Abstract: Improvement of the characteristics in the linear region of n-MOSFET using the backsurface Ar ＋ bombardment has been investigated．A low energy （550eV） argon-ion-beam is applied to bombard the backside of n-MOSFET chip‚thus the electrical characteristics of the transconductance‚channel conductance‚threshold voltage‚effective inversion layer carrier mobility and low-frequency noise of the devices in the linear region can be improved．The experiment results indicate that‚as the bombardment time increases‚the transconductance‚channel conductance and effective inversion layer carrier mobility increase at first‚and then decrease；the change tend of the threshold voltage is on the contrary；but the low-frequency noise decreases evidently after bombardment．It is proved that the improvement of these parameters is due to the decrease of interface state density and fixed charge density． 

Key words: backsurface Ar ＋ bombardment；MOSFET, transconductance, mobility, noise