Study of the Vacuum Pressure Sensing from the Electrical Resistance Response of Porous Silicon Fabricated via Photo-Electrochemical Technique

*Corresponding Author: Noor S. Dawood as.18.06@grad.uotechnology.edu.iq Abstract The manufacturing of vacuum sensors is critical to several vacuumbased applications. Porous silicon (PSi) was chosen as the vacuum sensor due to the possibility of moving air particles settled inside the pores while being put in the vacuum. The characteristics of porous silicon sensing to the evacuation of gases during vacuum was inferred by changing in the electrical resistivity. This work depends on the change in the electrical resistance of the PSi layers that was prepared via photo-electrochemical technique on the n-type (100) oriented silicon wafer. The surface topography of porous silicon is necessary to understand the morphological properties. Therefore, structural and morphological characterization of PSi samples were studied and analyzed using the scanning electron microscope (SEM) and X-Ray Diffraction (XRD) pattern. The etching process was carried out with various etching times, hydrofluoric acid (HF) concentration, and constant current density. The results showed that the pore size is increased as the etching time increased. The etching time produced pores of different sizes. The electrical resistance values were calculated after placing the sample in the vacuum system, starting from atmospheric pressure down to 10torr. The electrical properties of PSi indicate that electrical resistance gradually decreases with increasing vacuum pressure.