High sensitivity vanadium–vanadium pentoxide–aluminium metal–insulator–metal diode

Abstract

This work reports on the fabrication of an improved sensitivity metal-insulator-metal (MIM) diode. They devise an asymmetric structure diode that cascades vanadium, vanadium pentoxide, and aluminium (V-V 2 O 5-Al) thin film layers. The MIM diode is fabricated using electron-beam lithography, sputter deposition and metal liftoff techniques. X-ray photoelectron spectroscopy analysis is performed to determine the phase composition of the V 2 O 5 insulating thin film. Electrical characterisation of the fabricated V-V 2 O 5-Al shows a clear high sensitivity at −316 mV that reaches −8.52 V −1 with a dynamic resistance of 5.024 kΩ.

Oxides for Rectenna Technology

“…Other oxides that have been considered for inclusion in MIM diodes include ZnO [81,82], V 2 O 5 [20,83], SiO 2 [84,85], Nb 2 O 5 [86,87], CuO [8], TiO 2 [69], Cr 2 O 3 [88], HfO 2 [89] and Sc 2 O 3 [90]. A simple process for fabricating planar-type MIM tunneling diodes using electron beam writing and a boiling water oxidation process has been proposed, achieving high diode sensitivity of −31 V −1 for Poly Si/PolySi [85] and −14.5 V −1 for PolySi/Au electrodes [84] but too high R 0 .…”

“…The constraint of only growing a derivative oxide layer of the underlying polycrystalline metal can be resolved by directly depositing an insulator on the bottom metal electrode using different deposition techniques and thus facilitating the use of any type of bottom metal electrode irrespective of its native oxide formation properties. These deposition techniques include sputtering [14,17,20,27,28,45,51,59,74,80,83,90,97,98], electron beam evaporation [88] and atomic layer deposition [8,9,18,30,51,56,58,75,81,89,96,[99][100][101], as listed in Tables 2 and 3. Among these techniques, ALD offers the best quality oxides with low defect density, excellent conformality and uniformity.…”

“…The selection of materials for both metals and insulators as well as the insulator thickness control the diode electrical characteristics. A selection of typical metals that have been used in MIM diode fabrication is shown in Figure 2 and Table 1 with values of work function as reported in the literature [11][12][13][14][15][16][17][18][19][20]. At terahertz frequencies, the metal conductivity decreases, hence the skin effect should be considered.…”

“…Furthermore, conductive oxides (indium tin oxide (ITO) and SrRuO3 (SRO)) and nitrides (TiN and NbN, see References in [29]) as well as multicomponent amorphous metals (ZCAN (ZrCuAlNi) and TiAl3) [18,30,31] can also act as electrodes in MIM diodes. [11][12][13][14][15][16][17][18][19][20] for typical metals used in a rectenna.…”

“…Furthermore, the reported measured values of oxide band gap (Table 1) are found to vary depending on the stoichiometry and structural properties (amorphous, crystalline, polycrystalline) of films fabricated by different deposition techniques. As can be seen from Table 1, the band gap of amorphous [11][12][13][14][15][16][17][18][19][20] for typical metals used in a rectenna. is likely to be related to the variations in fabrication conditions.…”