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

Abstract

High-κ dielectrics are insulating materials with higher permittivity than silicon dioxide. These materials have already found application in microelectronics, mainly as gate insulators or passivating layers for silicon (Si) technology. However, since the last decade, the post-Si era began with the pervasive introduction of wide band gap (WBG) semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), which opened new perspectives for high-κ materials in these emerging technologies. In this context, aluminium and hafnium oxides (i.e., Al2O3, HfO2) and some rare earth oxides (e.g., CeO2, Gd2O3, Sc2O3) are promising high-κ binary oxides that can find application as gate dielectric layers in the next generation of high-power and high-frequency transistors based on SiC and GaN. This review paper gives a general overview of high-permittivity binary oxides thin films for post-Si electronic devices. In particular, focus is placed on high-κ binary oxides grown by atomic layer deposition on WBG semiconductors (silicon carbide and gallium nitride), as either amorphous or crystalline films. The impacts of deposition modes and pre- or postdeposition treatments are both discussed. Moreover, the dielectric behaviour of these films is also presented, and some examples of high-κ binary oxides applied to SiC and GaN transistors are reported. The potential advantages and the current limitations of these technologies are highlighted.

FROM Si NANOWIRES TO Ge NANOCRYSTALS FOR VIS-NIR-SWIR SENSORS AND NON-VOLATILE MEMORIES: A REVIEW

“…enhanced data retention and lower operation voltage, and thus being suitable for small devices and high density NVMs [92]. One problem related to high-κ oxides is that they have higher electronic defect density because their chemical bonds cannot easily relax, in contrast to SiO2 with low coordination number that favors the healing/repairing of dangling bonds [93]. However, the quality of high-κ oxide layers regarding to electronic defects density can be improved by conducting deposition and annealing treatments under controlled conditions.…”

SiGeSn Quantum Dots in HfO2 for Floating Gate Memory Capacitors

“…is the atomic composition of the SiGe target (provided by Kurt J. Lesker Company Ltd., East Sussex, Hastings, United Kingdom). In this work, we will present results on structures M1 and M2 with slightly different designed thicknesses of 16 Finally, MOS capacitors are obtained by depositing top and bottom Al electrodes using thermal evaporation. Shadow masks with 1 mm × 1 mm areas were used for top Al contacts deposition.…”

“…As embedding matrix and gate oxide, the high-k dielectric HfO 2 is suitable to be used in high-density NVMs. HfO 2 is already used in the CMOS industry due to its high CMOS compatibility and high scalability [15], and shows potential as a gate dielectric layer for post-Si electronic devices as well [16]. HfO 2 is also promising for integrated ferroelectric memory devices due to nanoscale ferroelectricity [17,18].…”

Ground-State Structure of Quaternary Alloys (SiC)1−x (AlN)x and (SiC)1−x (GaN)x

“…Materials known as III-V binary nitrides (III-N = AlN, SiC, and GaN) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ] and their related alloys have recently drawn attention owing to their outstanding optoelectronic properties making them useful for many practical applications, such light-emitting diode lasers (LEDs). The reasons for their successful application are their plethora of physical characteristics, such as their small lattice parameter, large direct bandgap, high hardness, high temperature stability, good piezoelectric properties, and polytypism.…”