An efficient solution scheme for the spherical-harmonics expansion of the Boltzmann transport equation [MOS transistors]

This paper investigates a number of numerical schemes applicable to the solution of the Boltzmann transport equation by means of a spherical-harmonics expansion (SHE). A new scheme is proposed that improves the solution at low energies, keeping the desired accuracy in the calculation of the mean quantities while saving a significant amount of CPU time. This is important in view of the applications of the method since the typical number of nodes to be used in the combined space-energy domain is in the range of 10/sup 4/-10/sup 5/.