B1500a semiconductor parameter analyzer

All electrical measurements were carried out using a Signatone probe station and an Agilent B1500A semiconductor parameter analyzer. Laser diodes (Osram PLP520-B1 for 520 nm, LPC-826 for 650 nm, Thorlabs L808P200 for 808 nm, and Thorlabs L980P010 for 980 nm) were mounted onto the probe station and focused onto the sample. The laser power was controller by a DC power supply (Keithley 2450 Sourcemeter) in current source mode and measured using an optical power meter (Thorlabs PM100D and S121C). The size of the laser beam spot was intentionally made large enough to cover the whole channel region (100 × 200 μm²) of the device. The laser beam was projected onto a white paper with printed 1 mm × 1 mm grids and captured with a CCD camera mounted on the microscope for estimating the beam size and calculating the laser intensity. For the temperature measurement, the samples were attached to a Peltier heater, whose temperature was precisely controlled by a temperature controller (Thorlabs TED4015).

Experimental data have been taken from ref. 4 (link) where MIS capacitors were developed by spin–coating P(NDI2OD-T2) upon a gold bottom contact. The semiconductor was patterned^{22 (link)} to suppress the spurious effect of lateral carrier spreading^{23 (link)–25 (link)}. PMMA was then spin coated as insulator and Aluminum was evaporated as gate contact. MIS capacitors were measured by means of an Agilent E4980A Precision LCR Meter, applying to the gate an oscillation amplitude of 100 mV of variable frequency superimposed to a biasing constant voltage.
On the same substrate OTFTs were realized in a staggered, top–gate bottom–contact configuration with gold source and drain contacts and Al gate and a channel width and length of 10 mm and 10, 20, 40 μm. Transfer characteristic curves were measured applying a drain–to–source voltage of 5 V by means of Agilent B1500A Semiconductor Parameter Analyzer.

The morphology and thickness of the MoTe₂/SnS₂ vdW heterostructure were investigated using OM and AFM. Raman spectra were collected on a LabRam HR‐800 Raman spectrometer (Jobin Yvon), with a laser wavelength of 532 nm. Electrical measurements were performed under vacuum (<10⁻⁵ torr) in a cryogenic probe station (Lakeshore TTPX) with an Agilent B1500A semiconductor parameter analyzer.

The DC and pulse endurance of a self-selective cell were tested by an Agilent B1500A semiconductor parameter analyzer connected to the experimental device. The pulse measurements were performed using the HV-SPGU module of Agilent B1500A. During the electrical measurement, the W top electrode was biased, while the TiN bottom electrode was grounded.

The metal–insulator (double functional layer)–metal structure and the cross-sectional transmission electron microscopy (TEM) image of the Ta/TaO_x/Al₂O₃/Pd device are shown in Figure 1a,b, respectively. The fabrication process of the device is shown in Figure 1c. First, the Si substrate was cleaned with acetone, ethanol, and de-ionized water. 30 nm-thick Pd and 15 nm-thick Ta as the bottom electrode were deposited on the Si substrate by magnetron sputtering. A TaO_x layer was formed by rapid thermal annealing (RTA) carried out for 300 s in plasma O₂ by plasma-enhanced chemical vapor deposition (PECVD) at 275 °C. Direct oxygen plasma with a power of 100 W was applied on the Ta film. After RTA, 7 nm-thick Al₂O₃ was deposited by atom layer deposition (ALD). Finally, 40 nm Pd as the top electrode was deposited by magnetron sputtering after the lithography process. For our device, the highest temperature of the process is only 275 °C (below 400 °C), and all the materials (Pd, Ta, Al) were CMOS compatible. As a result, our device was fully CMOS compatible.
The DC electrical characteristics of the device were measured by an Agilent B1500A semiconductor parameter analyzer (Santa Rosa, CA, US). During the electrical measurement, the voltage was applied to the top Pd electrode, while the Ta/Pd bottom electrode was tied to ground.

Electrical measurements of the FTJs were performed using a Keithley 4200A-SCS semiconductor parameter analyzer (for I − V measurements) and Agilent B1500A semiconductor parameter analyzer (for C − V measurements) connected to a probe station under atmospheric pressure and at room temperature. For the BSO-based FTJs, source measurement units (SMUs) with preamplifiers were used in quasi-static electrical measurements, pulse measurement units (PMUs) with remote preamplifier (RPM)/switch modules were used for the pulsed measurements, and the multi-frequency capacitance measurement units (MFCMUs) were used for C − V measurements. During the measurements, the two probes were connected to the top electrode on BSO film and the NSTO substrate under BSO layer, respectively.