A quantum mechanical and numerical charge control scheme, which includes strain effect and inplane dispersion of subband edges by k-p theory, was developed to simulate HEMT structure and other two dimensional electron gas device structures. Self-consistent calculation of energy levels, carrier density profile, and conduction band edge profile was performed. Schrodinger's equation and Poisson's equation were reduced into matrix equations and were solved iteratively by using standard routines. The calculation is carried out for InAsP/InP strained HEMT structure. The results were found to have a good agreement with published experimental data in qualitative manner. And the scheme was applied to $n^{+\delta}$ doped channel with buried $p^{+\delta$ MESFET, dipole barrier delta doped channel MESFET and conventional delta doped MESFET. The implications of these calculations on device performance was pointed out.
