Sub-micron Resolution CT

For Failure Analysis and Process Development

M. Feser, H. Chang, H. Cui, F. Duewer, S.H. Lau, A. Tkachuk, W. Yun

Xradia Inc., 5052 Commercial Circle, Concord, CA, 94520, USA, Email: m.feser@xradia.com

ABSTRACT

Many modern industrial processes and research applications place increasingly higher demands on x- ray CT imaging resolution and sensitivity for low contrast, low-Z samples. The three approaches to increasing imaging resolution are: 1) reduction in the x-ray spot size, 2) higher resolution detectors, or

3) to employ x-ray optical elements. Systems are available and under continued development that pursue one or more of these approaches. The Xradia MicroXCT projection type microscope described in this paper has been optimized for high-resolution x-ray CT by employing a high resolution detector paired with a microfocus x-ray source. Large working distances in this CT system enable full tomographic data collection at micrometer resolution of large samples, such as flip-chip packages.

X-ray CT instruments using x-ray optical elements for condenser optics and imaging objective lenses, are a new development and they reach sub-50 nm resolution and find various applications, for example for die level imaging in the semiconductor industry or for the process development for fuel cells, which we describe here as one application. Sub-um resolution CT instruments without x-ray optical elements have a large applications base already, however new instruments optimized for soft materials and low contrast specimens, as described in this paper, offer completely new capabilities and open new applications, for example also in biomedical and small-animal imaging.

New developments in the area of phase contrast imaging enable unprecedented image contrast for specimens with very low absorption, which for research applications enables for the first time to image many specimens in their natural state, such as arteries to examine calcification, etc. Zernike phase contrast for sub-50nm x-ray CT even enables the imaging of single cells or thin tissue slices for biological or medical applications.

Keywords X-ray microscopy, Zone plates, x-ray optics, x-ray CT, Zernike phase contrast