Bond-specific reaction kinetics during the oxidation of (111) Si: Effect of n-type doping

Abstract

It is known that a higher concentration of free carriers leads to a higher oxide growth rate in the thermal oxidation of silicon. However, the role of electrons and holes in oxidation chemistry is not clear. Here, we report real-time second-harmonic-generation data on the oxidation of H-terminated (111)Si that reveal that high concentrations of electrons increase the chemical reactivity of the outer-layer Si-Si back bonds relative to the Si-H up bonds. However, the thicknesses of the natural oxides of all samples stabilize near 1 nm at room temperature, regardless of the chemical kinetics of the different bonds.Usage: Secondary publications and information retrieval purposes. PACS numbers:1 arXiv:1011.4386v1 [cond-mat.mtrl-sci]

Effect of p-type doping on the oxidation of H–Si(111) studied by second-harmonic generation

“…For carrier concentrations of p = ∼ 10 15 cm −3 as well as 10 16 cm −3 we see that the incubation periods for the back bonds Here the incubation appears to be completely missing and the evolution is a simple exponential rise with a negative time constant, suggesting that the oxidation process is rising to a saturation level. Our ellipsometric data (not shown) show that for both n-and p-type samples oxidation continues until the thickness reaches a certain value, that is independent of carrier type and concentration [20]. These results are consistent with corrosion studies of Si and Ge in aqueous solutions, where the availability of holes which weakens the surface bonds is the rate-limiting step.…”

“…[19] In addition, we found that the excess electrons in a heavily n-type sample change oxidation kinetics of the different surface bonds dramatically. [20] Here, we extend these studies to (111) surfaces of p-type Si wafers. We also performed atomic force microscopy (AFM) measurements, which provide additional information via changes in surface morphology.…”

The Effect of Doping on the Digital Etching of Silicon-Selective Silicon–Germanium Using Nitric Acids

“…It was demonstrated that the carrier type—instead of dopant type—enhanced the etching rate of n + -Si in the H 2 O 2 q-ALE process. The high concentration of electrons in n + -Si might accelerate oxide growth in H 2 O 2 solutions, which could be explained by the improved relativity of Si-Si back bonds [ 33 ].…”

Intrinsic and extrinsic effects on the electrostatic field at the surface of Bi2Se3

“…[45][46][47][48] This would lead to important microscopic insights into surface chemical bonding via the associated changes in bond hyperpolarizabilities.…”