Browsing by Author "Chang, Shih-Chieh"

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A Novel Synthesis of a CuInSe2 Thin Film from Electrodeposited Cu-Se-In-Se Precursors with Three Steps Annealing
(2012-09-01)
Hu, Shao-Yu
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Wang, Ying-Lang
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照明與能源光電研究所
In this study, copper indium diselenide (CIS) films were synthesized from electrodeposited Cu-Se In Se precursors by three step annealing. The Se layer between Cu and In layer was grown to prevent the formation of Cu/In compound. The Cu Se precursors were first annealed to grow uniform and conductive Cu2Se surface. After deposition of the four layers precursors, two steps annealing was employed to form Cu2Se-In2Se3 precursors. Transforming Cu2Se-In2Se3 to CIS required less thermal energy. Therefore, high quality CIS film can be synthesized by two steps annealing due to its high crystallinity. The properties of the CIS films were characterized by scanning electron microscopy (SEM), X-ray Diffraction (XRD), and Raman Spectra.
A Study on the Diffuse Mechanism and the Barrier Property of Copper Manganese Alloy on Tantalum
(2015-05-01)
Su, Ying-Sen
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Wang, Ying-Lang
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照明與能源光電研究所
In this paper, the electrical and material properties of CuMn/silicon oxide (SiO2) and CuMn/tantalum (Ta)/SiO2 were investigated, and an optimized concentration of Mn in the CuMn alloy as barrier layers in these two structures was also determined. CuMn alloy (0 similar to 10 atomic % Mn) deposited on SiO2 and Ta were used in this paper. A diffusion barrier layer self-formed at the interface during annealing, and the growth behavior was found to follow a logarithmic rate law. The microstructures of the CuMn films were analyzed by transmission electron microscopy and could be correlated with the electrical properties of the CuMn films. After thermal treatment, only Cu-5 at.% Mn/ SiO2 successfully avoided the diffusion of Cu atoms. Thermal stability of the films grown on Ta/SiO2 was found to be better than that on SiO2. When a Ta layer was added, the Mn atoms diffused not only to the interface, but also to the grain boundaries in the Ta layer and the interface between Ta and SiO2. This phenomenon could be explained by the surface energy. As the thickness of CuMn shrunk from 150 to 50 nm and the sample was covered with a 100-nm-thick Cu layer, the amount of Mn atoms increased at the interface of CuMn/Ta. This is because the Cu layer had higher chemical potential which induced the Mn atoms to move toward the Ta layer and reduced the amount of Mn atoms in Cu after heat treatment.
Abnormal Renal Resistive Index in Patients with Mild-to-moderate Chronic Obstructive Pulmonary Disease
(2013-04-01)
Chen, Cheng-Yu
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Hsu, Ta-Wei
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Mao, Simon J. T.
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Chang, Shih-Chieh
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Yang, Pan-Chyr
Background: Arterial rigidity and endothelial dysfunction are systemic manifestations of chronic obstructive pulmonary disease (COPD). The decrease in renal vascular resistance in order to adapt the increase in glomerular filtration rate after oral protein loading is known as normal renal functional reserve. We tested the hypothesis that COPD patients, even in those with mild-to-moderate airflow obstruction, are affected by systemic inflammation associated with abnormal renal functional reserve. Materials and Methods: The study enrolled 24 current smokers with a cigarette smoking history >= 25 pack-years and 8 nonsmokers with normal spirometry as control. Doppler sonography detected the renal resistive index (RRI) before and after oral protein loading to determine the renal functional reserve. Pulmonary function and serum tumor necrosis factor alpha (TNF-alpha) levels were analyzed to compare with the renal functional reserve. Results: The smokers were stratified into 3 groups (Group 1: smokers with normal spirometry, Group 2: mild COPD, Group 3: moderate COPD); nonsmokers as Group 4. The baseline RRI levels were similar in Group 1 and Group 4. After protein loading, the RRI elevated in all smoking groups; moreover, Group 3 had the highest RRI and with longer duration than other groups. The smokers with higher serum TNF-alpha levels had a longer RRI elevation. Multiple linear regression revealed forced expiratory volume in one second (FEV 1), serum TNF-alpha levels and aging were independently predictive factors of impaired renal functional reserve. Conclusions: A greater impairment in renal functional reserve of COPD patients was correlated with more severe airway obstruction and inflammation.
