PdEr-Silicide Formation and Contact Resistivity Reduction to n-Si(100) Realized by Dopant Segregation Process

Abstract

In this paper, we have investigated the PdEr-silicide formation utilizing a developed PdEr-alloy target for sputtering, and evaluated the contact resistivity of PdEr-silicide layer formed on n-Si(100) by dopant segregation process for the first time. Pd₂Si and ErSi₂ have same hexagonal structure, while the Schottky barrier height for electron (Φ_bn) is different as 0.75 eV and 0.28 eV, respectively. A 20 nm-thick PdEr-alloy layer was deposited on the n-Si(100) substrates utilizing a developed PdEr-alloy target by the RF magnetron sputtering at room temperature. Then, 10 nm-thick TiN encapsulating layer was in-situ deposited at room temperature. Next, silicidation was carried out by the RTA at 500℃ for 5 min in N₂/4.9%H₂ followed by the selective etching. From the J-V characteristics of fabricated Schottky diode, qΦ_bn was reduced from 0.75 eV of Pd₂Si to 0.43 eV of PdEr-silicide. Furthermore, 4.0x10^-8Ωcm² was extracted for the PdEr-silicide to n-Si(100) by the dopant segregation process.