Oxide Semiconductor Transistor Negative Capacitance Gate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Oxide semiconductor transistors have limited application in low power devices due to high threshold voltage and insufficient on-current, primarily because of the thick gate insulation layer required for low leakage current, which restricts the use of these devices in low power operations.
Innovation Solution
Incorporating a ferroelectric material layer between the metal gate and internal electrode to create a negative capacitance effect, which amplifies the gate voltage, increases on-current, and allows for a thinner gate insulation layer without compromising low leakage current performance, enabling the transistor to be used in low power operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gate insulation layer is made thick to maintain low leakage current, then leakage current is reduced, but on-current is limited and threshold voltage becomes too high
Solution Approach 1:
The gate structure is segmented into multiple functional layers: gate insulation layer, internal electrode, and ferroelectric material layer. This segmentation allows each layer to perform its specific function independently - the gate insulation layer maintains low leakage current while the ferroelectric layer enhances on-current through negative capacitance effect
Solution Approach 2:
The ferroelectric material layer acts as an intermediary between the gate insulation layer and the channel, providing negative capacitance that amplifies the gate voltage effect. This mediator enables the gate insulation layer to be thinner while still achieving low leakage current, thereby improving on-current without sacrificing reliability
2Reliability
If the gate insulation layer is made thick to ensure low leakage current, then leakage current performance is maintained, but the transistor cannot be applied in low power devices
Solution Approach 1:
The ferroelectric material layer changes the electrical parameters of the gate structure by introducing negative capacitance. This parameter change enables voltage amplification, allowing the transistor to operate at lower gate and drain voltages, thereby reducing power consumption while maintaining acceptable leakage current performance
3Reliability
If a thicker gate insulation layer is used to maintain low leakage current, then leakage current is kept low, but on-current is limited
Solution Approach 1:
The gate structure uses composite materials including gate insulation layer, internal electrode, and ferroelectric material layer. The ferroelectric material provides negative capacitance that amplifies the gate voltage effect, enabling higher on-current while the gate insulation layer maintains low leakage current, thus resolving the contradiction through material composition
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 negative capacitance effect enhances on-current and reduces sub-threshold swing, allowing oxide semiconductor transistors to be applied in low power devices with reduced gate and drain voltages, expanding their application field.
Implementation Method 1
a ferroelectric material layer disposed between the metal gate and the internal electrode, wherein the ferroelectric material layer and the internal electrode form a negative capacitance effect
Data Source
AI summary
An oxide semiconductor transistor includes an oxide semiconductor channel layer, a metal gate, a gate insulation layer, an internal electrode, and a ferroelectric material layer. The metal gate is disposed on the oxide semiconductor channel layer. The gate insulation layer is disposed between the metal gate and the oxide semiconductor channel layer. The internal electrode is disposed between the gate insulation layer and the metal gate. The ferroelectric material layer is disposed between the internal electrode and the metal gate. The ferroelectric material layer in the oxide semiconductor transistor of the present invention is used to enhance the electrical characteristics of the oxide semiconductor transistor.