Ferroelectric transistor memory arrays on flexible foils

In this paper, we successfully fabricated and operated passive matrix P(VDF-TrFE) transistor arrays, i.e. memory arrays in which no pass-transistors or other additional electronic components are used. Because of the smaller cell, a higher integration density is possible. We demonstrate arrays up to a size of 16 × 16, processed on thin (25 μm) poly(ethylene naphthalate) substrates, using Indium-Gallium-Zinc-Oxide (IGZO) as the semiconductor and 200 nm-thick P(VDF-TrFE) as a ferroelectric gate dielectric. The memory transistors have remnant current modulations of ∼105 with a retention time of more than 12 days. They can be switched in less than 1 μs at operating voltages of 25 V. Switching speed is strongly decreased with decreasing voltage: at ∼10 V the transistors do not switch within 10 s. This difference in switching speed of more than 4 orders in magnitude when changing the electric field by a factor of only 2.5 makes these memories robust towards disturb voltages, and forms the basis of integration of these transistors in passive matrix-addressable transistor arrays that contains only one (memory) transistor per cell. It is shown that with current technology and memory characteristics it is possible to scale up the array size in the future. © 2013 Elsevier B.V. All rights reserved.