Initial Processes of Atomic Layer Deposition of Al2O3 on InGaAs: Interface Formation Mechanisms and Impact on Metal-Insulator-Semiconductor Device Performance |
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| Authors: | Wipakorn Jevasuwan Yuji Urabe Tatsuro Maeda Noriyuki Miyata Tetsuji Yasuda Hisashi Yamada Masahiko Hata Noriyuki Taoka Mitsuru Takenaka Shinichi Takagi |
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| Affiliation: | 1.National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8562, Japan; E-Mails: (Y.U.); (T.M.); (N.M.); (T.Y.);2.Sumitomo Chemical Co., Ltd, Tsukuba, Ibaraki 300-3294, Japan; E-Mails: (H.Y.); (M.H.);3.Department of Electrical Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan; E-Mails: (N.T.); (M.T.); (S.T.) |
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| Abstract: | Interface-formation processes in atomic layer deposition (ALD) of Al2O3 on InGaAs surfaces were investigated using on-line Auger electron spectroscopy. Al2O3 ALD was carried out by repeating a cycle of Al(CH3)3 (trimethylaluminum, TMA) adsorption and oxidation by H2O. The first two ALD cycles increased the Al KLL signal, whereas they did not increase the O KLL signal. Al2O3 bulk-film growth started from the third cycle. These observations indicated that the Al2O3/InGaAs interface was formed by reduction of the surface oxides with TMA. In order to investigate the effect of surface-oxide reduction on metal-insulator-semiconductor (MIS) properties, capacitors and field-effect transistors (FETs) were fabricated by changing the TMA dosage during the interface formation stage. The frequency dispersion of the capacitance-voltage characteristics was reduced by employing a high TMA dosage. The high TMA dosage, however, induced fixed negative charges at the MIS interface and degraded channel mobility. |
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| Keywords: | InGaAs Al2O3 ALD MISFET trimethylaluminum |
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