Effect of Post Metallization Annealing for La 2 O 3 Thin Film

4.1.2 Summary of the Investigation into the Annealing with GoldUpper per ElectrodesPMA for La2O3 thin films with gold upper electrodes were investigated. Asa result,1. PMA shifted VFB toward negative side and increased leakage current, butalso decreased the value of EOT.2. As compared with the case of HF-last treatment, chemical oxidationtreatment suppressed leakage current, decreased the value of EOTslightly in the case of PMA, but shifted VFB toward negative side in thecase of both PDA and PMA.3. Longer time annealing increased the value of EOT in the case of PDA, butdecreased in the case of PMA.4. Oxygen ambience decreased the value of EOT as compared with nitrogenambience..4.1.3 Summary of the Investigation into the Annealing withPlatinum Upper ElectrodesPMA for La2O3 thin films with platinum upper electrodes were investigated.As a result,1. PMA recovered VFB shift toward positive side until the annealing at300 o C, but shifted toward negative side from the annealing at 400 o C, andincreased the value of EOT as compared with the case of PDA2. Longer time annealing recovered VFB toward positive side and decreasedthe value of EOT until 10minutes annealing in the case of PMA3. As compared with the annealing in nitrogen ambience, PMA in oxygenambience recovered VFB toward positive side, but increased the value ofEOT.4. As compared with the annealing in nitrogen ambience, the annealing informing gas ambience recovered VFB toward positive side in the case ofPDA, but shifted toward negative side in the case of PMA.- 91 -