AVS 66th International Symposium & Exhibition
    Advanced Ion Microscopy and Ion Beam Nano-engineering Focus Topic Thursday Sessions
       Session HI+NS-ThA

Paper HI+NS-ThA4
A New FIB for Deterministic Single Ion Implantation

Thursday, October 24, 2019, 3:20 pm, Room B231-232

Session: Emerging Ion Sources, Optics, and Applications
Presenter: Nathan Cassidy, UK National Ion Beam Centre, University of Surrey, UK
Authors: N. Cassidy, UK National Ion Beam Centre, University of Surrey, UK
D. Cox, Advanced Technology Institute, University of Surrey, UK
R. Webb, UK National Ion Beam Centre, University of Surrey, UK
B. Murdin, Advanced Technology Institute, University of Surrey, UK
B. Blenkinsopp, Ionoptika Ltd., UK
I. Brown, Ionoptika Ltd., UK
R. Curry, The Photon Science Institute, University of Manchester, UK
Correspondent: Click to Email
Single isolated dopant atoms implanted into solid state devices have been shown to be a viable architecture for quantum technologies. Ion implantation provides many advantages as a manufacturing method for such devices, such as speed and scalability, however controlling the number of implanted ions with single-ion precision poses a significant challenge. In this paper we will present a new instrument designed for the deterministic implantation of single ions with high precision.

The SIMPLE (Single Ion Multi-species Positioning at Low Energy) tool, is a new focused ion beam tool in operation designed for the manufacture of quantum technologies. The tool has a 25kV LMIG set up for femtoAmp sample currents, with ultra-fast beam blanking, neutral blocking and a highly efficient secondary electron detection system. Deterministic ion implantation is achieved through extraction of single ions through fast beam blanking with low currents, ion implant detection through collection of secondary electron (SE) signal from the target and high spatial precision in ion placement.

To date we have demonstrated > 85% probability of implanting a single Bi+ ion into silicon without error, with a 20nm beam determining dopant placement precision. This surface secondary electron detection efficiency has been validated through simultaneous measurements of a transmitted electron signal, achieved by implanting through thin lamellae. The ion placement precision has been determined through imaging of ion induced damage on highly oriented pyrolytic graphite (HOPG) surfaces. Much work has taken place maximizing the detection efficiency for secondary electrons and investigating the factors which affect the SE yield.

Currently the system is running with Bi source, and there are In sources available. Alongside the development of the instrument there is also research into developing a series of liquid-metal ion sources for elements with optical and quantum applications including P, Te, Se and Cd. A second SIMPLE tool has also been installed at the UK National Ion Beam Centre, which operates with a 20kV duoplasmatron arc source, capable of 50nm spot sizes. SIMPLE #2 will initially operate with nitrogen source for the fabrication of NV centres in diamond.