Electroless Copper Deposition for Ultralarge-Scale Integration

Abstract

The characteristics of electroless copper plating on different substrates of TiN/SiO 2 /Si, Cu seed /Ta/SiO 2 /Si, and Cu seed /TaN/SiO 2 /Si have been investigated. Continuous copper films with good surface morphology are obtained, and hydrogen-induced blister formation is inhibited by optimizing plating solution and conditions. Surface roughness of the electrolessly plated copper films increases with increasing film thickness, and the average roughness is 11 nm at a film thickness of 1 m on Cu seed /TaN/SiO 2 /Si substrate. Conformal copper deposition with excellent step coverage completely fills deep subquarter-micrometer features of high aspect ratios up to five. Copper growth orientation depends on the underlayer structure. A copper film with strong (111) texture is plated on the (111) textured copper seed layer of Cu seed /TaN/SiO 2 /Si substrate, while no preferred orientation is found on the other substrates. After thermal annealing at 400ЊC in N 2 /H 2 for 1 h, Cu(111) texture is enhanced in all systems. By thermal annealing, defects in the plated copper are reduced, and the electrical resistivity of the plated copper is lowered to 1.75 ⍀ cm at room temperature.

Electroless Cu deposition process on TiN for ULSI interconnect fabrication via Pd/Sn colloid activation

“…This finding may result from a stronger binding force between Cu and TiN substrate due to their interdiffusion. Similar results have been reported by Hsu et al 9 The crystal structure and the resistivity of the deposit also change after the thermal annealing process. Figure 7 shows the crystal morphology before and after the thermal process.…”

Structure and wettability control of Cu–Ni–P alloy synthesized by electroless deposition

“…Recently, we have obtained the Cu cone structure by electroless deposition with addition of crystallization modifier (PEG) [13]. Among them electroless plating technique [14] has unique advantages as a facile and promising method for fabricating uniform metallic thin films on any kind of substrates including metals and nonmetals.…”

Electroless plating of copper on Si(100) surfaces modified by surface‐initiated atom‐transfer radical polymerization of 4‐vinylpyridine

“…[16] For practical application, the modification of the silicon surface prior to the electroless metallization process is a necessary step. The methods of modification of silicon surfaces have included dry seeding via sputtering, [17] chemical vapor deposition [18] and plasma immersion ion implantation. [19] Chemical modification of silicon surfaces via the deposition of organic and inorganic layers is currently of great research interest.…”