Electrical Properties of the La₂O₃/4H-SiC Interface Prepared by Atomic Layer Deposition Using La(iPrCp)₃ and H₂O

Abstract

The La2O3 and Al2O3/La2O3 layers were grown on 4H-SiC by atomic layer deposition (ALD) method. The electrical properties of La2O3 on 4H-SiC were examined using metal-insulator-semiconductor (MIS) structures of Pt/La2O3(18nm)/4H-SiC and Pt/Al2O3(10nm)/La2O3(5nm)/4H-SiC. For the Pt/La2O3(18nm)/4H-SiC structure, even though the leakage current density was slightly reduced after the rapid thermal annealing at 500 oC, accumulation capacitance was gradually increased with increasing bias voltage due to a high leakage current. On the other hand, since the leakage current in the accumulation regime was decreased for the Pt/Al2O3/La2O3/4H-SiC MIS structure owing to the capped Al2O3 layer, the capacitance was saturated. But the saturation capacitance was strongly dependent on frequency, indicating a leaky interfacial layer formed between the La2O3 and SiC during the fabrication process of Pt/Al2O3(10nm)/ La2O3(5nm)/ 4H-SiC structure.

Physical characterization of post-deposition annealed metal-organic decomposed cerium oxide film spin-coated on 4H-silicon carbide

“…One approach to overcome this is to replace the relatively low-k nitrided-SiO 2 with a gate oxide with higher k value [1]. Numerous high-k gate oxides, such as Al 2 O 3 [21][22][23][24], La 2 O 3 [25], HfO 2 [26][27][28], Gd 2 O 3 [29], AlN [30], and ZnO [31], have been deposited on SiC substrate to reduce the electric field in the oxides.…”

Structural and Insulating Behaviour of High-Permittivity Binary Oxide Thin Films for Silicon Carbide and Gallium Nitride Electronic Devices

“…In summary, among the pure high-κ oxides, Al2O3 thin films represent the bes promise, especially in combination with a very thin SiO2 interfacial layer. Some po Few other papers have been dedicated to thin films of simple high-κ oxides such as La 2 O 3 [59,60], Ta 2 O 5 [61], or TiO 2 [62], which, when directly grown on 4H-SiC, showed analogous results as in the case of simple HfO 2 oxide. Generally, they demonstrated good dielectric constant values, but their high interface state density and low breakdown voltages made them still far from possible implementation in real devices.…”

“…This latter is schematically depicted in Figure 4, showing that the presence of the OH species on the SiO2 surface favours the nucleation process by increasing the number of nucleation sites and the formation of denser Al2O3 films. Other high-κ oxides have been also grown on SiC substrates as thin amorphous films, such as HfO 2 [56][57][58], La 2 O 3 [59,60], Ta 2 O 5 [61], and TiO 2 [62]. Among these materials, HfO 2 thin films have been widely investigated because of their superior theoretical properties, such as much higher permittivity.…”

“…Nevertheless, after the annealing ment at 800 °C in N2, the nanolaminated stack showed an improvement of the die properties, since the dielectric constant value increased to 13.4 and the Not value dec to 1.15 × 10 12 cm −2 . Few other papers have been dedicated to thin films of simple high-κ oxides s La2O3 [59,60], Ta2O5 [61], or TiO2 [62], which, when directly grown on 4H-SiC, sh analogous results as in the case of simple HfO2 oxide. Generally, they demonstrated dielectric constant values, but their high interface state density and low breakdow ages made them still far from possible implementation in real devices.…”

“…Moreover, other high-κ binary oxides with larger band gaps and more favourable band alignment with SiC, such as Al 2 O 3 [101], La 2 O 3 [59,103], and ZrO 2 [104,105], have been investigated.…”