scholarly journals Formation of Si Nanorods and Discrete Nanophases by Axial Diffusion of Si from Substrate into Au and AuPt Nanoalloy Nanorods

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 68
Author(s):  
Nele Berger ◽  
Ayoub Laghrissi ◽  
Yee Yan Tay ◽  
Thirumany Sritharan ◽  
Jacek Fiutowski ◽  
...  

Interdiffusion between Si substrate and nanorod arrays of Au, Pt, and AuPt nanoalloys is investigated at temperatures lower than the AuSi eutectic temperature. When the nanorod is pure Au, Si diffusion from the substrate is very rapid. Au atoms are completely replaced by Si, converting the nanostructure into one of Si nanorod arrays. Au is diffused out to the substrate. The Au nanorod arrays on Si are unstable. When the nanorod is pure Pt, however, no diffusion of Si into the nanorod or any silicide formation is observed. The Pt nanorods are stable on Si substrate. When the nanorods are an alloy of AuPt, interesting interactions occur. Si diffusion into the nanorods is rapid but the diffusing Si readily reacts with Pt forming PtSi while Au diffuses out to the substrate. After annealing, nanophases of Au, Pt, PtSi, and Si may be present within the nanorods. When the Pt content of the alloy is low (12 at%) all Pt atoms are converted to silicide and the extra Si atoms remain in elemental form, particularly near the tip of the nanorods. Hence, the presence of Au accelerates Si diffusion and the ensuing reaction to form PtSi, a phenomenon absents in pure Pt nanorods. When the Au content of the alloy is low, the Si diffusion would cease when all Au atoms have diffused out of the nanorod, thereby arresting the silicide formation resulting in excess Pt in elemental form within the nanorod. This is a technique of making Si nanorods with and without embedded PtSi nanophase consisting of heterojunctions which could have unique properties.

1998 ◽  
Vol 525 ◽  
Author(s):  
L. P. Ren ◽  
P. Liu ◽  
G. Z. Pan ◽  
Jason C. S. Woo

ABSTRACTA novel low temperature self-aligned Ti silicidation with Ge+ pre-amorphization implant (PAI) is presented. Compared to conventional high temperature PAM silicidation, the advantages of Ti salicidation at temperatures below the recrystallization of a pre-amorphized layer are: (1) C49 TiSi2 silicide formation occurs only in the pre-amorphized layer so that the silicide depth can be well controlled, forming a very sharp interface between the silicide and the Si substrate; (2) Ti just reacts with the amorphous layer, avoiding the so-called bridging issue in which the silicide grows laterally over the isolation or spacer; (3) the effects of metal thickness and substrate doping on silicide formation are suppressed.


2016 ◽  
Vol 27 (30) ◽  
pp. 305403 ◽  
Author(s):  
Zhijia Bao ◽  
Xiaoyong Xu ◽  
Gang Zhou ◽  
Jingguo Hu

2010 ◽  
Vol 405 (1) ◽  
pp. 413-419 ◽  
Author(s):  
Sining Yun ◽  
Juneyoung Lee ◽  
Jahyun Yang ◽  
Sangwoo Lim

2008 ◽  
Vol 3 (9) ◽  
pp. 309-314 ◽  
Author(s):  
H. Wang ◽  
Z. P. Zhang ◽  
X. N. Wang ◽  
Q. Mo ◽  
Y. Wang ◽  
...  

1983 ◽  
Vol 25 ◽  
Author(s):  
Chuen-Der Lien ◽  
Meir Bartur ◽  
Marc-A. Nicolet

ABSTRACTEvaporated W, implanted Xe, and implanted 18O were used as markers to study the dominant moving species during (a) solid phase epitaxy (SPE) of evaporated Si, (b) silicide formation, and (c) oxidation of silicides on Si substrate.MeV 4He+ backscattering spectrometry and 18O (p, α)15 N nuclear reaction were used to monitor the evolution of elemental profiles as well as the change in the marker position. In most cases, the dominant moving species in SPE is the same as that observed in the formation and oxidation of that silicide. However, in CrSi2 the dominant moving species is Si during silicide formation, but Cr during SPE or oxidation.


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