Ferroelectric Capacitor Gate Integration for Low-Voltage Analogue Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-volatile transistors adjustable in analogue fashion, such as memristors, have not been developed effectively, with existing two-terminal memristors exhibiting small adjustment ranges, high thermal sensitivity, and integration complications in fabrication processes.
Innovation Solution
An integrated electronic circuit comprising a first transistor and a ferroelectric capacitor with a non-ferroelectric material first and second electrode layers and a ferroelectric interlayer, where the ferroelectric interlayer is between the electrode layers, connected to the transistor's gate, using lead-free materials compliant with EU Directive 2011/65/EU, allowing for low-voltage control and high scalability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If two-terminal memristors are used as analogue-switchable devices, then analogue switching capability is achieved, but adjustment range is very small and thermal sensitivity is high
Solution Approach 1:
The invention divides the system into two separate components: a transistor for analogue switching and a ferroelectric capacitor for non-volatile memory. This segmentation allows each component to perform its specialized function optimally - the transistor provides wide-range analogue control while the capacitor provides stable non-volatile storage, avoiding the thermal sensitivity and limited adjustment range of two-terminal memristors.
Solution Approach 2:
The gate terminal of the transistor acts as an intermediary between the control signal and the channel current. By coupling the ferroelectric capacitor to the gate terminal, the system achieves analogue switching through the transistor's channel while the ferroelectric material provides non-volatile state retention, combining the benefits of both components without the drawbacks of direct memristor implementation.
2Volume of moving object
If ferroelectric capacitor thickness is reduced for miniaturization, then scalability is improved, but breakdown strength decreases
Solution Approach 1:
The invention uses a composite structure with the ferroelectric interlayer (e.g., hafnium oxide, zirconium oxide) sandwiched between two electrode layers. This composite configuration, with the ferroelectric material being only a few nanometers to tens of nanometers thick, achieves both miniaturization and adequate breakdown strength through the synergistic combination of materials and the protective role of the electrode layers.
Solution Approach 2:
The ferroelectric interlayer is implemented as an ultrathin film (thickness < 100 nm, particularly < 40 nm) that provides the necessary ferroelectric functionality while enabling miniaturization. The thin film structure, combined with the overlying electrode layers, maintains breakdown strength despite the reduced thickness, allowing for scalable and miniaturized device designs.
3Use of energy by moving object
If control voltage is reduced for low-power applications, then energy consumption is reduced, but polarization switching becomes difficult
Solution Approach 1:
The invention changes the material parameter of the ferroelectric interlayer by selecting materials with high spontaneous polarization and coercive field characteristics (such as doped hafnium oxide or zirconium oxide). These material parameter changes enable reliable polarization switching even at low control voltages (< 5 V, preferably < 3 V), achieving both low-power operation and dependable switching capability.
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 provides a reliable, analogue-switchable, and non-volatile electronic circuit with enhanced scalability and miniaturization capabilities, achieving significant capacitance changes at low voltages and enabling high integration density and low-power applications.
Implementation Method 1
The ferroelectric capacitor comprises a first electrode layer composed of a non-ferroelectric material, a ferroelectric interlayer, and a second electrode layer composed of a non-ferroelectric material. The ferroelectric interlayer is arranged between the first electrode layer and the second electrode layer.
Implementation Method 2
The thickness of the ferroelectric interlayer is preferably less than 100 nm, particularly preferably less than 40 nm. With these thicknesses, a change in the polarization state of the ferroelectric is achieved even at low electrical voltages of less than 5 V and preferably less than 3 V.
Data Source
AI summary
The present invention relates to an integrated electronic circuit and method of making comprising a first transistor (1) and a ferroelectric capacitor (2). The ferroelectric capacitor (2) comprises a first electrode layer composed of a non-ferroelectric material, a ferroelectric interlayer having a thickness that is less than the thickness of the first electrode layer, and a second electrode layer composed of a non-ferroelectric material, wherein the ferroelectric interlayer is arranged between the first electrode layer and the second electrode layer, and the first electrode layer is electrically conductively connected to a gate terminal of the first transistor (1).