Determination of the surface segregation ratio of P in Si(1 0 0) during solid-source molecular beam epitaxial growth

Thompson, Phillip E.; Jernigan, Glenn G.

doi:10.1088/0268-1242/22/1/s19

Cited by 9 publications

(8 citation statements)

References 12 publications

(18 reference statements)

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“…The high surface concentration may result not only from direct surface doping, but also from surface segregation of P atoms, which has been predicted to occur in Si nanowires 23,24 and has been extensively studied in thin films. 25,26 Specifically, the segregation of P to the Si-SiO interface, 27 and the stability of this interfacial excess upon annealing, has been observed before in Si thin films. 28 The high dopant concentration measured in the annealed nanowires is consistent with the expectation of surface segregation.…”

Section: C(r T)mentioning

confidence: 68%

Obtaining Uniform Dopant Distributions in VLS-Grown Si Nanowires

Koren¹,

Hyun

Givan³

et al. 2010

Nano Lett.

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Semiconducting nanowires grown by the vapor-liquid-solid method commonly develop nonuniform doping profiles both along the growth axis and radially due to unintentional surface doping and diffusion of the dopants from the nanowire surface to core during synthesis. We demonstrate two approaches to mitigate nonuniform doping in phosphorus-doped Si nanowires grown by the vapor-liquid-solid process. First, the growth conditions can be modified to suppress active surface doping. Second, thermal annealing following growth can be used to produce more uniform doping profiles. Kelvin probe force microscopy and scanning photocurrent microscopy were used to measure the radial and the longitudinal active dopant distribution, respectively. Doping concentration variations were reduced by 2 orders of magnitude in both annealed nanowires and those for which surface doping was suppressed.

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Section: C(r T)mentioning

confidence: 68%

Obtaining Uniform Dopant Distributions in VLS-Grown Si Nanowires

Koren¹,

Hyun

Givan³

et al. 2010

Nano Lett.

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“…18) The segregation lengths are usually uniquely given for a given material at a given growth temperature, growth rate and substrate orientation, and hence, the length is uniquely determined under the same condition. [18][19][20][21][22][23] However, the present study shows successfully that such a characteristic can be changed drastically by the addition of an appropriate amount of carbon into Ge. Two different slopes are observed in the ranges of 0 to −7 nm and −10 to −60 nm in sample C. In the range of 0 to −4 nm, the concentration of carbon is much higher than 10 19 cm −3 and the P segregation is suppressed.…”

Section: Experimental Methodsmentioning

confidence: 62%

Suppression of segregation of the phosphorus δ-doping layer in germanium by incorporation of carbon

Yamada

Sawano

Uematsu

et al. 2016

Jpn. J. Appl. Phys.

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The successful formation of abrupt phosphorus (P) δ-doping profiles in germanium (Ge) is reported. When the P δ-doping layers were grown by molecular beam epitaxy (MBE) directly on Ge wafers whose surfaces had residual carbon impurities, more than a half the phosphorus atoms were confined successfully within a few nm of the initial doping position even after the growth of Ge capping layers on the top. On the other hand, the same P layers grown on Ge buffer layers that had much less carbon showed significantly broadened P concentration profiles. Current-voltage characteristics of Au/Ti/Ge capping/P δ-doping/n-Ge structures having the abrupt P δ-doping layers with carbon assistance showed excellent ohmic behaviors when P doses were higher than 1 ' 10 14 cm %2 and the capping layer thickness was as thin as 5 nm. Therefore, the insertion of carbon around the P doping layer is a useful way of realizing ultrashallow junctions in Ge.

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“…14b) of 0.51% ±0.03% (or 2.55x10 20 ±0.15x10 20 cm -3 , taking the Si solid concentration to be 5x10 22 cm -3 ) before and after annealing. The high surface concentration may result not only from direct surface doping, but also from surface segregation of P atoms, which has been predicted to occur in Si nanowires (Fernandez-Serra, Adessi et al 2006;Peelaers, Partoens et al 2006) and has been extensively studied in thin films (Nutzel and Abstreiter 1996;Thompson and Jernigan 2007). Specifically, the segregation of P to the Si-SiO interface (Lau, Mader et al 1989).…”

Section: Obtaining Uniform Dopant Distribution In Si Nanowiresmentioning

confidence: 99%