Abstract
In a previous study, the authors introduced a novel technique of using low-beam energy Gallium Focused Ion Beam to expose a large area of Shallow Trench Isolation (STI) over a Dynamic Ring Oscillator (DRO) incurring virtually no change of its operating frequency. In this paper, the authors further investigate the influence of extended dose delivery of 5 kV Ga+ after the initial exposure of the STI over a DRO on modern 7 nm process. The motivation of this study is to understand the dynamics between the Ga+ ion interaction at lower beam energies on live and functional devices and the failure mechanism of the device from such interaction. The frequency of the DROs after the initial STI exposure at 5 kV exhibits <1% increase. Additional dosage of lowkV exposure was performed over the exposed STI and its effects on the DRO frequency was monitored. Finally TEM analysis of the irradiated DROs will be analyzed to understand the failure mechanism of transistors.
