Adhesive Force Characterization for MEM Logic Relays With Sub-Micron Contacting Regions

Abstract

Contact adhesive force (F a ) scaling is critical for relay miniaturization, since the actuation area and/or actuation voltage must be sufficiently large to overcome the spring restoring force (F k ) in order to turn on the relay and F k must be larger than F a in order to turn off the relay. In this work, contact adhesive force is investigated in MEM logic relays with contact dimple regions as small as 100 nm in lateral dimension. The results indicate that van der Waals force is predominant. An adhesive force of 0.02 nN/nm 2 is extracted for tungsten-to-tungsten contact. F a reduction should be possible with contact dimple size reduction and contact surface coating.[ 2013-0057]Index Terms-MEM relay, stiction, adhesive force, pull-in mode.

Reducing adhesion energy of micro-relay electrodes by ion beam synthesized oxide nanolayers

“…While the results extracted from the electrical characterization showed an adhesive force of 0.02 nN/nm 2 between the W electrodes, the indirect AFM measurement showed a much lower adhesive force of 1.6 × 10 5 nN/nm 2 . The direct AFM based experimental analysis performed here between W-W contacts shows that the adhesive force is about 0.17 nN/nm 2 , which is an order of magnitude higher than the estimates by Yaung et al 9 We believe that this difference is due to the assumptions used in estimating the 2017) contact area: While Yaung et al 8 have used the dimple (apparent) contact area for the calculation of force per unit area, here we use the DMT model to estimate the microscopic (real) contact area.…”

“…7 As all relays operate on the basic principle of formation and breaking of mechanical contacts, contact adhesion energy plays an important role in determining the performance and energy efficiency of a relay. 8,9 Studies also have been performed to understand the effects of contact area scaling and the dynamics of contact opening/closing. [9][10][11] A general understanding gained from such analyses 7,11 is that the minimum energy needed to switch a relay is proportional to the contact adhesive force (F ad .…”

“…Adhesive force per unit area in a functional NEM relay has been extracted by Yaung et al 8 and Lee et al 23 using indirect methods such as electrical characterization and indirect AFM-based analysis wherein the force is applied on the movable electrode of the relay. While the results extracted from the electrical characterization showed an adhesive force of 0.02 nN/nm 2 between the W electrodes, the indirect AFM measurement showed a much lower adhesive force of 1.6 × 10 5 nN/nm 2 .…”

Amorphous carbon active contact layer for reliable nanoelectromechanical switches

“…Miniaturization of the contact reduces the adhesion forces in a metallic contact [2]; however, the size of a single contact asperity and the tendency of metals to form a neck impose practical limits. Contacts using non-metallic materials, such as graphene [3], carbon nanotubes [4] and metal oxides [5,6], have been explored as a means to achieve high reliability and low adhesion forces in NEM relays.…”

Effect of Body Biasing on the Energy-Delay Performance of Logic Relays

“…This is not possible, however, unless the relay is designed to operate in non-pull-in mode, i.e. g d ≤ g 0 /3 [12]. The solid line in Fig.…”