低消費電力デバイス向け化合物半導体と高誘電率絶縁膜及び金属電極の界面設計指針創出

本研究的重点是了解和工程的接口在高k和InGaAs，使低功耗，高性能的设备应用在移动的设备。本研究选用稀土氧化物La 2 O3作为高k氧化物。高k/InGaAs界面面临的主要问题是形成不稳定的氧化物，这导致在氧化物和衬底内形成几种类型的缺陷，例如界面陷阱（Dit）和体陷阱。然而，发现由于LaInGaO界面层的形成，通过使用La 2 O3可以制造极低缺陷的界面。该界面层具有非晶性质，并防止形成不稳定的氧化物，从而改善界面的质量。在InGaAs衬底上的最小等效氧化物厚度上的最低报告Dit在低于10的11次方的数量级中通过在本研究中进行的在InGaAs上的La 2 O3的原子层沉积（ALD）报告。由于finFET设计的流行， ...更多信息 近年来的器件结构中，重要的是评估的La 2 O3界面上的各种取向的InGaAs衬底的特性。与平面器件结构相反，FinFET器件中的器件沟道区由多个取向组成。因此，重要的是在所有衬底取向上实现高质量界面，以便受益于finFET设计的上级静电栅极特性。在本研究中，制作了具有ALD沉积的La 2 O3氧化物在[100]、[110]和[111]取向的InGaAs衬底上的MOSFET。MOSFET中使用的所有p型衬底都具有预形成的源极和漏极区。发现在所有衬底上都可以实现类似的Dit。所有MOSFET的亚阈值摆幅约为130 mV/dec，这意味着类似的接口特性。然而，具有[111]取向的衬底实现了更高的漏电流和漏电流值。这种效应可能与该表面中的电子有效质量较低有关，这是晶体表面的材料性质。这些结果显示了La_（20）_3在工业上用于各种InGaAs器件的潜力。少

This research focuses on understanding and engineering the interface at high-k and InGaAs for enabling low power, high performance devices for application in mobile devices. Rare metal earth oxide La203 is chosen as the high-k oxide in this research. The main issues facing high-k/InGaAs interface, is the formation of unstable oxides which lead to formation of several types of defects such as interface traps (Dit) and bulk traps within both the oxide and substrate. However, it was found that extremely low defect interfaces can be fabricated by using La203 due to formation of LaInGaO interfacial layer. This interfacial layer has an amorphous nature and prevents the formation of unstable oxides, thus improving the quality of the interface. Lowest reported Dit on smallest equivalent oxide thickness on InGaAs substrates in the order of lower 10 to the power of 11 was reported by atomic layer deposition(ALD) of La203 on InGaAs conducted in this research. Due to prevalence of finFET design in … More recent devices structures, it is important to evaluate the characteristics of La203 interface on various orientations of InGaAs substrate. Contrary to a planar device structure, the device channel region in a FinFET device is composed of multiple orientations. Therefore, it is important to achieve high quality interface on all substrate orientations in order to benefit from the superior electrostatic gate properties of the finFET designs. In this research, MOSFETs with ALD-deposited La203 oxide on [100], [110] and [111] oriented InGaAs substrates were fabricated. All p-type substrates used in MOSFETs had pre-formed source and drain regions. It was found that a similiar Dit can be achieved on all substrates. The substhreshold swing in all MOSFETs was ~130 mV/dec which imply similar interface characteristics. However, higher drain current and transconductance values were achieved for the substrate with [111] orientation. This effect could be related to lower effective mass of electrons in this surface which is a material property of crystalline surface. These resutls show the potential for using La203 in various InGaAs devices in idustry. Less