A high-resolution measurement system for novel scanning thermal microscopy resistive nanoprobes

Abstract

In this paper, a scanning thermal microscopy (SThM) module with a modified Wheatstone bridge is presented. It is intended to be used with a novel four-terminal thermoresistive nanoprobe, which was designed for performing thermal measurements in standard static-mode atomic force microscopes. The modified Wheatstone bridge architecture is also compared to a Wheatstone bridge and a Thomson bridge in terms of their temperature measurement sensitivities. In fixed conditions, they are found to be (7.05 ± 0.04) μV K−1 for the modified Wheatstone, while (5.43 ± 0.06) μV K−1 for the Wheatstone and (0.91 ± 0.09) μV K−1 for the Thomson bridge. The usability of the three set-ups with four-terminal nanoprobes is also discussed. The design of devices included in the module is presented and the noise level of the modified Wheatstone bridge is estimated. A proportional–integral–derivative controller for active-mode SThM is also introduced.

Scanning Thermal Microscopy (SThM)

“…The most general one is to consider the type of phenomenon that is involved in recording any type of image, usually beginning with the surface shape (i.e., the topography Figure 2 Schematic of an AFM measurement system with optical detection of the deflection of the cantilever, in which it is the microprobe that is mounted on the piezoelectric scanner (see also Wielgoszewski et al, 2011b).…”

“…The many papers on applications of SThM published since 1995 have been accompanied by works on new probe types (Luo, Shi, Varesi, & Majumdar, 1997;Mills, Zhou, Midha, Donaldson, & Weaver, 1998;Janus et al, 2010;Zhang, Dobson, & Weaver, 2011;Tovee, Pumarol, Zeze, Kjoller, & Kolosov, 2012;Janus et al, 2014;Hofer et al, 2015), calibration methods (Lefèvre, Saulnier, Fuentes, & Volz, 2004;Dobson, Mills, & Weaver, 2005;Wielgoszewski, Babij, Szeloch, & Gotszalk, 2014), and attempts to improve the SThM technique itself (Oesterschulze & Stopka, 1996;Pollock & Hammiche, 2001;Kim et al, 2008;Wielgoszewski et al, 2011b;Juszczyk, Wojtol, & Bodzenta, 2013). To date, the greatest impact on the development of AFM-based thermal analysis comes from the following elements: • Development of microthermal analysis (μTA) (Pollock & Hammiche, 2001) and the closely related development of doped-silicon probes (discussed in the section entitled "Thermoresistive SThM Probes," later in this chapter), which enabled localized calometric measurements.…”

“…The temperature of the tip is measured as a difference between the measurement tip and the reference tip. In this specific setup, described more thoroughly by Wielgoszewski et al (2011b), the signal from the current source comprises of two components: one for temperature measurement f meas % 10 kHz and the other for tip heating f heat 2 (0 Hz, 1 kHz). The amplitude ratio would generally be in the range of I heat : I meas 2 (10, 30).…”

“…This allows basic passive-and active-mode operation. However, more advanced modes would use ac voltage: it is required for 3ω-SThM operation, but it is also useful in standard P-SThM and A-SThM, where it would help to obtain a better signal-to-noise ratio (Wielgoszewski et al, 2011b). Additionally, combined dc and AC may offer more stable operation with high-current heating of the sample (Bodzenta, Juszczyk, & Chirtoc, 2013).…”

“…Simple dc-current Wheatstone bridges, which are used in commercial solutions, are accurate enough to provide basic thermal images. Nonetheless, the measurement resolution and accuracy can be improved by enhancing the probe design [e.g., by using four connections, as did Aubry et al (2007); Janus et al (2010Janus et al ( , 2014] or the measurement setup Wielgoszewski et al, 2011b;Bodzenta et al, 2013). Another important advantage is that thermoresistive probes can be utilized in both P-SThM and A-SThM modes, as the thermoresistor can be used easily as a heat source.…”