[15a-1C-1~7] 13.5 Semiconductor devices and related technologies

[15a-1C-2] Characterization of physically-defined double quantum dots on highly-doped silicon substrate

〇Yu Yamaoka¹, Shunri Oda¹, Tetsuo Kodera¹ (1.Tokyo Tech.)

Keywords:silicon,quantum dot

Devices on highly-doped silicon substrate are easier to fabricate than MOS-type devices since top gates are not necessary for inducing carriers. However, obtaining clear characteristics of double quantum dots (DQDs) has been considered difficult because of fluctuated dopant potentials. Here, we improved the precision of electron beam lithography (EBL) and dry etching techniques, and then fabricated physically well-defined DQDs on highly-doped silicon-on-insulator (SOI) substrate. Measured transport properties show we obtained the characteristics of the designed DQDs without unintentional localized states. This result indicates that fluctuated dopant potentials may not be as problematic in our current device size scale (~40 nm in diameter) because there are still several thousand dopants in our device.