University of Twente Student Theses

Login

Charge sensing of single-hole tunneling events using a single-electron transistor

Ven, B. van de (2018) Charge sensing of single-hole tunneling events using a single-electron transistor.

[img] PDF
31MB
Abstract:Charge sensing of single-hole tunneling events using a single-electron transistor (SET) is an important step towards the fabrication and read-out of hole qubits in silicon. The goal is the fabrication of an SET that is capacitively coupled to a single-hole transistor (SHT). The metalic top gate and oxide materials used to fabricate these devices are varied to overcome several complication. It is demonstrated that using palladium gates, an accumulation SET and a depletion SHT can be formed. Titanium gates, with their enhanced stiction, are used to actively and passively sense hole tunneling events past the limit of direct transport at 4.2 K. However, due to the presence of an unintentional 2DHG, this could not be reproduced. Titanium-palladium devices are used to allow for the removal of the unintentional 2DHG using UV-ozone. Such a device is used to perform passive sensing past the limit of direct transport at 440 mK. Active sensing was not possible due to a high number of defects introduced during UV-ozone. Hafnium oxide is used in an attempt to remove the unintentional 2DHG by replacing the oxide interface. This interface is thought to contain negative charges that induce the 2DHG. Hafnium oxide is shown to reduces the 2DHG density as well as the turn-on voltage, making it a promising material for future devices.
Item Type:Essay (Master)
Faculty:TNW: Science and Technology
Subject:33 physics
Programme:Nanotechnology MSc (60028)
Link to this item:http://purl.utwente.nl/essays/76818
Export this item as:BibTeX
EndNote
HTML Citation
Reference Manager

 

Repository Staff Only: item control page