NUMERICAL-ANALYSIS OF DEVICE PERFORMANCE OF METAMORPHIC INYAL1-YAS INXGA1-XAS LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.6) HEMTS ON GAAS SUBSTRATE/

A numerical model describing the influence of InAs mole fraction on me tamorphic HEMT structures ((MM-HEMT) is proposed. The material propert ies are calculated using the Monte Carlo method, while the charge cont rol law is calculated using a self-consistent solution of Poisson's an d Schrodinger's equations. The modeling of the de, ac, noise and high frequency performance of a device with 0.25-mu m gate length is perfor med using the quasi-two-dimensional (Q2D) approach, This analysis show s that an InAs mole fraction of about 0.40 is an optimum composition f or manufacturing high gain, low noise amplifiers, In this range of com position, the performance of MM-HEMT structures is similar to that obt ained for lattice-matched HEMT's on InP substrates,