  Confocal x-ray fluorescence microscopy (CXRF) allows direct detection of
x-ray fluorescence from a micron-scale 3D volume of an extended, unthinned
sample. We have previously demonstrated the use of a novel collection optic,
fabricated from silicon, that improves the spatial resolution of this approach
by an order of magnitude over CXRF using polycapillaries. The optic, called a
collimating channel array (CCA), consists of micron-scale,
lithographically-fabricated arrays of collimating channels, all directed
towards a single source position. Due to the limited absorbing power of
silicon, the useful energy range of these optics was limited to fluorescence
emission below about 10 keV. Here, we report fabrication of CCAs from germanium
substrates, and demonstrate their practical use for CXRF up to 20 keV.
Specifically we demonstrate a nearly energy-independent critical spatial
resolution $d_R$ of 2.1$\pm$0.17 \um from 2-20 keV, as well as excellent
background reduction compared to silicon-based CCAs throughout this energy
range. Design details of the optic and background-reduction holder are
described. Two versions of the optic are now available upon request at the
beamline 20ID-B, Advanced Photon Source (APS) - Argonne National Laboratory.
