Topological Analysis of the Effect of Annealing on the Grain-Boundary Structure of Polysilicon Films

Authors T.V. Rodionova1, P.M. Lytvyn2, Yu.A. Len1, S.P. Kulyk1

1Taras Shevchenko National University of Kyiv, 64, Volodymyrska St., 01601 Kyiv, Ukraine

2Institute of Semiconductor Physics of NASU, 41, Nauky Prosp., 03028 Kyiv, Ukraine

Issue Volume 13, Year 2021, Number 6
Dates Received 19 October 2021; revised manuscript received 04 December 2021; published online 20 December 2021
Citation T.V. Rodionova, P.M. Lytvyn, Yu.A. Len, S.P. Kulyk, J. Nano- Electron. Phys. 13 No 6, 06020 (2021)
PACS Number(s) 68.37.Ps, 68.55._a
Keywords Polysilicon films, Grain boundaries (2) , Grain growth mechanisms, Topological analysis.

The effect of annealing on the grain-boundary structure of phosphorus-doped silicon films obtained by chemical vapor deposition was investigated by comparative analysis of atomic force microscopy data and existing model concepts. It is shown that the decisive factor for the applicability of the topographic model is the character of grain growth in the films. The model is applicable for annealing temperatures  1000 C, at which normal grain growth is observed. In this temperature range, the distributions of different types of grain boundaries in polysilicon films are symmetric with respect to growing and disappearing boundaries. The structure of polysilicon films is equiaxed, there is no preferred orientation. At annealing temperatures  1000 C, anomalous grain growth takes place in the films, and the distribution of the types of grain boundaries indicates that the topological model is inapplicable in this temperature range. It can be assumed that the differences in the ratios of growing and disappearing grain boundaries in polysilicon films at different annealing temperatures are due to different mechanisms and driving forces of grain growth during normal and abnormal growth. With normal grain growth, the driving force prevails, that is caused by the difference in the density of dislocations in the adjacent grains. With abnormal grain growth, the driving force prevails, that is due to the difference in the average surface energy of the grains, which causes a sharp increase in the rate of grain growth.

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