Semiconductor Substrate Doping Layout to Suppress Ringing
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Solution Overview
Problem
Existing semiconductor devices face challenges in increasing speed and improving operation guarantee temperatures, particularly in power devices used in electric vehicles, due to issues with switching loss and ringing when reducing substrate thickness.
Innovation Solution
A manufacturing method involving the introduction of impurities and hydrogen donors in specific layers of a semiconductor substrate, followed by controlled heat treatments, to form defect regions and adjust carrier concentration distributions, thereby enhancing device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If substrate thickness is reduced to increase switching speed, then speed is improved, but ringing occurs and operation guarantee temperature deteriorates
Solution Approach 1:
The patent introduces a hydrogen donor layer at a specific depth (0.5-2.0 μm from the front surface) with localized hydrogen concentration (1×10^19 to 1×10^21 atoms/cm³) to suppress ringing in the critical region where it occurs, while maintaining overall substrate thickness reduction for high switching speed. This localized treatment allows different regions to have different properties: the hydrogen donor layer region suppresses ringing, while the overall thin substrate enables fast switching.
Solution Approach 2:
The patent changes physical parameters by introducing hydrogen donors with specific concentration ranges (1×10^19 to 1×10^21 atoms/cm³) at controlled depths (0.5-2.0 μm), and by performing heat treatment at specific temperature ranges (200-400°C) to optimize the hydrogen distribution. These parameter changes enable the substrate to simultaneously achieve fast switching and high temperature reliability.
2Speed
If substrate thickness is reduced to improve switching speed, then speed is improved, but switching loss increases
Solution Approach 1:
The hydrogen donor layer is positioned at a specific depth (0.5-2.0 μm from the front surface) with optimized hydrogen concentration to suppress ringing locally, thereby reducing switching loss associated with ringing while preserving the overall thin substrate structure for fast switching and low switching loss.
3Reliability
If hydrogen is introduced to suppress ringing, then operation guarantee temperature is improved, but device complexity increases
Solution Approach 1:
The patent combines the hydrogen donor layer formation with existing manufacturing steps by introducing hydrogen donors through ion implantation or in-diffusion during the same heat treatment process used for other layer formations. This integration reduces the number of separate process steps and minimizes device complexity while achieving the reliability improvement.
Solution Approach 2:
The patent optimizes hydrogen donor parameters (concentration: 1×10^19 to 1×10^21 atoms/cm³, depth: 0.5-2.0 μm, heat treatment temperature: 200-400°C) to achieve effective ringing suppression with minimal process complexity. By carefully controlling these parameters, the manufacturing process remains simple while achieving the desired reliability improvement.
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 method increases speed and improves operation guarantee temperatures by reducing switching loss and suppressing ringing, while allowing for flexible adjustment of device characteristics.
Implementation Method 1
introducing hydrogen from the lower surface and forming a first semiconductor layer; performing first heat treatment on the semiconductor substrate, and donating the hydrogen introduced into the first semiconductor layer
Implementation Method 2
introducing an impurity having a first conductivity type from an upper surface of a semiconductor substrate; introducing from the lower surface an impurity of a second conductivity type opposite to the first conductivity type
Implementation Method 3
performing first heat treatment on the semiconductor substrate, and donating the hydrogen introduced into the first semiconductor layer; performing second heat treatment on the semiconductor substrate at a temperature higher than a temperature of the first heat treatment
Data Source
AI summary
A method of manufacturing a semiconductor device according to the present disclosure includes: introducing an impurity having a first conductivity type from an upper surface of a semiconductor substrate having the upper surface and a lower surface; forming a metal layer on the upper surface; introducing hydrogen from the lower surface and forming a first semiconductor layer; performing first heat treatment on the semiconductor substrate, and donating the hydrogen introduced into the first semiconductor layer; introducing from the lower surface an impurity of a second conductivity type opposite to the first conductivity type, and forming a second semiconductor layer at a position shallower than a position of the first semiconductor layer; and performing second heat treatment on the semiconductor substrate at a temperature higher than a temperature of the first heat treatment, and applying the second conductivity type to the second semiconductor layer.