| 摘要 |
PURPOSE: A method for forming multi-phase lead germanate film is provided to improve their ferroelectric properties, to form PGO films having a higher polarization and lower coercive field, and to improve the ferroelectric properties of c-axis oriented Pb5 Ge3 O11 for one-transistor memory applications could be developed. CONSTITUTION: A method for forming a lead germanium oxide(PGO) film on an integrated circuit(IC) wafer comprises the steps of: a) mixing (Pb(thd)2) and (Ge(ETO)4) to form a PGO mixture having a molar ratio of approximately 5:3, for example between 5:3 and 5.3:3; b) dissolving the mixture of Step a) with a solvent of tetrahydrofuran, isopropanol, and tetraglyme, having a molar ration of 8:2:1, to form a precursor solution having a concentration of approximately 0.1 to 0.3 moles of PGO mixture per liter of solvent; c) introducing the precursor solution of Step b) at a rate in the range of approximately 0.1 to 0.5 milliliters per minute(ml/min), and heating the solution to a temperature in the range of approximately 140 to 250 °C, creating a precursor gas; d) introducing the precursor vapor to the IC wafer; and e) decomposing the precursor gas formed in Step c) on the wafer at a temperature in the range of approximately 400 to 650 °C to form a PGO film, having ferroelectric properties, including a first phase of Pb5 Ge3 O11 and a second phase of Pb3 GeO5. In this manner, the ferroelectric characteristics of the first phase are improved by adding the second phase.
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