Experimental Study on Electrical Breakdown for Devices with Micrometer Gaps

Abstract

The understanding of electrical breakdown in atmospheric air across micrometer gaps is critically important for the insulation design of micro & nano electronic devices. In this paper, planar aluminum electrodes with gaps ranging from 2 µm to 40 µm were fabricated by microelectromechanical system technology. The influence factors including gap width and surface dielectric states were experimentally investigated using the home-built test and measurement system. Results showed that for SiO2 layers the current sustained at 2-3 nA during most of the pre-breakdown period, and then rose rapidly to 10-30 nA just before breakdown due to field electron emission, followed by the breakdown. The breakdown voltage curves demonstrated three stages: (1) a constantly decreasing region (the gap width d <5 µm), where the field emission effect played an important role just near breakdown, supplying enough initial electrons for the breakdown process; (2) a plateau region with a near constant breakdown potential (5 µm< d <10 µm); (3) a region for large gaps that adhered to Paschen's curve (d >10 µm). And the surface dielectric states including the surface resistivity and secondary electron yield were verified to be related to the propagation of discharge due to the interaction between initial electrons and dielectrics.

A review on recent advances and challenges of ionic wind produced by corona discharges with practical applications

“…The consistency between the breakdown voltage and Paschen's law was shown in the silicon configuration, while a deviation existed in the metal configuration. The same deviation was found in different planar microscale electrode structures [117,119,120,135], which is attributed to the lower potential barrier of the cathode material due to a high electric field, promoting electrons to tunnel, and electron field emission dominates the breakdown under a fairly small electrode gap [131,136].…”

“…One of the mechanisms responsible for the invalidation at microscale gaps is the field emission. The field emission effect plays an important role in the breakdown phenomenon, supplying enough initial electrons for the breakdown process, which results in the gas breakdown deviating from the classic Paschen's Law [119,129]. Pai et al [130] pointed out that the ion-enhanced field emission reduces the breakdown voltage and that the breakdown voltage of such electrode gaps depends linearly on the electrode spacing.…”

“…They also emphasized the importance of the electrode structure and pointed out that the discharge surface area was the main factor dominating the discharge current and breakdown voltage for planar miniaturized IWGs. Meng et al [119] conducted research on the influence of the surface substrate states, including the surface resistivity and secondary electron coefficient on discharge. They reported that a larger surface resistivity and secondary electron coefficient result in a lower threshold of breakdown.…”