Oxide Semiconductor Gate Stack for Oxygen Vacancy Control
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Solution Overview
Problem
Semiconductor devices with oxide semiconductor channels face challenges in maintaining high mobility while minimizing oxygen vacancies and defects in the insulating layer, leading to variations in characteristics and reliability issues.
Innovation Solution
A semiconductor device configuration featuring a metal oxide layer with aluminum as the main component, an oxide semiconductor layer with a high indium ratio, and a gate insulating layer that releases oxygen during the manufacturing process to supply oxygen to the oxide semiconductor layer, thereby reducing oxygen vacancies and defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insulating layer is formed with more oxygen-containing conditions to supply oxygen to the oxide semiconductor layer, then oxygen supply to the oxide semiconductor layer is improved, but the insulating layer contains more defects causing abnormal characteristics and variation in reliability test
Solution Approach 1:
The patent applies local quality by forming the insulating layer with different oxygen concentrations at different depths. The surface region has lower oxygen concentration (fewer defects) while the deeper region has higher oxygen concentration (better oxygen supply capability). This gradient structure allows the insulating layer to simultaneously achieve low defect density near the interface and sufficient oxygen supply to the oxide semiconductor layer below.
Solution Approach 2:
The patent changes the oxygen concentration parameter within the insulating layer to resolve the contradiction. By controlling the oxygen concentration to decrease from the surface toward the oxide semiconductor layer interface, the insulating layer achieves optimal balance between having fewer defects (for reliability) and providing sufficient oxygen supply (for stable operation).
2Speed
If the ratio of indium contained in the oxide semiconductor layer is increased to achieve high mobility, then mobility is improved, but oxygen vacancies are likely to be formed in the oxide semiconductor layer
Solution Approach 1:
The patent uses the insulating layer as an intermediary to supply oxygen to the high-indium oxide semiconductor layer. The insulating layer acts as an oxygen reservoir that compensates for the oxygen vacancies naturally formed in the high-mobility, high-indium oxide semiconductor material, thereby maintaining both high mobility and low oxygen vacancy concentration.
Solution Approach 2:
The patent performs preliminary oxygen supply by forming the insulating layer with sufficient oxygen content before the oxide semiconductor layer is fully operational. This pre-positioned oxygen reservoir in the insulating layer proactively prevents oxygen vacancy formation in the high-indium oxide semiconductor layer, ensuring stable operation from the outset.
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 achieves high mobility and reliability by uniformly supplying oxygen to the oxide semiconductor layer, reducing defects and variations in electrical characteristics, and maintaining stable performance in reliability tests.
Implementation Method 1
a gate insulating layer between the oxide semiconductor layer and the gate electrode... that releases oxygen during the manufacturing process to supply oxygen to the oxide semiconductor layer
Implementation Method 2
an oxide semiconductor layer above the metal oxide layer... the oxide semiconductor layer includes two or more metals including indium, and a ratio of indium in the two or more metals is 50% or more
Data Source
AI summary
A semiconductor device according to an embodiment includes: a metal oxide layer above a substrate, the metal oxide layer containing aluminum as a main component; an oxide semiconductor layer above the metal oxide layer; a gate electrode facing the oxide semiconductor layer; and a gate insulating layer between the oxide semiconductor layer and the gate electrode, wherein the oxide semiconductor layer includes two or more metals including indium, and a ratio of indium in the two or more metals is 50% or more.