Aging-aware Chip Health Prediction Adopting an Innovative Monitoring Strategy
(2019-01-01)
Wang, Yun-Ting
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Wu, Kai-Chiang
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Chou, Chung-Han
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Chang, Shih-Chieh
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資訊工程學系
Concerns exist that the reliability of chips is worsening because of downscaling technology. Among various reliability challenges, device aging is a dominant concern because it degrades circuit performance over time. Traditionally, runtime monitoring approaches are proposed to estimate aging effects. However, such techniques tend to predict and monitor delay degradation status for circuit mitigation measures rather than the health condition of the chip. In this paper, we propose an aging-aware chip health prediction methodology that adapts to workload conditions and process, supply voltage, and temperature variations. Our prediction methodology adopts an innovative on-chip delay monitoring strategy by tracing representative aging-aware delay behavior. The delay behavior is then fed into a machine learning engine to predict the age of the tested chips. Experimental results indicate that our strategy can obtain 97.40% accuracy with 4.14% area overhead on average. To the authors' knowledge, this is the first method that accurately predicts current chip age and provides information regarding future chip health.
An electroplating method for copper plane twin boundary manufacturing
(2013-10-01)
Wang, Yu-Sheng
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Nian, Jun-Nan
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Wang, Ying-Lang
A twin boundary is a special kind of grain boundary that plays an important role in the deformation process of nanocrystalline metals, as it may affect the migration of atoms and electrons in polycrystalline solids, resulting in different electrical and mechanical properties. In this study, plane twin structures were introduced into an electroplated copper film by an electroplating method that inserts an interlayer film with a very small current density (<3 mA/cm(2)). It was found that the small-current interlayer formed a demarcation line for copper grain growth, and enhanced the twin boundaries by self-annealing at room temperature. Based on this, a method was developed to manufacture multi-plane twin boundaries to improve electron migration. Transmission electron microscopy, focused ion beam analysis, and secondary ion mass spectrometry were employed to examine this interesting phenomenon. (C) 2013 Elsevier B. V. All rights reserved.
Effect of Annealing on the Microstructure and Electrical Property of RuN Thin Films
(2011)
Wu, Chia-Yang
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Cheng, Yi-Lung
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Wang, Ying-Lang
Ruthenium (Ru) and ruthenium nitride (RuN) thin films have been investigated as candidates for barrier layers in copper (Cu) damascene processes. In order to study the thermal stability of the Ru and RuN films, the as-deposited films were annealed by rapid thermal annealing (RTA), and the film resistance was real-time measured by a four-point probe, which was embedded in the RTA tool. The X-ray diffraction data show that the grain size of Ru decreased with the increase of the nitrogen (N) content. The Ru phases gradually changed to the RuN phases, and the resistivity of the RuN films decreased with annealing time due to nitrogen effusion. Discontinuous RuN films were found when the annealing temperature was higher than 800 degrees C and then caused a poor Cu diffusion barrier property. We also demonstrated that the Cu film could be directly electroplated on the RuN films with adequate adhesion. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3537825] All rights reserved.
Effect of bis-(3-sodiumsulfopropyl disulfide) byproducts on copper defects after chemical mechanical polishing
(2008-01-01)
Hung, Chi-Cheng
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Lee, Wen-Hsi
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Hu, Shao-Yu
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Chang, Shih-Chieh
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Chen, Kei-Wei
In the semiconductor metallization process, the superior gap-fill capability of copper (Cu) electroplating is mainly due to external additives, such as bis-(3-sodiumsulfopropyl disulfide) (SPS), which is used as an accelerator. This study demonstrates that the byproducts of SPS induced Cu defects after a chemical-mechanical-polishing (CMP) process. In conventional cyclic-voltammetric-stripping analysis, the byproducts generated from organic additives are very difficult to quantify. In this study, the authors used mass-spectrum analysis to quantify SPS byproducts and found that the SPS byproduct, 1,3-propanedisulfonic acid, correlated with the formation of Cu defects because it influenced the properties of electroplated Cu films and the chemical corrosion rate, then induced defects after the CMP process. (C) 2008 American Vacuum Society.
