Mechanisms of damage formation in Eu-implanted AlN

Leclerc, S.; Lacroix, B.; Declémy, A.; Lorenz, K.; Ruterana, P.
October 2012
Journal of Applied Physics;Oct2012, Vol. 112 Issue 7, p073525
Academic Journal
X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to investigate the evolution of damage during implantation of 300 keV Eu ions at room temperature in AlN. At low fluence, a strain increase is observed in a buried layer where clusters of point defects and stacking faults (SFs) coexist. At higher fluence, a saturation of the strain is observed in this layer, and the XRD curves exhibit characteristic features which coupled with TEM results enable the identification of additional, spatially separated, dilated and contracted regions. From these observations, the following damage mechanisms are proposed. As the SFs grow by trapping point defects, a dense network of basal and prismatic SFs forms, which leads to the ejection of point defects from the buried damaged layer and consequently to the saturation of the strain. In this process, interstitials in excess migrate towards the undamaged bulk where they form clusters inducing large strain values. In contrast, defects ejected towards the surface either remain isolated or form isolated dislocation loops and SFs depending on their nature, i.e., interstitial or vacancy. This is probably the main difference with GaN where the defects ejected from the buried damaged layer contribute to the fast propagation of the dense SFs network towards the surface due to their relatively low formation energies. As a consequence, whilst nanocrystallization occurs at the surface of GaN, the relative confinement of defects and implanted atoms in the buried layer of AlN results in its amorphization, although at extremely high fluences (∼1017 Eu/cm2).


Related Articles

  • Sequential structural characterization of layers in the GaN/AlN/SiC/Si(111) system by X-ray diffraction upon every growth stage. Ratnikov, V. V.; Kalmykov, A. E.; Myasoedov, A. V.; Kukushkin, S. A.; Osipov, A. V.; Sorokin, L. M. // Technical Physics Letters;Nov2013, Vol. 39 Issue 11, p994 

    X-ray diffraction and transmission electron microscopy techniques have been used to study the dynamics of variation of the structural characteristics and deformation state in SiC, AlN, and GaN epilayers sequentially grown on a Si(111) substrate. In this system, the SiC layer has been grown by...

  • Coexistence of wurtzite GaN with zinc blende and rocksalt studied by x-ray power diffraction and high-resolution transmission electron microscopy. Xie, Yi; Qian, Yitai; Zhang, Shuyuan; Wang, Wenzhong; Liu, Xianming; Zhang, Yuheng // Applied Physics Letters;7/15/1996, Vol. 69 Issue 3, p334 

    X-ray powder diffraction and high-resolution transmission electron microscopy (HRTEM) have found coexistence of three structures of GaN: wurtzite, zinc blende, and rocksalt in the samples prepared through benzene thermal process at 280–300 °C under pressure about 5 MPa. Previously, GaN...

  • Fabrication of bamboo-shaped GaN nanorods. Li, H.; Li, J.Y.; He, M.; Chen, X.L.; Zhang, Z. // Applied Physics A: Materials Science & Processing;2002, Vol. 74 Issue 4, p561 

    Bamboo-shaped GaN nanorods were formed through a simple sublimation method. They were characterized by means of X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selected-area electron diffraction (SAED). The TEM...

  • Metastable rocksalt phase in epitaxial GaN on sapphire. Lada, M.; G., Cullis, A.; Parbrook, P.J.; Hopkinson, M. // Applied Physics Letters;10/6/2003, Vol. 83 Issue 14, p2808 

    In a series of GaN epilayers grown by metalorganic chemical vapor deposition on sapphire, the GaN rocksalt structure has been detected by x-ray diffraction (XRD) and directly observed by high resolution transmission electron microscopy. The rocksalt GaN phase was found to coexist with...

  • Transmission electron microscopy study of the nitridation of the (0001) sapphire surface. Vannegues, P.; Beaumont, B. // Applied Physics Letters;12/27/1999, Vol. 75 Issue 26, p4115 

    Studies the nitridation of the (0001) sapphire surface which is key step for the fabrication of high-quality gallium nitride (GaN) materials. Formation of a fully crystalline 10-atomic-planes-thick aluminum nitride film; Chemical transformation of the aluminum oxide surface.

  • Influence of AIN nucleation layers on growth mode and strain relief of GaN grown on 6H - SiC (0001). Waltereit, P.; Brandt, O. // Applied Physics Letters;6/14/1999, Vol. 74 Issue 24, p3660 

    Studies the growth mode and strain state of gallium nitride (GaN) layers grown either directly on 6H-SiC(0001) or on thin, coherently strained aluminum nitride nucleation layers. Compressive lattice mismatch strain; Strain state of the GaN layer determined by its growth mode; High-energy...

  • Inversion domains and pinholes in GaN grown over Si(111). Sánchez, A. M.; Ruterana, P.; Benamara, M.; Strunk, H. P. // Applied Physics Letters;6/23/2003, Vol. 82 Issue 25, p4471 

    High-resolution transmission electron microscopy is used to analyze the connection between pinholes and inversion domains at the AlN/GaN interface. From some pinholes on top of the AlN buffer layer, the subsequent growth of GaN was observed to lead to the formation of inversion domains. In...

  • Dependence of crystallographic tilt and defect distribution on mask material in epitaxial lateral overgrown GaN layers. Tomiya, S.; Funato, K.; Asatsuma, T.; Hino, T.; Kijima, S.; Asano, T.; Ikeda, M. // Applied Physics Letters;7/31/2000, Vol. 77 Issue 5 

    We have investigated the dependence of crystallographic tilt and defect distribution on mask material in metalorganic chemical vapor deposition grown GaN layers formed utilizing an epitaxial lateral overgrowth (ELO) technique using x-ray diffraction and transmission electron microscopy....

  • Study on threading dislocations blocking mechanism of GaN/AlxGa1-xN superlattices. Sang, L. W.; Qin, Z. X.; Fang, H.; Zhou, X. R.; Yang, Z. J.; Shen, B.; Zhang, G. Y. // Applied Physics Letters;5/12/2008, Vol. 92 Issue 19, p193110 

    GaN/AlxGa1-xN superlattices (SLs) with different period thicknesses tp were grown as interlayers between GaN and AlyGa1-yN epilayers. The effect of threading dislocations (TDs) blocking became more evident with increasing tp. Transmission electron microscopy analysis shows that TDs are inclined...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics