Contactless Electrical and Structural Characterization of Semiconductor Nanowires with Axially Modulated Doping Profiles

Abstract

Efficient characterization of semiconductor nanowires having complex dopant profiles or heterostructures is critical to fully understand these materials and the devices built from them. Existing electrical characterization techniques are slow and laborious, particularly for multisegment nanowires, and impede the statistical understanding of highly variable samples. Here, it is shown that electro‐orientation spectroscopy (EOS)—a high‐throughput, noncontact method for statistically characterizing the electrical properties of entire nanowire ensembles—can determine the conductivity and dimensions of two distinct segments in individual Si nanowires with axially encoded dopant profiles. This analysis combines experimental measurements and computational simulations to determine the electrical conductivity of the nominally undoped segment of two‐segment Si nanowires, as well as the ratio of the segment lengths. The efficacy of this approach is demonstrated by comparing results generated by EOS with conventional four‐point‐probe measurements. This work provides new insights into the control and variability of semiconductor nanowires for electronic applications and is a critical first step toward the high‐throughput interrogation of complete nanowire‐based devices.

Electrorotation of semiconducting microspheres

“…For example, semiconductor nanowires are rotated and transported within microchannels [4,5]. Also, electrical properties of semiconductor nanowires can be determined from their orientation rate when subjected to ac fields [6][7][8]. The rotation velocity of metallic microspheres [9][10][11] and nanowires [12][13][14] can be precisely controlled by adjusting the frequency and amplitude of an externally applied rotating electric field.…”

Reducing Conductivity Variability in Si Nanowires via Surface Passivation for Nanoelectronics

“…EOS has been used to measure a range of nanowire materials, including Si, Ge, TiO 2 , and Al 2 O 3 , 14,15 as well as nanowires containing multiple segments with distinct carrier densities. 16 These studies collectively demonstrate the highthroughput capability of EOS, verify the accuracy of the technique by comparison with conventional, direct-contact electrical measurements, and show its applicability to functionally encoded nanowires. These capabilities make EOS an ideal method, when combined with systematic changes in nanowire processing, to not only identify the causes of variability in nanowire electronic properties but also develop techniques to reduce it.…”

“…Akin et al developed contactless electro-orientation spectroscopy (EOS) to rapidly measure the electrical conductivity of individual nanowires. , EOS determines nanowire conductivity by observing the frequency-dependent electric-field-induced rotational speed of a nanowire suspended in a fluid. EOS has been used to measure a range of nanowire materials, including Si, Ge, TiO 2 , and Al 2 O 3 , , as well as nanowires containing multiple segments with distinct carrier densities . These studies collectively demonstrate the high-throughput capability of EOS, verify the accuracy of the technique by comparison with conventional, direct-contact electrical measurements, and show its applicability to functionally encoded nanowires.…”

Electric-field-controlled diffusion of anisotropic particles: theory and experiment

“…The ability to effectively manipulate microparticles or nanoparticles, especially anisotropic particles, in a fluid using an external field, opens up new possibilities in a variety of applications (Yuan, Liu & Shan 2017; Yuan et al. 2019; Cetindag et al. 2017; Castellano et al.…”