Silicon nitride gate dielectric metal-nitride-semi conductor (MNS) having a Si3N4 film grown at 400 degreesC by microwave-excited high-density plasma has been developed. We demonstrated the electric characteristics of the MNS capacitors with the Si3N4 film grown by microwave-excited high-density plasma using krypton (Kr) gas. The MNS capacitors have larger TDDB lifetime and have lower leakage current capability compared with the MOS capacitors. The TDDB lifetime of the Kr/NH3 Si3N4 is three times larger than that of the Ar/NH3 Si3N4. Furthermore the TDDB characteristics of Si3N4 on (1 1 0)Si are same as those of Si3N4 on (1 0 0)Si. (C) 2003 Published by Elsevier Science B.V.