Pretreatment Effects on High-k/In_xGa_1–xAs MOS Interface Properties and Their Physical Model

Abstract

The electrical and physical properties of atomic layer deposition high-k (Al2O3 and HfO2) /InxGa1-xAs (x = 0.53, 0.7, and 1) MOS interfaces with (NH4)Sy, BHF, and HF pretreatment are examined. It is found that, as the In content (x) becomes higher, InxGa1-xAs MOS interfaces with BHF and HF cleaning show better C-V characteristics and lower interface state density (Dit) than with (NH4)Sy pretreatment. Also, the amounts of arsenic oxides, evaluated by X-ray photoelectron spectroscopy, at the high In content Al2O3/InxGa1-xAs MOS interfaces are found to increase with BHF and HF cleaning than with (NH4)Sy cleaning. These results suggest that arsenic oxides can contribute to passivation of high-k/InxGa1-xAs MOS interface defects and the decrease in Dit for x = 0.7 and 1. Finally, we propose a physical model to explain the relationship between possible interface defects responsible for Dit and the pretreatment effects with the different In contents.

Keywords

• BHF
• C-V%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> <italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">C-V</italic>
• Dit%22%2C%22default_operator%22%3A%22AND%22%7D%7D%7D"> <italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">D</italic>it
• HF
• InAs
• InGaAs