The effects of boron in the Cu(B)/Ti/SiO2 system on the Cu-Ti reaction, resistivity, and diffusion barrier properties

Abstract

The behavior of boron in Cu(4.8at.%B)/Ti/SiO2 was investigated as a function of temperature, and its influences on the Cu-Ti interaction, resistivity, and diffusion barrier properties were also studied. The results showed the formation of a titanium boride layer at the Cu-Ti interface, after heating the Cu(B)/Ti/SiO2 at 400°C and higher, effectively served as a barrier for the Cu and Ti diffusion, and significantly enhanced the Cu (111) texture. The resistivity dropped from 16.3 to 2.33 μΩ-cm after heating at 600°C, and continued to decrease up to 800°C. As a result, the Cu, in the form of B(O)x/Cu/TiB2/Ti(O) x/SiO2 multilayers, obtained by heating the Cu(B)/Ti/SiP2, showed high thermal stability with low resistivity and, thus, can be used as interconnections in advanced integrated circuits. Since the Cu, in the form of B(O)x/Cu/TiB2/Ti(O) x/SiO2 multilayers, obtained by heating the Cu(B)/Ti/SiO2, showed high thermal stability with low resistivity, it can be used as interconnections in advanced integrated circuits.