region and N-type source regions, providing current monitoring capability without the complexity of Hall effect sensors.
2Reliability
If desaturation detection is used to protect against short-circuits, then protection capability is improved, but peripheral circuit complexity and cost increase
Solution Approach 1:
The semiconductor device performs its own protection function through the integrated sampling structure. The sampling electrode directly monitors voltage differences within the device, and the control circuit uses this information to detect short-circuit states and activate protection, eliminating the need for external high-voltage sampling circuits and high-voltage diodes.
Solution Approach 2:
The patent introduces a sampling electrode as an intermediary element that safely bridges the high-voltage power circuit and the low-voltage control circuit. The sampling electrode monitors voltage differences and transmits this information to the control circuit, which then determines short-circuit states without requiring complex peripheral protection circuits.
3Measurement precision
If high-voltage sampling circuits are used for desaturation detection, then protection accuracy is improved, but cost and circuit complexity increase
Solution Approach 1:
The sampling structure is formed using the same semiconductor fabrication processes as the main device (ion implantation, diffusion, oxidation, deposition). The sampling electrode, N-type base region, P-type well region, and N-type source regions are all created during standard device manufacturing, eliminating the need for separate high-voltage sampling circuit fabrication and reducing overall manufacturing cost.
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 enables real-time detection of short-circuit states without increasing power consumption, ensuring stable operation and reducing the risk of damage from high voltage and current, while minimizing the complexity and cost of peripheral circuits.
Implementation Method 1
uses PN junctions to block electron emission
Data Source
AI summary
A vertical semiconductor structure with an integrated sampling structure and a method for manufacturing the same; the vertical semiconductor structure includes a vertical-semiconductor-structure unit cell, a sampling unit cell, a control electrode, a first electrode, a second electrode, and a sampling electrode. The sampling electrode performs real-time sampling of a voltage difference between the first electrode and the second electrode; a PN junction is formed between a first/second P-type diffusion region and a second N-type base region, which forms a potential barrier blocking electron emission from the sampling electrode. Therefore, a voltage signal of the sampling electrode is input into a protection circuit, which detects whether the vertical-semiconductor-structure unit cell is desaturated when it determines that the unit cell is in the open state. Second, a sampling resistor is connected between the sampling electrode and the first electrode to ensure the stable operation of the sampling unit cell.