Phase Change Memory using InSbTe Chalcogenide Materials Deposited by Metal-organic Chemical Vapor Deposition

The feasibility of InSbTe (IST) chalcogenide new materials by metalorganic chemical vapor deposition (MOCVD) was demonstrated for PRAM applications. The IST films grown below 225oC exhibit an amorphous structure and the films grown at 300oC include various crystalline phases of IST, In-Sb, and In-Te. Samples grown at 225oC for various working pressures have a stoichiometric composition (In3Sb1Te2). The IST films grown at 225oC exhibit smooth morphologies having an rms (root mean square) roughness below 1nm and the step-coverage on trench structure with 5:1 aspect ratio was approximately above 90%. An increase of the deposition time increases the filling rate keeping the conformal step-coverage. IST-MOCVD is a powerful candidate method for reliable PRAM device applications.