Effect of linear dimensions of the drain-source 2D-channel of AlGaN/GaN hemt on its static current-voltage characteristics (lateral size effect)

It is shown that in the local approximation, the fractality of electrical properties of the 2D-channel has strong influence on the behavior of static CVC of the drain-source channel of AlGaN/GaN HEMT. An increase of the linear resistance ρ(l,d) with decreasing length l and width d of the channel down to the values less than the limit of the local approximation L leads to a slower growth of the drain current Id and a more rapid increase of Rd. Only in the global approximation, when l and d > L, the parameters Id and Rd have the well-known classical dependences on the length and width of the channel for the specific resistance R_sp = R^-.