NEMO - 1D
The primary objective of the NEMO-1D tool was the quantitative modeling of high performance Resonant Tunneling Diodes (RTDs). The software tool was intended for Engineers (concepts, fast turn-around, interactive) and Scientists (detailed device anaysis). Therefore various degrees of sohphistication have been built into the tool which allow the users to trade off accuracy and completeness of the models against computation time and memory usage. The basic operation of an RTD is explained in an animation.
The four key modeling aspects that resulted in the accurate modeling of RTDs are:
Proper treatment of extended contacts. Contacts typically contain resonance states which modify the injection of carriers into the central RTD structure.
Proper treatment of the quantum mechanical charging in the central RTD AND the contacts.
Proper treatment of the material bandstructure properties, such as non-parabolicity, band-warping, and Gamma-X transistions.
and at low temperatures the proper treatement of electron scattering due to optical phonons, acoustic phonons, and interface roughness.
Some of these aspects are depicted in the figures in the left column and linked to more detailed explanations.Several of the RTD modeling issues addressed in NEMO are discussed in the following web pages:
- Animation of the basic operation.
- Animation of the temperature dependence.
- Basic charge distributions.
- Animation of the charge development.
- Animation of the effects of resonances in the contacts.
- Animation of the different contact treatments
- An example of quantitative RTD modeling.
- A discussion on realistic electron dispersion relations.