Study of electrical and interfacial properties of CVD-W/p-Si_0.83Ge_0.17/Si(001)

The interfacial and electrical properties of CVD-W/p-Si_1-xGe_x (x = 0.17)/Si(001) were studied by structural, chemical, and electrical characterizations. W layers were deposited on p-Si_0.83Ge_0.17/Si(001) at the growth temperature T_s = 350-500 °C by low pressure chemical vapor deposition (LPCVD) utilizing the WF₆ source gas. Electrical properties of the CVD-W/p-Si_1-xGe_x (x = 0.17) Schottky diodes were characterized by the current-voltage (I-V) measurements. The measured effective Schottky barrier heights (φ_BP) were decreased from 0.434 to 0.378 eV at the reverse bias of 5 V as the deposition temperature, T_s, of W layers increases from 350 to 500 °C. The structural and chemical properties of CVD-W/p-Si_1-xGe_x (x = 0.17) interfaces were analyzed by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), and Auger electron spectroscopy (AES). A strong penetration of W layers into the p-Si_1-xGe_x (x = 0.17) layers caused by the Si and Ge reduction reactions by WF₆ at the initial stages of W film growth was observed.