Effect of Cu-Ion Concentration in Concentrated H(3)PO(4) Electrolyte on Cu Electrochemical Mechanical Planarization
(2010-01-01)
Kung, Te-Ming
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Liu, Chuan-Pu
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Chang, Shih-Chieh
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Chen, Kei-Wei
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Wang, Ying-Lang
The influence of Cu-ion concentration in a concentrated H(3)PO(4) electrolyte on the Cu removal rate and planarization efficiency (PE) of electrochemical mechanical planarization (ECMP) was investigated. With increasing Cu-ion concentration in the electrolyte, results show that the Cu removal rate significantly decreased because more Cu ions in the electrolyte facilitated the formation of a surface passive film. Electrochemical analysis shows that the current density decreased from 91 to 62 mA/cm(2) when the Cu-ion concentration was increased from 35.8 to 158.6 mM. In a low Cu-ion concentration electrolyte, Cu(OH)(2) is dominant, while in a high Cu-ion concentration electrolyte, CuO predominates. A high Cu-ion concentration in the electrolyte during ECMP promotes the formation of CuO, which retards Cu-ion diffusion from the Cu surface to the electrolyte solution, resulting in a decrease in the Cu removal rate. The intensity ratio of CuO/[Cu(OH)(2)+CuO] in the Cu 2p(3/2) X-ray photoelectron spectroscopy spectrum increased from 22.1 to 85.6% when the Cu-ion concentration was increased. The effect of Cu-ion concentration on the microscale PE of Cu ECMP is discussed. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3425807] All rights reserved.
Effect of Cu-Ion Concentration in Concentrated H3PO4 Electrolyte on Cu Electrochemical Mechanical Planarization
(2010-01-01)
Kung, Te-Ming
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Liu, Chuan-Pu
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Chang, Shih-Chieh
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Chen, Kei-Wei
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Wang, Ying-Lang
The influence of Cu-ion concentration in a concentrated H3PO4 electrolyte on the Cu removal rate and planarization efficiency (PE) of electrochemical mechanical planarization (ECMP) was investigated. With increasing Cu-ion concentration in the electrolyte, results show that the Cu removal rate significantly decreased because more Cu ions in the electrolyte facilitated the formation of a surface passive film. Electrochemical analysis shows that the current density decreased from 91 to 62 mA/cm(2) when the Cu-ion concentration was increased from 35.8 to 158.6 mM. In a low Cu-ion concentration electrolyte, Cu(OH)(2) is dominant, while in a high Cu-ion concentration electrolyte, CuO predominates. A high Cu-ion concentration in the electrolyte during ECMP promotes the formation of CuO, which retards Cu-ion diffusion from the Cu surface to the electrolyte solution, resulting in a decrease in the Cu removal rate. The intensity ratio of CuO/[Cu(OH)(2)+CuO] in the Cu 2p(3/2) X-ray photoelectron spectroscopy spectrum increased from 22.1 to 85.6% when the Cu-ion concentration was increased. The effect of Cu-ion concentration on the microscale PE of Cu ECMP is discussed. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3425807] All rights reserved.
