Phase formations in Co–Silicon system

Formation of an extended CoSi2 thin nanohexagons array coherently buried in silicon single crystal

“…7,8 The specific type of Co-Si compounds that develops during the growth processes is also a relevant issue because the different phases of the equilibrium phase diagram of this binary system exhibit quite different resistivities, namely 10-20, 110, 140, and 20 lX/cm for Co, Co 2 Si, CoSi, and CoSi 2 , respectively. 9 Previous investigations established that the silicide phase nucleates locally on structural defects of the Si surface during an exothermic reaction, this first step being followed by a self-ordered lateral growth. [10][11][12][13][14][15][16][17][18][19] Wang et al 20 reported the fabrication of micro/nanoscale pits with facile shape, orientation, and size controls on a Si surface via an Au-nanoparticles-assisted vapor transport method.…”

Linear growth kinetics of nanometric silicides in Co/amorphous-Si and Co/CoSi/amorphous-Si thin films

“…Our observations refine the earlier picture because we observed simultaneous growth of the Co 2 Si layer and consumption of the Co and CoSi layers. Moreover, in all previous investigations [10][11][12][16][17][18][19][20][21] the kinetic exponents for the growth of CoSi and Co 2 Si phases were found to be 0.5. In contrast, we observed a very definite deviation from the parabolic growth law.…”

Cobalt silicide formations and magnetic properties of laser ablated Co(Cr) thin films

“…It is well known that three cobalt silicides can be formed through atom diffusing between the Si substrate and the pure cobalt film [1,2]. The preferred orientation and forming temperature of cobalt silicide depend upon the film synthesis method and processing conditions.…”

“…Another compound CoSi, with a FeSi-type simple cubic structure and lattice parameter of 4.438 Å, has also been widely investigated as a novel electrochemical hydrogen storage alloy [4]. The third compound Co 2 Si has orthorhombic PbCl 2 structure with lattice parameter of a ¼ 7.11 Å, b ¼ 4.92 Å and c ¼ 3.74 Å.…”

“…Hong and coworkers [5,6] studied the Co-Si film system and showed that the first stable phase to be formed is Co 2 Si at 350 C, followed by CoSi at 375 C and then CoSi 2 at 550 C. The CoSi 2 phase transforms to CoSi phase when the temperature is greater than 650 C. Liu et al [7,8] suggested that the formation temperature of CoSi 2 ranges from 650-700 C by studying a series of epitaxial Co/Si, Co/Ti/Si films produced through electron evaporation. However, Guo and coworkers [9] observed a different formation temperature of cobalt silicide at sputtering Co/Si films by a stress measuring method, of which Co 2 Si, CoSi and CoSi 2 phases appears at about 394 C, 439 C and 510 C, respectively.…”