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Abstract

The structure and the optical properties of thin Si layer hydrogenated by shallow plasma ion implantation with different fluences up to 1015 cm-2 are studied using spectroscopic ellipsometry and simulation of the distributions of the ions and implantation induced defects. The implantation was regarded to proceed into Si through the native SiO2. Two-layer optical models are applied for examination of the composition and dielectric function behavior of the formed structures. The native oxide is found to be 3 nm thick. The thickness of the Si modified layer decreased 23 to 14 nm with ion fluence due to increased formation of highly hydrogenated surface region that hinder further H-penetration into the Si bulk, especially at the highest fluence. Shifts of the features in the obtained dielectric functions related with Si interband transitions at about 3.4 and 4.2 eV are found caused by process-induced tensile stress. The modified Si region is related rather to defects created by the ion implantation process than the projected range of hydrogen ions. The overall layer modification can be characterized by a low degree of amorphization (up to 5.8%), creation of structural defects and internal tensile stress.

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... It is evident that the nucleation and growth of pores in silicon during implantation is accompanied by the amorphization of the irradiated matrix which begins immediately from the onset of implantation. It has been shown for implantation of silicon with H + , Si + , Ge + , Co + , B + , P + , As + , Ar + , Xe + and + 2 N ions [3][4][5][6][7] that one of the most informative methods of studying the partially disordered (amorphized) crystalline surface layers of silicon is spectral ellipsometry (SE). This is because of a large difference in the optical constants of amorphous and crystalline silicon. ...
... It is diffi cult to compare our CE data on silicon implanted with Ag + ions with published data, since there are no data on lowenergy implantation of silicon. Besides [5], there is only an CE analysis [6] of silicon samples implanted with 30-40 keV As + ions, but they also have a lower mass than Ag + . ...
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The existence of both the strain and microroughness at the interface of thermally grown SiO 2 films on Si was ascertained unambiguously for the first time by high accuracy spectroscopic ellipsometry. The dielectric function of the interface was determined by a comprehensive data analysis procedure. By carefully examining the dielectric function obtained by our model, the strain was seen to cause a red shift of 0.042 eV of the interband critical point E 1 compared with the bulk silicon value. The thickness of the interface region was found to be 2.2 nm of which a significant part is due to the strain.
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Hydrogen ion implantation in the Smart-Cut production process leads to fracture of Si–Si bonds, formation of microcavities and splitting of a single-crystal silicon wafer. In the present paper, an analysis model for defect nucleation induced by hydrogen ion implantation is established based on the continuum mechanics theory accounting for the crystal structure of silicon. Using this model and probability theory, an analytical expression is derived to calculate the defect density as a function of the hydrogen ion implantation dose and the temperature.
Properties of Crystalline Silicon, INSPEC, The Institution of Electrical Engineers
  • M Stavola
M. Stavola, Hydrogen diffusion and solubility in c-Si, in: R. Hull (Ed.), Properties of Crystalline Silicon, INSPEC, The Institution of Electrical Engineers, London, UK, 1999, pp. 511–522.