Stepped Gate Electrode Layout for Low-Field Imaging Transistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor devices and imaging apparatuses face challenges in improving transistor performance due to electric field concentration issues, which affect sensitivity and overall performance.
Innovation Solution
A semiconductor device with a transistor design featuring a gate electrode comprising a first part opposing the semiconductor substrate and a second part with a smaller contribution to channel formation, where the gate end is positioned above or below the surface via a stepped portion on the substrate, increasing the shortest distance and alleviating electric field concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the gate end is positioned close to the one region to reduce device area, then device area is reduced, but electric field concentration occurs at the gate end
Solution Approach 1:
The patent introduces a stepped portion that creates a vertical dimension difference between the gate end and the one region. Instead of only adjusting horizontal positioning, the gate end is positioned at a different elevation level, transforming a two-dimensional layout problem into a three-dimensional structural solution. This increases the shortest distance between the gate end and the one region while maintaining planar footprint.
Solution Approach 2:
The stepped portion acts as an intermediary structural element between the gate electrode and the one region. It provides a transitional geometry that physically separates the gate end from direct proximity to the one region, thereby reducing electric field concentration without requiring larger device area.
2Object-affected harmful factors
If the gate end is positioned far from the one region to reduce electric field concentration, then electric field concentration is reduced, but device area increases
Solution Approach 1:
By utilizing the vertical dimension through the stepped portion, the patent achieves increased separation distance between the gate end and the one region without expanding the horizontal device footprint. The stepped structure allows the gate end to be positioned farther away in three-dimensional space while maintaining compact two-dimensional layout.
3Object-affected harmful factors
If a stepped portion is introduced to increase distance between gate end and one region, then electric field concentration is alleviated, but device complexity increases
Solution Approach 1:
The stepped portion is integrated with the existing gate electrode structure rather than being a separate component. The step is formed as part of the gate electrode's geometric configuration, merging the distance-increasing function with the gate structure itself, thereby minimizing additional complexity.
Solution Approach 2:
The stepped portion serves multiple functions: it increases the distance between the gate end and the one region to reduce electric field concentration, while also defining the gate electrode's active region and providing structural support. This multi-functionality reduces the need for additional separate structures.
Data Source
AI summary
To provide a semiconductor device and an imaging apparatus capable of improving performance of a transistor. The semiconductor device includes a semiconductor substrate and a transistor provided on the semiconductor substrate. A gate electrode of the transistor includes a first part disposed at a position opposing the semiconductor substrate via a gate insulating film of the transistor and configured to form a channel on the semiconductor substrate and a second part positioned on top of the first part and configured to have a smaller contribution toward the formation of the channel than the first part. The first part includes a gate end which is positioned on a side of one region of a drain region and a source region of the transistor and in which an electric field concentrates with respect to the one region. The gate end is positioned above or below a surface of the one region via a stepped portion provided on a side of a first surface of the semiconductor substrate and is flush with a side surface of the second part.