Vertical Power Semiconductor Gate Implantation for Channel Control
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Solution Overview
Problem
Current vertical semiconductor devices face challenges in achieving high performance and cost-effectiveness due to complex and costly fabrication processes, particularly in forming gate regions with precise doping and geometry, which affect the device's conductivity and blocking capabilities.
Innovation Solution
The method involves forming vertical semiconductor devices with a substrate, drift region, and upper precursor region, using a series of implants with different dopants and depths to create gate regions and a channel region, allowing for a conducting gap between the gate regions, and employing various masking and implantation techniques to control the doping concentration and geometry of the gate regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional fabrication processes are used to form gate regions with precise doping and geometry, then device performance is improved, but fabrication complexity and cost increase
Solution Approach 1:
The gate region formation is divided into multiple ion implantation steps, each targeting specific depth ranges and doping concentrations. This segmentation allows precise control over the vertical doping profile while using standard implantation equipment, avoiding the need for complex single-step processes
Solution Approach 2:
The patent transitions from planar doping approaches to vertical depth-controlled implantation. By using multiple implantation angles and energy levels, precise 3D doping profiles are achieved within the gate region, enabling complex geometry control through simplified top-down processing
2Manufacturing precision
If multiple masks and implants are used to form gate regions, then doping precision is improved, but manufacturing cost and process time increase
Solution Approach 1:
Multiple doping functions are merged into a single ion implantation step by using energy-stratified implantation. Different dopant concentrations and depths are achieved in one process by varying implantation energy, eliminating the need for sequential masking and implantation steps
Solution Approach 2:
The patent changes the energy parameter of ion implantation to control doping depth and concentration profiles. By adjusting implantation energy from low to high, precise vertical doping gradients are created without additional process steps, reducing both time and complexity
3Manufacturing precision
If complex masking techniques are employed to control gate region geometry, then manufacturing precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The complex masking steps are extracted and replaced with direct ion implantation through the existing device surface. The implantation process itself defines the gate geometry through angular and energy control, eliminating the need for separate mask fabrication and alignment steps
Solution Approach 2:
The ion implantation process self-defines the gate region geometry and doping profile through controlled energy deposition. The process automatically achieves the desired vertical concentration gradients and lateral boundaries without external masking, making the fabrication self-regulating and simpler
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 enhances the control over channel resistance and current blocking in the on-state and off-state, improving the overall performance and reducing fabrication complexity and costs by simplifying the implantation process and achieving precise doping profiles.
Implementation Method 1
a series of implants with a second dopant are provided in the upper precursor region via the top surface to form gate regions
Data Source
AI summary
A precursor for a vertical semiconductor device is provided with a substrate, a drift region over the substrate, and an upper precursor region over the drift region. The top surface of the precursor is substantially planar, and the substrate and the drift region are doped with a first dopant of a first polarity. In a first embodiment, a series of implants with a second dopant is provided in the upper precursor region via the top surface to form each of at least two gate regions such that each implant of the series of implants is provided at a different depth below the top surface. In a second embodiment, a series of implants with the first dopant is provided in the upper precursor region via the top surface to form a channel region that has at least a portion between two gate regions.