  Superconducting Tunnel Junctions (STJ's) are currently being developed as
photon detectors for a wide range of applications. Interest comes from their
ability to cumulate photon counting with chromaticity (i.e. energy resolution)
from the near infrared (2 $\mu$m) to the X-rays wavelengths and good quantum
efficiency up to 80%. Resolving power can exceed 10 in the visible wavelength
range. Our main goal is to use STJ's for astronomical observations at low light
level in the near infrared. This paper put the emphasis on two main points: the
improvement of the tantalum absorber epitaxy and the development of a new
version of the fabrication process for making Ta/Al-AlOx-Al/Ta photon counting
STJ's. The main features of this process are that pixels have aligned
electrodes and vias patterned through a protecting SiO2 layer. These vias are
then used to contact the top electrode layer. We use a double thin aluminum
trapping layer on top of a 150 nm thick Ta absorber grown epitaxially. Photon
counting experiments with Ta junction array are presented at \lambda = 0.78
$\mu$m. Digital filtering methods are used to compute the photon counting data
in order to minimize the effects of noise.
