Low-temperature operation of junctionless nanowire transistors: Less surface roughness scattering effects and dominant scattering mechanisms

2014 ◽  
Vol 105 (26) ◽  
pp. 263505 ◽  
Author(s):  
Dae-Young Jeon ◽  
So Jeong Park ◽  
Mireille Mouis ◽  
Sylvain Barraud ◽  
Gyu-Tae Kim ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Low Temperature ◽  
Nanowire Transistors ◽  
Scattering Mechanisms ◽  
Surface Roughness Scattering ◽  
Scattering Effects

scholarly journals Simulation of the Impact of Ionized Impurity Scattering on the Total Mobility in Si Nanowire Transistors

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 124 ◽  
Author(s):  
Toufik Sadi ◽  
Cristina Medina-Bailon ◽  
Mihail Nedjalkov ◽  
Jaehyun Lee ◽  
Oves Badami ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Small Diameter ◽  
Golden Rule ◽  
Impurity Scattering ◽  
Boltzmann Transport ◽  
Nanowire Transistors ◽  
Scattering Mechanisms ◽  
Relaxation Time Approximation ◽  
Ionized Impurity Scattering ◽  
The Impact

Nanowire transistors (NWTs) are being considered as possible candidates for replacing FinFETs, especially for CMOS scaling beyond the 5-nm node, due to their better electrostatic integrity. Hence, there is an urgent need to develop reliable simulation methods to provide deeper insight into NWTs’ physics and operation, and unlock the devices’ technological potential. One simulation approach that delivers reliable mobility values at low-field near-equilibrium conditions is the combination of the quantum confinement effects with the semi-classical Boltzmann transport equation, solved within the relaxation time approximation adopting the Kubo–Greenwood (KG) formalism, as implemented in this work. We consider the most relevant scattering mechanisms governing intraband and multi-subband transitions in NWTs, including phonon, surface roughness and ionized impurity scattering, whose rates have been calculated directly from the Fermi’s Golden rule. In this paper, we couple multi-slice Poisson–Schrödinger solutions to the KG method to analyze the impact of various scattering mechanisms on the mobility of small diameter nanowire transistors. As demonstrated here, phonon and surface roughness scattering are strong mobility-limiting mechanisms in NWTs. However, scattering from ionized impurities has proved to be another important mobility-limiting mechanism, being mandatory for inclusion when simulating realistic and doped nanostructures, due to the short range Coulomb interaction with the carriers. We also illustrate the impact of the nanowire geometry, highlighting the advantage of using circular over square cross section shapes.

scholarly journals Effect of Spontaneous Polarization Charges on the Electron Mobility in ZnO Surface Quantum Wells

2015 ◽  
Vol 19 (4) ◽  
Author(s):  
Nguyen Thanh Tien ◽  
Le Tuan ◽  
Doan Nhat Quang
Keyword(s):  
Surface Roughness ◽  
Low Temperature ◽  
Quantum Wells ◽  
Spontaneous Polarization ◽  
Theoretical Study ◽  
Impurity Scattering ◽  
Hydrogen Ions ◽  
Dimensional Electron ◽  
Surface Roughness Scattering ◽  
Dimensional Electron Gas

We present a theoretical study of the effect due to spontaneous polarization of ZnO on the low-temperature mobility of the two-dimensional electron gas (2DEG) in a ZnO surface quantum well (SFQW). We proved that for the O-polar face this causes an attraction of electrons by the positive charges bound on the surface, while for the Zn-polar face a repulsion of them far away therefrom by the negative bound charges of the same magnitude. Accordingly, surface roughness scattering is drastically enhanced in the former case, but reduced in the latter one. Therefore, the low-% temperature 2DEG mobility in ZnO SFQWs with O-polar face is found to be dominated by surface roughness. Our theory was illustrated for the sample prepared by bombardment of the O-polar face by 100-eV hydrogen ions. The surface roughness scattering enables an explanation of the 2DEG mobility, especially, the reason of low values for the mobility in the dependence from the carrier density which has not been understood when starting from impurity scattering.

scholarly journals Theoretical investigation of surface roughness scattering in silicon nanowire transistors

2005 ◽  
Vol 87 (4) ◽  
pp. 043101 ◽  
Author(s):  
Jing Wang ◽  
Eric Polizzi ◽  
Avik Ghosh ◽  
Supriyo Datta ◽  
Mark Lundstrom
Keyword(s):  
Surface Roughness ◽  
Theoretical Investigation ◽  
Silicon Nanowire ◽  
Nanowire Transistors ◽  
Surface Roughness Scattering

Calibration of Mobility and Interface Trap Parameters for High Temperature TCAD Simulation of 4H-SiC VDMOSFETs

2012 ◽  
Vol 717-720 ◽  
pp. 1101-1104 ◽  
Author(s):  
M.G. Jaikumar ◽  
Shreepad Karmalkar
Keyword(s):  
Surface Roughness ◽  
Measured Data ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Material Parameters ◽  
Velocity Saturation ◽  
Physical Mechanisms ◽  
Surface Roughness Scattering ◽  
Wide Range ◽  
Tcad Simulation

4H-Silicon Carbide VDMOSFET is simulated using the Sentaurus TCAD package of Synopsys. The simulator is calibrated against measured data for a wide range of bias conditions and temperature. Material parameters of 4H-SiC are taken from literature and used in the available silicon models of the simulator. The empirical parameters are adjusted to get a good fit between the simulated curves and measured data. The simulation incorporates the bias and temperature dependence of important physical mechanisms like interface trap density, coulombic interface trap scattering, surface roughness scattering and velocity saturation.

Ultra-precision grinding of 4H-SiC wafer by PAV/PF composite sol-gel diamond wheel

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110449
Author(s):  
Kaiping Feng ◽  
Tianchen Zhao ◽  
Binghai Lyu ◽  
Zhaozhong Zhou
Keyword(s):  
Surface Roughness ◽  
Low Temperature ◽  
Polyvinyl Alcohol ◽  
Feed Rate ◽  
Hot Pressing ◽  
Phenolic Resin ◽  
Sol Gel ◽  
Diamond Wheel ◽  
Sic Wafer ◽  
Better Than

To eliminate the deep scratches on the 4H-SiC wafer surface in the grinding process, a PVA/PF composite sol-gel diamond wheel was proposed. Diamond and fillers are sheared and dispersed in the polyvinyl alcohol-phenolic resin composite sol glue, repeatedly frozen at a low temperature of −20°C to gel, then 180°C sintering to obtain the diamond wheel. Study shows that the molecular chain of polyvinyl alcohol-phenolic resin is physically cross-linked to form gel under low-temperature conditions. Tested by mechanical property testing machines, microhardness tester, and SEM. The results show that micromorphology is more uniform, the strength of the sol-gel diamond wheel is higher, the hardness uniformity is better than that of the hot pressing diamond wheel. Grinding experiments of 4H-SiC wafer were carried out with the prepared sol-gel diamond wheel. The influence of grinding speed, feed rate, and grinding depth on the surface roughness was investigated. The results showed that by using the sol-gel diamond wheel, the surface quality of 4H-SiC wafer with an average surface roughness Ra 6.42 nm was obtained under grinding wheel speed 7000 r/min, grinding feed rate 6 µm/min, and grinding depth 15 µm, the surface quality was better than that of using hot pressing diamond wheel.

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