Oxygen-doped Si15Sb85 thin film for good data retention and high speed phase-change memory application

Abstract

Te-free SixSb100−x (x = 5, 15, 25, 42) thin films are proposed for electronic phase-change memory application and the oxygen doping effect on Si15Sb85 film is investigated in detail. Improved electrical properties are obtained when the oxygen partial pressure ratio is 10%. The crystalline resistivity of Si15Sb85 film is enhanced and the amorphous/crystalline resistivity ratio is also increased to more than 104. The crystallization temperature of the oxygen-doped Si15Sb85 film is 229 °C and maximum temperature for a 10 year lifetime is estimated to be 129 °C with crystallization activation energy of 3.11 eV, which promises better data retention than conventional Ge2Sb2Te5 film. X-ray diffraction patterns indicate that both pure and oxygen-doped Si15Sb85 films crystallize into a hexagonal phase similar to Sb. A phase-change memory device using oxygen-doped Si15Sb85 film can be successfully switched with a 100 ns-1.4 V SET pulse and a 20 ns-7 V RESET pulse. And a SET process as fast as 40 ns is achieved along with a RESET/SET resistance ratio of about 35.