Dark current suppression of short wavelength infrared InGaAs/GaAsSb-AlGaAsSb avalanche photodiodes by dual passivation layer

IF 3.8 3区物理与天体物理 Q2 INSTRUMENTS & INSTRUMENTATION

Infrared Physics & Technology Pub Date : 2026-05-01 Epub Date: 2026-02-12 DOI:10.1016/j.infrared.2026.106457

Jiaqi Wei , Peng Cao , Zeyu Wang , Tiancai Wang , Chunxu Song , Yidan Hu , Minghui You , Hongling Peng , Qiandong Zhuang , Wanhua Zheng

{"title":"Dark current suppression of short wavelength infrared InGaAs/GaAsSb-AlGaAsSb avalanche photodiodes by dual passivation layer","authors":"Jiaqi Wei , Peng Cao , Zeyu Wang , Tiancai Wang , Chunxu Song , Yidan Hu , Minghui You , Hongling Peng , Qiandong Zhuang , Wanhua Zheng","doi":"10.1016/j.infrared.2026.106457","DOIUrl":null,"url":null,"abstract":"<div><div>In this work, we propose a dual-passivation strategy to suppress dark current in short-wavelength infrared (SWIR) type-II superlattice (T2SL) avalanche photodiodes (APDs) featuring a separate-absorption-grading-charge-multiplication (SAGCM) architecture. It is noted that conventional single-layer dielectrics such as PECVD (Plasma Enhanced Chemical Vapor Deposition) SiO<sub>2</sub> or ALD (Atomic Layer Deposition) Al<sub>2</sub>O<sub>3</sub> offer only limited leakage suppression under high electric fields, making them insufficient for deeply etched devices. To mitigate this challenge, we introduce a dual-passivation layer consisting of 35-nm ALD Al<sub>2</sub>O<sub>3</sub> and 450-nm PECVD SiO<sub>2</sub> which effectively reduces interface traps and easing electric-field crowding along the mesa sidewall. As a result, the dark current is reduced by more than one order of magnitude, and thermal stability is improved across 120–295 K. Leakage current analysis further reveals a transition from surface-dominated to bulk-dominated transport, confirming that DPL effectively suppresses surface contributions and enables low-noise operation. Such performance indicates strong potential for reliable, high-gain SWIR T2SL APDs in practical sensing applications.</div></div>","PeriodicalId":13549,"journal":{"name":"Infrared Physics & Technology","volume":"155 ","pages":"Article 106457"},"PeriodicalIF":3.8000,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Infrared Physics & Technology","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1350449526000927","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/2/12 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"INSTRUMENTS & INSTRUMENTATION","Score":null,"Total":0}

引用次数: 0

Abstract

In this work, we propose a dual-passivation strategy to suppress dark current in short-wavelength infrared (SWIR) type-II superlattice (T2SL) avalanche photodiodes (APDs) featuring a separate-absorption-grading-charge-multiplication (SAGCM) architecture. It is noted that conventional single-layer dielectrics such as PECVD (Plasma Enhanced Chemical Vapor Deposition) SiO₂ or ALD (Atomic Layer Deposition) Al₂O₃ offer only limited leakage suppression under high electric fields, making them insufficient for deeply etched devices. To mitigate this challenge, we introduce a dual-passivation layer consisting of 35-nm ALD Al₂O₃ and 450-nm PECVD SiO₂ which effectively reduces interface traps and easing electric-field crowding along the mesa sidewall. As a result, the dark current is reduced by more than one order of magnitude, and thermal stability is improved across 120–295 K. Leakage current analysis further reveals a transition from surface-dominated to bulk-dominated transport, confirming that DPL effectively suppresses surface contributions and enables low-noise operation. Such performance indicates strong potential for reliable, high-gain SWIR T2SL APDs in practical sensing applications.

查看原文本刊更多论文

双钝化层抑制短波红外InGaAs/GaAsSb-AlGaAsSb雪崩光电二极管的暗电流

在这项工作中，我们提出了一种双钝化策略来抑制具有分离吸收-分级-电荷倍增（SAGCM）结构的短波红外（SWIR） ii型超晶格（T2SL）雪崩光电二极管（apd）中的暗电流。值得注意的是，传统的单层介质，如PECVD（等离子体增强化学气相沉积）SiO2或ALD（原子层沉积）Al2O3，在高电场下只能提供有限的泄漏抑制，这使得它们不足以用于深蚀刻器件。为了缓解这一挑战，我们引入了一种由35纳米ALD Al2O3和450纳米PECVD SiO2组成的双钝化层，该钝化层有效地减少了界面陷阱，并缓解了沿台面侧壁的电场拥挤。因此，暗电流减少了一个数量级以上，并且在120-295 K范围内的热稳定性得到了改善。泄漏电流分析进一步揭示了从表面主导传输到大块主导传输的转变，证实了DPL有效地抑制了表面贡献，并实现了低噪声运行。这样的性能表明可靠的高增益SWIR T2SL apd在实际传感应用中的强大潜力。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Infrared Physics & Technology 物理-光学

CiteScore

5.70

自引率

12.10%

发文量

400

审稿时长

67 days

期刊介绍： The Journal covers the entire field of infrared physics and technology: theory, experiment, application, devices and instrumentation. Infrared'' is defined as covering the near, mid and far infrared (terahertz) regions from 0.75um (750nm) to 1mm (300GHz.) Submissions in the 300GHz to 100GHz region may be accepted at the editors discretion if their content is relevant to shorter wavelengths. Submissions must be primarily concerned with and directly relevant to this spectral region. Its core topics can be summarized as the generation, propagation and detection, of infrared radiation; the associated optics, materials and devices; and its use in all fields of science, industry, engineering and medicine. Infrared techniques occur in many different fields, notably spectroscopy and interferometry; material characterization and processing; atmospheric physics, astronomy and space research. Scientific aspects include lasers, quantum optics, quantum electronics, image processing and semiconductor physics. Some important applications are medical diagnostics and treatment, industrial inspection and environmental monitoring.