Effect of Electric Potential and Mechanical Force on Copper Electro-Chemical Mechanical Planarization
(2012-03-01)
Chen, Sheng-Wen
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Kung, Te-Ming
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Liu, Chuan-Pu
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Chang, Shih-Chieh
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Cheng, Yi-Lung
In this study, the dependence of Cu electrochemical mechanical planarization (ECMP) rate on electric potential and mechanical force in electrolyte is investigated using potentiodynamic analysis, electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). In chemical etching, CMP, electropolishing, and ECMP processes, the Cu removal rate is mainly affected by the interplay between electric potential and mechanical force. An equivalent circuit is built by fitting the EIS results to explain the behavior of Cu dissolution and Cu passive film. The Cu dissolution rate increased with decreasing charge-transfer time-delay. The resistance of the Cu passive film (R-p) is proportional to the intensity ratio of Cu2O/[Cu(OH)(2) + CuO]. (C) 2012 The Japan Society of Applied Physics
Effect of Electrolyte Composition on Cu Stripping of Pt Contact Pins in Semiconductor Cu Electroplating Process
(2011-11-01)
Hu, Shao-Yu
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Wang, Ying-Lang
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照明與能源光電研究所
In Cu electroplating processes, the wet-contact pins are deposited with Cu films. The Pt contact pins should be stripped to remove extra Cu films to maintain contact quality and plating efficiency. However, the stripping behavior is affected by electrolyte composition. The proportion of copper sulphate and sulfuric acid changes the conductivity, pH, and cupric-ion concentration of the electrolyte solution. In this study, an electrochemistry analysis system is employed to characterize the behavior of the Pt stripping process in electrolytes having various electrolyte proportions. It was found that increasing the copper sulphate and sulfuric acid concentrations suppresses the Cu stripping current but enhances the water electrolysis reaction on the Pt surface. Copper sulphate decreased the rate of oxide dissolution and cupric diffusion. The dissolution rate was limited by denser cation layer. Sulfuric acid decreased the dissolubility of cupric ions and suppressed the electrode from releasing more cupric ions. There is no significant influence of additives such as leveler suppressor on the stripping. Minute quantity of HNO3 and H3PO4 were also added to the plating electrolyte. The additional acid HNO3 eliminated the inhibition form dense cupric layer and enhanced the stripping performance without changing the quality of the deposited films during the plating process.
Effect of N(2)/H(2) plasma treatment on the moisture adsorption of MOCVD-TiN films
(2011-05-31)
Huang, J. K.
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Huang, Cheng-Liang
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Chang, Shih-Chieh
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Cheng, Yi-Lung
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Wang, Ying-Lang
In the application of contact glue layer for semiconductor devices, a nitrogen/hydrogen (N(2)/H(2)) plasma treatment is usually used to reduce the amount of C and O impurities of metallorganic chemical vapor deposition titanium nitride (MOCVD-TiN) films. This study found that the sheet resistance of as-deposited MOCVD-TiN film without N(2)/H(2) plasma treatment dramatically increased with exposure time due to moisture adsorption. Increasing plasma treatment power and time was able to retard the increase in sheet resistance. From residue gas analysis at 200 degrees C, it was found that the amount of H(2)O outgases from the MOCVD-TiN films decreased with increasing plasma treatment power and time. TEM images reveal that the surface of the MOCVD-TiN films became compact as it received more plasma treatment energy, making it difficult for the external moisture to diffuse into and react with the MOCVD-TiN films. (C) 2011 Elsevier B.V. All rights reserved.
Effect of N-2/H-2 plasma treatment on the moisture adsorption of MOCVD-TiN films
(2011-05-31)
Huang, J. K.
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Huang, Cheng-Liang
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Chang, Shih-Chieh
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Cheng, Yi-Lung
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Wang, Ying-Lang
In the application of contact glue layer for semiconductor devices, a nitrogen/hydrogen (N-2/H-2) plasma treatment is usually used to reduce the amount of C and O impurities of metallorganic chemical vapor deposition titanium nitride (MOCVD-TiN) films. This study found that the sheet resistance of as-deposited MOCVD-TiN film without N-2/H-2 plasma treatment dramatically increased with exposure time due to moisture adsorption. Increasing plasma treatment power and time was able to retard the increase in sheet resistance. From residue gas analysis at 200 degrees C, it was found that the amount of H2O outgases from the MOCVD-TiN films decreased with increasing plasma treatment power and time. TEM images reveal that the surface of the MOCVD-TiN films became compact as it received more plasma treatment energy, making it difficult for the external moisture to diffuse into and react with the MOCVD-TiN films. (C) 2011 Elsevier B.V. All rights reserved.
