Modulation of the band offsets between La2Hf2O7 and fully depleted SiGe on insulator by NH3 treatment

Abstract

Band alignments of La2Hf2O7 (LHO) films grown on fully depleted SiGe on insulator (FD SGOI) substrates have been investigated by x-ray photoelectron technique. The valence and conduction band offsets for LHO/FD SGOI systems are determined to be 3.25 and 1.49 eV, respectively. Such asymmetric band alignment can be modulated to be quite symmetric by the surface nitridation of FD SGOI using NH3 treatment. The impact of NH3-treatment temperature on band offsets is also investigated.

Progress of High-k Dielectrics Applicable to SONOS-Type Nonvolatile Semiconductor Memories

“…In order to overcome these problems, higher permittivity (k) materials, which allows an equivalent capacitance to be achieved using a physically thicker insulating layer, can replace the conventional SiO 2 gate dielectric to realize further scaling down. Therefore, in the past several years, much attention have been given to alternative high-k dielectric oxides such as silicates (e.g., Zr and Hf silicate [27,28]), single metal oxides (e.g., HfO 2 [29], ZrO 2 [30], Al 2 O 3 [31], La 2 O 3 [32], Pr 2 O 3 [33], Y 2 O 3 [34], Gd 2 O 3 [35], Nd 2 O 3 [36]), and binary metal oxides [37][38][39][40]. In order to meet the requirements of CMOS field effect transistors, the high-k dielectrics should satisfy some requirements, as summarized in the Table 1 [41].…”