Surface conductivity induced by fullerenes on diamond: Passivation and thermal stability
Surface conductivity induced by fullerenes on diamond: Passivation and thermal stability
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DOI：
10.1016/j.diamond.2005.10.034
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发表时间：
2006-04-01
影响因子：
4.1
通讯作者：
Boltalina, O.
中科院分区：
文献类型：
--
作者：
Strobel, P.;Ristein, J.;Boltalina, O.
氢端金刚石在大气条件下的表面电导率是一个众所周知的现象。受表面转移掺杂模型的启发[F]。Maier， M. Riedel， B. Mantel， J. Ristein， L. Ley，物理学家。我们最近研究了薄的C-60层作为大气吸附剂的替代品。我们确实可以证明，C-60诱导了一个地下蓄积层，导致了与空气诱导的表面电导率相当的表面电导率[P]。Strobel， M. Riedel， J. Ristein， L. Ley, Nature,(2004) 439]。在本工作中，我们研究了氟化fallerene，即C60F18， C60F36和C60F48作为转移掺杂剂。氟化富勒烯引起的表面电导率随着氟化程度的提高而增加，C60F48的电导率达到大气条件下观察到的水平的三倍。此外，我们研究了金刚石上富勒烯层的热稳定性以及不同介电膜（SiO， CaF2和Si3N4）的钝化稳定性。在氟化富勒烯的情况下，我们观察到电介质钝化后热稳定性有显着改善，但不能保持原始的导电性水平。C-60实现了不同类型的稳定。同时暴露于氧气、光和约150℃的温度下后，C-60诱导的表面电导率在高达350℃的真空中保持稳定，掺杂效率不降低。我们将这种效应归因于氧介导的C-60层聚合。(c) 2005 Elsevier B.V.版权所有
The surface conductivity of hydrogen terminated diamond under atmospheric conditions is a well known phenomenon. Inspired by the surface transfer doping model [F. Maier, M. Riedel, B. Mantel, J. Ristein, L. Ley, Phys. Rev. Lett. 85, (2000) 3472] we have recently investigated thin C-60 layers as an alternative to atmospheric adsorbates. We could indeed show that C-60 induces a sub-surface accumulation layer that results in a surface conductivity comparable to the air induced one [P. Strobel, M. Riedel, J. Ristein, L. Ley, Nature 430, (2004) 439]. In the present work we investigate fluorinated fallerenes, namely C60F18, C60F36, and C60F48, as transfer dopants. The surface conductivity induced by fluorinated fullerenes increases with higher fluorination and achieves for C60F48 a level that exceeds that observed under atmospheric conditions by up to a factor of three.Furthermore, we study the thermal stability of the fullerene layers on diamond and their stabilisation by passivation with different dielectric films (SiO, CaF2, and Si3N4). In the case of fluorinated fullerenes we observe a significant improvement in thermal stability after passivation with dielectrics but the pristine conductivity level cannot be kept, A different kind of stabilisation is achieved for C-60. After the simultaneous exposure to oxygen, light, and temperature of about 150 degrees C the surface conductivity induced by C-60 is stable up to 350 degrees C in vacuum with an undiminished doping efficiency. We ascribe this effect to an oxygen mediated polymerisation of the C-60 layer. (c) 2005 Elsevier B.V. All rights reserved.