Oxide Semiconductor Transistor Tapered Side Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Miniaturization of oxide semiconductor transistors is hindered by increased contact resistance due to reduced contact regions, which degrades on-state characteristics and field-effect mobility.
Innovation Solution
The transistor design incorporates an island-shaped oxide semiconductor film with a tapered side surface having a taper angle between 1° and 10°, allowing increased contact area with the source and drain electrodes, and includes low resistance regions to reduce contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the contact region is reduced to achieve miniaturization, then the transistor size is reduced, but the contact resistance increases
Solution Approach 1:
The patent transitions from planar contact (2D) to three-dimensional contact by forming tapered side surfaces on the oxide semiconductor film. The source and drain electrodes contact both the top surface and the tapered side surfaces of the semiconductor film, effectively adding a vertical dimension to the contact region. This increases the total contact area without increasing the planar footprint, thereby reducing contact resistance while maintaining miniaturization.
Solution Approach 2:
The patent changes the geometric parameters of the oxide semiconductor film by forming tapered side surfaces with specific angles (greater than 0 degrees and less than or equal to 45 degrees). This parameter change transforms the contact geometry from a simple planar interface to a multi-faceted three-dimensional interface, increasing the effective contact area between the electrodes and the semiconductor film.
2Volume of moving object
If the oxide semiconductor film thickness is thinned to achieve miniaturization, then the transistor size is reduced, but the contact region area is decreased and contact resistance increases
Solution Approach 1:
By forming tapered side surfaces on thinned oxide semiconductor films, the patent compensates for the reduced planar contact area by adding vertical contact area. The tapered geometry allows source and drain electrodes to contact the semiconductor film along the sloped sides, effectively increasing the total contact area despite the reduced film thickness and planar dimensions.
Solution Approach 2:
The patent changes the side surface geometry parameter by creating tapered surfaces with controlled angles, transforming the contact interface from a horizontal plane to an inclined surface. This parameter change enables the contact region to extend vertically along the tapered sides, increasing the effective contact area without requiring increased planar dimensions.
Data Source
AI summary
A semiconductor device which achieves miniaturization with favorable characteristics maintained is provided. In addition, a miniaturized semiconductor device is provided with high yield. In a semiconductor device including an oxide semiconductor, the contact resistance between the oxide semiconductor and the source electrode or the drain electrode is reduced with miniaturization advanced. Specifically, an oxide semiconductor film is processed to be an island-shaped oxide semiconductor film whose side surface has a tapered shape. Further, the side surface has a taper angle greater than or equal to 1° and less than 10°, and at least part of the source electrode and the drain electrode is in contact with the side surfaces of the oxide semiconductor film. With such a structure, the contact region of the oxide semiconductor film and the source electrode or the drain electrode is increased, whereby the contact resistance is reduced.