Yong-kuk Jeong

Rugged Metal Electrode (RME) for High Density Memory Devices

Rugged metal electrode (RME) was suggested and evaluated as a bottom electrode of high-density memory capacitors. Rugged ruthenium films (RME-Ru) were successfully fabricated through volume shrinking of ruthenium oxide films under reduction ambient (RuOx+H2=Ru+H2O). The effective surface area of RME-Ru films was significantly enlarged due to the formation of wrinkle on its surface, which resulted in low SiO2 equivalent thickness (Tox) as low as ~ 6 A with Ru/TaOx(110 A)/RME-Ru capacitor. It is believed that RME technique will be very useful to realize and extend MIM (Metal-Insulator-Metal) capacitor era in the mass production of high density memory devices.

High quality high-k MIM capacitor by Ta/sub 2/O/sub 5//HfO/sub 2//Ta/sub 2/O/sub 5/ multi-layered dielectric and NH/sub 3/ plasma interface treatments for mixed-signal/RF applications

Novel high-k MIM capacitor technology for mixed-signal/RF applications has been successfully developed by introducing multilayered high-k dielectric(Ta/sub 2/O/sub 5//HfO/sub 2//Ta/sub 2/O/sub 5/) and NH/sub 3/ plasma electrode-dielectric interfaces treatments. For the first time, we have simultaneously achieved high capacitance of 4fF/um/sup 2/ and low leakage current of 100nA/cm/sup 2/ at high temperature of 125/spl deg/C with ultra low VCC(a=16.9ppm/V/sup 2/, b=5.2ppm/V) and high Q(/spl sim/107 at 2.4GHz and 5.4pF).

Novel plasma enhanced atomic layer deposition technology for high-k capacitor with EOT of 8 /spl Aring/ on conventional metal electrode

We have developed a plasma enhanced atomic layer deposition(PEALD) technology for high-k dielectrics such as Al/sub 2/O/sub 3/,Ta/sub 2/O/sub 5/ and HfO/sub 2/. Film quality and throughput of PEALD are far superior to that of ALD which has been spotlighted as a deposition technology for next generation semiconductor devices. We have obtained a extremely low equivalent oxide thickness(EOT) of 8 /spl Aring/ from HfO/sub 2/ film, which has not been reported in conventional metal-based memory capacitors up to now. It was confirmed that PEALD-Al/sub 2/O/sub 3/ and Ta/sub 2/O/sub 5/ films are superior to those using any other deposition techniques and very useful as System-on-Chip(SoC) capacitors.

Development of CVD-Ru/Ta/sub 2/O/sub 5//CVD-Ru capacitor with concave structure for multigigabit-scale DRAM generation

RIR(Ru/Crystalline-Ta/sub 2/O/sub 5/Ru) capacitor with concave structure was studied for the application into multigigabit-scale DRAM device. In this work, several novel technologies were successfully developed to solve current issues in the fabrication of RIR concave capacitor; such as 1) two-step deposition of Ta/sub 2/O/sub 5/ films 2) formation of Ta/sub 2/O/sub 5/ spacer 3) new separation process of Ru storage node using maskless etch-back method 4) H/sub 2/ pre-annealing and 5) Ar plasma pre-treatment on Ru bottom electrode. The RIR concave capacitor (design rule/spl sim/0.12 /spl mu/m, node height/spl sim/0.85 /spl mu/m) fabricated with these novel technologies showed excellent electrical properties (25fF/cell, 1fA/cell at /spl plusmn/ 1V), which indicates that RIR structure is the one of the most promising candidate for the next generation DRAM capacitor.