The characteristics of ZrO2 gate dielectric along with the interfacial layer on O2- and N2O-plasma treated partially strain-compensated Si0.69Ge0.3C0.01/Si heterostructures have been investigated using spectroscopic and electrical measurements. Time-of-flight secondary ion mass spectroscopy and x-ray photoelectron spectroscopy analyses show the formation of an oxygen or nitrogen rich Zr-germanosilicate interfacial layer between the deposited ZrO2 and SiGeC films. The electrical and charge trapping properties under a constant current stressing have been studied using a metal-oxide-semiconductor structure. The N2O-plasma treated SiGeC film has a higher effective dielectric constant (k∼14) than that of the O2-plasma treated (k∼12) films. The equivalent areal densities of charge defects, Neq (cm-2), are found to be ∼1.8×1012 and ∼6×1011 cm-2 for O2- and N2O-plasma treated films, respectively. Considerably less trapped charges in the N2O-treated gate dielectric stack under constant current stressing make it highly attractive for SiGeC based scaled metal-oxide-semiconductor device applications.