The Evolution of (001) Si / SiO2 Interface Roughness during Thermal Oxidation

Abstract

In this work, w e first demonstrate the interface roughness as a function o f oxide thickness. For intentionally roughened samples, interface roughness always decreases as oxide thickness increases. O n the other hand, samples only treated with a regular preoxidation clean show a different quantitative trend. For such samples, the interface is initially roughened, and then becomes smooth as oxide thickness increases. This implies that the evolution o f interface roughness depends on h o w samples are pre ared Our results suggest that the most important factor dictating interface morphology is the oxide thickness, rather txan thermal history and growth ambient. Instead o f using simple statistical descriptions, such as root-mean-square roughness, w e also employ power spectral density o n atomic force microscopy image analysis. Our results suggest that the roughness components o f higher spatial frequencies are greatly reduced during thermal oxidation. ABSTRACT The photovoltage and the fill factor o f (indium-tin oxide (ITO)/silicon oxide/polycrystalline n-Si) junction solar cells are increased b y immersing S i i n a potassium cyanide solution before the deposition o f a n I T 0 film. Measurements o f the temperature dependence o f the dark current-voltage curves show that the mechanism o f the current flow through the S i depletion layer is changed from trap-assisted multistep tunneling t o thermionic-assisted tunneling b y the KCN treatment, indicating a decrease in the density o f the trap states i n the S i depletion layer. Measurements o f the electrode conductance also show that the trap density is greatly reduced b y the KCN treatment. The improvement o f the electrical characteristics is attributed t o the decrease i n the trap density and an increase i n the barrier height i n n-Si caused b y t h e inclusion o f cyanide ions at t h e oxide/Si interface and/or i n t h e silicon oxide layer.

Silicon-Germanium Strained Layer Materials in Microelectronics

“…Here the spread of the interface is defined as the distance between the Si 0.71 Ge 0.29 and Si 0.99 Ge 0.01 points. The spread of the interface after annealing at 1000 C is substantially worse than the rms roughness measured on Si/SiO 2 interfaces [71] of only 0.3 nm for thin oxides. As annealing at 1000 C for many minutes is common in many CMOS processes, care has to be taken in designing annealing processes that do not degrade the heterointerfaces if Si 1±x Ge x is to be processed using CMOS techniques.…”

Role of surface morphology on desorption kinetics of water molecules from uncoated silicon microcantilever

“…It is indeed possible to study desorption kinetics with a more stable thermally grown SiO 2 film on MC surface. However, any potential experiment intending to grow SiO 2 on MC will alter the surface morphology and may introduce the residual intrinsic stress [20][21][22], which will influence the desorption kinetics.…”

On the Operation Modes of Dual-Gate Reconfigurable Nanowire Transistors

“…The dry oxidation is carried out for 3 min at a temperature of 1100 • C, i.e., higher than the viscous flow point. Although such a high temperature prevents a self-limiting oxidation [15], it allows transforming the cross section of the SiNW from triangular to a circular shape while minimizing the degradation of the Si-SiO 2 interface due to roughness induced by the oxidation process [16]. Next, etch windows are patterned in source/drain contact areas and opened up by removing the oxide shell with buffered oxide etch (BOE).…”

“…In order to elaborate further on the behavior of RFETs and in particular to understand the difference in the nonlinear behavior of the PGAD and PGAS operation modes, self-consistent device simulations using the nonequilibrium Green's function (NEGF) approach on a finite-difference grid have been carried out [22]. An effective mass approximation with symmetric conduction and valence band is assumed; the complex band structure within the bandgap is considered with Flietner's dispersion relation [23].…”