Silicon-Carbide Ion Implantation Using Lattice Blocking Regions
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Solution Overview
Problem
The manufacturing of localized ion implants in silicon-carbide substrates for power electronic devices is complex, time-consuming, and costly, often resulting in planarity issues due to lattice stress effects from traditional masking methods.
Innovation Solution
A channeled ion implantation process is used, where intentionally damaged regions are created on the substrate surface to inhibit channeling, allowing for self-aligned, mask-free implantation of doping ions, thereby controlling the depth and profile of implanted regions with high precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional masking methods are used for localized ion implantation, then implantation can be localized to specific regions, but planarity issues occur due to lattice stress effects
Solution Approach 1:
The patent removes the mask layer entirely from the process, extracting the problematic masking step that causes planarity issues. Instead of using masks to define implantation regions, the invention uses direct ion beam scanning to achieve localized implantation without any mask material on the substrate surface.
Solution Approach 2:
The patent replaces the mechanical masking system (physical mask layers) with a beam control system. The ion beam is steered and scanned across the substrate surface using magnetic or electric fields to define implantation regions dynamically, eliminating the need for physical masks and their associated stress effects.
2Manufacturing precision
If multiple implant steps are performed to achieve desired doping profile, then doping precision is improved, but manufacturing time and complexity increase
Solution Approach 1:
The patent employs dynamic beam scanning where the ion beam is continuously moved across the substrate in programmed patterns. This dynamic control allows a single implantation step to achieve complex doping profiles that would traditionally require multiple static implant steps, reducing manufacturing time while maintaining precision.
Solution Approach 2:
The system dynamically changes implantation parameters (beam position, scanning speed, beam intensity) during a single implantation process to achieve varying doping concentrations and profiles across different regions, replacing the need for multiple implant steps with different fixed parameters.
3Manufacturing precision
If masking methods are used for localized implantation, then implantation localization is achieved, but process complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the mask formation, alignment, and removal process steps from the manufacturing flow. By using direct beam scanning, the complex multi-step masking process is replaced with a simpler single-step implantation process controlled by beam positioning.
Solution Approach 2:
The ion beam system itself performs the localization function that would otherwise require separate mask layers. The beam scanning system inherently defines the implantation regions through its programmed motion, making the process self-sufficient without auxiliary mask materials or steps.
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 simplifies and cost-reduces the manufacturing process while achieving precise control over doping profiles and depths, improving the electrical characteristics of power electronic devices without the planarity issues associated with traditional masking methods.
Implementation Method 1
performing a channeled ion implantation, for implanting doping ions within the semiconductor body and forming the implanted regions at the implant portions of the semiconductor body
Implementation Method 2
constituting damaged regions of the silicon carbide crystallographic lattice such as to block propagation of the channeled ion implantation along a vertical axis orthogonal to the front surface
Data Source
AI summary
A manufacturing process provides for: forming a semiconductor body of silicon carbide, having a front surface; performing a localized ion implantation to form implanted regions in implant portions in the semiconductor body. The step of performing a localized ion implantation provides for: forming damaged regions at the front surface, separated from each other by the implant portions in a direction parallel to the front surface; performing a channeled ion implantation, for implanting doping ions within the semiconductor body and forming the implanted regions at the implant portions of the semiconductor body. The channeled ion implantation is performed in a self-aligned manner with respect to the damaged regions, which represent damaged regions of the silicon-carbide crystallographic lattice such as to block a propagation of the channeled ion implantation along a vertical axis orthogonal to the front surface, in a depth direction of the semiconductor body.