Charge defects, Vt shifts, and the solution to the high-k metal gate n-MOSFET problem

An acceptable high-k metal gate n-mosfet is one with a low Tinv (<1.5 nm), high mobility (∼200 @ 1MV/cm) and a threshold voltage in the range of 0-0.2V. We show that this can be achieved by the use of thin lanthanum oxide layers as part of the gate stack. This layer provides a shift in the flatband or threshold voltage of the stack. The underlying physics behind this is discussed in light of the results from single lanthanum oxide and lanthanum yttrium oxide capacitor structures. copyright The Electrochemical Society.