Effect of Under-Layer Treatment of Ta/TaN Barrier Film on Corrosion Between Cu Seed and Ta in Chemical-Mechanical-Polishing Slurry
(2010-07-01)
Lee, Wen-Hsi
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Hung, Chi-Cheng
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Wang, Yu-Sheng
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Chang, Shih-Chieh
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Wang, Ying-Lang
Tantalum/tantalum nitride (Ta/TaN(x)) composite film is widely used as a copper (Cu) diffusion barrier layer. In order to reduce via-resistance, an additional argon (Ar) re-sputtering process is used to thin the barrier thickness at the feature bottom. In this study, the effect of (Ar) re-sputtering of the under-layer of TaN(x) barrier films on the corrosion between Cu seeds and upper Ta films in chemical-mechanical-polishing (CMP) slurries was investigated. The results show that Ar re-sputtering of the under-layer of the TaN(x) barrier has a strong influence on the corrosion of Cu seeds and Ta films. The equivalent circuit, simulated using data from electrochemical analysis, reveals changes in resistance and capacitance elements of the Cu-Ta electrochemical system, proving that the phase transformation of upper Ta films under different TaN(x) conditions leads to different degrees corrosion of Cu seeds and the Ta films.
Enhancement of the Thermal Stability of TiN(x) Capping Layer on the Nickel Silicides
(2011-04-01)
Wu, Chi-Ting
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Cheng, Yi-Lung
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Wang, Ying-Lang
In this study, the effects of TiN(x) capping layers on the thermal stability of nickel silicides have been investigated in a rapid thermal annealing (RTA) process. Various TiN(x) films were deposited on the nickel film by different N(2) flow rates. It was found that the TIN(x) capping layer could improve the thermal stability of nickel silicides and suppress silicide agglomeration. The TIN(x) film deposited with higher N(2) flow rates had better thermal stability than those with lower N(2) flow rates. The corrosion behaviors of the TIN(x) films deposited with various N(2) flow rates and nickel films in the H(2)SO(4):H(2)O(2) (4:1) solution were investigated. We found that the corrosion currents (I(corr)) of the nickel and NiSi films were much higher than those of the TiN(x) films, while the I(corr) of the TiN(x) films deposited with higher N(2) flow rates was much lower than that of the TiN(x) films deposited with lower N(2) flow rates.
Enhancement of the Thermal Stability of TiNx Capping Layer on the Nickel Silicides
(2011-04-01)
Wu, Chi-Ting
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Cheng, Yi-Lung
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Wang, Ying-Lang
In this study, the effects of TiNx capping layers on the thermal stability of nickel silicides have been investigated in a rapid thermal annealing (RTA) process. Various TiNx films were deposited on the nickel film by different N-2 flow rates. It was found that the TINx capping layer could improve the thermal stability of nickel silicides and suppress silicide agglomeration. The TINx film deposited with higher N-2 flow rates had better thermal stability than those with lower N-2 flow rates. The corrosion behaviors of the TINx films deposited with various N-2 flow rates and nickel films in the H2SO4:H2O2 (4:1) solution were investigated. We found that the corrosion currents (I-corr) of the nickel and NiSi films were much higher than those of the TiNx films, while the I-corr of the TiNx films deposited with higher N-2 flow rates was much lower than that of the TiNx films deposited with lower N-2 flow rates.
