Suppressing Acoustomigration and Temperature Rise for High-power Robust Acoustics

TL;DR

This paper introduces a layered acoustic wave platform that significantly reduces temperature rise and enhances power handling in high-frequency SAW devices by innovative thermal and mechanical boundary engineering.

Contribution

It presents a novel multilayer design that enables simultaneous stress redistribution and thermal dissipation, surpassing previous substrate-focused thermal management approaches.

Findings

Achieves 70% reduction in temperature rise at 2 GHz under same power.

Demonstrates a threshold power density over 45.61 dBm/mm2, surpassing state-of-the-art.

Attains a temperature coefficient of frequency of -13 ppm/C with minimal dispersion.

Abstract

High-frequency acoustic wave transducers, vibrating at gigahertz (GHz), favored for their compact size, are not only dominating the front-end of mobile handsets but are also expanding into various interdisciplinary fields, including quantum acoustics, acoustic-optics, acoustic-fluids, acoustoelectric, and sustainable power conversion systems. However, like strong vibration can "shake off" substances and produce heat, a long-standing bottleneck has been the ability to harness acoustics under high-power vibration loads, while simultaneously suppressing temperature rise, especially for IDT-based surface acoustic wave (SAW) systems. Here, we proposed a layered acoustic wave (LAW) platform, utilizing a quasi-infinite multifunctional top layer, that redefines mechanical and thermal boundary conditions to overcome three fundamental challenges in high-power acoustic wave vibration: self-heating, thermal instability, and acoustomigration. By simply leveraging a simplified, thick single-material overlayer to achieve electro-thermo-mechanical co-design, this acoustic platform moves beyond prior substrate-focused thermal management in SAW technology. It demonstrates, for the first time from the top boundary, simultaneous redistribution of the von Mises stress field and the creation of an efficient vertical thermal dissipation path. The LAW transducer, vibrating at over 2 GHz, achieves a 70% reduction in temperature rise under identical power loads, a first-order temperature coefficient of frequency (TCF) of -13 ppm/C with minimal dispersion, and an unprecedented threshold power density of 45.61 dBm/mm2 - over one order-of-magnitude higher than that of state-of-the-art thin-film surface acoustic wave (TF-SAW) counterparts at the same wavelength.