THE FABRICATION AND CHARACTERIZATION OF METAL-OXIDE-SILICON CAPACITORS AND FIELD-EFFECT TRANSISTORS USING Dy₂O₃ AND Sm₂O₃ GATE DIELECTRICS

ABSTRACT

Metal-oxide-semiconductor (MOS) capacitors and transistors with Sm₂O₃ and Dy₂O₃ gate dielectrics were fabricated. The effective electron mobilities of Sm₂O₃-and Dy₂O₃-gated transistors were 211 and 251 cm²/V-s, respectively. The conduction mechanism in Sm₂O₃ films was also studied. The conduction mechanism in the electrical field of 0.1 MV/cm < E < 0.8 MV/cm and in the temperature range of 325 K < T < 500 K was found to be Schottky emission. At 77 K and with the electrical field above 0.9 MV/cm, the conduction mechanism was Fowler-Nordheim tunneling. The surface roughnesses at the high-k/Si interface after various annealing processes were measured by atomic force microscope.

Keywords:

• Conduction mechanism
• Schottky emission
• Fowler-Nordheim tunneling
• surface roughness
• Sm₂O₃
• Dy₂O₃

ACKNOWLEDGMENT

The authors would like to that the National Science Council, Taiwan, Republic of China for supporting this work under Contract No. NSC94-2215-E-007-027.