Analyse von Gds und fT in pseudomorphen Gatelängen bis 1 mym

: Braunstein, J.; Tasker, P.J.; Hülsmann, A.; Köhler, K.; Bronner, W.; Schlechtweg, M.

Abstract
Developing circuits for higher frequencies requires not only shorter gate lengths (l sub g), but also proper scaling of the epilayer structure. A common problem with reducing only l sub g is increasing output conductance (g sub ds), thus no f sub max improvement is achieved. To quantify the effect of scaling on MODFET performance a set of pseudomorphic MODFETs with different epilayer structures and gate lengths between 1 mym and 0.1 mym were investigated. A linear dependence of the intrinsic output resistance as a function of aspect ratio was derived. In addition no velocity overshoot was observed when analyzing f sub T l sub g. These results indicate that simple scaling rules can be applied to gate lengths even down to 0.1 mym.