Study On Plasma Process Induced Damage In Gate Oxide Of MOSFET

The ddriensions of semiconductor devices are continuously being scaied down toboprove the speed and reduce the power dissiPation. So the plasma process is requiredbecause of its merit. The presence of energetic ions and electrOns as well as ultr8Violetradiation, can cause severe damage to devices exposed to the plasma. In this paPef, thethree maln troes of plasma daxnage, i.e. plasma charging damage, plasma edge damageand electron shading damage are described in detail. The low frequency chargepUInPing is presented as a method to characterize the interface State density in MOSFETThe inteffoce is created in plasma ashing and etChing. the correlation of plasma etchingatnna effect on iflterface state and plasma atenna current, oxide thickness scaling andcharging damage, plasma damage and overetch and position, plasma damage and Q..has been presented. By the local low frequency charge pUInPing method, the interfacestate in LDD area has been measured. Enhanced edge degradation results in increasededge oxide thickness during the poly reoxidation step. We use the LCI technology tomeasure it. Finally the lateral profile of the LDD interface density was performed. Theresult clearly showed that plasma edge damage is imporan in submicron devices andthis effect can dramatically influence the hot-carrier reliability of the devices. Theelectron shading effect is also the impodrit failure mechanism. It can cause muchdamage in the special gate pattem. The anenna aspect determine the number of damage,so it is the parameter of electron shading damage.