Self-aligned titanium silicide device technology by NH3 plasma assisted thermal annealing

Author(s):  
Bing-Zong Li
1987 ◽  
Vol 62 (10) ◽  
pp. 4319-4321 ◽  
Author(s):  
R. Pantel ◽  
D. Levy ◽  
D. Nicolas ◽  
J. P. Ponpon

1991 ◽  
Vol 224 ◽  
Author(s):  
Po-Ching Chen ◽  
Jian-Yang Lin ◽  
Huey-Liang Hwang

AbstractTitanium silicide was formed on the top of Si wafers by arsenic ion beam mixing and rapid thermal annealing. Three different arsenic-ion mixing conditions were examined in this work. The sheet resistance, residue As concentration post annealing and TiSi2 phase were characterized by using the* four-point probe, RBS and electron diffraction, respectively. TiSi2 of C54 phase was identified in the doubly implanted samples. The thickness of the Ti silicide and the TiSi2/Si interface were observed by the cross-sectional TEM.


1989 ◽  
Vol 146 ◽  
Author(s):  
Leonard Rubin ◽  
Nicole Herbots ◽  
JoAnne Gutierrez ◽  
David Hoffman ◽  
Di Ma

ABSTRACTA method for producing shallow silicided diodes for MOS devices (with junction depths of about 0.1 µm), by implanting after forming the silicide layer was investigated. The key to this integrated process is the use of rapid thermal annealing (RTA) to activate the dopants in the silicon, so that there is very little thermal broadening of the implant distribution. Self-aligned titanium silicide (TiSi2) films with thicknesses ranging from 40 to 80 nm were grown by RTA of sputter deposited titanium films on silicon substrates. After forming the TiSi2, arsenic and boron were implanted. A second RTA step was used after implantation to activate these dopants. It was found that implanting either dopant caused a sharp increase in the sheet resistivity of the TiSi2. The resistivity can be easily restored to its original value (about 18 µΩ-cm) by a post implant RTA anneal. RBS analysis showed that arsenic diffuses rapidly in the TiSi2 during RTA at temperatures as low as 600°C. SIMS data indicated that boron was not mobile up to temperatures of 900°C, possibly because it forms a compound with the titanium which precipitates in the TiSi 2. Coalescence of TiSi2 occurs during post implant furnace annealing, leading to an increase in the sheet resistivity. The amount of coalescence depends on the film thickness, but not on whether or not the film had been subject to implantation. Spreading resistance profiling data showed that both arsenic and boron diffused into the TiSi2 during furnace annealing, reducing the surface concentrations of dopant at the TiSi2/Si interface. Both N+/P and P+/N diodes formed by this technique exhibited low leakage currents after the second RTA anneal. This is attributed to removal of the implant damage by the RTA. In summary, the second RTA serves the dual purpose of removing implant damage in the TiSi2 and creating the shallow junction by dopant activation.


1992 ◽  
Vol 72 (2) ◽  
pp. 815-817 ◽  
Author(s):  
F. Richter ◽  
E. Bugiel ◽  
H. B. Erzgräber ◽  
D. Panknin

2001 ◽  
Vol 670 ◽  
Author(s):  
Lin Zhangand ◽  
YongKeun Lee

ABSTRACTIn this paper, the effect of pre-cooling treatment on the low resistivity C54 phase titanium silicide film growth was investigated. Our experimental results and micro-structural analysis show that, by introducing such cooling treatment into the titanium silicide process to precede the conventional rapid thermal annealing, the low resistivity C54 phase formation can be enhanced. Defects at the Si/Ti interface caused by the thermal mismatch between titanium and silicon layers during the cooling treatment were found to contribute to the increase of the C49 nucleus sites. This help to supply more C49 grain boundaries and triple junction sites at which the C54 phase could nucleate. This discovery has the potential to reduce the complexity and cost associated with forming low resistivity titanium silicide on sub-micron structures for future ULSI application.


1988 ◽  
Vol 128 ◽  
Author(s):  
Leonard M. Rubin ◽  
N. Herbots ◽  
D. Hoffman ◽  
D. Ma

ABSTRACTThe combination of arsenic and boron implantation with rapid thermal annealing (RTA) has been investigated to form shallow p-n junctions under a titanium silicide (TiSi2) metallization. The use of TiSi2 as a connection material can lead to the destruction of the junction if the kinetics of silicidation and doping are not well controlled. The purpose of this study is to better understand and control these kinetics, using far-from equilibrium processing such as ion implantation and RTA. The structures were characterized by Rutherford Backscattering Spectometry (RBS) for arsenic and silicide profiling, Secondary Ion Mass Spectometry (SIMS) for boron profiling, Scanning Electron Microscopy (SEM), and electrical sheet resistance measurements. Two procedures were investigated. Both involved the thermal reaction of Ti thin films, sputter-deposited with thicknesses ranging between 40 and 80 nm. In the first experiment, the as-deposited films were implanted with either 115 keV arsenic or 28 keV boron to form the junction, disperse the native oxide, and ion beam mix the Ti and Si. The films were then subjected to an RTA at 750°C for 15 to 60 seconds, which leads to TiSi2 formation in unimplanted films. Implantation was found to actually prevent TiSi2 formation. Ion transport calculations indicated that dopant pile-up at the interface might inhibit silicidation while higher energies and larger implant doses can more effectively ion beam mix Ti and Si. A more attractive solution consists of first forming TiSi2 from the as-deposited Ti by RTA, and then implanting to form the junction. This resulted in better control of the junction thickness. A sharp increase in the TiSi2 resistivity was found after implantation but the original value could be restored by a second RTA. This RTA also electrically activated the dopants and recrystallized the junction. The material properties of Ti/Si and TiSi2/Si under ion bombardment, RTA, doping, and conventional furnace annealing will be discussed.


1985 ◽  
Vol 38 (1) ◽  
pp. 23-29 ◽  
Author(s):  
D. Levy ◽  
J. P. Ponpon ◽  
A. Grob ◽  
J. J. Grob ◽  
R. Stuck

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