FET Dielectric Structure for Hot-Carrier and Breakdown Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing field effect transistors face challenges in balancing area-specific on-state resistance, switching efficiency, and reliability, particularly due to hot carrier-induced effects, when optimizing device geometries for increased functionalities per unit area.
Innovation Solution
The design incorporates a dielectric structure with a gate electrode and a field electrode spaced laterally, combined with a field dielectric structure in a recess, which enhances electric field distribution and reduces hot carrier effects, improving reliability and breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If device geometries are shrunk to increase functionalities per unit area, then area-specific on-state resistance and cost are improved, but reliability deteriorates due to hot carrier induced effects
Solution Approach 1:
A field dielectric structure is introduced as an intermediary element between the channel region and the drain region. This field dielectric structure modifies the electric field distribution in the drift region, reducing peak electric fields that cause hot carrier effects. The field dielectric structure acts as a mediator that protects the channel from harmful high-field effects while maintaining device functionality.
Solution Approach 2:
The field dielectric structure is positioned specifically in the drift region near the drain, creating a localized modification of electric field distribution. This local quality change reduces hot carrier effects in the critical region where they occur most frequently, without affecting other parts of the device. The field dielectric structure provides targeted protection where it is most needed.
2Productivity
If device geometries are shrunk to increase functionalities per unit area, then area-specific on-state resistance and cost are improved, but switching efficiency and reliability requirements become more difficult to meet
Solution Approach 1:
The field dielectric structure extends in the vertical dimension below the surface, creating a three-dimensional electric field modification. This vertical extension allows the device to maintain improved functionalities per unit area while compensating for reliability issues through enhanced field control in the depth direction. The field dielectric structure adds a dimensional solution to a two-dimensional scaling problem.
3Ease of manufacture
If conventional FET structures are used, then manufacturing is simpler, but breakdown voltage is lower and hot carrier effects are more pronounced
Solution Approach 1:
The field dielectric structure is nested within the existing FET structure, positioned in the drift region between the channel and drain. This nested configuration allows the field dielectric structure to be integrated into conventional FET manufacturing processes while providing enhanced breakdown voltage and reduced hot carrier effects. The field dielectric structure fits within the existing device architecture without requiring complete redesign.
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 breakdown voltage and reduces hot carrier effects, enhancing the reliability and performance of the field effect transistor.
Implementation Method 1
The dielectric structure includes a gate dielectric on the first surface, and a field dielectric structure having a bottom side below the first surface
Data Source
AI summary
A field effect transistor, FET, is proposed. The FET includes a source region of a first conductivity type that is electrically connected to a source electrode at a first surface of a semiconductor body. The FET further includes a drain region of the first conductivity type that is electrically connected to a drain electrode at the first surface. A dielectric structure is arranged between the source region and the drain region along a first lateral direction. The dielectric structure includes a gate dielectric on the first surface and a field dielectric structure having a bottom side below the first surface. The FET further includes a gate electrode on the gate dielectric. The gate electrode and the field dielectric structure are spaced from each other along the first lateral direction. The FET further includes a field electrode having a bottom side below a top side of the field dielectric structure.