Abstract
To enhance film conformality together with electrical property suitable for dynamic random access memory (DRAM) capacitor dielectric, the effects of oxidant and post heat treatment were investigated on aluminum and titanium oxide (Al2O3–TiO2) bilayer (ATO) thin film formed by atomic layer deposition method. For the conformal deposition of Al2O3 thin film, the O3 oxidant required a higher deposition temperature, more than 450 °C, while H2O or combined oxygen sources (H2O+O3) needed a wide range of deposition temperatures ranging from 250 to 450 °C. Conformal deposition of the TiO2 thin film was achieved at around 325 °C regardless of the oxidants. The charge storage capacitance, measured from the ATO bilayer (4 nm Al2O3 and 2 nm TiO2) deposited at 450 °C for Al2O3 and 325 °C for TiO2 with O3 oxidant on the phosphine-doped poly silicon trench, showed about 15% higher value than that of 5 nm Al2O3 single layer thin film without any increase of leakage current. To maintain the improved electrical property of the ATO bilayer for DRAM application, such as enhanced charge capacitance without increase of leakage current, upper electrode materials and post heat treatments after electrode formation must be selected carefully.
Similar content being viewed by others
References
Cho MH, Ko DH, Choi YG, Jeong K, Lyo IW, Noh DY, Kim JJ, Whang CN (2001) J Vac Sci Technol A 19:192
Alers GB, Serder DJ, Chabal Y, Lu HC, Gusev EP, Garfunkel D, Gustafsson T, Urdahl RS (1998) Appl Phys Lett 73:1517
Campbell SA, Gilmer DC, Wang X, Hsieh M, Kim HS, Gladfelter WL, Yan J (1997) IEEE Trans Electron Devices 44:104
Kwon KW, Kang CS, Park SO, Kang HK, Ahn ST (1996) IEEE Trans Electron Devices 43:919
Cho MH, Roh YS, Whang CN, Nahm SW, Ko DH, Lee JH, Lee NI, Fujihara K (2002) Appl Phys Lett 81:472
Wilk GD, Wallace RM, Anthony JM (2001) J Appl Phys 89:5243
Kim YS, Yun SJ (2005) J Cryst Growth 274:585
Kukli K, Ihanus J, Ritala M, Leskela M (1997) J Electrochem Soc 144:300
Johnson RS, Hong JG, Hinkle C, Lucovsky G (2002) J Vac Sci Technol B 20:1126
Park HB, Cho M, Park J, Lee SW, Hwang CS, Jeong J (2004) Electrochem Solid-State Lett 7:F25
Kukli K, Ihanus J, Ritala M, Leskela M (1996) Appl Phys Lett 68:3737
George SM, Ott AW, Klaus JW (1996) J Phys Chem 100:13121
Suntola T, Simpson M (1987) Atomic layer epitaxy. Blackie, Glasgow, UK
Rees S Jr (1996) CVD of nonmetals. VCH, New York
Hwang KH, Choi SJ, Lee JD, You YS, Kim YK, Kim HS, Song CL, Lee SI (2001) ALD symposium. Monterey, CA, P-326
Ritala M, Leskela M, Niinisto L, Haussalo P (1993) Chem Mater 5:1174
Yun SJ, Lee KH, Skarp J, Kim HR, Nam KS (1997) J Vac Sci Technol A 15:2293
Kim JB, Kwon DR, Chakrabarti K, Lee C, Oh KY, Lee JH (2002) J Appl Phys 92:6738
Author information
Authors and Affiliations
Corresponding author
Additional information
Dedicated to Professor Su-Il Pyun on the occasion of his 65th birthday.
Rights and permissions
About this article
Cite this article
Ko, C.H., Lee, WJ. Formation of Al2O3–TiO2 bilayer using atomic layer deposition and its application to dynamic random access memory. J Solid State Electrochem 11, 1391–1397 (2007). https://doi.org/10.1007/s10008-007-0359-4
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10008-007-0359-4