Electrical Characterization of AlSiCu-on-AlSiTi/TiN Structured Contacts for Schottky Photodiodes

Si-based Schottky photodiodes offer detection in the SWIR range with CMOS compatibility. The introduction of a thin film metal as Schottky contact offers promising improvements in overall performance through internal quantum efficiency enhancement with the cost of introducing an optical cavity. One challenging aspect arises therefore from the metal-metal connection of such a system including thin film structures. We investigate the contact area created by a TiN/AlSiTi thin film and an AlSiCu metallization in regards of resistance. The thicknesses of the sputtered thin film as well as the pre- and post-treatment of the AlSiCu metallization serve as process parameters.