Poly-Si gate CMOSFETs with HfO2-Al2O3 laminate gate dielectric for low power applications

For the first time, we have integratcd poly-Si gate CMOSFETs with HfO2-Al2O3 laminate gate dielectric (EOT-14.6Angstrom) grown by Atomic Layer Deposition (ALD). The gate leakage currents are 3.7muA/cm(2) (Vg=+1.0V) for nMOSFET and 0.2 muA/cm(2) (Vg=-1.0V) for pMOSFET. These extremely low leakage currents sufficiently satisfy the specification (EOT=12similar to20Angstrom, Jg=2.2mA/cm(2)) estimated by ITRS. The fixed charge is decreased using HfO2-Al2O3 laminate gate dielectric, arid consequently flatband voltage (Vfb) shift is within 0.20V compared with the Vfb of nitrided SiO2 control. In addition, the low gate induced drain leakage (GIDL) is obtained using HfO2-Al2O3 laminate gate dielectric. Ion vs. loff plots of the planar CMOS transistor with high-k is shown for the first time in this paper. The measured saturation currents at 1.2V Vdd are 430muA/mum (I-off=10nA/mum) for nMOSFET and 160muA/mum (I-off=10nA/mum) for pMOSFET. These are the highest currents compared with previous reports for the planar poly-Si gate CMOSFETs with high-k gate dielectric.