Two-dimensional dopant profiling by electrostatic force microscopy using carbon nanotube modified cantilevers

Abstract

A two-dimensional (2D) dopant profiling technique is demonstrated in this work. We apply a unique cantilever probe in electrostatic force microscopy (EFM) modified by the attachment of a multiwalled carbon nanotube (MWNT). Furthermore, the tip apex of the MWNT was trimmed to the sharpness of a single-walled carbon nanotube (SWNT). This ultra-sharp MWNT tip helps us to resolve dopant features to within 10 nm in air, which approaches the resolution achieved by ultra-high vacuum scanning tunnelling microscopy (UHV STM). In this study, the CNT-probed EFM is used to profile 2D buried dopant distribution under a nano-scale device structure and shows the feasibility of device characterization for sub-45 nm complementary metal-oxide-semiconductor (CMOS) field-effect transistors.

Quantitative phase‐mode electrostatic force microscopy on silicon oxide nanostructures

“…For instance, the charge distribution in finite size systems (Yalcin et al ., 2012; Roy‐Gobeil et al ., 2015; Miyahara et al ., 2017), even in the presence of spatial, compositional and energy disorder (El Khoury, 2017), can be visualized by these techniques. Local electrostatic techniques provide information on the 2D spatial distribution of charge carriers in semiconductors (Chin et al ., 2008; Musumeci et al ., 2017), nanostructures (Krauss & Brus, 1999; Cherniavskaya et al ., 2003; Marchi et al ., 2008; Borgani et al ., 2016) and devices (Pingree et al ., 2009) and, more recently, in volume (3D) (Collins et al ., 2015; Fabregas & Gomila, 2020) and in time (Araki et al ., 2019; Borgani & Haviland, 2019; Mascaro et al ., 2019). These techniques were proven useful in studying the localization of trapped charges in thin films (Silveira & Marohn, 2004; Chen et al ., 2005a; Chen et al ., 2005b; Muller & Marohn, 2005), quantum dots (Tevaarwerk et al ., 2005) and nanotubes (Chin et al ., 2008); to measure the resistance at metal–semiconductor interfaces and grain boundaries in operating devices (Annibale et al ., 2007); to relate electrical properties, such as dielectric permittivity (Gramse et al ., 2009; El Khoury et al ., 2016; Fumagalli et al ., 2018), conductivity (Castellano‐Hernández & Sacha, 2015; Aurino et al ., 2016), piezoelectricity (Moon et al ., 2017) and percolation pathways (Barnes & Buratto, 2018), directly to the organization of the material at the mesoscopic length scales.…”

High Throughput Nanofabrication of Silicon Nanowire and Carbon Nanotube Tips on AFM Probes by Stencil-Deposited Catalysts

“…This can, however, be improved through sharpening during growth. 16 If the CNT is opened at the tip, the free carbon bonds are excellent for functionalization used for chemical AFM, as shown by Hafner et al, where a carboxyl group was used to detect changes in surface chemistry. 7 If the CNTs have a nickel particle at the apex, they could be used for magnetic force microscopy.…”

“…Stevens et al reported that CNTs with very high aspect ratios collapse onto the probe support when penetrating the air−liquid interface, due to the their high hydrophobicity, which turned out to be solvable by a hydrophilic coating. , The lateral resolution of MWNT probe tips is generally determined by the diameter of the catalyst particle from which the nanotube is grown. This can, however, be improved through sharpening during growth …”

Electrostatic Force Microscopy and Kelvin Force Microscopy as a Probe of the Electrostatic and Electronic Properties of Carbon Nanotubes

“…An example of such a probe [16] is given in Fig. Adapted from [16] As can be obviously seen from Sect. Transmission electron microscopy image of a cantilever tip modified with a glued multiwalled carbon nanotube.…”

“…4.4, showing a multiwalled carbon nanotube tip mounted on a standard AFM cantilever tip. 4.2.3, such a high-aspect ratio tip is ideal to reduce parasitic effects associated with side capacitances, leading to increased lateral resolution, which has been demonstrated in the case of dopant profiling [16], and on contact potential measurements on biased Al/Al 2 O 3 /Al junctions [17] as well as on bundles of nanotubes [17] or individual MWCNT [18]. Adapted from [16] As can be obviously seen from Sect.…”