TY - JOUR
T1 - Characterization of NiCo composite silicides by 10 nm-Ni 50Co50 alloy films with additional annealing
AU - Song, Ohsung
AU - Yoon, Kijeong
AU - Kim, Sangyeob
PY - 2009/4
Y1 - 2009/4
N2 - We fabricated 10 nm-Ni50Co50 alloy films into a single crystal and a polycrystalline silicon substrate, and applied silicidation annealing to these substrates at 600 °C to 1100 °C for 40 s. To test the thermal stability of the processed silicide layers, we examined the change in their physical properties after an additional 30-min annealing at the given rapid thermal annealing (RTA) temperatures. To characterize the physical properties of the silicide layers, we used a four-point probe, an x-ray diffractometer (XRD), a transmission electron microscope, a scanning electron microscope, an Auger electron spectroscope, and an atomic force microscope. The silicide layer formed only through RTA showed low resistance (20 Ω/sq) at up to 1100 °C and 900 °C for the single crystal and for the polycrystalline silicon substrate, respectively. Sheet resistance after the additional 30-min annealing was low, and did not differ significantly before and after the additional annealing for the single crystal substrate, but it became high at all temperatures for the polycrystalline substrate. The XRD confirmed the formation of the NiSi (or Ni(Co)Si) phase, in which there were no changes after the additional annealing. The thickness of the RTA-formed silicide layers varied from 11 ran to 13 ran, 20 nm and 28 nm, depending on whether the temperature was 700 °C or 1000 °C, for both the single and the polycrystalline substrates. The thickness of the silicide layers tended to increase from 22 nm to 25 nm, 48 nm and 82 nm after the additional 30-min annealing. Auger depth profiling also confirmed changes in thickness with the additional annealing. The surface roughness was no greater than lOnm in all cases, even with the additional annealing. We verified that the nano-silicide layer formed with the proposed nano-NiCo alloy films satisfied the requirements for the nano-CMOS process.
AB - We fabricated 10 nm-Ni50Co50 alloy films into a single crystal and a polycrystalline silicon substrate, and applied silicidation annealing to these substrates at 600 °C to 1100 °C for 40 s. To test the thermal stability of the processed silicide layers, we examined the change in their physical properties after an additional 30-min annealing at the given rapid thermal annealing (RTA) temperatures. To characterize the physical properties of the silicide layers, we used a four-point probe, an x-ray diffractometer (XRD), a transmission electron microscope, a scanning electron microscope, an Auger electron spectroscope, and an atomic force microscope. The silicide layer formed only through RTA showed low resistance (20 Ω/sq) at up to 1100 °C and 900 °C for the single crystal and for the polycrystalline silicon substrate, respectively. Sheet resistance after the additional 30-min annealing was low, and did not differ significantly before and after the additional annealing for the single crystal substrate, but it became high at all temperatures for the polycrystalline substrate. The XRD confirmed the formation of the NiSi (or Ni(Co)Si) phase, in which there were no changes after the additional annealing. The thickness of the RTA-formed silicide layers varied from 11 ran to 13 ran, 20 nm and 28 nm, depending on whether the temperature was 700 °C or 1000 °C, for both the single and the polycrystalline substrates. The thickness of the silicide layers tended to increase from 22 nm to 25 nm, 48 nm and 82 nm after the additional 30-min annealing. Auger depth profiling also confirmed changes in thickness with the additional annealing. The surface roughness was no greater than lOnm in all cases, even with the additional annealing. We verified that the nano-silicide layer formed with the proposed nano-NiCo alloy films satisfied the requirements for the nano-CMOS process.
KW - Composite silicide
KW - Ni silicide
KW - Salicide
KW - Silicide
KW - Thermal stability
UR - http://www.scopus.com/inward/record.url?scp=67649134833&partnerID=8YFLogxK
U2 - 10.1007/s12540-009-0285-3
DO - 10.1007/s12540-009-0285-3
M3 - Article
AN - SCOPUS:67649134833
SN - 1598-9623
VL - 15
SP - 285
EP - 291
JO - Metals and Materials International
JF - Metals and Materials International
IS - 2
ER -