Interface States in p-Type GaAs/GaAs1-xBix Heterostructure

• Published in: Jpn J Appl Phys 2012-11, Vol.51 (11), p.11PC02-11PC02-5
• Main Authors: Fuyuki, Takuma, Kashiyama, Shota, Oe, Kunishige, Yoshimoto, Masahiro
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.51.11PC02

The characteristics of interface states in a GaAs/GaAs 1-x Bi x heterointerface have been evaluated by capacitance--frequency measurements, thermal admittance spectroscopy, and isothermal capacitance transient spectroscopy. The interface states density $D_{\text{it}}$ is evaluated to be approximately $9 \times 10^{11}$ cm -2 eV -1 for the first time. The large density is probably caused by the fact that the surface of GaAs and GaAs 1-x Bi x are shown to be nonmetallic and metallic, respectively. The interface states density is reduced by half by insertion of a Bi graded layer into the GaAs/p-GaAs 1-x Bi x heterointerface, which is on the same order as other III--V heterointerfaces such as GaAs/GaAs 0.97 N 0.03 and In 0.5 Ga 0.5 P/Al 0.25 Ga 0.75 As.