Formation of locally aluminum-doped p-type silicon regions by in-line high-rate evaporation

Abstract

Locally aluminum-doped p-type silicon regions are formed by in-line high-rate evaporation of aluminum. We deposit aluminum layers of 28 μm thickness at dynamic deposition rates of 20 μm×m/min on locally laser-ablated Al2O3 / SiNx passivation layers. Due to the high substrate temperature of up to 778°C during deposition an Al-doped p+ region is formed. Using the camera-based dynamic infrared lifetime mapping technique we determine a contact recombination velocity of 1000 ± 100 cm/s for local Al-p+ regions on p-type silicon wafers of 1.5 ωcm resistivity. The recombination velocity between the contacts is determined to 4.4 ± 0.5 cm/s after deposition.