Manufacturing process of a vertical-channel semiconductor device and vertical-channel semiconductor device
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Solution Overview
Problem
Existing IGBT devices have a low reliability due to the inadequacy of the field-stop region in withstanding high emitter-collector voltages and high temperatures, leading to malfunctioning and failure in power applications.
Innovation Solution
A manufacturing process for a vertical-channel semiconductor device that forms a thermally diffused conduction region via dopant diffusion, which acts as a robust field-stop region, enhancing the device's reliability under high voltage and temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a field-stop region is used in known IGBT devices, then the device structure is simple and manufacturing is easier, but the reliability is low under high voltage and temperature conditions
Solution Approach 1:
The patent changes the physical and chemical parameters of the field-stop region by forming it through thermal diffusion of dopant atoms at high temperatures (900-1300°C). This thermal diffusion process creates a region with specific doping concentration gradients and crystal structure properties that enhance reliability under high voltage and temperature conditions while maintaining manufacturing feasibility
Solution Approach 2:
The field-stop region is formed preliminarily during the manufacturing process before the device is put into operation. The thermal diffusion process pre-establishes the dopant concentration profile and structural characteristics needed for high reliability, so that when the device operates under high voltage and temperature, the field-stop region is already optimized to prevent malfunction
2Reliability
If a field-stop region is used in known IGBT devices, then the manufacturing process is simpler, but the device fails under high emitter-collector voltages and high temperatures
Solution Approach 1:
The patent employs parameter changes by utilizing high-temperature thermal diffusion (900-1300°C) to create a field-stop region with optimized dopant concentration and distribution. This process transforms the material properties to achieve electrical robustness under high voltage and temperature while integrating into the existing manufacturing workflow
Solution Approach 2:
The patent replaces simple mechanical doping or implantation methods with thermal diffusion processes. Instead of using physical implantation techniques, the dopant atoms are introduced and distributed through thermal energy-driven diffusion, which creates a more reliable field-stop region structure that better withstands high voltage and temperature conditions
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 process results in a semiconductor device with improved reliability and electrical robustness, reducing the likelihood of malfunction and failure, especially under high emitter-collector voltages and high temperatures, making it suitable for power applications.
Implementation Method 1
a thermally diffused conduction region (64), of an N type, extending over the back conduction region (60)
Data Source
Figure 1~2
Figure 3~4
Figure 5~8
AI summary
For manufacturing a vertical-channel semiconductor device (50), starting from a work wafer (1, 6) having a first side (1A) and a second side (1B) opposite to the first side along a direction (Z), a first doped region (42, 64) is formed in the work wafer, from the second side of the work wafer. The work wafer has a first conductivity type (N) and a first doping level, the first doped region has the first conductivity type and a second doping level higher than the first doping level. A device active region (25, 62) having a channel region (76) extending in the direction is formed in the work wafer, on the first side of the work wafer. The first doped region and the device active region delimit, in the work wafer, a drift region (30, 66). The first doped region is formed before the device active region.