On the matching behavior of MOSFET small signal parameters

An array test structure for precise characterization of the matching behavior of MOSFETs is presented. Besides the standard mismatch parameter drain current I_D, the high resolution measurement principle allows the characterization of the small signal parameters transconductance g_m and in particular differential output conductance g_DS. Measured data are shown to demonstrate the performance of the method. Whereas for the normalized standard deviations of I_D and g_m the well known proportionality to (WL)^-12/ is obtained, the normalized standard deviation of g_DS clearly deviates from this width and length dependence. For this parameter, proportionality to W^-12/ is found.