RT info:eu-repo/semantics/conferenceObject
T1 CONTROLLING DOPING PROFILES OF SILICON NANOWIRES FOR QUANTUM COMPUTING AND PHOTOVOLTAICS USING MICRO-RAMAN SPECTROSCOPY
A1 Serrano Gutierrez, Jorge
A1 Hinojosa Chasiquiza, Vanessa Giselle
A1 Mediavilla, Irene
A1 Jiménez López, Juan Ignacio
A1 Bricio, David
A1 Pérez-Murano, Francesc
A1 Bausells, Joan
A1 Antoja-Lleonart, Jordi
A1 Llobet, Jordi
A1 Bassani, Franck
A1 Baron, Thierry
A1 Bassem, Salem
K1 qubits, semiconductor, silicon, doping, Raman
AB Silicon technology has been the cornerstone for the advance of the current age of information since theinception of the first transistor, due to an exponential development of microelectronics and chipminiaturization. Based on this success, some of the emerging technologies in photovoltaics and quantumcomputing are being developed using silicon nanowires as a fundamental building block. In the case ofphotovoltaics, p-n axial and core-shell junctions in Si nanowires allow the integration of silicon technologywith other materials and thus a potential larger solar cell efficiency [1]. In quantum computing, siliconnanowires serve as one of the semiconducting platforms for qubit development by controlling the electronspin levels using a tailored selected doping and voltage in gates that split the nanowire into different quantumdots [2]. In both scenarios it is of paramount importance to control several key parameters, among them thedopant concentration in the nanowire, the stress, and the concentration of defects. They can all affect theoperation of the corresponding device and result in critical failure or lack of reliability. Accessing theseparameters with nanoscale resolution has been a challenge for spectroscopic techniques due to the diffractionlimit of currently widespread optical spectroscopy. We present here a characterization using micro-Ramanimaging and tip-enhanced Raman spectroscopy (TERS) that shows the potential of these techniques todetermine the doping profile of silicon nanowires in both p-n junctions and silicon nanostructures for qubits,and to distinguish doping effects from others such as the presence of strain, crystal grains, and defects. Highdopant concentrations lead to Fano asymmetric line shape of the Raman spectrum of silicon with anasymmetry parameter proportional to the dopant concentration and character – p- or n-type doping [3].Confinement of the electric field due to the nanoscale diameter of the nanowires results in an enhancement ofthe Raman signal that yields higher resolution than that expected without this antenna effect. Thisenhancement allows us to employ micro-Raman spectroscopy successfully to distinguish several of theabove mentioned effects in nanostructures. In the case of p-n axial junctions in silicon nanowires, we observean asymmetry with higher spectral weight in the low and high energy side for p-type and n-type doping,respectively, being the effect more pronounced in the case of p-type doping. This effect is more significantfor doping concentrations above 1017 cm-3. In the case of nanostructured silicon for qubits we observeresidual strain and crystallite grain boundaries close to the nanowire, tentatively attributed to the presence ofWe analyze the Raman spectra employing several asymmetric functions and compare the results obtained innanowires with those reported in the literature and achieved in bulk silicon as a function of doping. Finally,we employ TERS to reach nanoscale spatial resolution and compare the accuracy and limitations ofmicro-Raman in the determination of the doping profile.
PB Acta Microscopica
YR 2023
FD 2023
LK https://uvadoc.uva.es/handle/10324/66797
UL https://uvadoc.uva.es/handle/10324/66797
LA eng
NO Nanoscience Summer School @ Yachay 2023, Puerto Ayora, Galapagos 23th-29th April 2023
NO Producción Científica
DS UVaDOC
RD 19-dic-2024