FOWLER-NORDHEIM STRESSING OF POLYCRYSTALLINE SI OXIDE SI STRUCTURES -OBSERVATION OF STRESS-INDUCED DEFECTS IN THE OXIDE, OXIDE SI INTERFACE, AND IN BULK SILICON/

Deep level transient spectroscopy and capacitance voltage measurements were used to study the Fowler-Nordheim (FN) stress induced defects in (+)-polycrystalline-Si/90-Angstrom-thick-SiO2/p-Si substrate capacito rs. These capacitors were fabricated using a 0.5 mu m complementary me tal-oxide-silicon process flow. The capacitors were subjected to const ant voltage FN stress at temperatures between 300 and 50 K. At all str ess temperatures positive charge buildup was observed to take place in the gate oxide, whereas at stress temperatures greater than or equal to 150 K a band of hole traps centered at 0.55 eV above the top of the valence band and similar to 0.2 eV wide was seen to be induced by the stress. However, FN stress below 150 K was observed to induce two bul k silicon defects 600 to 1000 Angstrom from the SiO2/Si interface. One of these defects is configurationally bistable with electronic states at 0.35 and 0.30 eV below the conduction band edge E-c. The second de fect gives rise to an electron trap located at E-c-0.37 eV. (C) 1997 A merican Vacuum Society.