Dopant Redistribution During Silicide Formation

1985 ◽  
Vol 54 ◽  
Author(s):  
I. Ohdomari ◽  
K. Konuma ◽  
M. Takano ◽  
T. Chikyow ◽  
H. Kawarada ◽  
...  
Keyword(s):  
Solubility Limit ◽  
Good Evidence ◽  
Dislocation Loops ◽  
Enhanced Diffusion ◽  
Si Substrates ◽  
Vacancy Generation ◽  
Lower Solubility ◽  
Before And After ◽  
Extrinsic Dislocation ◽  
Dopant Redistribution

ABSTRACTAfter the review of dopant redistribution phenomena observed during formation of near noble metal suicides, we describe the results of our recent experiments to get a better understanding of a mechanism of the dopant redistribution phenomenon in Si substrates. The key factors to understand the dopant redistribution are dopant segregation at the suicide/ Si interface due to lower solubility limit of dopants in suicides, enhanced diffusion of dopants into the Si substrate at much lower temperatures than the ordinary thermal diffusion, and electrical activation of the redistributed dopants. The results of As and carrier concentration measurements before and after Pd2Si formation to make clear the third factor show that the electrical activity of the redistributed As atoms in Si is strongly dependent on the initial activity before Pd2Si formation which is controlled by the temperature for the pre-annealing of As implanted Si.Shrinkage of extrinsic dislocation loops introduced by As implantation and subsequent annealing have been observed after Pd2Si formation, which is a good evidence of vacancy generation during Pd2Si formation. The role of the vacancies and interstitials on the second factor, the enhanced diffusion, has also been discussed. Finally we list a few issues to be answered in future by more detailed works in order to get a complete understanding of the redistribution phenomenon.

Transient Enhanced Diffusion of Dopants in Preamorphised Si Layers

1996 ◽  
Vol 438 ◽  
Author(s):  
A. Claverie ◽  
C. Bonafos ◽  
M. Omri ◽  
B. De Mauduit ◽  
G. Ben Assayag ◽  
...  
Keyword(s):  
Ostwald Ripening ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Interstitial Atoms ◽  
Extrinsic Dislocation ◽  
The Mean ◽  
Boron Diffusivity ◽  
Shed Light

AbstractTransient Enhanced Diffusion (TED) of dopants in Si is the consequence of the evolution, upon annealing, of a large supersaturation of Si self-interstitial atoms left after ion bombardment. In the case of amorphizing implants, this supersaturation is located just beneath the c/a interface and evolves through the nucleation and growth of End-Of-Range (EOR) defects.For this reason, we discuss here the relation between TED and EOR defects. Modelling of the behavior of these defects upon annealing allows one to understand why and how they affect dopant diffusion. This is possible through the development of the Ostwald ripening theory applied to extrinsic dislocation loops. This theory is shown to be readily able to quantitatively describe the evolution of the defect population (density, size) upon annealing and gives access to the variations of the mean supersaturation of Si self-interstitial atoms between the loops and responsible for TED. This initial supersaturation is, before annealing, at least 5 decades larger than the equilibrium value and exponentially decays with time upon annealing with activation energies that are the same than the ones observed for TED. It is shown that this time decay is precisely at the origin of the transient enhancement of boron diffusivity through the interstitial component of boron diffusion. Side experiments shed light on the effect of the proximity of a free surface on the thermal behavior of EOR defects and allow us to quantitatively describe the space and time evolutions of boron diffusivity upon annealing of preamorphised Si layers.

