The Current Status and the Future Prospects of Surface Passivation in 4H-SiC Transistors

Siddiqui, Amna; Elgabra, Hazem; Singh, Shakti

doi:10.1109/tdmr.2016.2587160

Cited by 28 publications

(7 citation statements)

References 54 publications

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“…[19][20][21][22][23] Among these methods, annealing in N 2 O ambient has been found to be the most effective technique. 24 However, recent reports on the impact of phosphorus pentoxide (P 2 O 5 ) depositions as a surface passivation for SBDs and MOSFETs 18,[25][26][27] have shown an improvement both in leakage current densities for SBDs and in channel mobility for transistors. As this treatment also improved the on-state performance of the measured devices, the benefits of nitridation prior to metallization of SBDs were exceeded.…”

Section: Introductionmentioning

confidence: 99%

The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment

Renz

Shah

Vavasour

et al. 2020

Journal of Applied Physics

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Molybdenum (Mo)/4H-silicon carbide (SiC) Schottky barrier diodes have been fabricated with a phosphorus pentoxide (P 2 O 5 ) surface passivation treatment performed on the SiC surface prior to metallization. Compared to the untreated diodes, the P 2 O 5 -treated diodes were found to have a lower Schottky barrier height by 0.11 eV and a lower leakage current by two to three orders of magnitude. Physical characterization of the P 2 O 5 -treated Mo/SiC interfaces revealed that there are two primary causes for the improvement in electrical performance. First, transmission electron microscopy imaging showed that nanopits filled with silicon dioxide had formed at the surface after the P 2 O 5 treatment that terminates potential leakage paths. Second, secondary ion mass spectroscopy revealed a high concentration of phosphorus atoms near the interface. While only a fraction of these are active, a small increase in doping at the interface is responsible for the reduction in barrier height. Comparisons were made between the P 2 O 5 pretreatment and oxygen (O 2 ) and nitrous oxide (N 2 O) pretreatments that do not form the same nanopits and do not reduce leakage current. X-ray photoelectron spectroscopy shows that SiC beneath the deposited P 2 O 5 oxide retains a Si-rich interface unlike the N 2 O and O 2 treatments that consume SiC and trap carbon at the interface. Finally, after annealing, the Mo/SiC interface forms almost no silicide, leaving the enhancement to the subsurface in place, explaining why the P 2 O 5 treatment has had no effect on nickel-or titanium-SiC contacts.

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Section: Introductionmentioning

confidence: 99%

The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment

Renz

Shah

Vavasour

et al. 2020

Journal of Applied Physics

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“…There have been a number of efforts focused on the reduction of D it at the SiO 2 /SiC interface through various engineering efforts, which have been summarized by Amna et al [3]. Among them, the lowest number of <10 11 cm −2 eV −1 of D it was achieved through post-oxidation annealing in oxygen at 800 °C [4].…”

Section: Introductionmentioning

confidence: 99%

Influence of annealing environment on the ALD-Al₂O₃/4H-SiC interface studied through XPS

Usman

Arshad

Suvanam

et al. 2018

J. Phys. D: Appl. Phys.

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The instability of Al2O3/4H-SiC interface at various process temperatures and ambient is investigated by the annealing of Al2O3/4H-SiC in low vacuum conditions as well as in N2 environments. Atomic layer deposited Al2O3 on a 4H-SiC substrate with 3, 6 and 10 nm of thicknesses is treated at 300, 500, 700 and 900 °C under the vacuum level of 10−1 torr. The as-deposited and annealed structures are analyzed using x-ray photoelectron spectroscopy. It is hypothesized that the minute quantity of oxygen present in low vacuum conditions diffuses through thin layers of Al2O3 and helps in forming SiO2 at the interface even at low temperatures (i.e. 300 °C), which plays a pivotal role in determining the electrical properties of the interface. It is also proved that the absence of oxygen in the ambient prevents the formation of SiO2 at low temperatures. Additionally, it is observed that Al–OH is present in as-deposited layers, which gradually reduces after annealing. However, at around 700 °C, the concentration of oxygen in the whole structure increases to maximum and reduces at 900 °C.

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“…Concerning the wet chemical cleaning of SiC, a very strong background knowledge obtained in the Si technology can be applied also in SiC processing. Furthermore, SiO 2 is a natural oxide for SiC but the SiC oxidation has been found to cause higher interface defect density as compared SiO 2 /Si [236][237][238]342]. However, including nitrogen at SiO 2 /SiC has been found to lead to a highly crystalline SiON/SiC interface (figure 19), which is also surprisingly stable in air [343][344][345].…”

Section: Is It Possible To Avoid High-temperature Degradation Of Sic ...mentioning

confidence: 99%

Bridging the gap between surface physics and photonics

Laukkanen,

Punkkinen,

Kuzmin

et al. 2024

Rep. Prog. Phys.

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Use and performance criteria of photonic devices increase in various application areas such as information and communication, lighting, and photovoltaics. In many current and future photonic devices, surfaces of a semiconductor crystal are a weak part causing significant photo-electric losses and malfunctions in applications. These surface challenges, many of which arise from material defects at semiconductor surfaces, include signal attenuation in waveguides, light absorption in light emitting diodes, non-radiative recombination of carriers in solar cells, leakage (dark) current of photodiodes, and light reflection at solar cell interfaces for instance. To reduce harmful surface effects, the optical and electrical passivation of devices has been developed for several decades, especially with the methods of semiconductor technology. Because atomic scale control and knowledge of surface-related phenomena have become relevant to increase the performance of different devices, it might be useful to enhance the bridging of surface physics to photonics. Toward that target, we review some evolving research subjects with open questions and possible solutions, which hopefully provide example connecting points between photonic device passivation and surface physics. One question is related to the properties of the wet chemically cleaned semiconductor surfaces which are typically utilized in device manufacturing processes, but which appear to be different from crystalline surfaces studied in ultrahigh vacuum by physicists. In devices, a defective semiconductor surface often lies at an embedded interface formed by a thin metal or insulator film grown on the semiconductor crystal, which makes the measurements of its atomic and electronic structures difficult. To understand these interface properties, it is essential to combine quantum mechanical simulation methods. This review also covers metal-semiconductor interfaces which are included in most photonic devices to transmit electric carriers to the semiconductor structure. Low-resistive and passivated contacts with an ultrathin tunnelling barrier are an emergent solution to control electrical losses in photonic devices.

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The Current Status and the Future Prospects of Surface Passivation in 4H-SiC Transistors

Cited by 28 publications

References 54 publications

The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment

The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment

Influence of annealing environment on the ALD-Al₂O₃/4H-SiC interface studied through XPS

Bridging the gap between surface physics and photonics

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The Current Status and the Future Prospects of Surface Passivation in 4H-SiC Transistors

Cited by 28 publications

References 54 publications

The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment

The improvement of Mo/4H-SiC Schottky diodes via a P2O5 surface passivation treatment

Influence of annealing environment on the ALD-Al2O3/4H-SiC interface studied through XPS

Bridging the gap between surface physics and photonics

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Product

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Influence of annealing environment on the ALD-Al₂O₃/4H-SiC interface studied through XPS