Oxide Semiconductor Transistor Sidewall Oxygen Doping
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Solution Overview
Problem
Oxygen vacancies in oxide semiconductor transistors lead to shifts in threshold voltage and parasitic channel formation, affecting the reliability and performance of semiconductor devices.
Innovation Solution
A semiconductor device structure with an oxide semiconductor film, a gate insulating film, and a sidewall insulating layer is developed, where the sidewall insulating layer has an oxygen-excess region formed through oxygen doping treatment, and a barrier film is used to prevent oxygen release and impurity entry, enhancing the stability and performance of the transistor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxygen doping treatment is applied to the sidewall insulating layer, then oxygen vacancies are compensated and threshold voltage stability is improved, but manufacturing process complexity increases
Solution Approach 1:
Oxygen doping treatment is performed on the sidewall insulating layer before transistor operation to preemptively compensate for oxygen vacancies that would otherwise form during device operation. This preliminary oxygen supply prevents threshold voltage shifts and parasitic channel formation before they occur, ensuring long-term stability without requiring complex real-time control mechanisms
Solution Approach 2:
The sidewall insulating layer acts as an intermediary oxygen reservoir between the external environment and the oxide semiconductor channel. By doping this intermediate layer with excess oxygen, the system creates a controlled oxygen supply mechanism that gradually compensates for oxygen vacancies in the channel region, stabilizing threshold voltage without direct exposure of the semiconductor to oxygen plasma or gas
2Speed
If the transistor is miniaturized to achieve high-speed operation, then response speed is improved, but on-state characteristics and reliability deteriorate
Solution Approach 1:
The sidewall insulating layer is selectively positioned at the gate electrode edges where parasitic channels most commonly form in miniaturized transistors. By concentrating oxygen doping in this specific location rather than uniformly throughout the device, the invention locally compensates for oxygen vacancies at the critical regions where miniaturization effects are most pronounced, maintaining reliability without sacrificing speed
Solution Approach 2:
The doped sidewall insulating layer preemptively counteracts the formation of parasitic channels that would otherwise occur in miniaturized transistors due to oxygen vacancy accumulation at high electric field regions near the gate edges. This preliminary anti-action prevents degradation of on-state characteristics before it occurs, enabling reliable high-speed operation
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
The solution improves the on-state characteristics and reliability of the transistor by compensating oxygen vacancies and preventing parasitic channel formation, enabling high-speed operation and stable electric characteristics.
Implementation Method 1
The sidewall insulating layer filled with excess oxygen in a region adjacent to the oxide semiconductor film and the gate insulating film prevents elimination of oxygen from the gate insulating film and the oxide semiconductor film and effectively serves as an oxygen supplying layer which supplies oxygen to the oxide semiconductor film and the gate insulating film
Data Source
AI summary
In a semiconductor device including a transistor using an oxide semiconductor film, stable electric characteristics can be provided and high reliability can be achieved. A structure of the semiconductor device, which achieves high-speed response and high-speed operation, is provided. In a semiconductor device including a transistor in which an oxide semiconductor film, a gate insulating film, and a gate electrode layer are stacked in order and a sidewall insulating layer is provided on the side surface of the gate electrode layer, the sidewall insulating layer has an oxygen-excess regions, which is formed in such a manner that a first insulating film is formed and then is subjected to oxygen doping treatment, a second insulating is formed over the first insulating film, and a stacked layer of the first insulating film and the second insulating film are etched.