In accordance with recent trends for thinness in an application processor (AP) for a smartphone, the necessity of a thinner thin film capacitor than a multilayer ceramic capacitor (MLCC) has increased.
The thin film capacitor has an advantage in that a thin capacitor may be developed using thin film technology. However, since the number of dielectric layers to be stacked is significantly restricted, as compared to an MLCC, it may be difficult to implement high capacitance.
The thin film capacitor may be manufactured by a sol-gel method, a sputtering method, a chemical vapor deposition (CVD) method, a pulsed laser deposition (PLD) method, or the like, the thin film technology, and a dielectric layer containing a material with high permittivity and having a wide area, a thin thickness, and a multilayer structure has been required for high capacitance.
More specifically, in a case of implementing high capacitance through a multilayer dielectric structure using the thin film technology, leakage current characteristics may not be secured.
Generally, in order to increase capacitance of a capacitor, a plurality of first and second electrode layers and dielectric layers are manufactured, and the dielectric layers are connected to each other in parallel. Since in a thin film capacitor having a multilayer structure in which dielectric layers are connected to each other in parallel, electrical fields applied to each of the dielectric layers are formed to have opposing polarities as each other, per the dielectric layer, leakage current characteristics may be deteriorated.
More specifically, in the dielectric layer formed on the electrode layer, a pyrochlore phase, a defect occurring due to a thin film process, is present in a region adjacent to the electrode layer, and a defect of a negative (−) charge (negative (−) charge defect) is formed below the dielectric layer, thereby causing a bias polarity phenomenon depending on a direction of an electrode applied with a voltage. That is, leakage current characteristics may be changed depending on a direction in which the voltage is applied, and in the case of the thin film capacitor having a multilayer structure in which the dielectric layers are connected to each other in parallel, the leakage current characteristics may be deteriorated.
Therefore, a method capable of securing the leakage current characteristics of the dielectric layer is been required.
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