Hong-Sik Shin

Ni Germanide Utilizing Ytterbium Interlayer for High-Performance Ge MOSFETs

In this article, ytterbium (Yb) incorporation into NiGe is proposed to improve the thermal stability of Ni germanide for high-performance Ge metal-oxide-semiconductor field-effect transistors (Ge MOSFETs). The Yb/Ni/TiN structure shows suppression of NiGe agglomeration and better surface morphology than the Ni/TiN structure after a postgermanidation annealing of up to 550°C for 30 min. It is notable that Yb atoms distribute uniformly at the top region of NiGe. NiGe agglomeration was retarded by Yb incorporation, and the thermal stability of NiGe was therefore improved.

Improvement of Thermal Stability of Nickel Silicide Using Co-sputtering of Ni and Ti for Nano-Scale CMOS Technology

In this paper, a thermally stable nickel silicide technology using the co-sputtering of nickel and titanium atoms capped with TiN layer is proposed for nano-scale metal oxide semiconductor field effect transistor (MOSFET) applications. The effects of the incorporation of titanium ingredient in the co-sputtered Ni layer are characterized as a function of Ti sputtering power. The difference between the one-step rapid thermal process (RTP) and two-step RTP for the silicidation process has also been studied. It is shown that a certain proportion of titanium incorporation with two-step RTP has the best thermal stability for this structure.

Thermally Robust Ni Germanide Technology Using Cosputtering of Ni and Pt for High-Performance Nanoscale Ge MOSFETs

Thermally robust Ni germanide (NiGe) using the cosputtering of Ni and Pt on Ge-on-Si substrate is proposed for high-performance nanoscale germanium metal-oxide-semiconductor field-effect transistors (Ge MOSFETs). The rapid thermal process temperature window for the stable sheet resistance of the proposed Ni-Pt cosputtered structures was about 50-100°C wider than that of the pure Ni structure, with neither NiGe agglomeration nor local penetration of Ni atoms into the substrate. In addition, the surface and interfacial morphologies of the Ni-Pt cosputtered structure were much smoother and more continuous than those of a pure Ni structure. The improvement in the thermal stability was attributed to the change of the crystal structure due to the suppression of the diffusion of Ni atoms and the uniform distribution of Pt atoms. Therefore, this proposed Ni-Pt cosputtered structure could be promising for high-mobility Ge-on-Si MOSFET applications.

Thermal Immune Ni Germanide for High Performance Ge MOSFETs on Ge -on- Si Substrate Utilizing

Highly thermally stable Ni germanide technology for high performance germanium metal-oxide-semiconductor field-effect transistors (Ge MOSFETs) is proposed, utilizing Pd incorporation into Ni germanide. The proposed Ni germanide shows not only the improvement of thermal stability but also the reduction of hole barrier height, which can improve the device on-current by reducing the Ni germanide to p+ source/drain contact resistance. The proposed Ni germanide showed a stable sheet resistance of up to 500degC 30-min postgermanidation annealing due to the suppression of agglomeration and oxidation of Ni germanide and the diffusion of Ni and Ge atoms by the incorporated Pd. Therefore, the proposed Ni0.95Pd0.05 alloy could be promising for the high mobility Ge MOSFET applications.

\hbox{Ni}_{0.95}\hbox{Pd}_{0.05}

Eighty-one dogs in the Chungnam province were tested for heartworm (Dirofilaria immitis) infection by ELISA (SNAP test, IDEXX Laboratories, Maine, USA). Seventeen (20.9%) of the 81 samples were found to be positive and further analyzed by 16S rRNA sequencing. In this study, all dogs tested lived outdoors. Using the chi(2) test and Fishers exact test, no significant differences in the prevalence of dirofilariasis were observed among different gender and age groups, although the prevalence of this disease among dogs 2-4yrs of age remains highest. Sequence analysis revealed that the species prevalent in Chungnam province were genetically distinct from the type strain of D. immitis based on the nucleotide deletion found at position nt 276 (cytosine) and nucleotide substitution at position 428 (G to A) of the partial 16S rRNA sequence of the type strain. Furthermore, phylogenetic analysis suggests at least 2 groups of D. immitis circulating in the Chungnam area between the year 2007 and 2008.

