Effect of Surrounded-Channel Structure on Electrical Characteristics of $c$ -Axis Aligned Crystalline In–Ga–Zn–O Field-Effect Transistor

In this letter, we report the electrical characteristics of a crystalline oxide semiconductor, especially c-axis aligned crystalline In-Ga-Zn-O (CAAC-IGZO) field-effect transistors (FETs) having a surrounded-channel structure with 51-nm channel lengths, 11-nm equivalent oxide thicknesses of the gate insulating films, and various channel widths. The results show that the influence of the gate electrode on the sides of the channel increases as the channel width is reduced, which leads to excellent OFF-state and ON-state current characteristics of the FET with a 51-nm channel length and a 50-nm channel width. By exploiting these characteristics, low-power large-scale integration (LSI) applications become possible that would not be possible with conventional Si-LSI techniques.