Investigation of phase change Si2Sb2Te5 material and its application in chalcogenide random access memory

A wide band-gap phase change material Si2Sb2Te5 for chalcogenide random access memory application was investigated. The material possesses a low threshold current from amorphous to polycrystalline state in voltage–current measurement, and shows a good data retention. Band-gap width of the amorphous and polycrystalline Si2Sb2Te5 are determined to be 0.89 and 0.62 eV by means of Fourier Transform Infrared Spectroscopy. Chalcogenide random access memory device with bottom electrode contact of 260 nm in diameter was fabricated and characterized. With a 50 ns width voltage pulse, RESET and SET voltage values of 3.2 and 1.4 V were achieved.