Platinum-assisted post deposition annealing of the n-Ge/Y2O3 interface

• Published in: Semiconductor science and technology Vol. 31; no. 7
• Main Authors: Zimmermann, C, Bethge, O, Lutzer, B, Bertagnolli, E
• Format: Journal Article
• Language: English
• Published: IOP Publishing 13.06.2016
• Subjects: electrical characterization; high-k oxide; MOS-capacitors; Pt-assisted PDA; XPS
• ISSN: 0268-1242; 1361-6641
• DOI: 10.1088/0268-1242/31/7/075009

The impact of annealing temperature and annealing duration on the interface properties of n-Ge/Y2O3/Pt MOS-capacitors is investigated employing an ultrathin catalytically acting Pt-layer. X-ray photoelectron spectroscopy analysis has been used to verify an enhanced growth of GeO2 and thermally stabilizing yttrium germanate at the n-Ge/Y2O3 interface induced by an oxygen post deposition annealing (PDA). Especially at 500 °C and 550 °C high quality Ge/Y2O3 interfaces have been achieved resulting in very low interface trap density of 7.41*1010 eV−1 cm−2. It is shown that either a short oxygen annealing at higher temperatures (550 °C) or a long time annealing at lower temperatures (450 °C) are appropriate to realize low interface trap density (Dit). It turns out that a Pt-assisted PDA in combination with a final PMA are needed to reduce hysteresis width significantly and to bring flat band voltages toward ideal values.