Integration of High Performance and Low Cost Cu/Ultra Low-k SiOC(k=2.0) Interconnects with Self-formed Barrier Technology for 32nm-node and Beyond

Abstract

A method of integrating high performance and low-cost Cu ultra low-k (ULK) SiOC(k=2.0) hybrid interconnects with SiOC(k=2.65) hard mask structure has been developed. The method combines Cu/ULK interconnects with the self-formed MnO x barrier layer that was shown to have lower resistance and higher reliability than Cu alloys. Moreover, dual-damascene (DD) interconnects with MnO x barrier layer showed excellent stress-induced voiding performance and significantly longer electromigration lifetime and required no additional pore-sealing process. It is concluded that this self-formed barrier process is the most feasible technology for 32nm-node Cu/ULK interconnects.

Copper Metal for Semiconductor Interconnects

“…Doping impurities such as Al [106,107], Ag [108], Mn [109][110][111], Magnesium (Mg) [112,113], Zirconium (Zr) [114], and Tin (Sn) [115] into the Cu layer is an effective method to improve the EM lifetime. The main disadvantage of this approach is that the impurities increase the resistivity of Cu line.…”

Process Technology for Copper Interconnects

“…Another method to improve the electromigration lifetime is to dope the Cu with impurities such as Al [135,136], Ag [137], or Mn [138][139][140]. The dopants are typically introduced into the Cu seed layer (Figure 8.21H-K).…”

In-situ surface and interface study of atomic oxygen modified carbon containing porous low-κ dielectric films for barrier layer applications

“…5,6 In addition to the changes of interconnect and barrier materials, low-j and ultra-low-j (ULK) dielectrics (j $ 2-3) are being introduced to replace silicon dioxide (j ¼ 4) within the interconnect stack. 7 Organosilicates (OSGs) are a promising class of organic-inorganic hybrid dielectric material for current and next-generation micro and nanoelectronic devices. 8 The introduction of hydrocarbon organic groups to the silicon oxygen network lowers the dielectric constant by decreasing the total density and polarizability of the material.…”

“…5,6,16,17 While the majority of studies to date have focused on the formation of MnSiO 3 barrier layers on SiO 2 surfaces, 6,18,19 the growth of the Mn based barrier layers on carbon containing ultra-low dielectric constant (ULK) materials has also been the subject of interest. 7,16,[20][21][22] The formation of effective barrier layers on these surfaces is essential if they are to be adopted by the industry. As such, a secondary focus of this study is to determine the impact of the atomic oxygen treatment of low-j materials on the subsequent Mn-based barrier layer formation.…”