Phase change random access memory devices with nickel silicide and platinum silicide electrode contacts for integration with CMOS technology

Abstract

Phase change random access memory (PCRAM) cells utilizing nickel monosilicide (NiSi) or platinum monosilicide (PtSi) as the bottom electrode as well as a heater material was demonstrated. Electrical and simulation results demonstrate the feasibility of employing silicides as a bottom electrode/heater in a PCRAM. The memory cells fabricated attained promising results such as low programming currents and sufficient resistance ratio between the crystalline (SET) and amorphous (RESET) states. A low RESET current of 0.8 mA and a SET current of 0.2 mA were obtained for contact dimensions of ∼1 μm, while a resistance ratio of 2 orders of magnitude could be achieved employing PtSi as the bottom electrode. This work therefore enables the integration of PCRAM directly on the silicided drain regions of field effect transistors, facilitating compact integration in complementary metal-oxide-semiconductor (CMOS) technology with reduced process complexity and cost. © 2011 The Electrochemical Society.