The Development of the Non-contact Electrical Leakage Property Measurement System for the High-K Dielectric Materials on DRAM Capacitors

We have used the non-contact electrical property measurement system to characterize the electrical leakage property of high-K materials such as Al₂O₃ and HfO₂ on a patterned wafer. The basic technology is to measure the surface voltage with micro Kelvin probe after the corona charge deposition on a measurement area. Because of the charge decay through a dielectric material, voltage-time spectra follow exponential time dependence that is the characteristic of leakage induced charge decay. We have measured the electrical leakage property of the storage capacitors on the direct cell area of DRAM device. The measured electrical leakage property can be classified according to the thickness of Al₂O₃ and HfO₂. Since the electrical leakage property depends on a thickness of a dielectric material, voltage-time spectra show different shapes according to the HfO₂ thickness. Using the technology, we can monitor the electrical leakage property of the storage capacitors of high-K materials on the direct cell area