Surface Acoustic Wave Structure With Ion Trap Layer for Energy Confinement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Surface acoustic wave (SAW) devices face energy loss due to mechanical characteristics, leading to a decrease in the quality factor, as surface acoustic wave energy is dissipated through the substrate.
Innovation Solution
An ion trap layer is formed on the substrate using ion implantation, with a predetermined thickness of 0.05 μm to 1.0 μm, to prevent energy leakage, and an intermediate and piezoelectric layer are added to enhance energy retention and signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional SAW device structure is used, then the device is simple and easy to manufacture, but surface acoustic wave energy is dissipated through the substrate leading to decreased quality factor
Solution Approach 1:
An ion trap layer is formed in the substrate before forming the piezoelectric layer and IDT electrodes. This preliminary action creates a energy confinement structure that prevents surface acoustic wave energy from dissipating into the substrate, thereby improving the quality factor without complicating the subsequent device fabrication steps
Solution Approach 2:
The ion trap layer acts as an intermediary between the substrate and the piezoelectric layer. It mediates the energy interaction by confining surface acoustic wave energy at the interface, preventing energy loss into the substrate while maintaining the simplicity of the overall device structure
2Reliability
If the quality factor is improved by reducing energy loss, then signal quality increases, but the manufacturing process becomes more complex
Solution Approach 1:
The ion trap layer is formed by modifying the substrate parameters through ion implantation, creating a region with different physical properties (higher acoustic impedance) than the bulk substrate. This parameter change enables energy confinement without requiring additional complex manufacturing steps or materials
Solution Approach 2:
The ion trap layer is created through a relatively simple ion implantation process that modifies the substrate itself, rather than requiring expensive additional materials or complex multi-layer structures. The substrate material serves dual purposes as both the base structure and the energy confinement medium
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 ion trap layer effectively suppresses energy loss, maintaining or improving the quality factor of the SAW device while simplifying the manufacturing process and reducing costs compared to conventional methods.
Implementation Method 1
an upper portion of the substrate is deformed by a predetermined thickness by ion implantation to form an ion trap layer
Implementation Method 2
when an electrical signal is applied through the input electrode, the piezoelectric effect causes piezoelectric distortion to occur corresponding to an overlap length between the IDT electrodes, and the piezoelectric distortion generates surface acoustic waves
Data Source
AI summary
A surface acoustic wave (SAW) device according to the present invention includes: a substrate; an intermediate layer formed on an upper surface of the substrate; a piezoelectric layer formed on an upper surface of the intermediate layer; and an inter-digital transducer (IDT) electrode formed on an upper surface of the piezoelectric layer to generate a SAW, wherein an upper portion of the substrate is deformed by a predetermined thickness by ion implantation to form an ion trap layer and the intermediate layer is formed on an upper surface of the ion trap layer.