IGBT Fabrication via Segmented Control and Turn-off Regions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional insulated gate bipolar transistors (IGBTs) face issues with long turn-off trailing time and high turn-off energy consumption due to high hole concentration in the collection region, which complicates the fabrication process and increases energy consumption.
Innovation Solution
A novel IGBT structure and fabrication method involving a bilayer substrate with control and turn-off regions, where emission regions are formed on both sides of gate structures, electrically connected to a well region, and separated from the drift region, reducing hole injection and energy consumption through electronic irradiation and ion implantation processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional IGBT fabrication methods are used, then the device structure is simple, but the turn-off trailing time is long and turn-off energy consumption is high
Solution Approach 1:
The device is divided into distinct control regions and turn-off regions, with further segmentation into emission regions, well regions, and drift regions. This spatial segmentation allows independent optimization of turn-off characteristics in specific areas without affecting the entire device structure, thereby reducing turn-off trailing time while maintaining manageable fabrication complexity.
Solution Approach 2:
Different regions of the device are assigned different doping concentrations and structural characteristics. The turn-off regions have specific well region depths and emission region configurations that differ from control regions, enabling localized optimization of carrier extraction and turn-off speed without requiring complete redesign of the entire device.
2Power
If high hole concentration is maintained in the collection region, then the bipolar transistor function is enhanced, but the turn-off energy consumption increases
Solution Approach 1:
The invention extracts excess holes from the drift region during turn-off through specifically designed emission regions and well regions in the turn-off regions. This extraction mechanism removes the harmful accumulation of carriers that would otherwise require high energy to clear, thereby reducing turn-off energy consumption while maintaining adequate hole concentration for bipolar function during operation.
Solution Approach 2:
The well regions and emission regions create a feedback mechanism where the electric field and carrier concentration automatically regulate hole extraction during turn-off. When hole concentration becomes excessive, the field effect enhances extraction, providing self-regulating control over energy consumption during switching transitions.
3Productivity
If emission regions are formed close to the drift region, then carrier injection is enhanced, but leakage current increases
Solution Approach 1:
The well region serves as an intermediary layer between the emission region and the drift region. This intermediate structure allows controlled carrier injection from the emission region while the well region's specific doping profile and depth act as a barrier to prevent excessive leakage current, thus mediating between injection efficiency and leakage control.
Solution Approach 2:
The invention optimizes the depth, doping concentration, and lateral dimensions of the well region and emission regions to achieve the desired balance. By carefully controlling these parameters, the structure enables efficient carrier injection when needed while maintaining low leakage current through proper potential barrier formation.
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 proposed solution reduces turn-off trailing time and energy consumption by controlling hole concentration and injection, enhancing the IGBT's switching speed and efficiency while simplifying the fabrication process without increasing leakage current.
Implementation Method 1
through electronic irradiation and ion implantation processes
Implementation Method 2
through electronic irradiation and ion implantation processes
Data Source
AI summary
Method for fabricating an insulated gate bipolar transistor (IGBT) is provided. A substrate includes a device region, that includes control regions and turn-off regions, arranged alternately. A drift region is formed in the substrate. A well region is formed in a portion of the substrate in the control regions and the turn-off regions, and first gate structures are formed in the control regions. The well region is in contact with the drift region, and the first gate structures are in contact with both the drift region and the well region. Emission regions are formed in the well region of the control regions and in the substrate on one or both sides of each first gate structure, the drift region and each emission region are separated by the well region, and the emission regions are electrically connected to a portion of the well region in the turn-off region.