Control of orientation from random to (220) or (400) in polycrystalline silicon films

Growth, structure, and transport properties of thin (>10 nm) n-type microcrystalline silicon prepared on silicon oxide and its application to single-electron transistor

“…40 This model agrees with the Raman results, which suggested that new nuclei were formed at/near the growth surface during film growth. In addition, unlike the case of preferentially oriented poly-Si, where lateral grain growth is enhanced by the driving force to decrease orientation fluctuation, 12 randomly oriented grains do not have a driving force for lateral grain growth after each grain is in contact with neighboring grains. Thus the grain size is determined by the nucleus density in the randomly oriented c-Si:H case.…”

“…As Nakahata et al report, Hall mobility has a good correlation with the lateral grain size measured by SEM and the lateral growth in preferentially oriented poly-Si occurs together with a decrease in orientation fluctuation. 12,22 Their results imply that the chemical bonding structure at the growth surface affects the structure of the subsequently grown film. In contrast, it is thought that the growth of the randomly oriented c-Si:H is not affected by the growth surface structure under the deposition condition used because the perpendicular grain size of the c-Si:H measured by XRD (D 220 ) is much smaller than the film thickness and also smaller than those measured in the ͑220͒ or ͑400͒ preferentially oriented poly-Si.…”

“…[7][8][9][10] In our previous work, we have reported on high crystallinity, high quality poly-Si:H films prepared on glass from SiF 4 and H 2 gas mixtures, where a fluorinated source gas enhances crystallization and crystallite growth. 11 The film microstructures including the grain orientation are controlled by selecting appropriate deposition conditions, 12,13 which would lead to suitable device applications. For example, ͑220͒ oriented poly-Si can be grown at small gas flow ratios ͑e.g., SiF 4 /H 2 Ͻ30/10 sccm͒ at 300°C.…”

Preferential growth of Si nanocrystals in SiO2/Si/SiO2 sandwich structure

“…The preferential growth can be affected by many factors, such as surface energy of crystal plane, the synthesis parameters or lattice mismatch between film materials and substrates [3]. Many attempts have been conducted to obtain preferred orientation of crystallization, such as electric field, metal-induced effect, stress and selective etching [4][5][6][7].…”

Addition of SiF4 to standard SiH4+H2 plasma: an effective way to reduce oxygen contamination in μc‐Si:H films

“…On the other hand, it was shown that changes in the preferential orientation of grains of highly crystallized µc-Si:F:H deposited from SiF 4 +H 2 +Ar were followed by significant changes in oxygen content [13]. However, in both cases changes in structure lead to the significant changes in ellipsometric spectra [12,14]. By contrast, we did not observe differences either between SE spectra, or IR and Raman spectra of µc-Si:H and µc-Si:F:H films deposited at the same conditions.…”