Yukinori Morita

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We evaluate the impact of tunnel junction quality on the performance of tunnel field-effect transistors (TFETs). Performing a sequential surface cleaning procedure prior to epitaxial channel growth for heavily arsenicand boron-doped Si surfaces improves the interface quality both for pand n-TFETs. Simultaneously, the subthreshold swing (SS) values of the(More)
The non-local band to band tunneling model developed and implemented into the three-dimensional device simulator by the authors is evaluated for the tunnel-FET modeling focused on device geometry effects. Measured characteristics of SOI, Fin, and parallel-plate silicon tunnel FETs fabricated by the authors are compared with simulations based on the(More)
We report guidelines for symmetric threshold voltage (Vth) in double gate (DG) tunnel FinFETs (tFinFETs) with single and dual metal gate electrodes. To realize the symmetric Vth=±0.2V, the work function difference (ΔΦm) of each gate electrode in nand p-type tFinFETs with a nondoped Si channel must be 1.34 eV, indicating that tuning the effective work(More)
Polycrystalline-silicon (poly-Si) and crystalline-silicon (crystal-Si) channel FinFET CMOS inverters were successfully fabricated and the variations of threshold voltage (V<sub>t</sub>) for their individual n- and p-channel transistors and the logic gate V<sub>t</sub> (V<sub>Thc</sub>) for the inverters were systematically investigated. It was found that(More)
あらまし CMOSの微細化限界などによる新原理トランジスタの候補として,トンネル FETの研究が行われ ている.筆者らは,成熟したシリコン技術を用いて,トンネル FET の試作・評価を行うのと並行し,デバイス シミュレーションを用いたモデリングを実施した.最初にバンド間トンネルのモデル化について,その仮定・精 度を実測と比較しながら検討し,非局所電界に基づくモデルを採用した.デバイスの設計指針や,実測される電 気特性の解釈には,そのモデルを用いたデバイスシミュレーションを使用した.応用の側面から回路シミュレー ションが必要となり,素子動作のコンパクトモデル化を,デバイスモデリングの経緯に基づいて行い,そのモデ ルは回路応用上の課題の検討に用いられた.また,このように新デバイスの開発とモデリングを同時並行に進め(More)
Tunnel FETs with vertical tunnel paths are fabricated and successfully modeled by the nonlocal band to band tunneling model. Although enhancement of ON currents are obtained by longer source gate overlap lengths, the increase of the ON current is less than proportional to the overlap lengths, because of non-uniformity of the band to band tunneling(More)