LDMOS Semiconductor Structure with Segmented Drain for Breakdown Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor technology, reducing dopant concentration in the drain region to increase breakdown voltage of LDMOS or EDMOS structures results in increased specific on-state resistance, making it difficult to improve both breakdown voltage and on-state resistance simultaneously.
Innovation Solution
A semiconductor structure comprising a first semiconductor region with a first and second doped region of the same conductivity type, a second semiconductor region with a third doped region of opposite conductivity type, and a dielectric structure with a diffused doped portion extending from the second doped region to the third doped region, along with a gate electrode layer, which reduces specific on-state resistance and increases breakdown voltage by optimizing the channel length and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dopant concentration of drain region is decreased to increase breakdown voltage, then breakdown voltage is improved, but specific on-state resistance is increased
Solution Approach 1:
The drain region is segmented into multiple doped regions with different dopant concentrations. The first doped region has higher concentration while the second doped region has lower concentration, allowing the structure to simultaneously achieve low on-state resistance (through the first region) and high breakdown voltage (through the second region).
Solution Approach 2:
Different portions of the drain region are assigned different dopant concentrations based on their functional requirements. The first doped region near the channel uses higher concentration for low resistance, while the second doped region extends into the drift region with lower concentration for high breakdown voltage, optimizing local properties for specific functions.
2Reliability
If drift length is increased to increase breakdown voltage, then breakdown voltage is improved, but device area and specific on-state resistance are increased
Solution Approach 1:
The drift region is segmented with respect to dopant concentration rather than just length. By creating a gradient from high to low concentration, the structure achieves voltage blocking capability without requiring excessive drift length, thereby reducing device area while maintaining breakdown voltage.
Solution Approach 2:
Instead of changing only the geometric parameter (drift length), the invention changes the material parameter (dopant concentration) to achieve breakdown voltage improvement. This allows for more compact device design with reduced area while maintaining the required electrical performance.
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
The proposed structure effectively reduces specific on-state resistance and increases breakdown voltage by creating a shorter current path and floating area in the drift region, allowing for improved performance without the trade-offs of traditional methods.
Implementation Method 1
The second doped region has a diffused doped portion extended from a top portion of the second doped region to the third doped region
Data Source
AI summary
A semiconductor structure and a method for forming the same are provided. The semiconductor structure comprises a first semiconductor region, a second semiconductor region, a dielectric structure and a gate electrode layer. The first semiconductor region has a first type conductivity. The second semiconductor region has a second type conductivity opposite to the first type conductivity. The first semiconductor region is adjoined to the second semiconductor region. The dielectric structure is on the first semiconductor region and the second semiconductor region. The gate electrode layer is on the dielectric structure.