Oxide Semiconductor Transistor Gate Insulation via ALD
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor technologies face challenges in miniaturization, integration, and achieving favorable electrical characteristics, particularly in transistors with oxide semiconductors, due to issues with oxygen diffusion and impurity entry, which affect reliability and performance.
Innovation Solution
The semiconductor device incorporates an oxide semiconductor with an insulator formed by the Atomic Layer Deposition (ALD) method to prevent oxygen diffusion and impurity entry, and includes a structure with paired gate electrodes and capacitors to enhance integration and density, utilizing metal oxides like In-M-Zn oxide for improved electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If transistors are miniaturized to achieve finer process rules (45 nm, 32 nm, 22 nm), then device size is reduced and integration is improved, but electrical characteristics and reliability deteriorate due to oxygen diffusion and impurity entry
Solution Approach 1:
A side surface insulating film is formed to cover the side surface of the gate electrode, creating a protective barrier that prevents oxygen diffusion and impurity entry. This thin film structure maintains the miniaturized transistor dimensions while providing the necessary protection to preserve electrical characteristics and reliability at fine process rules.
Solution Approach 2:
The side surface insulating film acts as an intermediary barrier between the gate electrode and the external environment. It mediates the interaction by blocking oxygen and impurities from reaching the gate electrode, thereby preventing degradation of electrical characteristics while allowing the transistor to maintain its miniaturized structure.
2Use of energy by moving object
If oxide semiconductor transistors are used to achieve low power consumption, then energy efficiency is improved, but oxygen diffusion from the gate insulating film causes reliability issues
Solution Approach 1:
The side surface insulating film forms a protective shell around the gate electrode, preventing oxygen diffusion from the gate insulating film to the oxide semiconductor. This maintains the low power consumption characteristics of oxide semiconductor transistors while eliminating the reliability issues caused by oxygen diffusion.
Solution Approach 2:
The side surface insulating film is formed in advance to prevent oxygen diffusion before it can occur. By establishing this protective barrier prior to operation, the film preemptively counteracts the harmful oxygen diffusion process, preserving both the low power consumption and reliability of the oxide semiconductor transistor.
3Reliability
If gate electrode coverage is increased to prevent oxidation, then reliability is improved, but device area and complexity increase
Solution Approach 1:
Instead of increasing gate electrode coverage, a side surface insulating film is formed to cover the side surface of the gate electrode. This approach prevents oxidation and maintains reliability without adding structural complexity or increasing device area, as the insulating film is a thin layer that does not significantly impact the overall device footprint.
Solution Approach 2:
The protection mechanism transitions from a planar approach (increasing gate electrode coverage in the plane) to a vertical approach (forming a side surface insulating film on the vertical side surface). This dimensional change allows oxidation prevention without increasing device area or structural complexity in the planar dimensions.
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 approach enables the creation of highly reliable, miniaturized semiconductor devices with low off-state current, high on-state current, and low power consumption, while maintaining high productivity and design flexibility.
Implementation Method 1
The insulator is preferably formed by an ALD method. When the insulator is formed by an ALD method, an insulator with few defects and excellent coverage with respect to a shape of unevenness can be obtained.
Implementation Method 2
an insulator with few defects and excellent coverage with respect to a shape of unevenness can be obtained. The provision of such an insulator in contact with the side surface of the gate insulating film can prevent outward diffusion of oxygen contained in the gate insulating film
Data Source
AI summary
A semiconductor device that can be highly integrated is provided. The semiconductor device includes a first transistor, a second transistor, a first capacitor, and a second capacitor. The first transistor includes an oxide over a first insulator, a second insulator over the oxide, a first conductor over the second insulator, a third insulator over the first conductor, a fourth insulator in contact with the second insulator, the first conductor, and the third insulator, and a fifth insulator in contact with the fourth insulator. The second transistor includes an oxide over the first insulator, a sixth insulator over the oxide, a second conductor over the sixth insulator, a seventh insulator over the second conductor, an eighth insulator in contact with the sixth insulator, the second conductor, and the seventh insulator, and a ninth insulator in contact with the eighth insulator. The first capacitor includes an oxide, a tenth insulator over the oxide, and a third conductor over the tenth insulator. The second capacitor includes an oxide, an eleventh insulator over the oxide, and a fourth conductor over the eleventh insulator.