Reinaldo Vega @ on
junction abruptness and quantization questions
When setting up the device structure in nanoMOS, the program asks for the source/drain gaussian profile abruptness in units of dec/nm. There are two problems here. First, there’s a typo: the source/drain profile that results shows up in nm/dec, not dec/nm. Second, gaussian profiles do not have constant abruptness. Is it an actual gaussian profile, or is this another typo and the profile is really just a log-linear profile? If it is an actual gaussian profile, then in what part of the profile is the junction abruptness defined? Is it as simple as the distance from the peak where the concentration drops by one decade, or are you using some other metric?
My other question regards the quantum ballistic transport model, which also accounts for, among other things, direct source-to-drain tunneling by solving the schrodinger equation in the transport direction. Does this only model tunneling along the transport direction, or is this schrodinger equation also being applied to solve for quantization within the off-state potential barrier along the transport direction? In other words, if I have a very small gate length, say 3 nm, for NMOS there should be significant hole quantization in the valence band of the off-state barrier along the transport direction, which would change the off-state barrier height. Any input would be appreciated…