Investigation of the Galvanic Effect between RuN Barriers and Cu Seed Layers
(2011-12-01)
Wu, Chia-Yang
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Wang, Ying-Lang
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照明與能源光電研究所
In this study, we investigated the galvanic effect between the Cu metals and ruthenium nitride (RuNx) films that were deposited at various nitrogen (N-2) gas flow rates in chemical mechanical polishing slurries. It was found that the galvanic corrosion of the RuNx films was inhibited with increasing N-2 gas flow ratio, whereas the galvanic corrosion of the Cu seed layers was enhanced. Electrochemical impedance spectroscopy showed that the galvanic corrosion resistance of RuNx increased and that of the ruthenium oxide layer decreased as N-2 flow ratio increased. This was because the increase in the N content in the RuNx films inhibited the corrosion and oxidation of the Ru metals. (C) 2011 The Japan Society of Applied Physics
Investigation the Electroplating Behavior of Self Formed CuMn Barrier
(2013-08-01)
Wu, Chia-Yang
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Wang, Ying-Lang
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照明與能源光電研究所
The electrical and material properties of Copper (Cu) mixed with [0 similar to 10 atomic% manganese (Mn)] and pure Cu films deposited on silicon oxide (SiO2)/silicon (Si) are explored. Cu electroplating on self formed CuMn barrier was investigated with different Mn content. The electrochemical deposition of the Cu thin film onto the electrode using CuMn barrier was investigated. Scanning electron microscopic (SEM) micrographs of copper electroplating on CuMn films were examined, and the copper nucleation behaviors changed with the Mn content. Since the electrochemical impedance spectroscopy (EIS) is widely recognized as a powerful tool for the investigation of electrochemical behaviors, the tool was also used to verify the phenomena during plating. It was found that the charge-trasfer impedance decrease with the rise in the Mn content below 5%, but increase with the rise in the Mn content higher than 5%. The result was corresponded to the surface energy, the surface morphology, the corrosion and the oxidation of the substrate.
Leak Stopper: An Actively Revitalized Snoop Filter Architecture with Effective Generation Control
(2017-05-01)
Peng, Yin-Chi
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Chen, Chien-Chih
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Tsai, Hsiang-Jen
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Yang, Keng-Hao
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Huang, Pei-Zhe
To alleviate high energy dissipation of unnecessary snooping accesses, snoop filters have been designed to reduce snoop lookups. These filters have the problem of decreasing filtering efficiency, and thus usually rely on partial or whole filter reset by detecting block evictions. Unfortunately, the reset conditions occur infrequently or unevenly (called passive filter deletion). This work proposes the concept of revitalized snoop filter (RSF) design, which can actively renew the destination filter by employing a generation wrapping-around scheme for various reference behaviors. We further utilize a sampling mechanism for RSF to timely trigger precise filter revitalizations, so that unnecessary RSF flushing can be minimized. The proposed RSF can be integrated to various existent inclusive snoop filters with only a minor change to their designs. We evaluate our proposed design and demonstrate that RSF eliminates 58.6% of snoop energy compared to JETTY on average while inducing only 6.5% of revitalization energy overhead. In addition, RSF eliminates 45.5% of snoop energy compared to stream registers on average and only induces 2.5% of revitalization energy overhead. Overall, these RSFs reduce the total L2 cache energy consumption by 52.1% (58.6% - 6.5%) as compared to JETTY and by 43% (45.5% - 2.5%) as compared to stream registers. Furthermore, RSF improves the overall performance by 1% to 1.4% on average compared to JETTY and stream registers for various benchmark suites.
Pulsed Electrodeposition of CuInSe(2) Thin Films onto Mo-Glass Substrates
(2011-01-01)
Hu, Shao-Yu
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Lee, Wen-Hsi
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Chang, Shih-Chieh
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Cheng, Yi-Lung
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Wang, Ying-Lang
In this study, copper indium selenide (CIS) films were deposited by pulsed electrodeposition with multi potentials to control the atomic ratio of the CIS film and improve the deposition uniformity. It was found that smaller duty cycle and pulsed period enhanced the cathodic current due to ion replenishment. The results show that the Cu/In ratio was significantly influenced by reverse voltage of pulsed electrodeposition. The uniformity of the CIS films can be improved by proper reverse voltage. The deposition rate did not decrease in direct proportion to the duty cycle because the plating current was enhanced by the pulse effect. The pulsed deposited CIS film with optimized composition show smaller grain size, smoother microstructure, and less secondary phase than constant deposited film. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3567762] All rights reserved.