Transient Enhanced Diffusion of Dopants in Preamorphised Si Layers

1996 ◽  
Vol 439 ◽  
Author(s):  
A. Claverie ◽  
C. Bonafos ◽  
M. Omri ◽  
B. De Mauduit ◽  
G. Ben Assayag ◽  
...  
Keyword(s):  
Ostwald Ripening ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Interstitial Atoms ◽  
Extrinsic Dislocation ◽  
The Mean ◽  
Boron Diffusivity ◽  
Shed Light

AbstractTransient Enhanced Diffusion (TED) of dopants in Si is the consequence of the evolution, upon annealing, of a large supersaturation of Si self-interstitial atoms left after ion bombardment. In the case of amorphizing implants, this supersaturation is located just beneath the c/a interface and evolves through the nucleation and growth of End-Of-Range (EOR) defects.For this reason, we discuss here the relation between TED and EOR defects. Modelling of the behavior of these defects upon annealing allows one to understand why and how they affect dopant diffusion. This is possible through the development of the Ostwald ripening theory applied to extrinsic dislocation loops. This theory is shown to be readily able to quantitatively describe the evolution of the defect population (density, size) upon annealing and gives access to the variations of the mean supersaturation of Si self-interstitial atoms between the loops and responsible for TED. This initial supersaturation is, before annealing, at least 5 decades larger than the equilibrium value and exponentially decays with time upon annealing with activation energies that are the same than the ones observed for TED. It is shown that this time decay is precisely at the origin of the transient enhancement of boron diffusivity through the interstitial component of boron diffusion. Side experiments shed light on the effect of the proximity of a free surface on the thermal behavior of EOR defects and allow us to quantitatively describe the space and time evolutions of boron diffusivity upon annealing of preamorphised Si layers.

Effects of Concurrent Co or Ti Silicidation on Transient Diffusion and End-of-Range Damage in Phosphorus Implanted Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
J.W. Honeycutt ◽  
J. Ravi ◽  
G. A. Rozgonyi
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Complete Removal ◽  
Dislocation Loops ◽  
Enhanced Diffusion ◽  
Depth Profiles ◽  
Enhanced Dissolution ◽  
Implantation Damage ◽  
Transmission Electron ◽  
Defect Behavior ◽  
Secondary Ion

ABSTRACTThe effects of Ti and Co silicidation on P+ ion implantation damage in Si have been investigated. After silicidation of unannealed 40 keV, 2×1015 cm-2 P+ implanted junctions by rapid thermal annealing at 900°C for 10–300 seconds, secondary ion mass spectrometry depth profiles of phosphorus in suicided and non-silicided junctions were compared. While non-silicided and TiSi2 suicided junctions exhibited equal amounts of transient enhanced diffusion behavior, the junction depths under COSi2 were significantly shallower. End-of-range interstitial dislocation loops in the same suicided and non-silicided junctions were studied by planview transmission electron microscopy. The loops were found to be stable after 900°C, 5 minute annealing in non-silicided material, and their formation was only slightly effected by TiSi2 or COSi2 silicidation. However, enhanced dissolution of the loops was observed under both TiSi2 and COSi2, with essentially complete removal of the defects under COSi2 after 5 minutes at 900°C. The observed diffusion and defect behavior strongly suggest that implantation damage induced excess interstitial concentrations are significantly reduced by the formation and presence of COSi2, and to a lesser extent by TiSi2. The observed time-dependent defect removal under the suicide films suggests that vacancy injection and/or interstitial absorption by the suicide film continues long after the suicide chemical reaction is complete.

Thermal Stability of Cu/Si (111) Films Prepared by Ionized Cluster Beam Technique

2011 ◽  
Vol 287-290 ◽  
pp. 2369-2372
Author(s):  
Bo Cao ◽  
Yan Hui Jia ◽  
Gong Ping Li ◽  
Seong Jin Cho ◽  
Hee Kim
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Interface Reaction ◽  
Atomic Diffusion ◽  
Cluster Beam ◽  
Copper Silicide ◽  
Cu Films ◽  
Si Substrates ◽  
Before And After ◽  
Different Temperatures ◽  
Cluster Beams

The Cu films were deposited on P type Si (111) substrates by ionized cluster beam (ICB) technique. The interface reaction and atomic diffusion of Cu/Si (111) system were studied at different annealing temperatures by X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). Some significant results were obtained: For the Cu/Si (111) samples prepared by ionized cluster beams atVa=3 kV, the interdiffusion of Cu and Si atoms occurred in the as deposited samples. The RBS spectra features were changed with a very small extent with increasing the annealing temperature. There are no copper-silicide phases observed by XRD before and after being annealed at different temperatures. The reason may be that there is a thermally stable interface between Cu films and Si substrates formed.

