Metal-Induced Trap States: The Roles of Interface and Border Traps in HfO<sub>2</sub>/InGaAs
Huy-Binh Do,
Quang-Ho Luc,
Phuong V. Pham,
Anh-Vu Phan-Gia,
Thanh-Son Nguyen,
Hoang-Minh Le,
Maria Merlyne De Souza
Affiliations
Huy-Binh Do
Faculty of Applied Science, Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan Street, Ho Chi Minh City 700000, Vietnam
Quang-Ho Luc
Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, 1001, Daxue Road, East District, Hsinchu 300093, Taiwan
Phuong V. Pham
Department of Physics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
Anh-Vu Phan-Gia
Faculty of Applied Science, Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan Street, Ho Chi Minh City 700000, Vietnam
Thanh-Son Nguyen
Faculty of Fundamental Sciences, University of Architecture Ho Chi Minh City, 196 Pasteur St., Dist. 3, Ho Chi Minh City 700000, Vietnam
Hoang-Minh Le
Faculty of electrical and electronics engineering, Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan Street, Ho Chi Minh City 700000, Vietnam
Maria Merlyne De Souza
EEE Department, University of Sheffield, Sheffield S10 2TN, UK
By combining capacitance–voltage measurements, TCAD simulations, and X-ray photoelectron spectroscopy, the impact of the work function of the gate metals Ti, Mo, Pd, and Ni on the defects in bulk HfO2 and at the HfO2/InGaAs interfaces are studied. The oxidation at Ti/HfO2 is found to create the highest density of interface and border traps, while a stable interface at the Mo/HfO2 interface leads to the smallest density of traps in our sample. The extracted values of Dit of 1.27 × 1011 eV−1cm−2 for acceptor-like traps and 3.81 × 1011 eV−1cm−2 for donor-like traps are the lowest reported to date. The density and lifetimes of border traps in HfO2 are examined using the Heiman function and strongly affect the hysteresis of capacitance–voltage curves. The results help systematically guide the choice of gate metal for InGaAs.
