No abstract

We evaluate the hole trapping rcsponsc of twcntytwo oxidcs subjected to twenty-two dikrcnt sets of processing parametcrs. Thc oxides were prepared in tbrec diffcrcnt €acilities, the Harris Semiconductor-Intersil Palm Bay facility, thc foriner Naval Research and Dcvclopinenl Laboratory (NRAD) 4" facility, aitd the new SPAWAR 6" fabrication facility in San Diego, Califoruia. In twenty of the tneiity-two cascs, oxidc hole trapping is almost coinplctcly determined by thc highest processing tcnipraturc aud is in reasonablc agrecment with a recently proposcd physically based prcdictivc model. We have also evaluated Si/SiOl interface trap (Dit) geucration in a subset of four vcry simply processcd oxides ntiliaed in the hole trapping study. Thc D, rcsults are also in rcasoiiable agreement with thc recently proposed modcl.Our results indicalc that it is possible lo make reasonably accurate predictions o€ radiatiou response from processing paranietcrs and that such predictious can be nude with our current understanding of radiation damagc phenomena. (It should be emphasizcd that the current level of undcrstanding is not yct complete. This work docs -not demonstrate that prccise predictious iuvolving all imaginable process paranicters are possible.)

We have made electron spin resonance and current density versus voltage measurements on a variety of thin SiO2 films on silicon. In some of the films we have generated fairly high (⩾1018 cm3) densities of neutral E′ centers near the Si/SiO2 interface. Neutral E′ centers are paramagnetic defects in which an unpaired electron resides in a high p-character wave function primarily located on a silicon atom bonded to three oxygen atoms. We find that the generation of these centers is consistently accompanied by the generation of large leakage currents in the oxide. We also find that the annihilation of these E′ centers by a low temperature (200 °C) anneal in air is consistently accompanied by the annihilation of the large leakage currents. Many investigations have established that high electric field stressing creates leakage currents in thin oxide films on silicon. Studies of at least two independent groups have also established that high electric field stressing generates significant E′ density within the stressed oxides. Our study demonstrates a strong link between E′ center density and oxide leakage currents. Our results, combined with the results of the earlier aforementioned studies, strongly indicate an important role for E′ centers in stress induced leakage currents. These leakage currents are a fundamental problem in the very thin SiO2 films on silicon utilized in present day metal oxide silicon devices.

Ahsrruct--Stress induced leakage current is an important and quite possibly fundamcntal physically limiting problem in the scaling of metal-oxide-silicon integrated circuitry. We present evidence linking specific atomic scale defects to leakage currents in thermally grown silicon dioxide thin films on silicon. The defects identified are oxygen deficient silicon "dangling bond" centers. 'These centers have been identified'through electron'spin resonance measurements. We find a strong correspondence between the generation of an oxygen deficient silicon dangling bond defect in the oxide and the appearance of oxide leakage currents.We observe a strong correlation between the disappearance of these centers and the disappearance of leakage currents in relatively low temperature anneals (200T) in air. We also propose a model which provides an extremely straightforward cxplana6on for the frequently reported close correspondence between the generation of stress induced leakage current and the generation of Si/SiOz interface states.