Interface effect on mn-containing self-formed barrier formation with extreme low-k dielectric integration

Diffusion Barriers

“…The growth of the MnSi x O y barrier follows a logarithmic rate law at T = 350 °C and 450 °C, which represents a field-enhanced growth mechanism in the early stage and self-limiting growth behavior in the late stage. According to Pan et al [242], implementing Cu(Mn)-based self-formed barrier layers in combination with ultra-low-k dielectrics can be a successful approach for future technology nodes. The self-formed MnSi x O y layer is thermally stable during annealing at T = 450 °C for t = 100 h and at T = 600 °C for t = 10 h [234][235][236].…”

“…Besides annealing temperature and time, the barrier layer thickness is influenced by the Mn concentration and ranges between 2 nm and 8 nm (Figure 6.11). However, it should be taken into account that the requirements for dielectric material selection, patterning approaches and integration processes might be higher than those for conventional Ta-based barriers [242]. For a Cu(4 at% Mn) film deposited onto TEOS-based SiO 2 , the dielectric constant of the barrier is determined after annealing at T = 450 °C for t = 0.5 h and 5 h to k = 11.4 and 5.1, respectively [237].…”

Geometry, kinetics, and short length effects of electromigration in Mn doped Cu interconnects at the 32nm technology node

“…In order to meet the high performance, high current density needs of new technologies, the EM performance of metal lines and vias can be improved by strengthening the Cu/cap interface to slow down Cu diffusion along the historically fastest diffusion path. Mn or Al doping in Cu has proven to be a very effective way to enhance the EM performance of advanced Cu interconnects [1][2][3][4]. To achieve the EM improvement, the dopant diffuses through the Cu to bind with oxygen at the top Cu/Cap interface.…”