Efficient Calculation of Quasi-Bound State Tunneling in CMOS Devices

For an accurate description of direct tunneling in CMOS devices under inversion conditions lifetime based approaches rely on the precise determination of quasi-bound states (QBS). We study the calculation of QBS in resonant tunneling diode (RTD) structures and MOS inversion layers by the perfectly matched layer (\x7f(PML) method. Introducing a complex coordinate stretching allows to apply artifical absorbing layers at the boundaries. The QBS appear as the eigenvalues of a linear non-Hermitian Hamiltonian where the QBS lifetimes are directly related to the imaginary part of the eigenvalues. The PML formalism has been compared to the established quantum transmitting boundary method where a computationally demanding scanning procedure yields the desired lifetimes. The PML method proves as an elegant, numerical stable, and efficient method to calculate QBS lifetimes.