*1.2. MEMS Test Structure Description*

The MEMS test nanostructures were manufactured in the Polish Institute of Electron Technology. The structure consists of two parallel platinum resistors, which have lengths equal to 10 μm. The cross-sectional area of each resistor is a 100 nm square. Moreover, the distance between both resistors is also equal to 100 nm. They are placed on a thin layer of silicon dioxide, with a thickness of 100 nm. All layers are stacked on a 0.5 mm thick silicon wafer. A more detailed structure description can be found in Janicki et al. [33].

The test structure was bonded to a metal-core PCB characterized by high thermal conductivity. Moreover, the structure was connected to a biasing circuit, using high-frequency coaxial cables that were mounted to a tiny Hirose U.FL connector attached to the silicon die. Real photos of the analyzed structure, as well as the control circuit, are included in Janicki et al. [32,33].

During the measurement process, one of platinum resistors played a role of a heater, while the second one served as a temperature sensor. A detailed description of the measurement process of the test structure and obtained results is presented in [32,33].
