MOSFET Longitudinal Double Gate Oxide Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing miniaturization of semiconductor devices, such as MOSFETs, leads to issues like decreased breakdown voltage of the gate oxide, increased leakage current due to drain-induced barrier lowering, and reduced controllability of the gate, which complicates the control of carrier concentration and threshold voltage.
Innovation Solution
The design incorporates a substrate with a well region, a shallow channel layer, a channel, a gate oxide layer, a gate region, a source region, and a drain region, featuring a first and second shallow channel region and gate oxide region on either side of the channel, allowing for accurate control of carrier concentration and improved gate control efficiency through a longitudinal double gate oxide structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the gate oxide thickness is continuously decreased to improve device miniaturization, then the device size is reduced, but the breakdown voltage of the gate oxide decreases
Solution Approach 1:
The patent employs a composite gate oxide structure consisting of a first gate oxide layer and a second gate oxide layer with different dielectric materials. This composite structure enables the gate oxide to maintain adequate breakdown voltage while allowing for overall thickness reduction, thus resolving the contradiction between device miniaturization and reliability.
2Volume of moving object
If the channel length is continuously decreased to improve device miniaturization, then the device size is reduced, but the drain-induced barrier lowering effect increases, reducing gate controllability and increasing leakage current
Solution Approach 1:
The patent introduces a vertical dimension by forming a second gate oxide layer beneath the first gate oxide layer, creating a stacked configuration. This dimensional change allows the gate to maintain effective control over the channel even when the channel length is reduced for miniaturization, thereby improving gate controllability while reducing device size.
3Productivity
If the device size is decreased to improve integration density, then more devices can be placed on a chip, but the threshold voltage control precision deteriorates due to decreased carrier concentration control
Solution Approach 1:
The patent uses a composite gate oxide structure with a first gate oxide layer and a second gate oxide layer having different dielectric properties. This composite configuration enables precise control of threshold voltage by adjusting the thickness and material composition of each layer, thereby maintaining manufacturing precision even as device size decreases for higher integration density.
Data Source
AI summary
A Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) is disclosed. The MOSFET includes a substrate, a well region formed in the substrate, a shallow channel layer, a channel, a gate oxide layer, a gate region, a source region, and a drain region. The shallow channel layer is formed on a portion of the well region and includes a first shallow channel region and a second shallow channel region. The channel is arranged between the first shallow channel region and the second shallow channel region and connects the first shallow channel region and the second shallow channel region. Further, the gate oxide layer is formed on a portion of the well region between the first shallow channel region and the second shallow channel region and includes a first gate oxide region and a second gate oxide region arranged on different sides of the channel. The gate region is formed on the channel and the gate oxide layer; the source region is formed in the first shallow channel region and vertically extends into the well region under the first shallow channel region; and the drain region is formed in the second shallow channel region and vertically extends into the well region under the second shallow channel region.