Comparison of Texture in Copper and Aluminum Thin Films Determined by Xrd and Ebsd

X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) are commonly used to perform texture analysis of thin films. However, due to principle differences in data acquisition these techniques can yield disagreeing results. In this paper, we aim to highlight possible error sources with given examples for aluminum and copper thin films. INTRODUCTION Texture in materials has a large influence on many properties of thin films; it is customarily determined by neutron or X-ray diffraction by measuring pole figures and evaluating orientationdistribution functions (ODF) [1]. X-ray diffraction (XRD) has been the primary method for the characterization of texture for many years. Recently, alternative techniques for localized measurements have been developed, such as electron backscatter diffraction (EBSD). EBSD is a highly flexible method to measure grain sizes, grain size distributions and orientation maps [1][2], in order to bring the characterization of texture to the nanoscale level. In this study, we compared measurements taken with XRD and EBSD for several selected cases of aluminum and copper thin films. We found that results obtained by both methods do not necessarily agree for the same sample. In the present paper, we highlight some possible sources of error and differences between these two techniques. EXPERIMENTAL DETAILS X-RAY DIFFRACTION A 2-circle X-ray powder diffractometer cannot give full information about the sample texture. For a closer examination of preferred orientations in a sample it is necessary to obtain pole figures, using a 4-circle goniometer. During a scan of this type (Fig. 1a), the sample normal is tilted outside of the diffraction plane (tilt angle , often also referred to as ) for a given Bragg reflection and rotated about the axis normal to its surface (rotation angle ). The stepsize for and is typically 5 . In this way, the intensity of a particular Bragg reflection is measured for pairs of and at a fixed -2 position and is normally presented as a direct pole figure. By combining several (for cubic crystal symmetry at least three) direct pole figures of independent crystallographic orientations, an indirect (or inverse) pole figure can be calculated (Fig. 2). We performed measurements using a commercial 4-axis diffractometer at a voltage of 45 kV and a current of 40 mA. During the measurement the sample was tilted to 90 out of the diffraction plane and rotated 180 about the surface normal. Raw data were corrected for background * Contribution of an agency of the U.S. Department of Commerce; not subject to copyright in the United States 201 Copyright ©JCPDS-International Centre for Diffraction Data 2006 ISSN 1097-0002