Bipolar Junction Transistor Base Segmentation for High Voltage
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Solution Overview
Problem
Current semiconductor bipolar junction transistors face challenges in optimizing current gain and breakdown voltage, particularly in high-voltage applications, due to limitations in doped region configurations and manufacturing processes.
Innovation Solution
The design incorporates doped regions with specific conductivity types and well regions separated by a first doped region, allowing for the formation of connecting regions that adjust current gain and increase base resistance, while also utilizing reduced surface field concepts to enhance breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional doped region configurations are used, then manufacturing simplicity is maintained, but current gain and breakdown voltage cannot be optimized for high-voltage applications
Solution Approach 1:
The base region is segmented into multiple well regions (first well region, second well region, third well region) separated by isolation regions. This segmentation allows independent optimization of different base sections to achieve both high breakdown voltage and optimized current gain, resolving the contradiction between reliability improvement and device complexity
Solution Approach 2:
Different doped regions are assigned different conductivity types and doping concentrations to perform specific local functions. The first doped region has first type conductivity, the well regions have second type conductivity, and the third doped region has first type conductivity again. This local differentiation enables simultaneous optimization of breakdown voltage in high-voltage regions and current gain in active regions
2Reliability
If doped regions are configured to increase current gain, then beta gain is improved, but lateral punch-through effects occur reducing breakdown voltage
Solution Approach 1:
Isolation regions are introduced as intermediary structures between the well regions. These isolation regions with first type conductivity act as barriers that prevent lateral punch-through effects while allowing the well regions to maintain their optimized doping for high current gain. The intermediary structure resolves the contradiction by blocking harmful lateral carrier flow
Solution Approach 2:
The patent introduces a lateral dimension of separation between vertically-aligned doped regions by placing isolation regions between well regions. This dimensional approach prevents lateral punch-through by creating physical barriers in the lateral direction, while maintaining vertical carrier flow for high current gain operation
Data Source
AI summary
A bipolar junction transistor and an operating method and a manufacturing method for the same are provided. The bipolar junction transistor comprises a first doped region, a second doped region and a third doped region. The first doped region has a first type conductivity. The second doped region comprises well regions formed in the first doped region, having a second type conductivity opposite to the first type conductivity, and separated from each other by the first doped region. The third doped region has the first type conductivity. The third doped region is formed in the well regions or in the first doped region between the well regions.