Time Dependent Diffusion of P-Type Dopants in Gallium Arsenide

1993 ◽  
Vol 300 ◽  
Author(s):  
H.G. Robinson ◽  
K.S. Jones ◽  
M.D. Deal ◽  
C.J. Hu
Keyword(s):  
Dose Rate ◽  
Dislocation Loops ◽  
Transient Effects ◽  
Simulation Tools ◽  
Transient Diffusion ◽  
Controlled Conditions ◽  
Physically Based ◽  
P Type ◽  
Dopant Redistribution ◽  
And Diffusion

ABSTRACTThe diffusion of implanted p-type dopants in GaAs often exhibits transient effects during annealing. This diffusion can greatly affect device performance and must be understood in order to create accurate, physically based process modeling simulation tools for compound semiconductors. The transient diffusion is believed to be related to defects created during implantation, but a direct correlation between implant damage and dopant redistribution has been difficult to establish. Results are presented in this paper of experiments designed to gain insights into the fundamental mechanisms underlying the relationship between defects and diffusion. Many anomalies in previous data are the result of implanting dopants under poorly controlled conditions, particularly implant dose rate and temperature. Special care was taken in this work to ensure that the implants were performed under well controlled conditions. Al was co-implanted with Mg and Be to study the effect of implant damage without affecting the position of the Fermi level. A correlation was found between the initial transient diffusion observed in low dose Be implants and the presence of dislocation loops. This may present a viable method for suppressing diffusion of implanted Be. SIMS profiles of Mg and Al co-implants were anomalous and difficult to interpret. Cap failure, dopant segregation to the surface and/or defects may be responsible for the discrepancies in the data. P-type doping appears to stabilize dislocation loops, probably by increasing the concentration of positively charged Ga interstitials. RBS measurements of implanted Mg indicates a link between damage production, implant dose rate, and diffusion. This result agrees with previous work on damage production in Si implanted GaAs.

The Effect of Fluorine Implantation on Boron Diffusion in Metastable Si0.86 Ge0.14

2004 ◽  
Vol 810 ◽  
Author(s):  
Huda A. W. A. El Mubarek ◽  
Yun Wang ◽  
Janet M. Bonar ◽  
Peter Hemment ◽  
Peter Ashburn
Keyword(s):  
Thermal Diffusion ◽  
Sige Layer ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Rich Region ◽  
Implantation Energy ◽  
Enhanced Diffusion ◽  
Partial Relaxation ◽  
Transient Enhanced Diffusion ◽  
Marker Layer

ABSTRACTThis paper investigates the effect of varying F+ implantation energy on boron thermal diffusion and boron transient enhanced diffusion (TED) in metastable Si0.86Ge0.14 by characterising the diffusion of a boron marker layer in samples with and without P+ and F+ implants. The effect of two F+ implantation energies (185keV and 42keV) was studied at two anneal temperatures 950°C and 1025°C. In samples implanted with P+ & 185keV F+, the fluorine suppresses boron transient enhanced diffusion completely at 950°C and suppresses thermal diffusion by 25% at 1025°C. In samples implanted with P+ & 42keV F+, the fluorine does not reduce boron transient enhanced diffusion at 950°C. This result is explained by the location of the boron marker layer in the vacancy-rich region of the fluorine damage profile for the 185keV implant but in the interstitial-rich region for the 42keV implant. Isolated dislocation loops are seen in the SiGe layer for the 185keV implant. We postulate that these loops are due to the partial relaxation of the metastable Si0.86Ge0.14 layer.

