【公開日：2024.07.25】【最終更新日：2024.04.11】
課題データ / Project Data
課題番号 / Project Issue Number
23AT0238
利用課題名 / Title
UTC-PD Fabrication on SiC
利用した実施機関 / Support Institute
産業技術総合研究所 / AIST
機関外・機関内の利用 / External or Internal Use
外部利用/External Use
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）加工・デバイスプロセス/Nanofabrication（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）高度なデバイス機能の発現を可能とするマテリアル/Materials allowing high-level device functions to be performed（副 / Sub）-
キーワード / Keywords
蒸着・成膜/ Vapor deposition/film formation,ALD,CVD,リソグラフィ/ Lithography,光リソグラフィ/ Photolithgraphy,膜加工・エッチング/ Film processing/etching,光デバイス/ Optical Device
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
Ssali Hussein
所属名 / Affiliation
九州大学
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
増田 賢一
利用形態 / Support Type
（主 / Main）技術補助/Technical Assistance（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
AT-019：多目的エッチング装置(ICP-RIE)
AT-023：電子ビーム真空蒸着装置
AT-030：プラズマCVD薄膜堆積装置
AT-011：i線露光装置
AT-031：原子層堆積装置_1[FlexAL]
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
A Uni-traveling carrier photodiode (UTC-PD) is a high-speed photodetector that can be used in a photo-mixing system to generate terahertz waves for high-speed wireless communication. Although the UTC-PD can offer higher saturation power than the conventional pin diode, its output power is still limited with regard to the required power for practical wireless transmission. One of the causes of this drawback is the low thermal conductivity of InP normally used as the substrate that cannot handle higher photocurrents thereby causing device saturation. Thus, we are attempting to fabricate the UTC-PD on Silicon Carbide (SiC) substrate with higher thermal conductivity using various semiconductor fabrication equipment at NPF. Herein, we report on the formation of the p and n electrodes of the UTC-PD.
実験 / Experimental
The p and n device electrodes were formed on the SiC substrate with InP/InGaAs UTC-PD epi layers using the electron beam vacuum evaporation equipment after lithographic patterns were made with i-line exposure device. Additionally, to reduce current leakage and improve performance, thin Al2O3 and SiO2 films were deposited using ALD and Plasma CVD thin film deposition equipment.
結果と考察 / Results and Discussion
The electrodes formed were made of gold (Au). For optimal contact between the metal and InGaAs layer, a 15 nm titanium (Ti) layer was deposited. However, since Ti is used as an adhesion layer while gold is a metal, Ti tends to diffuse into Au. To avoid this, we used a 15 nm Platinum (Pt) as a diffusion barrier between Ti and Au. Figure 1 shows the formed p and n electrodes. The measured leakage current was 2.5 µA at a bias voltage of -1 V for a 5 µm diameter device. Going forward, the aim is to further optimize the device and have the leakage current in the nanowatt range.
図・表・数式 / Figures, Tables and Equations
Figure 1. p and n UTC-PD electrodes
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件