The dependencies of hot-carrier-induced degradations on the effective channel length L_(ch,eff) are investigated for n-type metal-oxide-semiconductor Held effect transistor(MOSFETs).Our experiments find that,with decreasing L_(ch,eff),the saturation drain current(I_(dsat)) degradation is unexpectedly alleviated.The further study demonstrates that the anomalous L_(ch,eff) dependence of I_(dsat) degradation is induced by the increasing influence of the substrate current degradation on the I_(dsat) degradation with L_(ch,eff) reducing. The dependencies of hot-carrier-induced degradations on the effective channel length L_ (ch, eff) are investigated for n-type metal-oxide-semiconductor Held effect transistors (MOSFETs) .Our experiments find that with decreasing L_ (ch, eff ), the saturation drain current (I_ (dsat)) degradation is unexpectedly alleviated. The further study demonstrates that the anomalous L_ (ch, eff) dependence of I dsat degradation is induced by the increasing influence of the substrate current degradation on the I_ (dsat) degradation with L_ (ch, eff) reducing.