Thermal stability of Rui-inserted nickel monosilicides

Kijeong Yoon, Ohsung Song

Research output: Contribution to journalArticlepeer-review

Abstract

Thermally-evaporated 10 nm-Ni/1 nm-Ru/(30 nm or 70 nm-poly)Si structures were fabricated in order to investigate the thermal stability of Ru-inserted nickel monosilicide. The silicide samples underwent rapid thermal annealing at 300-1,100°C for 40 seconds. Silicides suitable for the salicide process were formed on the top of the single crystal and polycrystalline silicon substrates mimicking actives and gates. The sheet resistance was measured using a four-point probe. High resolution X-ray diffraction and Auger depth profiling were used for phase and chemical composition analysis, respectively. Transmission electron microscope and scanning probe microscope(SPM) were used to determine the cross-sectional structure and surface roughness. The silicide, which formed on single crystal silicon and 30 nm polysilicon substrate, could defer the transformation of Ni2Si and NiSi2, and was stable at temperatures up to 1,100°C and 1,000°C, respectively. Regarding microstructure, the nano-size NiSi preferred phase was observed on single crystalline Si substrate, and agglomerate phase was shown on 30 nm-thick polycrystalline Si substrate, respectively. The silicide, formed on 70 nm polysilicon substrate, showed high resistance at temperatures >700°C caused by mixed microstructure. Through SPM analysis, we confirmed that the surface roughness increased abruptly on single crystal Si substrate while not changed on polycrystalline substrate. The Ru-inserted nickel monosilicide could maintain a low resistance in wide temperature range and is considered suitable for the nano-thick silicide process.

Original languageEnglish
Pages (from-to)159-168
Number of pages10
JournalJournal of Korean Institute of Metals and Materials
Volume46
Issue number3
StatePublished - Mar 2008

Keywords

  • Nano-thick
  • Ni silicide
  • Ru-inserted Ni silicide
  • Salicide
  • Thermal stability

Fingerprint

Dive into the research topics of 'Thermal stability of Rui-inserted nickel monosilicides'. Together they form a unique fingerprint.

Cite this