Atomic layer deposition of high capacitance density Ta2O5–ZrO2 based dielectrics for metal–insulator–metal structures
✍ Scribed by Indrek Jõgi; Kaupo Kukli; Mikko Ritala; Markku Leskelä; Jaan Aarik; Aleks Aidla; Jun Lu
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 551 KB
- Volume
- 87
- Category
- Article
- ISSN
- 0167-9317
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✦ Synopsis
Nb y O z . Even though the capacitances of laminates were often higher compared to films of constituent materials with similar thickness, considerably higher charge storage factors, Q, were achieved only when tetragonal ZrO 2 was stabilized in ZrO 2 -Ta 2 O 5 laminate and when the laminate thickness exceeded 50 nm. The decreased Q values in the case of most laminates were the result of increased leakage currents. In the case of thinner films only Ta 2 O 5 -Zr x Nb y O z stack possessed capacitance density and Q value higher than reference HfO 2 . Concerning the conduction mechanisms, in the case of thinner films, the Ta 2 O 5 or Ta x Nb 1Àx O 5 apparently controlled the leakage either by Richardson-Schottky emission or Poole-Frenkel effect.