SiC Ion Implantation Angles for Deep Junctions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in manufacturing semiconductor devices using silicon carbide (SiC) lies in forming deep pn junctions due to low impurity diffusion coefficients, which requires high accelerating voltage in ion implantation, but is limited by the capabilities of existing ion implantation apparatuses and is costly.
Innovation Solution
The method involves implanting impurity ions into SiC layers at specific angles (±1 degrees) to leverage channeling effects, allowing for deeper implantation and formation of deep pn junctions with lower accelerating voltages, using oblique ion implantation techniques to create regions with varying impurity concentrations and structures like super-junction and RESURF regions in MOSFETs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If ion implantation is performed with high accelerating voltage to form deep pn junctions in SiC, then the implantation depth increases, but the apparatus capability is exceeded and cost increases
Solution Approach 1:
The patent changes the ion implantation parameters by using multiple implantation steps with different angles (0 degrees and oblique angles like 45 degrees) and different accelerating voltages, rather than relying on a single high-voltage implantation. This allows achieving deep junction formation within the capabilities of existing apparatuses
Solution Approach 2:
The patent divides the single deep implantation process into multiple sequential implantation steps. First, a preliminary implantation is performed at 0 degrees to create an initial impurity distribution, then subsequent oblique implantations are performed to extend the junction depth. This segmentation allows each step to operate within apparatus voltage limits while achieving the cumulative effect of deep implantation
2Length of moving object
If ion implantation is performed with high accelerating voltage to form deep pn junctions in SiC, then the implantation depth increases, but the manufacturing cost increases
Solution Approach 1:
The patent employs parameter changes by utilizing multiple implantation angles and voltage levels instead of a single high-voltage process. This approach achieves the required implantation depth using standard apparatus capabilities, thereby avoiding the excessive costs associated with high-voltage implantation equipment and processes
3Length of moving object
If multiple ion implantation steps are performed to form deep pn junctions, then the implantation depth increases, but the process complexity increases
Solution Approach 1:
The patent segments the implantation process into distinct steps with clear objectives: a first implantation at 0 degrees to establish baseline impurity distribution, followed by oblique implantations at angles like 45 degrees to extend depth. Each step has defined parameters that build upon the previous step, making the complex process systematic and controllable
Solution Approach 2:
The patent introduces angular dimension to the implantation process by performing implantations at different angles (0 degrees and oblique angles). This dimensional approach allows the process to achieve greater effective depth without simply increasing voltage, and the angular variation creates favorable impurity distribution profiles that simplify subsequent process 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 enables the formation of deep pn junctions with reduced on-resistance and improved breakdown voltage, while minimizing the risk of gate insulating film breakdown and allowing for device scaling, thus enhancing the performance and reliability of SiC semiconductor devices.
Implementation Method 1
implanting impurity ions into a SiC layer in a direction of ±1 degrees, ±1 degrees, ±1 degrees, or ±1 degrees
Implementation Method 2
leverage channeling effects, allowing for deeper implantation and formation of deep pn junctions with lower accelerating voltages, using oblique ion implantation techniques
Data Source
AI summary
A method for manufacturing a semiconductor device according to an embodiment includes implanting impurity ions into a SiC layer in a direction of <10-11>±1 degrees, <10-1-1>±1 degrees, <10-12>±1 degrees, or <10-1-2>±1 degrees.