Atomic layer deposition of ruthenium is studied as a barrierless metallization solution for future sub-10 nm interconnect technology nodes. We demonstrate the void-free filling in sub-10 nm wide single damascene lines using an ALD process in combination with 2.5 Å of ALD TiN interface and postdeposition annealing. At such small dimensions, the ruthenium effective resistance depends less on the scaling than that of Cu/barrier systems. Ruthenium effective resistance potentially crosses the Cu curve at 14 and 10 nm according to the semiempirical interconnect resistance model for advanced technology nodes. These extremely scaled ruthenium lines show excellent electromigration behavior. Time-dependent dielectric breakdown measurements reveal negligible ruthenium ion drift into low-κ dielectrics up to 200 °C, demonstrating that ruthenium can be used as a barrierless metallization in interconnects. These results indicate that ruthenium is highly promising as a replacement to Cu as the metallization solution for future technology nodes.

We investigated plasma treatment induced water absorption in a SiOCH low-k dielectric and the influence of the absorbed water components on the low-k dielectric reliability. By using thermal desorption spectroscopy (TDS), water absorption in SiOCH was evidenced for N2/H2 plasma treatments. Based on these TDS results, two anneal temperatures were selected to separate and quantify the respective contributions of two absorbed water components, physisorbed (α) and chemisorbed (β) water, to low-k dielectric reliability. With the physisorbed water desorbed by an anneal at 190 °C, the low-k dielectric shows reduced leakage currents and slightly improved time-dependent dielectric breakdown (TDDB) lifetimes. However, the observed failure mechanism represented by the TDDB thermal activation energy (Ea) does not change until the chemisorbed water component was desorbed by an anneal at 400 °C. The close similarity between Ea and the bond energy associated with the β water component demonstrates that the β bond is among the weakest links for the SiOCH low-k dielectric breakdown.

No abstract

Periodic mesoporous organosilicas (PMOs) are one of the most promising candidates to be used as ultra-low-k dielectrics in microelectronic devices. In this paper, PMO thin films that combine an ultralow-k value, a hydrophobic property and a high resistance against aggressive chemical conditions are presented. The films are synthesized via spin-coating of a 1,1,3,3,5,5-hexaethoxy-1,3,5trisilacyclohexane, hydrochloric acid, water and ethanol mixture using polyoxyethylene (10) stearyl ether as a porogen template. The obtained highly porous films are hydrophobic, crack-free and an ultra-low k-value of 1.8 is achieved. Finally, the chemical resistance of these PMO films against alkaline solutions is investigated in detail and compared with the resistance of mesoporous silicas and PMOs synthesized with cetyl trimethylammonium chloride.

No abstract