Semiconductor Doping Layout Using Self-Aligned Hard Masks
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Solution Overview
Problem
Existing semiconductor manufacturing methods face challenges in accurately aligning doping regions, leading to misalignment errors and suboptimal performance of semiconductor structures, particularly in high-pressure, high-temperature, and high-frequency applications.
Innovation Solution
The use of patterned hard masks in a self-aligned manner to form doping regions through sequential implantation processes, ensuring precise positioning and reducing misalignment errors by using multiple patterned hard masks as shielding layers during ion implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional alignment methods are used for doping regions, then manufacturing process is simpler, but alignment precision deteriorates leading to misalignment errors
Solution Approach 1:
The patent applies preliminary action by forming patterned hard masks before the doping process. The first patterned hard mask is formed on the epitaxial layer before first implantation, and the second patterned hard mask is formed before second implantation. These pre-formed masks serve as alignment references that enable precise positioning of doping regions without requiring complex real-time alignment adjustments during the doping process itself.
Solution Approach 2:
The patent uses patterned hard masks as intermediary elements between the doping process and the final doping region formation. The first patterned hard mask mediates the first implantation process to create the first doped region, while the second patterned hard mask mediates the second implantation process to create the second doped region. These intermediary masks enable precise control over doping region positions and overlap configurations.
2Manufacturing precision
If multiple implantation processes are performed to form overlapping doped regions, then doping precision is improved, but manufacturing time increases
Solution Approach 1:
The patent performs preliminary actions by forming both the first and second patterned hard masks before conducting the implantation processes. The first patterned hard mask is formed and used for first implantation, then the second patterned hard mask is formed and used for second implantation. This preliminary mask formation approach enables precise control of doping region positions and overlaps, reducing the need for iterative adjustments and rework that would otherwise extend manufacturing time.
3Manufacturing precision
If patterned hard masks are used as shielding layers during implantation, then alignment accuracy is improved, but device structure complexity increases
Solution Approach 1:
The patent employs patterned hard masks as intermediary shielding layers during the implantation processes. The first patterned hard mask serves as a shielding layer during first implantation to define the first doped region, and the second patterned hard mask serves as a shielding layer during second implantation to define the second doped region. These intermediary structures enable precise alignment control while maintaining relatively simple overall device architecture.
Solution Approach 2:
The patterned hard masks are temporary structures that are discarded after serving their alignment and shielding functions. The first patterned hard mask is used for first implantation and then removed, and the second patterned hard mask is used for second implantation and then removed. This approach allows the masks to provide necessary structural complexity during manufacturing without permanently increasing the final device structure complexity.
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 enables accurate placement of doping regions, enhancing the performance of semiconductor structures by improving alignment and reducing manufacturing errors, making them suitable for high-voltage and high-frequency applications.
Implementation Method 1
performing a first implantation process using the first patterned hard mask to form a first doped region in the epitaxial layer; performing a second implantation process using the first patterned hard mask to form a second doped region in the epitaxial layer
Data Source
AI summary
Various methods for manufacturing semiconductor structures are provided. An embodiment method includes forming a first patterned hard mask on a protective layer that is disposed on an epitaxial layer. The first patterned hard mask includes an opening exposing a portion of the protective layer and surrounded by side surfaces of the first patterned hard mask. A second patterned hard mask is formed on the side surfaces of the first patterned hard mask. A first doped region is formed in the portion of the epitaxial layer below the opening using a first implantation through the second patterned hard mask. With the second patterned hard mask removed, a second doped region surrounding the first doped region, and a third doped region are formed in the portion of the epitaxial layer using respective second implantation and third implantation through the first patterned hard mask.