tailieunhanh - Investigation of charge traps at al doped HfO2/(100)InGaAs interface by using capacitance and conductance methods

In this study, capacitance and conductance methods were used to investigate the charge traps at a HfO2/(100)InGaAs interface with an atomic layer deposition HfO2 layer doped with Al2O3 by co-deposition technique. | Vietnam Journal of Science and Technology 56 (1A) (2018) 110-118 INVESTIGATION OF CHARGE TRAPS AT Al-DOPED HfO2/(100)InGaAs INTERFACE BY USING CAPACITANCE AND CONDUCTANCE METHODS Thoan Nguyen-Hoang1, *, Sang Nguyen-Xuan2, Trung Nguyen-Ngoc1 1 School of Engineering Physics, Hanoi University of Science and Technology, No. 1 Dai Co Viet road, Ha Noi, Viet Nam 2 Low Energy Electronic Systems IRG (LEES), Singapore-MIT Alliance for Research and Technology, 1 CREATE Way, Singapore 138602, Singapore * Email: Received: 11 August 2017; Accepted for publication: 21 March 2018 ABSTRACT In this study, capacitance and conductance methods were used to investigate the charge traps at a HfO2/(100)InGaAs interface with an atomic layer deposition HfO2 layer doped with Al2O3 by co-deposition technique. The effect of Al doping on the quality of the HfO2/ interface will be evaluated. The density of interface traps (Dit) near midgap is close to 2×1012 cm−2eV−1. Based on comparison to the HfO2/ interface without Al2O3 interfacial passivation where the value Dit∼1013 cm−2eV−1 is encountered near the midgap, we can conclude that the presence of Al 2O3 passivation noticeably improves the interface quality. Keywords: HfO2, InGaAs, interface traps, capacitance method, conductance method. 1. INTRODUCTION III-V channel materials are expected to replace Si for nMOSFET components due to their very high electron mobility. It has already been demonstrated that ultra-high mobility compound semiconductor-based MOSFETs and quantum well FETs (., and InSb) [1, 2] operate at low VSD with high performance. Furthermore, MOSHEMTs with an InP barrier stack have been demonstrated with times higher effective carrier velocity than strained-Si n-MOSFETs [3]. In addition, another advantage of III-V semiconductors is their direct bandgap raising much interest for optical and photonic device application. .