Electrical optical switching and structural transformation of $Ge_{15}Sb_{85}$, $Sb_{65}Se_{35}$ and N2.0 sccm doped $Sb_{83}Si_{17}$ were studied to investigate the phase change characteristics for PRAM application. Sb-based materials were deposited by a RF magnetron co-sputtering system and the phase change characteristics were analyzed using an X-ray diffractometer (XRD), a static tester and a four-point probe. Doping Ge, Se or Si atoms reinforced the amorphous stability of the Sb-based materials, which affected the switching characteristics. The crystallization temperature of the Sb-based materials increased as the concentration of the Ge, Se or Si increased. The minimum time of $Ge_{15}Sb_{85}$, $Sb_{65}Se_{35}$ and N2.0 sccm doped $Sb_{83}Si_{17}$ for crystallization was 120, 50 and 90 ns at 12 mW, respectively. $Sb_{65}Se_{35}$ was crystallized at $170^{circ}C$. In addition, the difference in the sheet resistances between amorphous and crystalline states was higher than $10^4{Omega}/{gamma}$.