二次元半導体の直接成長ウェハ上でのトランジスタ基本動作を初実証 ―転写プロセスに頼らない集積回路用プラットフォームへ道―

2026-07-09 東京大学

サファイア基板上に直接形成された「MoS₂ウェハ」デバイス群と、その優れたオン・オフ特性（チャネル長L = 20 μm、チャネル幅W = 10 μm）。転写工程を一切介さず、界面制御のみで良好なトランジスタ動作（赤色：初期状態、黒色：アニール後）を実現した。

＜関連情報＞

• https://www.t.u-tokyo.ac.jp/press/pr2026-07-09-001
• https://advanced.onlinelibrary.wiley.com/doi/10.1002/adma.73931

ドライインターフェースエンジニアリングによる、トップゲートデバイス用転写不要プラットフォームとしてのMOCVD成長MoS₂ウェハ MOCVD-Grown MoS2 Wafers as a Transfer-Free Platform for Top-Gate Devices via Dry Interface Engineering

Shuhong Li, Juiteng Chang, Keisuke Atsumi, Kosei Matsumoto, Itsuki Tanaka, Tomonori Nishimura, Kaito Kanahashi, Takahiro Nagata, Jun Nara, Yoshiki Sakuma, Emi Kano,…
Advanced Materials  Published: 05 July 2026
DOI:https://doi.org/10.1002/adma.73931

ABSTRACT

We uncover the electronic origin of hidden interfacial doping in monolayer MoS₂ single-crystal wafers grown on sapphire by metal–organic chemical vapor deposition (MOCVD) and establish a transfer-free top-gate device platform. Despite structural perfection, as-fabricated devices exhibit degenerate electron doping and lack a clear off state. Hall measurements quantify an interfacial electron density of 2.7 × 10¹² cm⁻², evidencing substantial charge transfer across the nominal van der Waals interface. Interface-sensitive spectroscopy, lateral force microscopy, and thermal desorption analysis reveal a buried sulfate-derived layer accompanied by a water-like interfacial structure that acts as an intrinsic electron donor. A purely dry H₂/Ar annealing process selectively removes these species, suppressing charge transfer and restoring intrinsic FET characteristics without transfer or wet processing. Through this dry interface engineering approach, we demonstrate MOCVD-grown single-crystal MoS₂ wafers as a robust, transfer-free platform for the reliable evaluation of intrinsic gate stacks and device performance.