Salicidation process using NiSi and its device application

Abstract

Self-aligned silicidation is a well-known process to reduce source, drain, and gate resistances of submicron metal-oxide-semiconductor devices. This process is particularly useful for devices built on very thin Si layers (∼1000 Å or less) on insulators because of the large source and drain resistances associated with the thin Si layer. NiSi is a good candidate for salicidation process due to its low resistivity, low formation temperature, little silicon consumption, and large stable processing temperature window. In this article, the formation of nickel mono-silicide (NiSi) using rapid thermal annealing, the thermal stability of NiSi on n+ poly-Si and the contact resistance of NiSi on n+ Si layers in a SIMOX structure were investigated. NiSi salicidation process was, then, incorporated into a NMOS/SIMOX device fabrication for partial and full consumption of the Si in the source and drain regions during the salicidation process. The effects of void formation and silicide encroachment on the device performance were also studied.

Structural and electrical characterization of the nickel silicide films formed at 850°C by rapid thermal annealing of the Ni/Si(100) films

“…1 [20,23]. As the film thickness decreases from 400 to 170 nm, NiSi 2 (1 1 1), NiSi 2 (2 0 0) and NiSi(2 1 1) silicide phases are still present, however, the peak height of NiSi 2 (1 1 1) phase decreases, whereas that of the NiSi 2 (2 0 0) increases.…”

“…NiSi has been also reported to agglomerate during the silicidation process at temperature as low as 600 • C [6][7][8][9][10][11][12]. This thermal instability of NiSi is a drawback in applying it to CMOS manufacturing and integration process [3,12,[20][21][22]. However, nickel di-silicide (NiSi 2 ) formed from the low resistivity phase NiSi has the lowest lattice mismatch to Si and shows good epitaxial growth on Si [20,23].…”

“…This thermal instability of NiSi is a drawback in applying it to CMOS manufacturing and integration process [3,12,[20][21][22]. However, nickel di-silicide (NiSi 2 ) formed from the low resistivity phase NiSi has the lowest lattice mismatch to Si and shows good epitaxial growth on Si [20,23]. NiSi 2 exhibits good thermal stability up to high temperatures of about 1000 • C. NiSi 2 loses adhesion to Si near its melting point of ∼993 • C [21], thereafter it starts to agglomerate with grain boundary grooving, followed by grain separation and formation of silicide islands, resulting in a dramatic increase in sheet resistance [20,[24][25][26][27].…”

Formation of thermally stable Ni monosilicide using an inductively coupled plasma process

“…This phase transition behavior is in good agreement with the results previously reported by other groups, showing that NiSi transforms into NiSi 2 at temperatures between 700°C and 800°C in the presence of excess Si. [15][16][17][18] Figure 4 shows the annealing temperature dependence of the sheet resistance of the Ni-silicide samples with and without the Ar plasma treatment. For the untreated samples, as the annealing temperature increases, the sheet resistance only slightly increases and then increases rapidly at temperatures in excess of 600°C.…”

Ni-W-P Catalyzed Growth of Carbon Nanotubes on SiC Whiskers

“…As a candidate material for micro or nano-electronics, the nickel silicide formed at the Ni-SiC interface could provide lowresistivity metal contact and interconnect [21][22][23] between the semiconducting SiC whisker and the carbon nanotube. The contact or interconnect quality here should be further investigated by adjusting the reaction temperature and time, the yield of the silicides and the quantity of residual catalysts at the connecting areas.…”