RBS/C, XRR, and XRD Studies of Damage Buildup in Er‐Implanted ZnO

Abstract

Accumulation and transformation of defects formed in bulk ZnO crystals at room temperature upon 300 keV Er ions bombardment have been thoroughly examined using complementary techniques: Rutherford Backscattering Spectrometry in ion Channeling mode (RBS/C), X‐Ray Reflectivity (XRR), and X‐Ray Diffraction (XRD). Evaluation of RBS/C spectra has been performed using Monte Carlo (MC) simulations (McChasy software). Two defect types have been indicated: point defects (randomly displaced atoms, RDA) and extended ones (edge dislocations, DIS). Depth‐distributions of RDA and DIS turned out to be shifted toward deeper regions of ZnO crystals (relative to Er‐ions range) while DIS are localized even deeper than RDA. The MC simulations reveal three regions of defects accumulation separated by two regions of rapid defects transformation occurring at a certain critical Er fluence. Strain, suggested to be a driving force of defect transformation, has been determined using simulations of the XRD profiles based on the dynamical theory of X‐ray diffraction (MROX software). The presented research can help to better understand the interaction between impurity Er ions and ZnO target atoms during the implantation process. Hence, implantation conditions, for example, for luminescence purpose may now be more efficiently chosen based on the results discussed.

Monte Carlo simulations of ion channeling in crystals containing dislocations and randomly displaced atoms

“…The Random and the Aligned spectra refer to a sample implanted at RT with 300-keV Er ions to a fluence of 2.0x10 15 cm -2 . 37 The fits to the experimental data (solid black lines) were obtained using MC simulations using the new McChasy code. For the sake of clarity, the signal coming from Er ions is magnified 20 times.…”

“…Depth distributions of RDA and DIS in ZnO after implantation with 300 keV Er ions to a fluence of 2.0x10 15 cm -2 . The defect profiles are the result of MC simulations using the McChasy code: those obtained using the 2-dimensional classical PSA approach are denoted as old (dashed lines) and were reported in Ref 37,. those obtained using the 3-dimensional updated PSA approach (described in §II.C.1) are denoted as new (solid lines).…”

Crystal mosaicity determined by a novel layer deconvolution Williamson–Hall method

“…The earlier version of MROX, only targeted single reflections and with no name attributed was used in the work presented in refs. 35,[40][41][42][43][44] Finally, the LdCWH method is the main subject of this manuscript whose software description is addressed to 45 .…”

Estimating the uncertainties of strain and damage analysis by X-ray diffraction in ion implanted MoO3

“…[4] XRD has been used in many crystalline materials to investigate the strain introduced by implantation defects. [5][6][7][8][9][10][11][12][13][14][15] However, the estimation of the uncertainties associated with the strain and damage profiles is challenging since the fit results strongly depend on the considered fitting model. Therefore, simple statistical methods evaluating the goodness of fit may not be meaningful.…”