Browsing by Author "Cheng, Yi-Lung"

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Comparison of H-2 and NH3 Treatments for Copper Interconnects
(2013)
Chang, Yu-Min
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Leu, Jihperng
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Lin, Bing-Hong
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Wang, Ying-Lung
;
Cheng, Yi-Lung
The surface state, electrical, and reliability characteristics of copper (Cu) interconnects after ammonia (NH3) or hydrogen (H-2) plasma treatment were investigated in this study. The experimental results show that H-2 plasma treatment has excellent Cu oxide removal efficiency, less impact on the formation of Cu hillocks, and less damage on low-dielectric constant (low-k) dielectrics in comparison to NH3 plasma treatment. However, H-2 plasma treatment results in a higher leakage current between the Cu lines and shorter electromigration (EM) failure time due to a weaker adhesion strength at the Cu film interface. On the other hand, NH3 plasma treatment without the sufficient treatment time would lead to an increased probability of delamination at the Cu/barrier layer interface since the Cu oxide layer can not be completely removed. As a result, extending NH3 plasma treatment time can efficiently reduce the adhesion failure and enlarge EM resistance as well.
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 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 fluorine flow and deposition temperature on physical characteristics and stability of fluorine-doped siloxane-based low-dielectric-constant material
(2010-05-01)
Cheng, Yi-Lung
;
Wu, Jiung
;
Chiu, Tai-Jung
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材料科學與工程學系
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Department of Materials Science and Engineering
The effects of SiF(4) flow rate and deposition temperature on the physical properties and stability of fluorine-doped organo-silica-glass (OFSG) films were investigated. The porosity of the as-deposited OFSG dielectrics declines as the flow rate of SiF(4) gas and the deposition temperature increase, increasing the dielectric constant. However, newly formed Si-F bonds have less electronic polarizability, reducing the dielectric constant. These traded-off properties yield a minimum dielectric constant of the OFSG film deposited at 250 degrees C with a SiF(4) flow rate of 100 SCCM (SCCM denotes cubic centimeter per minute at STP). The stability of Si-F bonds in the OFSG films is related to the deposition conditions. OFSG films deposited a higher SiF(4) flow rate (>400 SCCM) or a lower deposition temperature (< 300 degrees C) have lower thermal stability and are less well protected against moisture because of the instability of Si-F bonds. Therefore, more attention should be paid to the conditions for depositing fluorine-doped OFSG dielectrics.
Effect of Moisture on Electrical and Reliability Characteristics for Dense and Porous Low-k Dielectrics
(2013-01-01)
Cheng, Yi-Lung
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Huang, Jun-Fu
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Chang, Wei-Yuan
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Chang, Yu-Min
;
Leu, Jihperng
The effect of absorbed moisture on the electrical and reliability characteristics of the low-k dielectrics was investigated in this study. The experimental results indicate that the porous low-k dielectrics would absorb more moisture as compared to the dense low-k dielectrics. This absorbed moisture degrades the electrical and reliability performance of the low-k dielectrics. A higher temperature anneals at 400 degrees C is needed to decompose physicallyadsorbed water, which is benefit to restore reliability performance. On the other hand, the chemically-adsorbed moisture seems to be difficult to be removed by a 400 degrees C annealing, causing a degraded TDDB performance.