Alloy

This paper presents a study of the process temperature dependence of Al₂O₃ film grown by thermal atomic layer deposition (ALD) as a passivation layer in the crystalline Si (c-Si) solar cells. The deposition rate of Al₂O₃ film maintained almost the same until 250 ℃, but decreased from 300 ℃. Al₂O₃ film deposited at 250 ℃ was found to have the highest negative fixed oxide charge density (Qf) due to its O-rich condition and low hydroxyl group (-OH) density. After post-metallization annealing (PMA), Al₂O₃ film deposited at 250 ℃ had the lowest slow and fast interface trap density. Actually, Al₂O₃ film deposited at 250 ℃ showed the best passivation effects, that is, the highest excess carrier lifetime (τPCD) and lowest surface recombination velocity (Seff) than other conditions. Therefore, Al₂O₃ film deposited at 250 ℃ exhibited excellent chemical and field-effect passivation properties for p-type c-Si solar cells.

Serological update and molecular characterization of Dirofilaria immitis in dogs, South Korea.

Different kinds of post-deposition annealing (PDA) by a rapid thermal process (RTP) are used to enhance the field-effect passivation of Al2O3 film in crystal Si solar cells. To characterize the effects of PDA on Al2O3 and the interface, metalinsulator semiconductor (MIS) devices were fabricated. The effects of PDA were characterized as functions of RTP temperature from 400~700 °C and RTP time from 30~120 s. A high temperature PDA can retard the passivation of thin Al2O3 film in c-Si solar cells. PDA by RTP at 400 °C results in better passivation than a PDA at 400 °C in forming gas (H2 4% in N2) for 30 minutes. A high thermal budget causes blistering on Al2O3 film, which degrades its thermal stability and effective lifetime. It is related to the film structure, deposition temperature, thickness of the film, and annealing temperature. RTP shows the possibility of being applied to the PDA of Al2O3 film. Optimal PDA conditions should be studied for specific Al2O3 films, considering blistering.

Process Temperature Dependence of Al2O3Film Deposited by Thermal ALD as a Passivation Layer for c-Si Solar Cells

In this article, thermally stable Ni germanide using palladium (Pd) incorporation is proposed for high performance germanium metal-oxide-semiconductor field-effect transistors, and a microstructural analysis of the Ni germanide is performed in depth. The proposed Pd/Ni/TiN structure exhibited a stable sheet resistance despite high temperature postgermanidation annealing of up to 500°C for 30 min. The cause of the improved thermal stability is determined to be caused by the pileup of Pd atoms at the bottom region of NiGe, which resulted in the retardation of NiGe agglomeration by the formation of PdGe or NiPdGe there.

Blistering Induced Degradation of Thermal Stability Al2O3Passivation Layer in Crystal Si Solar Cells

Characterized herein is a different physical mechanism for the formation of Ni silicide by incorporating rare earth (RE) metals such as ytterbium (Yb), erbium (Er), and dysprosium (Dy). Although the incorporation of any RE metal increases the Schottky barrier height (SBH) for holes in Ni silicide due to the formation of a ternary phase silicide, Yb induced the greatest increase in SBH because, unlike the other metals, Yb atoms accumulated at the silicide/silicon interface.

Microstructural Innovation of Ni Germanide on Ge-on-Si Substrate by Using Palladium Incorporation

In this paper, a novel Al2O3/ZnO/Al2O3 stack is proposed as the silicon passivation layer for c-Si solar cell application. Recently, the Al2O3 film has been proved to be effective for passivating the p-type c-Si surface by forming the negative fixed oxide charge. It is confirmed by this experiment that the amount of negative fixed oxide charge can be controlled by inserting a ZnO interlayer (IL), which is explained by acceptor-like defect (VZn, Oi, and OZn) formation determined by the room-temperature photoluminescence (RTPL) analysis. The effect of ZnO IL is investigated using Al2O3 bottom layers of various thicknesses by electrical and physical analyses. The effective lifetime measurement shows that the electronic recombination losses at the silicon surface are reduced effectively by optimizing the Al2O3/ZnO/Al2O3 stack.