Diffusion of Boron in Germanium and Si1-xGex (x>50%) alloys Suresh Uppal

2003 ◽  
Vol 765 ◽  
Author(s):  
A.F.W. Willoughby ◽  
J.M. Bonar ◽  
N.E.B. Cowern ◽  
R.J.H. Morris ◽  
M. Bollani

AbstractBoron diffusion in germanium and relaxed Si1-xGex alloys with Ge content x>50% is reported. Relaxed SiGe layers were grown by LEPECVD and boron was introduced using ion implantation. Samples were given equal thermal budgets using furnace annealing. Diffusivity values of boron have been extracted. The results confirm that diffusion of boron in germanium is indeed slower than that reported in literature. The diffusivity of boron was found to increase gradually for x>50% at 900°C but the increase is not substantial. We found that pairing model is not sufficient to explain boron diffusivity behavior in SiGe alloys over the entire range of germanium content. The results suggest that an interstitial mediation of boron diffusion in germanium should be considered.

1995 ◽  
Vol 379 ◽  
Author(s):  
P. Kuo ◽  
J. L. Hoyt ◽  
J. F. Gibbons ◽  
J. E. Turner ◽  
D. Lefforge

ABSTRACTBoron diffusion in in-situ doped Si and strained Si1−xGex (x < 0.20) epitaxial layers, subjected to inert-ambient furnace annealing, was investigated as a function of temperature (T = 750 °C - 850 °C). Boron diffusivity parameters were extracted from SUPREM IV, a process simulation program. We observed slower B diffusion in strained Si1−xGex relative to that in Si for B concentration levels ranging from 2×1017 to 3×1019 cm−3. Using relaxed graded Si1−xGex as “substrates”, we also characterized B diffusion in relaxed Si1−xGex (x < 0.60) at T = 800 °C. We propose a reaction of mobile B atoms pairing with Ge atoms to model the slower B diffusion in both fully strained and relaxed Si1−xGex.


2004 ◽  
Vol 810 ◽  
Author(s):  
R. Duffy ◽  
V.C. Venezia ◽  
A. Heringa ◽  
M.J.P. Hopstaken ◽  
G.C.J. Maas ◽  
...  

ABSTRACTIn this work we investigate the diffusion of high-concentration ultrashallow boron, fluorine, phosphorus, and arsenic profiles in amorphous silicon. We demonstrate that boron diffuses at high concentrations in amorphous silicon during low-temperature thermal annealing. Isothermal and isochronal anneal sequences indicate that there is an initial transient enhancement of diffusion. We have observed this transient diffusion characteristic both in amorphous silicon preamorphized by germanium ion implantation and also in amorphous silicon preamorphized by silicon ion implantation. We also show that the boron diffusivity in the amorphous region is similar with and without fluorine, and that the lack of diffusion for low-concentration boron profiles indicates that boron diffusion in amorphous silicon is driven by high concentrations. Ultrashallow high-concentration fluorine profiles diffuse quite rapidly in amorphous silicon, and like boron, undergo a definite transient enhancement. In contrast, ultrashallow high- concentration phosphorus and arsenic profiles did not significantly diffuse in our experiments.


2013 ◽  
Vol 16 (6) ◽  
pp. 1655-1658 ◽  
Author(s):  
A. Belafhaili ◽  
L. Laânab ◽  
F. Cristiano ◽  
N. Cherkashin ◽  
A. Claverie

1989 ◽  
Vol 147 ◽  
Author(s):  
Samuel Chen ◽  
S.-Tong Lee ◽  
G. Braunstein ◽  
G. Rajeswaran ◽  
P. Fellinger

AbstractDefects induced by ion implantation and subsequent annealing are found to either promote or suppress layer intermixing in Ill-V compound semiconductor superlattices (SLs). We have studied this intriguing relationship by examining how implantation and annealing conditions affect defect creation and their relevance to intermixing. Layer intermixing has been induced in SLs implanted with 220 keV Si+ at doses < 1 × 1014 ions/cm2 and annealed at 850°C for 3 hrs or 1050°C for 10 s. Upon furnace annealing, significant Si in-diffusion is observed over the entire intermixed region, but with rapid thermal annealing layer intermixing is accompanied by negligible Si movement. TEM showed that the totally intermixed layers are centered around a buried band of secondary defects and below the Si peak position. In the nearsurface region layer intermixing is suppressed and is only partially completed at ≤1 × 1015 Si/cm2. This inhibition is correlated to a loss of the mobile implantation-induced defects, which are responsible for intermixing.


2000 ◽  
Vol 338-342 ◽  
pp. 877-880 ◽  
Author(s):  
D. Panknin ◽  
H. Wirth ◽  
W. Anwand ◽  
Gerhard Brauer ◽  
Wolfgang Skorupa

1987 ◽  
Vol 61 (4) ◽  
pp. 1380-1391 ◽  
Author(s):  
J. F. Marchiando ◽  
John Albers

1987 ◽  
Vol 97 ◽  
Author(s):  
Gerhard Pensl ◽  
Reinhard Helbig ◽  
Hong Zhang ◽  
Gonther Ziegler ◽  
Peter Lanig

ABSTRACTIon implantation of 14N and Rapid Isothermal Annealing (RIA) were employed to achieve n-type doping in epitaxial-grown 6H-SiC layers. The electrical properties of the implanted films were investigated by Hall effect measurements in order to optimize the annealing parameters. In comparison with standard furnace annealing (1470°C/7min), the annealing parameters for the RIA process could be considerably reduced (1050°C/4min). Based on planar technique, implanted p-n junctions were fabricated. The temperature dependence of I-V characteristics and of the quantum efficiency of photodiodes were studied. The maximum of the quantum efficiency at γ=330 nm reaches values of 35% at 400°C.


1988 ◽  
Vol 128 ◽  
Author(s):  
Gary A. Ruggles ◽  
Shin-Nam Hong ◽  
Jimmie J. Wortman ◽  
Mehmet Ozturk ◽  
Edward R. Myers ◽  
...  

ABSTRACTLow energy (6 keV) BF2 implantation was carried out using single crystal, Ge-preamorphized, and Si-preamorphized silicon substrates. Implanted substrates were rapid thermal annealed at temperatures from 600°C to 1050'C and boron channeling, diffusion, and activation were studied. Ge and Si preamorphization energies were chosen to produce nearly identical amorphous layer depths as determined by TEM micrographs (approximately 40 nm in both cases). Boron segregation to the end-of-range damage region was observed for 6 keV BF2 implantation into crystalline silicon, although none was detected in preamorphized substrates. Junction depths as shallow as 50 nm were obtained. In this ultra-low energy regime for ion implantation, boron diffusion was found to be as important as boron channeling in determining the junction depth, and thus, preamorphization does not result in a significant reduction in junction depth. However, the formation of junctions shallower than 100 rmu appears to require RTA temperatures below 1000°C which can lead to incomplete activation unless the substrate has been preamorphized. In the case of preamorphized samples, Hall measurements revealed that nearly complete electrical activation can be obtained for preamorphized samples after a 10 second rapid thermal anneal at temperatures as low as 600°C.


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