摘 要：场发射对于一维纳米结构是一个很有潜力的应用方向，人们对其在场发射显示、X射线源、微波器件等许多真空微电器件有着浓厚的兴趣。至今为止，作为场发射的以为纳米材料有很多，其中硅纳米线由于硅作为已经被人们熟知的半导体材料而受到瞩目。硅纳米线可以通过热退火和热蒸发得到，但是这样制作出来的硅纳米线排列无序、结构散乱，限制它的性能和应用性。近年来，人们已经可以在纯净的硅衬底上制备有序排列的硅纳米线，本文是对制备的硅纳米线阵列场发射性能的研究，采用了无电化学腐蚀的方法。将N型(100)晶向的单晶硅衬底(0.004Ω cm)在50℃的5.0mol L-1的HF和0.02mol L-1的AgNO3水溶液中腐蚀90分钟，之后用HNO3溶液去除在硅纳米线阵列上的银沉积层。我们用扫描电镜和隧道显微镜来观察硅纳米线阵列的形貌，可以看到制备的硅纳米线有着很好的排列着，且有着大约20μm的长度和十几至上百纳米的直径。J-E图显示这种样品的开启电压为7.45V μm-1，且电流-电压特性符合Fowler-Nordheim公式。此外场发射电流密度在测试的60分钟内并没有降低，表明了它优秀的场发射性能在场发射技术的潜在应用。通过在硅衬底上选择性刻蚀制备有序排列的硅纳米线阵列有着很大的场发射电流密度和低场开启电压。这种有序排列的硅纳米线在多种多样的电子场发射器件有很大的应用前景。
关键词：硅纳米线；场发射；无电化学腐蚀
Abstract：Field emitter is one of the promising applications for one-dimensional nanostructures, and got great commercial interest in vacuum microelectronic devices such as field emission displays(FED),X-ray sources , microwave devices , and so forth. Up to now , various 1D nanomaterials have been investigated, Si NWs are got particularly interest because Si as semiconducting material is known intimately . Si NWs have been synthesized via annealing and thermal evaporation . However , these Si NWs are randomly distributed and have disordered structures , restrictin studies on their properties and further applications . Recently , aligned Si NW arrays could be fabricated on Si wafer .Here we report field emission properties of the fabricated Si NWs ,Electroless metal deposition (EMD) is one technique that has been used in the study . Monocrystalline n-type silicon(100) wafers (0.004Ω cm)were initially cleaned and immersed into the etching solutions containing 5.0 mol L-1 HF and 0.02 mol L-1 AgNO3 ,and then treated at 50 ℃ for 90 min . Then immersed into HNO3 solution to remove the Ag film deposited on the Si NW arrays . The resultant products were characterized by using scanning electron microscopy (SEM,Sirion 200) and transmission electron microscopy(TEM,JEOL 2010), the aligned Si NWs are about 20 μm long with diameters from tens to hundreds of nanometers . The turn-on field of the as-etched bare Si NW arrays was 7.45V μm-1 obtained from the J-E curve , the field emission current-voltage characteristics were furtuer analyzed on the basis of the Fowler-Nordheim theory . what’s more the field emission current density recorded for a period of 60min at the same applied voltage that there is no degradation of current density over this period , indicating that the Si NW arrays have excellent emitting behavior with potentialapplications in field emission technology . Aligned Si NW arrays aynthesized via selectively etching Si wafer have large field emission current and low turn-on field . The aligned Si NWs have potentials in various electron field-emitting devices.
Key words：Si nanowire ; field emission ; electroless metal deposition
