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Abstract: SiO2 encapsulation layer was studied for aluminum (Al) and phosphorus (P) implant activation anneal in 4H-SiC. Both Al- and P+ implantation were carried out at 650°C followed by activation anneal at 1400°C to 1500°C. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and four-point-probe (FPP) measurements were performed to examine surface stoichiometry, roughness, and sheet resistance of the implanted SiC regions. The effect of using SiO2 encapsulation layer for Al implant activation on the performance of 4H-SiC p-i-n diodes with both p-type active region and JTE region formed by Al implantation was also investigated. Forward and reverse characteristics including saturation current density J 0 , ideality factor η, reverser leakage current density J L and threshold breakdown voltage V BR have been extracted. The results show that SiO2 encapsulation effectively protects the SiC surface during high temperature implant activation for both Al- and P+. [ABSTRACT FROM AUTHOR]

Highlights • Y 2 O 3 /Al 2 O 3 stacking films on p-type 4H-SiC were studied for the first time. • High-k Y 2 O 3 /Al 2 O 3 provides thicker film with equivalent capacitance. • Y 2 O 3 /Al 2 O 3 exploits the high breakdown strength of 4H-SiC in MOSFET. • Post deposition annealing affects properties of Y 2 O 3 /Al 2 O 3. Abstract In this paper, the effect of post deposition annealing (PDA) on the chemical, structural, and electrical properties of the high-k Y 2 O 3 /Al 2 O 3 stacking dielectric on p-type 4H-SiC were studied. High-k dielectric provides a physically thicker film with equivalent capacitance, therefore better exploits the high breakdown strength of 4H-SiC in its MOSFET devices. The Y 2 O 3 /Al 2 O 3 stacking films were deposited using RF magnetron sputtering, with PDA in Ar ambient at 400 °C, 600 °C, 800 °C and 1000 °C. X-ray diffraction (XRD) and angle resolved X-ray photoelectron spectroscopy (XPS) results show that an Al 5 O 12 Y 3 crystal layer was formed in between Y 2 O 3 and Al 2 O 3 films after annealing above 600 °C. High resolution transmission electron microscope (HRTEM) was used to investigate the atomic structure and measure the thickness of each layer. Charges and dielectric strength of the stacking films were characterized by high frequency capacitance-voltage (C-V) and current-voltage (I-V) measurements. The lower charge density and higher dielectric strength were found after PDA at 800 °C and 1000 °C. [ABSTRACT FROM AUTHOR]