  We describe a complete development process of a segmented-blade linear ion
trap. Alumina substrate is characterized with an X-ray diffraction and
loss-tangent measurement. The blade is laser-micromachined and polished,
followed by the sputtering and gold electroplating. Surface roughness is
examined at each step of the fabrication via both electron and optical
microscopies. On the gold-plated facet, we obtain a height deviation of tens of
nanometers in the vicinity of the ion position. Trapping of laser-cooled
$^{174}$Yb$^{+}$ ions is demonstrated.
