Scanning thermal microscopy based on a quartz tuning fork and a micro-thermocouple in active mode (2ω method)

Abstract

A novel probe for scanning thermal microscope using a micro-thermocouple probe placed on a Quartz Tuning Fork (QTF) is presented. Instead of using an external deflection with a cantilever beam for contact detection, an original combination of piezoelectric resonator and thermal probe is employed. Due to a non-contact photothermal excitation principle, the high quality factor of the QTF allows the probe-to-surface contact detection. Topographic and thermal scanning images obtained on a specific sample points out the interest of our system as an alternative to cantilevered resistive probe systems which are the most spread.

A Review on Principles and Applications of Scanning Thermal Microscopy (SThM)

“…More recently, Kim et al used SThM implemented in ultrahigh vacuum (UHV), which has the capability of quantitatively mapping temperature fields with high spatial resolution for thermocouple‐based probes. Bontempi et al attached an S‐type thermocouple on the quartz tuning fork (QTF) shown in Figure to replace the optical deflection detection unit of SThM, where shift of natural frequency of QTF could indicate the moment of contact.…”

“…Thermocouple probe integrated on a quartz tuning fork (QTF).The arrows point out to the thermocouple junction, which is made of Pt and Pt‐Rh10% wires with a tip diameter of ≈1.27 μm. Reproduced with permission . Copyright 2016, American Institute of Physics.…”

“…Other potential cantilevers are aforementioned piezoresistive cantilever whereby its deflection was converted to resistance change of the piezoresistive sensor integrated in the cantilever along with other microcircuits 38i,q. Another interesting idea of cantilever utilizes the mechanical dependence of natural frequency change of QTF as mentioned above . Overall, recognizing the importance cantilevers play in thermal management of SThM system is imperative for proper cantilever selection or design optimization in the future.…”

Low-Power Heating Platform for the Characterization and Calibration of Scanning Thermal Probes

“…Devices have been electro-thermally characterized by determining the temperature coefficient of the resistors (TCR = 0.00185 K −1 ) and by measuring temperature vs. power consumption using the SThM thermocouple probe presented in [2]. Figure 3 presents a scan result on the 1st design (temperature and topography maps) at 11 mW power supply and the temperature at the center of the device versus power.…”

“…Derived from Atomic Force Microscopes, they are able to operate in two complementary modes, either in passive mode for surface temperature measurements [1], or in active mode for thermal parameters estimation (thermal conductivity or diffusivity typically) [2]. However, none of these modes are reliable yet due to the complexity of the thermal interaction between the probe tip and a sample surface.…”