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F. Triendl, G. Pfusterschmied, S. Schwarz, G. Pobegen, J. Konrath, U. Schmid:
"Barrier height tuning by inverse sputter etching at poly-Si/4H-SiC heterojunction diodes";
Semiconductor Science and Technology, 36 (2021), 055021; 1 - 8.

Si/4H-SiC heterojunction diodes (HJDs) are fabricated by applying Ar+inverse sputter etching
(ISE) of the 4H-SiC substrate prior to Si deposition. A subsequent annealing step was used to
crystallize the sputter deposited amorphous Si. Numerical simulations and experiments were
conducted to investigate the amorphization depth and etch rate of low energy Ar+ions on the
Si-face of 4H-SiC. Electrical characterization of the HJDs showed a strong influence of the ISE
treatment in both n and p-type Si contacts compared to untreated diodes. The ISE power, as well
as the ISE time can be tailored to adjust the Schottky barrier height (SBH) in a certain range,
by simultaneously improving the device ideality for most ISE parameters compared to diodes
without any ISE treatment. In addition, the homogeneity of the SBHs is improved, resulting in
less variation over temperature and between different samples. The formation of a smooth
Si-SiC transition region instead of a sharp interface is found after both ISE treatment and
thermal annealing.

http://dx.doi.org/10.1088/1361-6641/abf29b