METHOD OF FOMRING A PHASE-CHANGABLE MEMEORY DEVICE

摘要

A method for forming a phase-changeable memory device is provided to obtain a programming requiring only a small electric current by forming a cone shaped lower electrode contact having a small upper surface thereof. An interlayer dielectric(114) is stacked on a semiconductor substrate(100). A mask pattern(116) having an opening is formed on the interlayer dielectric. An undercut area exposing the semiconductor substrate through the opening of the mask pattern is formed on the interlayer dielectric. A thin film is formed only on the top of the mask pattern. A cone shaped connector(122a) is formed on the semiconductor substrate within the undercut area by depositing a connection layer vertically. The connection layer stacked on the thin film is removed together with the thin film. The end of the connector is exposed by stacking and planarizing a dielectric film(124). A phase-changeable element(126) is formed. An upper electrode contact(130) electrically connecting with the phase-changeable element is formed.