The Influence of Amorphizing Implants on Boron Diffusion in Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
H. S. Chao ◽  
P. B. Griffin ◽  
J. D. Plummer
Keyword(s):  
Point Defects ◽  
Field Enhancement ◽  
Enhancement Effect ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Electric Field Enhancement ◽  
Diffusion Behavior ◽  
Enhanced Diffusion ◽  
Pile Up ◽  
Experimental Structure

ABSTRACTThe transient enhanced diffusion behavior of B after ion implantation above the amorphization threshold is investigated. The experimental structure uses a layer of epitaxially grown Si, uniformly doped with B to act as a diffusion monitor. Wafers using this structure are implanted with amorphizing doses of Si, As, or P and annealed for various times at various temperatures. The experimental results show that upon annealing after Si implantation, there is a large amount of B pile-up that occurs at the amorphous/crystalline (A/C) interface while B is depleted from the region just beyond the A/C interface. This pile-up/depletion phenomenon can be attributed to the dislocation loops that form at the A/C interface. These loops act as sinks for interstitial point defects. There is also B pile-up/depletion behavior for As and P implants as well. However, this behavior may be explained by an electric field enhancement effect. While dislocation loops are known to form at the A/C interface for all of the investigated implant conditions, it appears that while they are necessary to simulate for Si amorphizing implants, they may not be necessary to simulate for As and P amorphizing implants.

Integration of InGaN-based Optoelectronics with Dissimilar Substrates by Wafer Bonding and Laser Lift-off

2001 ◽  
Vol 681 ◽  
Author(s):  
William S. Wong ◽  
Michael Kneissl ◽  
David W. Treat ◽  
Mark Teepe ◽  
Naoko Miyashita ◽  
...  
Keyword(s):  
Thin Film ◽  
Wafer Bonding ◽  
Device Performance ◽  
Light Emitting ◽  
Si Substrates ◽  
Substrate Removal ◽  
Transparent Substrate ◽  
Before And After ◽  
Lift Off

ABSTRACTInGaN-based optoelectronics have been integrated with dissimilar substrate materials using a novel thin-film laser lift-off process. By employing the LLO process with wafer-bonding techniques, InGaN-based light emitting diodes (LEDs) have been integrated with Si substrates, forming vertically structured LEDs. The LLO process has also been employed to integrate InGaN-based laser diodes (LDs) with Cu and diamond substrates. Separation of InGaN-based thin-film devices from their typical sapphire growth substrates is accomplished using a pulsed excimer laser in the ultraviolet regime incident through the transparent substrate. Characterization of the LEDs and LDs before and after the sapphire substrate removal revealed no measurable degradation in device performance.

Effect of stress on the aluminum-induced crystallization of hydrogenated amorphous silicon films

2006 ◽  
Vol 21 (10) ◽  
pp. 2582-2586 ◽  
Author(s):  
Maruf Hossain ◽  
Husam H. Abu-Safe ◽  
Hameed Naseem ◽  
William D. Brown
Keyword(s):  
Amorphous Silicon ◽  
Initial Stress ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Films ◽  
Radius Of Curvature ◽  
Si Substrates ◽  
Before And After ◽  
Hydrogenated Amorphous ◽  
Induced Crystallization ◽  
Aluminum Induced Crystallization

The effect of stress, resulting from the presence of hydrogen, on the aluminum-induced crystallization of hydrogenated amorphous silicon films was studied. Layered thin films of hydrogenated and unhydrogenated amorphous silicon and aluminum, deposited by sputtering, were used to study this effect. The stress of the deposited films was determined by measuring the radius of curvature of c-Si substrates before and after deposition of the films. It was observed that unhydrogenated amorphous silicon films exhibit a high compressive stress compared with hydrogenated ones. The amount of stress is shown to decrease with increasing hydrogen content. It was also observed that aluminum always provides tensile stress. After the initial stress measurements, all the samples were annealed for 30 min at temperatures between 200 °C and 400 °C. X-ray diffraction was used to determine the crystallinity of the silicon films. The results of the study show that the temperature at which crystallization of amorphous silicon is initiated is lower for films with a lower initial stress.

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