Effects of thermal treatment on structures of Cu/atomic-layer-deposited TaN films/Si stacks

TY - JOUR

T1 - Effects of thermal treatment on structures of Cu/atomic-layer-deposited TaN films/Si stacks

AU - Wu, Y. Y.

AU - Eizenberg, M.

N1 - Funding Information: This work was supported by the “Magnet” program of the Chief Scientist Office at the Israel Ministry of Industry and Trade, Consortium of Emerging Dielectric and Conductor Technologies for the Semiconductor Industry. Y.Y. Wu acknowledges the support of the Lady Davis Fellowship Trust. The authors thank Dr. R. Brener at the Solid State Institute-Technion for XPS, AES measurements and helpful discussions, and C. Cytermann for SIMS measurements. We thank Applied Materials Inc., Santa Clara, CA for preparing the wafer samples.

PY - 2006/8/30

Y1 - 2006/8/30

N2 - Atomic layer deposition (ALD) TaN films are designed as diffusion barriers for Cu metallization of silicon devices. In a previous paper, we characterized the compositions and structures of ultrathin ALD TaN films. In this study, the effects of various thermal processes on the characteristics of Cu/ALD TaN/Si stacks are investigated by various analytical techniques. The results indicate that, for the as-received Cu/ALD TaN/Si samples (G1 set samples), thermal treatment at a temperature higher than 500 °C results in formation of the intermetallic compound Cu3Si on the surface. It is interesting to note that the amount of copper silicide on the surface increases with the ALD TaN thickness, as long as the later is less than 10 nm. No Cu3Si is detected after the same thermal process in similar stacks, when the top-layer Cu was deposited on pre-annealed ALD TaN/Si samples (G2 set samples). Cu dewetting occurs after thermally treating the Cu/ALD TaN/Si stacks for both G1 set and G2 set samples. Analysis indicates that impurities play an important role on the thermal behaviors of G1 and G2 stacks.

AB - Atomic layer deposition (ALD) TaN films are designed as diffusion barriers for Cu metallization of silicon devices. In a previous paper, we characterized the compositions and structures of ultrathin ALD TaN films. In this study, the effects of various thermal processes on the characteristics of Cu/ALD TaN/Si stacks are investigated by various analytical techniques. The results indicate that, for the as-received Cu/ALD TaN/Si samples (G1 set samples), thermal treatment at a temperature higher than 500 °C results in formation of the intermetallic compound Cu3Si on the surface. It is interesting to note that the amount of copper silicide on the surface increases with the ALD TaN thickness, as long as the later is less than 10 nm. No Cu3Si is detected after the same thermal process in similar stacks, when the top-layer Cu was deposited on pre-annealed ALD TaN/Si samples (G2 set samples). Cu dewetting occurs after thermally treating the Cu/ALD TaN/Si stacks for both G1 set and G2 set samples. Analysis indicates that impurities play an important role on the thermal behaviors of G1 and G2 stacks.

KW - Atomic layer deposition

KW - Impurities

KW - Tantalum nitride

KW - Thermal treatment

UR - http://www.scopus.com/inward/record.url?scp=33745761019&partnerID=8YFLogxK

U2 - 10.1016/j.tsf.2006.02.014

DO - 10.1016/j.tsf.2006.02.014

M3 - 文章

AN - SCOPUS:33745761019

SN - 0040-6090

VL - 514

SP - 33

EP - 44

JO - Thin Solid Films

JF - Thin Solid Films

IS - 1-2

ER -