AFM induced electrostatic charging of nanocrystalline diamond on silicon

Abstract

A nanocrystalline diamond (NCD) thin film (80 nm) is deposited on a p-type Si substrate and oxygen terminated by r.f. oxygen plasma. An atomic force microscope (AFM) is used to induce electrostatically charged micrometer-sized areas on the diamond film by applying a bias voltage on the AFM tip during contact mode scan. Trapped charge is detected by Kelvin force microscopy showing a potential difference of up to 1.4 V. The potential amplitude and spatial distribution are controlled by the bias voltage applied on the tip (AE30 V) and scan speed (2-20 mm/s). Contribution of diamond bulk and grain boundaries to the charging effects shows no significant variations. We compare the results with the charging of bare Si substrate.

Atomic Force Microscopy as a Tool to Explore Triboelectrostatic Phenomena in Mineral Processing

“…However, so far, this phenomenon was not observed after contact between different materials. In contrast to the observations presented in [29], it was found that charging of the same area with opposite biases introduced opposite charges. Both rubbing and static charging at the same location of the sample surface have been applied.…”

“…According to this information, in the experiments reported here the charged area is likely to be saturated right after the first charging. In contrast to the observations presented in [29], it was found that charging of the same area with opposite biases introduced opposite charges. Interestingly, the artificially introduced charge during earlier charging does not seem to influence the value of surface potential signal caused by opposite charging.…”

Guided assembly of nanoparticles on electrostatically charged nanocrystalline diamond thin films

“…The centers of the crosses show slightly higher potential compared to the rest because they were charged twice (horizontally and vertically). The potential is not double, though, since the charging exhibits saturation as reported before [20]. AFM in such large scale confirms the homogeneity of our samples and excludes possible external contributions to the observed electric potential shifts (i.e., topographical variations).…”

“…This has been attributed to the capacitor-like behavior of the NCD films [19]. Comparing charging of NCD films prepared on gold [19] and silicon [20] substrates demonstrates that the charging is not due to the substrate itself as could be argued in the case of silicon substrates. The charging has been also shown to be more effective when the NCD films contain more sp 2 phase [21].…”

Local electrostatic charging differences of sub‐100 nm nanocrystalline diamond films

“…As regards such local and intentional charging, diamond has been only little investigated 7, 8 even though it packs a unique set of properties for applications. It can, e.g ., be used as a semiconductor for device fabrication 9, is bio‐compatible 10, 11 and can be deposited on diverse substrates 12.…”