IGBT Thyristor Integration Parasitic Operation Avoidance
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Solution Overview
Problem
Conventional semiconductor devices with insulated-gate bipolar transistors (IGBTs) face challenges in miniaturization and manufacturing time due to the need for a thick N+ buffer layer and spatial separation from circuit regions to avoid parasitic operations, which complicates the integration of IGBTs and thyristors in the same semiconductor substrate.
Innovation Solution
The semiconductor device incorporates an IGBT with a reduced conduction capability, allowing it to drive a thyristor, eliminating the need for a buffer layer and enabling closer proximity to circuit regions, thereby miniaturizing the device and reducing manufacturing time by using a semiconductor substrate with a diffusion layer of a second conductivity type and a hole-current retrieval region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick N+ buffer layer is used to ensure IGBT performance and avoid parasitic operation, then the IGBT has a punch-through structure with improved reliability, but the manufacturing time increases and device miniaturization becomes difficult
Solution Approach 1:
The invention extracts and removes the thick N+ buffer layer from the semiconductor substrate, replacing it with a substrate having intrinsic or very low carrier concentration. This eliminates the need for the buffer layer while maintaining the ability to achieve punch-through structure, thereby reducing manufacturing time without compromising reliability
Solution Approach 2:
The invention changes the carrier concentration parameter of the semiconductor substrate from high (in N+ buffer layer) to intrinsic or very low. This parameter change allows the formation of a punch-through structure without requiring a thick buffer layer, thus reducing manufacturing time while maintaining reliability
2Reliability
If the IGBT and circuit region are spaced apart with a hole-current retrieval region to avoid parasitic operation, then the parasitic operation is avoided, but the device area increases and miniaturization becomes difficult
Solution Approach 1:
The invention removes the separate hole-current retrieval region by integrating hole current retrieval functionality directly into the IGBT structure through the anode region. This eliminates the need for additional spacing and retrieval regions, enabling device miniaturization while maintaining protection against parasitic operation
Solution Approach 2:
The invention merges the hole current retrieval function with the IGBT anode region. The anode region serves dual purposes: as part of the IGBT structure and as the hole current retrieval path. This integration eliminates the need for separate retrieval regions and spacing, enabling miniaturization while maintaining reliability
3Power
If the IGBT has a large effective area to maintain conduction capability, then the conduction capability is sufficient, but the device area increases and miniaturization becomes difficult
Solution Approach 1:
The invention changes the carrier concentration parameter of the semiconductor substrate to intrinsic or very low, which allows the IGBT to achieve sufficient conduction capability with a smaller effective area. This parameter change enables miniaturization while maintaining the required power handling capability
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 configuration reduces the effective area of the IGBT, allowing for a smaller semiconductor device with improved avoidance of parasitic operations and faster manufacturing, while maintaining the necessary conduction capabilities for thyristor driving.
Implementation Method 1
This specialized function greatly reduces the amount of hole-current injections from the diffusion layer of the second conductivity type
Implementation Method 2
a hole-current retrieval region separating the insulated-gate bipolar transistor and the circuit region in a plan view
Data Source
AI summary
A semiconductor device of the present invention achieves improved avoidance of a parasitic operation in a circuit region while achieving miniaturization of the semiconductor device and a reduction in the amount of time for manufacturing the semiconductor device. The semiconductor device according to the present invention includes an IGBT disposed on a first main surface of a semiconductor substrate provided with a drift layer of a first conductivity type; a thyristor disposed on the first main surface of the semiconductor substrate; a circuit region; a hole-current retrieval region separating the IGBT and the circuit region in a plan view; and a diffusion layer of a second conductivity type, the diffusion layer being disposed on a second main surface of the semiconductor substrate. The IGBT has an effective area equal to or less than an effective area of the thyristor in a plan view.