Diffusion in silicon

It will be noted that because of the low self-diffusion coefficients the numerical values for representations of self-diffusion in silicon and germanium by Anhenius expressions are subject to considerable uncertainty. It does appear, however, that if this representation is used to average most of the experimental data the equations are for silicon... 

W. Prank, U. Gosele, H. Mehrer, and A. Seeger. Diffusion in silicon and germanium. In G.E. Murch and A.S. Nowick, editors, Diffusion in Crystalline Solids, pages 63-142, Orlando, Florida, 1984. Academic Press. 

Point Defect Models of Diffusion in Silicon. Under conditions of thermal equilibrium, a Si crystal contains a certain equilibrium concentration of vacancies, C v°, and a certain equilibrium concentration of Si self-interstitials, Cz°. For diffusion models based on the vacancy, Cv° Cf and the coefficients of dopant diffusion and self-diffusion can be described by equation 27 (15)... 

Point Defect Generation During Phosphorus Diffusion. At Concentrations above the Solid Solubility Limit. The mechanism for the diffusion of phosphorus in silicon is still a subject of interest. Hu et al. (46) reviewed the models of phosphorus diffusion in silicon and proposed a dual va-cancy-interstitialcy mechanism. This mechanism was previously applied by Hu (38) to explain oxidation-enhanced diffusion. Harris and Antoniadis (47) studied silicon self-interstitial supersaturation during phosphorus diffusion and observed an enhanced diffusion of the arsenic buried layer under the phosphorus diffusion layer and a retarded diffusion of the antimony buried layer. From these results they concluded that during the diffusion of predeposited phosphorus, the concentration of silicon self-interstitials was enhanced and the vacancy concentration was reduced. They ruled out the possibility that the increase in the concentration of silicon self-interstitials was due to the oxidation of silicon, which was concurrent with the phosphorus predeposition process. 

Kijama, K., Shirasaki, S. (1976), Nitrogen self diffusion in silicon nitride , J. Chem. Phys., 65, 2668. 

QUANTUM CHEMICAL SIMULATION OF STRUCTURAL STABILITY AND ATOMIC DIFFUSION IN SILICON NANOTUBES... 

The randomizaton takes place by a a diffusion of atoms that is implicit in our earlier description of the initial randomization process as being akin to melting [1]. Later it was shown that the root-mean-square displacement of each atom must be of the order of the nearest-neighbor distance in order that the network lose all memory of the original crystal structure as measured by the structure factor S q) [21]. In this context, the melting point can be defined as that temperature for which the mean square displacement increases linearly with time. It appears, though, that a sequence of bond switches as illustrated in Fig. 1 is not the primary mechanism for self-diffusion in silicon [31,32]... 

Gunawan, R., Jung, M.Y.L., Seebauer, E.G. and Braatz, R.D. (2003b) Parameter Sensitivity Analysis of Boron Activation and Transient Enhanced Diffusion in Silicon. J. Electrochem. Soc., 150, G758-G765. 

Experimental and theoretical studies on H diffusion in silicon at lower temperatures, where trapping of hydrogen at defects and impurities and H2-molecule formation are significant, discovered much lower effective diffiisivities. Values for the H-diffiision coefficient in silicon expected from an extrapolation of the diffusion coefficient of (11.1) to lower temperatures are several orders of magnitude higher than experimentally obtained diffiisivities. This is illustrated in Fig. 11.2, which shows (11.1) and (11.2) extrapolated to low temperatures with experimentally determined values from Johnson et al. (1986). 

NMR has also been used to investigate iron containing silicates and borosilicates/ " the internal structure of Beta/MCM-41 and ZSM-5/MCM-41 composites/ diffusion in silicon imidonitriles, several carbonaceous materials,transition-metal-complex nanochannels, and microporous silica materials. " ... 

Gomer R (1990) Diffusion of adsorbates on metal-surfaces. Rep Prog Phys 53(7) 917-1002 Gruener S, Huber P (2008) Knudsen diffusion in silicon nanochannels. Phys Rev Lett 100(6) 064502-064504... 

Relationship Between Structure and Dynamics From the data reported above of the coordination number and the diffusivity, it is evident at a qualitative level that the diffusivity in silicon is correlated with coordination number, with higher coordination number corresponding to larger diffusivity. It has been shown in Ref. [32] that the diffusivity depends quite strongly on coordination number and has only a weak-temperature dependence (see Fig. 31). Scaling the diffusivity to... 

The electronic industry benefits from boron trichloride in many applications. It is used in the production of optical fibers, as a p-type dopant for thermal diffusion in silicon, and for ion implantation. 

BAR Barrer, R.M., Barrie, J.A., and Raman, N.K., Solution and diffusion in silicone rubber. I. A comparison with natural robber. Polymer, 3, 595, 1962. 

It is necessary to know the main components of self-diffusion coefficients for understanding of diffusion in silicon carbide and a scientific approach to crystal growth technology. Temperature dependences of self-diffusion coefficients of silicon and carbon in pure and doped n-type 6H-SiC crystals obtained using isotopes C and Si are shown in Fig. 7. These dependences can be written in the following form ... 

Figure 8 Dopant concentration profiles for acceptor (Al, B, Be) diffusion in silicon carbide crystals (hatched parts, compensated regions of the crystals).

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