High Dielectric Constant ZrO2 Films by Atomic Layer Deposition Technique on Germanium Substrates

• Published in: SILICON Vol. 8; no. 3; pp. 345 - 350
• Main Authors: Mahajan, A. M., Khairnar, Anil G., Thibeault, B. J.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-07-2016; Springer Nature B.V
• Subjects: Atomic layer epitaxy; Bilayers; Chemistry; Chemistry and Materials Science; Current voltage characteristics; Electrical measurement; Electron beams; Environmental Chemistry; Germanium; Inorganic Chemistry; Lasers; Materials Science; Materials substitution; Metallizing; MOS devices; Optical Devices; Optics; Original Paper; Photonics; Polymer Sciences; Substrates; Thin films; Titanium; Zirconium dioxide; Electrical properties; Thin Films; ZrO; X-ray difraction; Ellipsometry
• ISSN: 1876-990X; 1876-9918
• DOI: 10.1007/s12633-015-9322-7

Germanium has been reconsidered as a potential substitute channel material for high-performance MOSFETs due to its intrinsic high mobilities for both electrons (3900 cm
2
s
-1
V
-1
) and holes (1900 cm
2
s
-1
V
-1
). In the present work we have fabricated Pt/Ti metal bilayered ALD-ZrO
2
/n-Ge based MOS capacitors. The ZrO
2
thin film was deposited on n-Ge (100) substrates by using ZrEMA and oxygen precursors at 300
°
C in a PEALD system. The Pt/Ti bilayer metallization was carried out using e-beam evaporation and PMA using a RTA system at 350
°
C in the forming gas. The thickness of the ZrO
2
gate stack was measured to be 3.61 nm using an ellipsometer. The electrical study was done by analyzing capacitance voltage and current voltage measurements. The flat-band shift was found to be 0.22 V, Q
eff
was 3.55×10
12
cm
-2
and D
it
was 8.53×10
12
cm
-2
eV
-1
. Current voltage characteristics have been analyzed to know the conduction mechanism in fabricated MOS devices.