Resistance Switching Structures Based on Hydrogen Silsesquioxane (HSQ) Thin Films

In recent years, resistance switching (ReRAM) devices have attracted a lot of attention due to their properties in low programmable energy and fast switching speed which could lead to potential applications in non-volatile memory. Hydrogen silsesquioxane (HSQ) is commonly used in electronic industry as a flowable dielectric material, and here we present our recent study of using HSQ thin film as an active switching material. We carried out x-ray photoelectron spectroscopy (XPS) on HSQ thin films; results showed that they are SiO 2 like after spin-coating and soft baking. Electrical characterisation results showed our metal-insulator-metal devices required typically -1.2V to switch from a high resistance state (HRS) to low resistance state (LRS). The voltage required to reset the device from LRS to HRS was typically +1.5V. The device was capable of bipolar switching and multiple setting and resetting cycles could be achieved with voltage pulses. Retention studies showed the device had retention properties of up to 10 5 seconds. We have also fabricated HSQ nanopillar array and addressed individual nanopillars with a conductive atomic force microscope (CAFM). Results showed we could change the conductivity of individual pillars by applying bias on the sample via the CAFM tip. These encouraging results show HSQ is potentially a very promising material for non-volatile ReRAM applications.