We evaluated the structural, electrical and optical properties of tungsten (W)-doped Ge8Sb2Te11 thin films. In a previous work, GeSbTe alloys were doped with different materials in an attempt to improve thermal stability. 200 mm thick Ge8Sb2Te11 and W-doped Ge8Sb2Te11 films were deposited on p-type Si (100) and glass substrates using a magnetron co-sputtering system at room temperature. The fabricated films were annealed in a furnace in the 0~400℃ temperature range. The structural properties were analyzed using X-ray diffraction (X`pert PRO, Phillips). The results showed increased crystallization temperature (Tc) leading to thermal stability in the amorphous state. The optical properties were analyzed using an UV-Vis-IR spectrophotometer (Shimadzu, U-3501, range : 300~3,000 nm). The results showed an increase in the crystalline material optical energy band gap (Eop) and an increase in the Eop difference (△Eop). This is a good effect to reduce memory device noise. The electrical properties were analyzed using a 4-point probe (CNT-series). This showed increased sheet resistance (Rs), which reduces programming current in the memory device.
