绝缘衬底上的铌酸锂（LNOI）上外延InGaAs的SH-SAW声电放大器
SH-SAW Acousto-Electric Amplifier in Epitaxial InGaAs on Lithium Niobate on Insulator
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中文总结 AI 辅助
本研究基于外延InGaAs/LNOI异质结构实现SH-SAW声电放大，通过钝化提升器件稳定性，明确增益影响因素，为非互易射频组件等提供低功耗平台。
中文摘要 AI 辅助
本研究展示了基于Al₂O₃介导晶圆键合形成的外延InGaAs/X切绝缘衬底上的铌酸锂（LNOI）异质结构的水平剪切表面声波（SH-SAW）声电（AE）放大特性。可部署的钝化器件在1.11 GHz、30 V偏置、64 mW功耗下表现出稳定的基模非互易性，达到32 dB/mm；未钝化器件在1.1-2.8 GHz范围内的非互易性可达174 dB/mm，此为报告的上限值。器件表征明确了模式相关的K²在确定可实现增益中的作用。转移外延InGaAs的霍尔效应测量作为定量诊断手段：提取的载流子密度因外延过程中无意的硅掺杂而升高，当将其代入分析模型时可解释绝对声电增益，并表明外延工艺控制是进一步提升性能的关键途径。研究还发现，裸露InGaAs表面的环境氧化是一种独特的老化机制，会在数周内消除声电响应，而InP或原子层沉积（ALD）Al₂O₃钝化层可抑制该老化，代价是压电场会从沟道中重新分布。这些结果确立了InGaAs-on-LNOI作为紧凑、低功耗平台，适用于非互易射频组件和声电延迟线，与带内全双工（IBFD）收发器及频谱高效无线前端具有重要关联。
英文摘要
This work demonstrates shear-horizontal surface acoustic wave (SH-SAW) acoustoelectric (AE) amplification on an epitaxial InGaAs / X-cut lithium niobate on insulator (LNOI) heterostructure formed by Al2O3-mediated wafer bonding. Deployable passivated devices show a stable fundamental-mode non-reciprocity of 32 dB/mm at 1.11 GHz (30 V bias, 64 mW consumed), while unpassivated devices reach 174 dB/mm across 1.1-2.8 GHz, reported as upper bounds. Device characterization establishes the role of mode-dependent K^2 in determining the achievable gain. Hall-effect measurements of the transferred InGaAs serve as a quantitative diagnostic: the extracted carrier density, elevated by unintentional silicon doping during epitaxy, accounts for the absolute AE gain when inserted into the analytical model and identifies epitaxial process control as a clear lever for further enhancement. We further identify ambient oxidation of the bare InGaAs surface as a distinct aging mechanism that extinguishes the AE response within weeks, and show that an InP or ALD Al2O3 passivation layer suppresses it, at the cost of redistributing the piezoelectric field away from the channel. These results establish InGaAs-on-LNOI as a compact, low-power platform for non-reciprocal RF components and acoustoelectric delay lines, with strong relevance to in-band full-duplex (IBFD) transceivers and spectrum-efficient wireless front ends.
