A high aspect ratio and large current 3D electrochemical sensor was de- signed. This miniaturized sensor was built by using silicon microfabrication technologies in comparison to screen printed electrode. New tilting tool for CHA solution platinum evaporator is designed and realized. The analysis of tilt angles and rotation for evaporation of platinum on 3D structure in evap- orator is done. Different recipe of DRIE etching have been tested in order to get straight pillars. Different recipe in both ”Trikon Omega 201” and ”Rapier Omega i2L DRIE etcher” were tested to minimise the scalloping effects on the pillars. The final sensor with straight pillar structure with platinum working electrode is fabricated.