Fabrication of Resonance Tunnel Diode by γ-Al2O3/Si Multiple Heterostructures
Fabrication of Resonance Tunnel Diode by γ-Al2O3/Si Multiple Heterostructures
复制标题
γ-Al2O3/Si多重异质结构制作谐振隧道二极管
DOI：
10.1143/jjap.41.2602
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发表时间：
2002
影响因子：
1.5
通讯作者：
M. Ishida
中科院分区：
文献类型：
--
作者：
M. Shahjahan;Y. Koji;K. Sawada;M. Ishida
本文报道了用于谐振隧道二极管结构的表面光滑的外延γ-Al_2O_3（111）/Si（111）异质结的制备。采用分子束外延（MBE）技术制备了γ-Al 2 O3薄膜，用小型电子束蒸发器制备了Si薄膜。用反射高能电子衍射（RHEED）和原子力显微镜（AFM）研究了这些薄膜的外延生长和表面形貌。对于Si（111）衬底上的γ-Al_2O_3（3 nm）和γ-Al_2O_3/Si（111）衬底上的Si（4 nm），所获得的表面粗糙度均方根（RMS）值分别为0.39nm和0.65nm。利用Fowler-Nodheim隧穿电流测量方法研究了γ-Al 2 O3/Si异质结的导带偏移，得到了2.2eV的导带偏移值。利用该异质结制备了双势垒和三势垒的共振隧穿二极管（RTD）结构。这些RTD的电性能进行了研究，找到负微分电阻（NDR）。首次在两种结构中观察到室温下的NDR，双势垒RTD的峰谷（P/V）电流比为3.0，三势垒RTD为4.5。
Fabrication of epitaxial γ-Al2O3(111)/Si(111) heterostructures with smooth surfaces for resonance tunnel diode structures is presented in this study. γ-Al2O3 layers were fabricated by molecular beam epitaxy (MBE) and Si layers were fabricated by a mini e-beam evaporator. Epitaxial growth and surface morphology of these layers were studied by reflection high energy electron diffraction (RHEED) and atomic force microscopy (AFM). The obtained root mean square (RMS) values of the surface roughness of these layers were 0.39 nm for γ-Al2O3 (3 nm) on Si(111)-substrate and 0.65 nm for Si (4 nm) on γ-Al2O3/Si(111)-substrate. Conduction band offset of the γ-Al2O3/Si heterostructure was studied by Fowler-Nodheim tunneling current measurement, and the conduction band offset (ΔEc) value of 2.2 eV was obtained. Then, resonant tunneling diode (RTD) structures with double and triple barriers were fabricated using this γ-Al2O3(111)/Si(111) heterostructure. Electrical properties of these RTDs were studied to find negative differential resistance (NDR). The NDR at room temperature was observed in both structures for the first time with a peak to valley (P/V) current ratio of 3.0 for the double barrier RTD, and 4.5 for the triple barrier RTD.