Published online by Cambridge University Press: 28 August 2013
An improved 2D device model is generated to simulate the DC properties of hydrogen- terminated diamond MISFETs by taking into account the effect of electric field on hole mobility. At high lateral field, the mobility degrades due to velocity saturation and at high transverse field, the mobility decreases because of strong surface phonon scattering. As either field increases to a certain level (∼ 1MV/cm), the mobility becomes independent of doping concentration and the maximum transverse field appears at the boundary between surface acceptor region and bulk. The threshold voltage is found to be a strong function of gate length and can change from negative to positive, which will change the operation mode of the device. In addition, the simulation also shows that the transconductance reaches a maximum value at 80nm gate length but decreases after further shrinkage, which might be also related to the velocity saturation effect induced by large lateral field.