[19a-E305-1~12] 13.3 Insulator technology

[19a-E305-2] Re-Examination of sulfur treatment effects on Al₂O₃/InGaAs MOS interface properties

〇SANghee YOON¹, Kimihiko Kato¹, Chiaki Yokoyama¹, Daehwan Ahn¹, Mitsuru Takenaka¹, Shinichi Takagi¹ (1.Tokyo University)

Keywords:InGaAs, pre-treatment, S passivation

The effects of wet chemical treatments before a treatment using (NH₄)₂S solutions in atomic layer deposition Al₂O₃/InGaAs metal-oxide-semiconductor interfaces are experimentally examined. It is found that no chemical treatment before sulfur passivation leads to high interface state density (D_it) in spite of the (NH₄)₂S treatment. Furthermore, the HCl + (NH₄)₂S and BHF + (NH₄)₂S combinations show the lowest values of D_it. In addition, all of the Al₂O₃/InGaAs MOS interfaces with the sulfur treatment show a small amount of arsenic oxides. Thus, much higher D_it of the interfaces with the sulfur treatment indicates that the amount of arsenic oxides is not a deterministic factor for D_it. On the other hand, the amount of arsenic oxides before the sulfur treatment is found to correlate with D_it after sulfur treatment. Also, the interfaces with higher D_it after the sulfur treatment show a larger amount of sulfur atoms remaining at the interfaces. These experimental results mean that there is a strong correlation among D_it, the amount of arsenic oxides and the amount of sulfur atoms remaining at Al₂O₃/InGaAs interfaces.