Misorientation dependent epilayer tilting and stress distribution in heteroepitaxially grown silicon carbide on silicon (111) substrate

THIN SOLID FILMS

卷:564

Article

Wang, Li¹  Iacopi, Alan¹  Dimitrijev, Sima¹  Walker, Glenn¹  Fernandes, Alanna²  Hold, Leonie¹  Chai, Jessica¹ 

[1] Griffith Univ, Queensland Micro & Nanotechnol Ctr, Nathan, Qld 4111, Australia

[2] Bluglass Ltd, Silverwater, NSW 2128, Australia

关键词: Silicon carbide;    On-axis;    Off-axis;    Tilting;    Stress;    Surface steps;    X-ray diffraction;    Curvature;   

DOI  :  10.1016/j.tsf.2014.05.052

来源: Elsevier

【 摘 要 】

The advantages and disadvantages of using off-axis substrates for heteroepitaxial growth of 3C-SiC on Si(111) substrates are investigated in this paper. 3C-SiC is deposited on on-axis and 4 degrees off-axis 150 mm Si(111) substrates using low pressure chemical vapour deposition. The dependence of surface morphology, roughness, crystallinity, alignment between the epilayer and the substrate, and film stress are evaluated using atomic force microscopy, X-ray diffraction, and wafer curvature measurement. Highly parallel steps are observed on both on-axis and off-axis Si substrates after surface preparation, yet step density is doubled and step height is much larger (>21 times of single step height) for 4 degrees off-cut Si compared to on-axis Si. X-ray diffraction results indicate that SIC grown on on-axis Si substrates are well-aligned with the Si substrates, while the SiC grown on off-axis substrates are tilted positively by as large angle as 1.66 degrees. The well-aligned SiC grown on on-axis Si substrate exhibits lower and uniform residual stress compared to the film grown on off-axis Si substrates, which exhibits a nonuniform distribution of higher stress. The stress distribution is found to be dependent on Si surface step direction and height. These misorientation dependent tilting and stress distribution mechanisms are expected to be applicable to other hetero-epitaxial growth systems with similar mismatch magnitude. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

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