Semiconductor Device Doping Gradient for Hot Carrier Reliability
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Solution Overview
Problem
As semiconductor devices shrink in size, they face challenges with increased substrate current due to the hot carrier effect, which damages device elements and reduces structural reliability.
Innovation Solution
A semiconductor device design that includes a substrate with a first conductive type well region, a gate structure, lightly-doped drain and source regions, a second conductive type first doped region with lower doping concentration, and heavily-doped source and drain regions, which enlarges the depletion region to reduce the electric field change rate and substrate current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor devices are scaled down to increase integration density, then the number of interconnected devices per unit area increases, but substrate current increases due to the hot carrier effect causing device damage and reduced reliability
Solution Approach 1:
The drain region is segmented into multiple doped regions with different doping concentrations (first doped region with lower concentration, second doped region with higher concentration). This segmentation creates a gradient structure that extends the depletion region and reduces the hot carrier effect, thereby maintaining device reliability while allowing continued scaling for higher integration density
Solution Approach 2:
Different regions of the drain are given different doping concentrations to optimize local properties. The first doped region has lower doping concentration to extend depletion region and reduce hot carriers, while the second doped region has higher doping concentration for other performance requirements. This local quality variation resolves the contradiction between scaling and reliability
2Length of moving object
If device size is decreased to continue scaling, then more devices can be integrated per unit area, but the electric field change rate increases causing hot carrier effect and substrate current
Solution Approach 1:
The doping concentration parameter is changed across different regions of the drain. By creating a doping concentration gradient (lower in the first doped region, higher in the second doped region), the electric field distribution is modified to reduce the electric field change rate, thereby reducing substrate current and hot carrier effect even as device size decreases
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 design decreases substrate current, thereby reducing damage to device elements and enhancing structural reliability by lowering the electric field change rate within the semiconductor device.
Implementation Method 1
enlarges the depletion region to reduce the electric field change rate and substrate current
Data Source
AI summary
A semiconductor device is provided. The semiconductor device includes a substrate including a first conductive type well region; a gate structure; a lightly-doped drain region and a lightly-doped source region disposed at two opposite sides of the gate structure; a second conductive type first doped region disposed in the lightly-doped drain region, wherein the doping concentration of the second conductive type first doped region is less than the doping concentration of the lightly-doped drain region; a heavily-doped source region disposed in the lightly-doped source region; and a heavily-doped drain region disposed in the second conductive type first doped region. The present disclosure also provides a method for manufacturing the semiconductor device.