Interface engineering for Ge metal-oxide–semiconductor devices

Deposition and electrical characterization of hafnium oxide films on silicon

“…Many different deposition techniques have been used to form hafnium oxide on silicon substrate. We name MOCVD [2], CVD [3], ALD [4], MBE [5] and sputtering [6]. When the later has been used a hafnium film is usually first deposited that is subsequently oxidized to form the insulator.…”

Post deposition annealing studies of lanthanum aluminate and ceria high-k dielectrics on germanium

“…Rare earth oxides have the advantage that can be deposited directly on Ge showing good electrical characteristics [3,4] without the formation of an interfacial layer, as for example in the case of HfO 2 /GeON/nGe. As illustrated in Fig.…”

“…In addition, the GeON/HfO 2 system shows poor electrical characteristics, large hysteresis, frequency dispersion especially in inversion [2], and large ac conductance values. On the other hand, rare earth oxides could be considered as alternative passivating layers since they produce improved electrical characteristics [3,4].…”

Impacts of Ti on electrical properties of Ge metal–oxide–semiconductor capacitors with ultrathin high-k LaTiON gate dielectric

“…To overcome this problem, various techniques including NH 3 surface treatment [2][3][4][5] and Si interlayer [11,12] have been applied in Ge-based MOS devices to enhance device performances. Recently, it was reported that rare-earth metal oxides such as CeO 2 [13,14], Gd 2 O 3 [15] and Dy 2 O 3 [16] produced promising electrical properties when directly in contact with Ge. Especially, La 2 O 3 thin film shows many advantages, including low interface-states density, very small frequency dispersion and hysteresis due to formation of stable lanthanum germanate (La-Ge-O) [16][17][18].…”

“…Recently, it was reported that rare-earth metal oxides such as CeO 2 [13,14], Gd 2 O 3 [15] and Dy 2 O 3 [16] produced promising electrical properties when directly in contact with Ge. Especially, La 2 O 3 thin film shows many advantages, including low interface-states density, very small frequency dispersion and hysteresis due to formation of stable lanthanum germanate (La-Ge-O) [16][17][18]. However, a relatively low permittivity due to Ge diffusion into the highk dielectric prevents further decrease in equivalent oxide thickness [17].…”