Completely　hard　amorphous　Si-C-N　films　were　prepared　by　electron　cyclotron　resonance　microwave　plasma　assisted　chemical　vapor　deposition　and　characterized　by　atomic　force　microscopy　and　nanoindentation.　In　contrast　to　common　findings　of　sink-in　effects　for　hard　films　on　soft　substrates,　anomalous　pile-up　effects　were　observed　in　such　kinds　of　hard　films.　Inherently　different　from　the　traditional　measurements　of　hardness,　which　are　taken　from　the　residual　impression　after　unloading,　load-displacement　curves　from　nanoindentation　measurements　reveal　the　feature　of　a　large　elastic　deformation　based　on　the　evaluation　of　the　total　work　and　the　elastic　work.　The　reduced　modulus　shows　an　approximately　linear　relationship　with　the　measured　hardness,　while　no　linear　relation　can　be　extracted　for　the　energy　dissipation　and　the　ratio　of　hardness　and　Young　modulus,　H/E.　Mechanical　behaviors　of　Si-C-N　films　measured　by　the　Oliver　and　Pharr　method　match　well　with　the　fitted　data　from　the　modified　King＇s　model　within　the　investigated　range　of　the　indentation　depth.　(C)　2015　Elsevier　B.V.　All　rights　reserved.