Ion Beam Doping of Silicon Nanowires

Abstract

We demonstrate n- and p-type field-effect transistors based on Si nanowires (SiNWs) implanted with P and B at fluences as high as 10(15) cm (-2). Contrary to what would happen in bulk Si for similar fluences, in SiNWs this only induces a limited amount of amorphization and structural disorder, as shown by electrical transport and Raman measurements. We demonstrate that a fully crystalline structure can be recovered by thermal annealing at 800 degrees C. For not-annealed, as-implanted NWs, we correlate the onset of amorphization with an increase of phonon confinement in the NW core. This is ion-dependent and detectable for P-implantation only. Hysteresis is observed following both P and B implantation.

Visualising discrete structural transformations in germanium nanowires during ion beam irradiation and subsequent annealing

“…6 With the aim to achieve enhanced control over the dopant levels and their uniform distribution, ion implantation has been applied to introduce dopants in Si and Ge nanowires. [7][8][9][10] In particular, Ge is a potential material for logic and optoelectronic devices due to its high hole and electron mobilities. 11,12 Nonetheless, the processing of bulk and particularly nanostructured Ge, including ion implantation and subsequent crystal recovery, is still poorly understood.…”

In operandi observation of dynamic annealing: A case study of boron in germanium nanowire devices

“…14,16 However, only a few studies can be found in literature concerning the modification of the electrical properties of synthetic NWs upon ion implantation. [17][18][19] In a recent work by Zeiner et al, 17 a marked decrease in resistivity upon doping of device-integrated Ge NWs with Ga from a FIB source was demonstrated without thermal annealing. Other works on Si:Ga 18 (FIB) and Ge:B and Ge:P 19 (full area) NWs opted for adding the electrical contacts subsequent to the implantation.…”

Ion irradiation of multi‐walled boron nitride nanotubes

“…Interaction of energetic particles such as electrons [6][7][8] and ions [9][10][11] with nanostructures has recently been in the focus of research as well. This subject is interesting from both fundamental and practical points of view: the nano-size of such systems and quantum-mechanical size quantization effects give rise to new interesting phenomena which can be used for engineering the atomic and electronic structure of nanosystems [12].…”