The dependence of the interface and shape on the constrained growth of nc-Si in

2019-12-06 18:27:37

NC Si size shape sublayer

责任者: Lin Zhang;Kai Chen;Li Wang;Wei Li;Jun Xu;Xinfan Huang;Kunji Chen 单位: Nat. Lab. of Solid State Microstructures, Nanjing Univ., China 来源出处: Journal of Physics: Condensed Matter(J. Phys., Condens. Matter. (UK)),2002/11/04,14(43):10083-91 摘要: Size-controlled nanocrystalline silicon (nc-Si) has been prepared from a-SiNx/a-Si:H/a-SiNx (`a standing for amorphous) structures by thermal annealing. Transmission electron microscope analyses show that the lateral size of the nc-Si is controlled by the annealing conditions and the a-Si sublayer thickness. The deviation of the nc-Si grain size distribution decreases with the a-Si sublayer thickness, so thinner a-Si sublayers are favourable for obtaining uniform nc-Si grains. In the a-Si:H (10 nm) sample annealed at 1000°C for 30 min, an obvious bi-modal size distribution of nc-Si grains appears, but no obvious bi-modal size distribution is found in other samples with thinner a-Si:H sublayers. On the basis of the experimental results, we discuss the process of transition from the sphere-like shape to the disc-like shape in the growth model of the nc-Si crystallization. The critical thickness of the a-Si sublayer for the constrained crystallization can be determined by the present model. Moreover, the increase of the crystallization temperature in the ultrathin a-Si sublayer is also discussed 关键词: amorphous semiconductors;annealing;crystallisation;elemental semiconductors;grain size;hydrogen;nanostructured materials;silicon;silicon compounds;transmission electron microscopy;constrained growth;nanocrystalline silicon;thermal annealing;transmission electron microscopy;lateral size;sublayer thickness;grain size distribution;bimodal size distribution;sphere-like shape;disc-like shape;critical thickness;crystallization;ultrathin sublayer;1000 degC;30 min;10 nm;SiN-Si:H-SiN;Si