Techniques for reducing off-state current in dual channel CMOS devices are provided. In one aspect, a method for forming a dual channel finFET includes: patterning NFET/PFET fins on a wafer from a first channel material and a second Ge-containing channel material; depositing a GeO2 layer on the fins; annealing the fins to selectively oxidize the at least one PFET fin; depositing a liner onto the fins which induces a negative charge in the PFET fin(s); removing unreacted GeO2 and the liner from the NFET fin(s); depositing a dielectric layer onto the fins which induces a positive charge in the NFET fin(s). A dual channel finFET device is also provided.