Nanoscale Study of the Hole-Selective Passivating Contacts with High Thermal Budget Using C-AFM Tomography

Abstract

We investigate hole-selective passivating contacts that consist of an interfacial layer of silicon oxide (SiO x ) and a layer of boron-doped SiC x (p). The fabrication process of these contacts involves an annealing step at temperatures above 750 °C which crystallizes the initially amorphous layer and diffuses dopants across the interfacial oxide into the wafer to facilitate charge transport, but it can also disrupt the SiO x layer necessary for wafer-surface passivation. To investigate the transport mechanism of the charge carriers through the selective contact and its changes during the annealing process, we utilize various characterization methods, such as transmission electron microscopy, micro Raman spectroscopy, and conductive atomic force microscopy. Combining the latter with a sequential removal of material, we assemble a tomographic reconstruction of the crystallized layer that reveals the presence of preferential vertical transport channels.

Probe chip nanofabrication enabled reverse tip sample scanning probe microscopy concept and measurements

“…electrical). Since then, this methodology has been employed to study various materials for different purposes [34][35][36][37][38], among which is also Si, because of its dominance in the nanoelectronics industry [39,40]. For this reason, we tested our probe chip on a Si surface, using a Si tipless cantilever (MikroMasch HQ:NSC35/tipless/No Al (5.4 N m −1 )) as our sample.…”

Nanoscale Visualization of the Electron Conduction Channel in the SiO/Graphite Composite Anode

“…Among the various modes of AFM, conductive AFM (C-AFM) has the advantage of visualization of electronic conductivity, which reflects the internal electron conduction pathway. − Therefore, C-AFM has been widely used to observe current signals in various electronic and mixed conductors, including battery materials. − However, the possible artifacts in C-AFM have not been discussed as extensively as those in other AFM modes. To improve the reliability of C-AFM, it is imperative to reveal the origin of the artifacts and develop artifact-free C-AFM.…”