Materials Design on the Origin of Gap States in a High-κ/GaAs Interface

作     者：Weichao Wang Cheng Gong Ka Xiong Santosh K.C. Robert M.Wallace Kyeongjae Cho 

作者机构：Department of Materials Science and Engineering The University of Texas at Dallas College of Electronic Information and Optical Engineering Nankai University 

出 版 物：《Engineering》 (工程（英文）)

年 卷 期：2015年第1卷第3期

页      面：372-377页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 081201[工学-计算机系统结构] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China (11304161, 11104148, and 51171082) the Tianjin Natural Science Foundation (13JCYBJC41100 and 14JCZDJC37700) the National Basic Research Program of China (973 Program) (2014CB931703) Specialized Research Fund for the Doctoral Program of Higher Education (20110031110034) the Fundamental Research Funds for the Central Universities supported by the Global Frontier Center for Multiscale Energy Systems at Seoul National University in Korea 

主　　题：high-mobility device high-κ/Ⅲ-Ⅴ interface interfacial gap states first-principle calculations 

摘      要：Given the demand for constantly scaling micro- electronic devices to ever smaller dimensions, a SiO2 gate dielectric was substituted with a higher dielectric-constant material, Hf（Zr）O2, in order to minimize current leakage through dielectric thin film. However, upon interfacing with high dielectric constant （high-κ） dielectrics, the electron mobility in the conventional Si channel degrades due to Coulomb scattering, surface-roughness scattering, remotephonon scattering, and dielectric-charge trapping.Ⅲ-Ⅴ and Ge are two promising candidates with superior mobility over Si. Nevertheless, Hf（Zr）O2/Ⅲ-Ⅴ（Ge） has much more complicated interface bonding than Si-based interfaces. Successful fabrication of a high-quality device critically depends on understanding and engineering the bonding configurations at Hf（Zr）O2/Ⅲ-Ⅴ（Ge） interfaces for the optimal design of device interfaces. Thus, an accurate atomic insight into the interface bonding and mechanism of interface gap states formation becomes essential. Here, we utilize first- principle calculations to investigate the interface between HfO2 and GaAs. Our study shows that As--As dimer bonding, Ga partial oxidation （between 3＋ and 1＋） and Ga- dangling bonds constitute the major contributions to gap states. These findings provide insightful guidance for optimum interface passivation.