Jin-kwon Bok

Bulk silicon photonic wire for one-chip integrated optical interconnection

We report a nano-sized silicon waveguide by forming partial silicon-on-insulator structure with SPE on bulk silicon substrate. The propagation loss is as low as 6.1 dB/cm, which is close to that of silicon-on-insulator based waveguide.

Mach-Zehnder silicon modulator on bulk silicon substrate; toward DRAM optical interface

We present a Mach-Zehnder silicon modulator fabricated on a bulk silicon substrate featuring active length of 200 µm, modulation speed up to 5 Gb/s, power consumption of 2 pJ/bit, and extinction ratio of 10 dB.

Leakage current reduction mechanism of oxide-nitride-oxide inter-poly dielectrics through the post plasma oxidation treatment

High quality oxide–nitride–oxide (ONO) inter-poly dielectrics were successfully fabricated by the optimized plasma oxidation without H2. The bottom low pressure chemical vapor deposition (LPCVD) oxides treated by the conventional N2O annealing step were subjected to the post deposition process using a plasma treatment. This process reduces both the leakage current and the stress-induced leakage current (SILC), while no thickness increase of the bottom LPCVD oxides was observed due to the plasma treatment. Based on the photo electron injection technique, it is found that the O2 plasma oxidation method significantly reduces the defect centers located at 1.67 nm away from the bottom oxide/floating gate interface.

Analysis of oxide bulk trapped charge distribution and densities from photo injection characteristics of oxide-nitride-oxide (ONO) structures

The thickness of ONO inter-poly dielectrics dominates the program and erase speed of a flash memory cell transistor with a stack gate structure. Therefore, as flash devices shrink, it is important to prevent the degradation in reliability while scaling down the thickness of the oxide. However, the thickness of the bottom oxide formed on a heavily doped poly-silicon cannot be easily reduced because of its high defect density due to a high concentration of dopants in the floating gate and an enhancement of the oxide thickness caused by oxidation of the doped polysilicon [1]. In order to overcome these problems, advanced LPCVD technology has been introduced, but the LPCVD oxide films still have many defect densities in comparison with thermal oxide films. In this work, the bulk trapped charges distribution and density in the bottom LPCVD oxide were quantitatively investigated by photocurrent-voltage characteristics. In addition, we found that the defect density and distribution in the bottom LPCVD oxide were remarkably decreased using post plasma oxidation.