Chang-soo Park

Oxidation resistance of tantalum–ruthenium dioxide diffusion barrier for memory capacitor bottom electrodes

The effect of the RuO2 addition into a Ta film on the oxidation resistance of a diffusion barrier for the Ta+RuO2/Si system was investigated. The Ta+RuO2/Si system was sustained up to 800 °C without an increase in resistivity, while the Ta/Si structure completely degraded after annealing at 450 °C. The Ta+RuO2 diffusion barrier showed an amorphous microstructure for an as-deposited state and formed a conductive RuO2 phase after annealing. Ta was sufficiently bound to oxygen of RuO2 for an as-deposited state, but RuO2 was divided into Ru and Ru–O binding states. Ta–O bonds showed a little change compared to the as-deposited state with increasing annealing temperature, whereas Ru–O bonds significantly increased. Therefore, the Ta layer deposited by the RuO2 addition effectively prevented the indiffusion of oxygen up to 800 °C and its oxidation resistance was superior to those of polycrystalline nitride (TiN, TaN) and ternary amorphous (TaSiN) barriers reported by others.

Investigation of Ta–RuO2 diffusion barrier for high density memory capacitor applications

The properties of both oxygen indiffusion and oxidation resistance in a Ta+RuO2 layer for high density memory devices were investigated by using Rutherford backscattering spectroscopy, four point probe, x-ray diffraction, x-ray photoelectron spectroscopy, and planar transmission electron microscopy. The Ta+RuO2/Si system sustained up to 800 °C without an increase in resistivity. The Ta+RuO2 diffusion barrier showed a Ta amorphous microstructure and an embedded RuOx nanocrystalline structure in the as-deposited state. The Ta+RuO2 film showed the formation of RuO2 phase by reaction with the indiffused oxygen from atmosphere after annealing in an air ambient. The Ta+RuO2 diffusion barrier showed that Ta is sufficiently bound to oxygen in the as-deposited state, but RuO2 consists of Ru and Ru–O binding state. The Ta–O bonds showed little change compared to the as-deposited state with increasing annealing temperature, whereas Ru–O bonds significantly increased and transformed to conductive oxide, RuO2. Therefo...

An H.265/HEVC codec for UHD(3840×2160) capturing and playback

An H.265/HEVC codec(encoder/decoder) for UHD(3840×2160) capturing and playback is presented. Implemented codec has 0.97 mm2 logic area in 20nm with 170KB internal memory. By exploiting sophisticated low-power design, 56/190 mW power consumption is achieved in UHD 30fps decoding/encoding. Maintaining UHD 30fps real-time encoding, the encoder allows about 1.0 dB quality drop compared to HM reference model. By introducing pixel cache for reference pixel read for motion estimation/compensation, the codec consumes 1.2 / 2.0 GB/s external memory bandwidth at UHD 30fps decoding/encoding.