MINIMIZING FLOATING-BODY-INDUCED THRESHOLD VOLTAGE VARIATION IN PARTIALLY DEPLETED SOI CMOS

Pulse propagation problems associated with dynamic floating-body effec ts, e.g,, pulse stretching, is measured in partially depleted SOI CMOS inverter chains, Pulse stretching is found to be dependent on pulse f requency and V-DD. Such behavior is attributed to floating-body-induce d transient threshold voltage variation in partially depleted SOI CMOS devices,dee to floating-body charge imbalance between logic states du ring CMOS switching, Such an imbalance can be minimized through proper device design because of the different dependencies of the gate and d rain depletion charges on channel length, silicon film thickness, gate oxide thickness, channel doping, and-supply voltage, This is confirme d by measuring the maximum transient threshold voltage variation in di screte partially depleted SOI NMOS devices in configurations which are predictive of CMOS switching behavior.