Bipolar Transistor Doped Regions for Gain and Breakdown
Solution Overview
Problem
It is challenging to simultaneously increase the common-emitter current gain and breakdown voltage between the collector and emitter in bipolar junction transistors (BJTs) while maintaining their operational efficiency and durability.
Innovation Solution
The semiconductor device incorporates a specific doped region structure with recess and protruded portions, along with insulating and conductive stacks, to enhance carrier passage and adjust electric fields, thereby increasing current gain and breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the breakdown voltage between collector and base is fixed, then the common emitter current gain is inversely proportional to the breakdown voltage between collector and emitter, but it is difficult to simultaneously increase both parameters
Solution Approach 1:
The base region is segmented into multiple doped regions (second doped region with recess portions and third doped region with protruded portions) that are spatially separated and have different doping concentrations. This segmentation allows different regions to perform different functions: some regions enhance current gain while others maintain breakdown voltage, resolving the contradiction between these two parameters
Solution Approach 2:
Different doped regions are assigned different local qualities through varying doping concentrations and geometries. The second doped region has lower doping concentration and recess portions to enhance carrier injection and current gain, while the third doped region has higher doping concentration and protruded portions to control electric field distribution and maintain breakdown voltage. This local differentiation allows simultaneous optimization of both parameters
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 configuration increases the common-emitter current gain and breakdown voltage, improving the performance and reliability of BJTs as signal amplifiers and switching devices.
Implementation Method 1
a first doped region, a second doped region and a third doped region. The first doped region and the second doped region are of a first conductive type, and the third doped region is of a second conductive type
Implementation Method 2
adjust electric fields, thereby increasing current gain and breakdown voltage
Data Source
AI summary
A semiconductor device is provided. The semiconductor device includes a first doped region and a second doped region of a first conductive type and a third doped region of a second conductive type located in a substrate. The second doped region is located at a side of the first doped region. A top-view pattern of the second doped region has at least one recess portion. The third doped region is located between the first doped region and the second doped region. A top-view pattern of the third doped region has at least one protruded portion corresponding to the at least one recess portion.