Xray Services.com

AMIA Laboratories uses X-ray analysis to characterize thin film material properties such as composition, orientation, and stress/strain at the molecular level. X-ray diffraction (XRD) is the definitive non-destructive technique for sub-surface analysis.

Crystallographic texture affects electrical and magnetic properties. Pole figures describe the orientation of crystallites in a material. Most electronic thin films exhibit fiber texture, which implies an axially-symmetric pole figure. AMIA Laboratories typically uses fiber texture plots to quantify primary texture strength, % random, and secondary orientations.

In-plane and out-of-plane stress, and normal micro-strain can influence magnetic properties of thin films and the reliability of devices. Mechanical stresses in interconnect lines, which arise from differences in thermal expansion between the metallic interconnect and the substrate that rigidly confines it, vary with different fabrication methods and aspect ratios. AMIA Laboratories has developed micro-beam stress techniques to characterize features as small as 50 µm on patterned wafers. Blanket film strain measurements are also available.

Unlike conventional X-ray diffraction, reflectometry is a "reflection" experiment in which X-rays are reflected off of the sample at glancing angles in much the same way that visible light is reflected. Film thickness, density and interfacial roughness are obtained from this modeling method.

In an attempt to produce completely amorphous films, processing techniques can induce crystallite growth resulting in either small well formed crystallites or crystallites with defined structure in only one or two dimensions. AMIA Laboratories measures and reports a % crystallinity for single films or film stacks, as well as provides information about the crystallite size and structure.

As thin films are deposited, the deposition conditions influence the crystallinity and crystallographic phases forming. AMIA Labs specializes in phase identification of oriented thin films and barriers, and films with low crystallinity or crystallite size. Identification of phases such as Ta₂N, TaN, WSi₂, etc… is typically done using a 2-D detector observing a large section of the Debye ring, in order to identify all on axis and off axis peaks and weak peaks.

With the remarkable progress of thin film technology comes a need to characterize crystal materials that range from Silicon to III-V compound semiconductors. AMIA Labs provides HRXRD, including high resolution rocking curves (0.36 arc sec resolution), crystal composition ratio, lattice strain, lattice distortion and mosaicity, and reciprocal space maps. Measurements are accomplished using the Rigaku ATX-G high resolution diffractometer (see the Rigaku XRD page at www.Rigakumsc.com for further details).