Detection of the first charged states in ultrasmall Si single-hole transistor using dual-channel radio frequency reflectometry

Si CMOS single-electron transistors (SET) fabricated using fully depleted SOI [1] enable an understanding of charging mechanisms in ultimately scaled CMOS devices down to a transport through a single dopant [2]. A schematic representation of such a device is shown in Fig 1. Radio-frequency (RF) reflectometry [3] is an effective tool for charge detection in various single-electron systems. Since it does not require any DC current flow the detection of electrons passing even through a single tunnel junction [4] is possible. When a Si SET is populated with electrons, one intriguing question need to be answered: where do the first charge carriers spatially accumulate during the formation of the conducting “island”? To address this issue we use a dual channel technique that enables spatial identification of charging processes within the device. Here we present results obtained using this technique for single-hole transistors (SHT). A micrograph of a typical studied SHT device.