Simulation study on influence of interface trap position in Sii-xGex Gate-All-Around (GAA) field-effect transistor
In this paper, performance degradation of Si1−xGex gate-all-around (GAA) Field-Effect Transistor (FET) depending on interface trap position was investigated through TCAD simulations. Interface traps were located at three different points along the channel. Parameters such as hole mobility and energy band were analyzed to understand the effects of partially generated interface traps by unstable GeOx.
Preferential oxidation of Si in SiGe for shaping Ge-rich SiGe gate stacks
The oxidation of SiGe is quite different from that of Si or Ge. By paying attention to the oxidation kinetics of SiGe, a gate stack formation guideline on SiGe is proposed. Based on the understanding of oxidation kinetics, we design the gate stack formation process and demonstrate very good C-V characteristics on SiGe with Si-cap free passivation, by direct deposition of a designed dielectric film, followed by an optimal post-deposition annealing.
Oxygen Permeability of Y2SiO5
The oxygen permeation through a wafer of Y 2 SiO 5 has been measured in the temperature range from 1973 to 2033 K and the oxygen permeability constant of Y 2 SiO 5 has been determined, because Y 2 SiO 5 is favorable for the outer layer of our proposed oxidation protection double layered coating on C/C composites. We presented a data reduction, which can separate lattice diffusion through the wafer from other contributions. The experimental data are in agreement with previous data reported in the literature for Ca stabilized zirconia and alumina in a maximum error of 10 -12 kg/(m.s). The oxygen permeability constant of Y 2 SiO 5 at 1973 K is 10 -10 kg/(m.s). A 100 μm-thick Y 2 SiO 5 outer layer would extend a life time of a 100 μm-thick SiC inner layer up to 70 hours, assuming that the SiC layer is consumed by oxygen permeated through the Y 2 SiO 5 layer. The mechanism of the oxygen transport is discussed in accordance with the activation energy of the oxygen permeation and relationship between the oxygen permeability constants and oxygen partial pressure. Experimental results indicate that vacancy diffusion is dominant below 1913 K and interstitial diffusion is dominant above 1913 K. It is estimated that there is a mechanism to switch vacancy diffusion to interstitial diffusion with increasing temperature, because interstitial diffusion should not be active at higher temperature.