Amorphous ternary rare-earth gate oxides for future integration in MOSFETs

• Published in: Microelectronic engineering 2009-07, Vol.86 (7), p.1646-1649
• Main Authors: Lopes, J.M.J., Durğun Özben, E., Roeckerath, M., Littmark, U., Lupták, R., Lenk, St, Luysberg, M., Besmehn, A., Breuer, U., Schubert, J., Mantl, S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Electrical properties; Electronics; Exact sciences and technology; High- k gate dielectrics; Higher- k gate dielectrics; Microelectronic fabrication (materials and surfaces technology); Rare-earth based gate oxides; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Ternary high- k oxides; Transistors
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2009.03.065

In this contribution we present results on the structural and electrical properties of amorphous REScO 3 ( RE = La, Gd, Tb, Sm) and LaLuO 3 thin films. The study reveals that these oxides are potential candidates for so-called higher- k dielectrics for forthcoming MOSFET generations. High dielectric constants up to 32, low leakage currents and low interface trap densities are determined for amorphous thin films prepared by pulsed-laser deposition, molecular beam deposition and e-gun evaporation. Moreover, we show that LaLuO 3 gate stacks annealed up to 1050 °C maintain low leakage current densities without substantial EOT increase. Finally, promising results for n-MOSFETs with GdScO 3 as gate dielectric processed on strained silicon-on-insulator substrates are also shown.