Effect of moisture on electrical properties and reliability of low dielectric constant materials
(2014-02-01)
Cheng, Yi-Lung
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Leon, Ka-Wai
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Huang, Jun-Fu
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Chang, Wei-Yuan
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Chang, Yu-Min
The effect of absorbed moisture on the electrical characteristics and reliability of low dielectric constant materials (low-k) was investigated in this study. The experimental results reveal that porous low-k dielectrics absorb more moisture than dense low-k dielectrics. This absorbed moisture degrades the electrical performance and reliability of both classes of low-k dielectrics. Annealing at a higher temperature of 400 degrees C is required to decompose the physically-adsorbed moisture and thereby restore reliability performance. However, the chemically-adsorbed moisture seems to be difficult to remove by annealing at 400 degrees C, causing a degraded TDDB performance. Crown Copyright (C) 2013 Published by 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 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
;
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 NH3/N-2 ratio in plasma treatment on porous low dielectric constant SiCOH materials
(2014-05-01)
Huang, Jun-Fu
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Bo, Tain-Cih
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Chang, Wei-Yuan
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Chang, Yu-Min
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Leu, Jihperng
This study investigates the effect of the NH3/N-2 ratio in plasma treatment on the physical and electrical properties as well as the reliability characteristics of porous low-k films. All of the plasma treatments resulted in the formation of a thin and modified layer on the surface of porous low-k films, and the properties of this modified layer were influenced by the NH3/N-2 ratio in the plasma. Experimental results indicated that pure N-2 gas plasma treatment formed an amide-like/nitride-like layer on the surface, which apparently leads to a higher increase in the dielectric constant. Plasma treatment with a mixture of NH3/N-2 gas induced more moisture uptake on the surface of the low-k dielectric, degrading the electrical performance and reliability. Among all plasma treatment with NH3/N-2 mixed gas, that with pure NH3 gas yielded low-k dielectrics with the worse electrical and reliability characteristics. (C) 2014 American Vacuum Society.
Effect of thermal treatment on physical, electrical properties and reliability of porogen-containing and porogen-free ultralow-k dielectrics
(2013-01-15)
Chang, Yu-Min
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Chang, Wei-Yuan
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Huang, Jun-Fu
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Leu, Jihperng
;
Cheng, Yi-Lung
The effects of thermal annealing on the physical, electrical properties and reliability of porogen-containing and porogen-free ultralow-k dielectrics prepared by plasma-enhanced chemical vapor deposition (PECVD) are investigated. The porogen-free low-k dielectrics are obtained by using UV curing process to removal organic sacrificial phase and to generate open porosity. The results are compared with PECVD porogen-containing low-k films fabricated without UV curing process and PECVD low-k dielectrics deposited without organic sacrificial phase. The experimental results show that all low-k films remained stable after they were experimentally heating to temperatures up to 700 degrees C. The non-porous low-k films also showed the highest reliability. Although the porous-free low-k film requires an additional UV curing process, the heat stress confirmed that its thermal stability was better than that of the porogen-containing low-k film. At an annealing temperature above 500 degrees C, the heating process is comparable to UV curing, but does not provide Si-O-Si cross-linking within the film. At an annealing of 600 degrees C, the porogen-free low-k films have a relatively higher breakdown electric-field and longer failure time in comparison to the porogen-containing low-k films. However, pores generated in porogen-containing low-k films at high temperature cause reliability to degrade with annealing temperature. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.
Effect of UV curing time on physical and electrical properties and reliability of low dielectric constant materials
(2014-11-01)
Kao, Kai-Chieh
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Chang, Wei-Yuan
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Chang, Yu-Min
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Leu, Jihperng
;
Cheng, Yi-Lung
This study comprehensively investigates the effect of ultraviolet (UV) curing time on the physical, electrical, and reliability characteristics of porous low-k materials. Following UV irradiation for various periods, the depth profiles of the chemical composition in the low-k dielectrics were homogeneous. Initially, the UV curing process preferentially removed porogen-related CHx groups and then modified Si-CH3 and cage Si-O bonds to form network Si-O bonds. The lowest dielectric constant (k value) was thus obtained at a UV curing time of 300 s. Additionally, UV irradiation made porogen-based low-k materials hydrophobic and to an extent that increased with UV curing time. With a short curing time (<300 s), porogen was not completely removed and the residues degraded reliability performance. A long curing time (>300 s) was associated with improved mechanical strength, electrical performance, and reliability of the low-k materials, but none of these increased linearly with UV curing time. Therefore, UV curing is necessary, but the process time must be optimized for porous low-k materials on back-end of line integration in 45 nm or below technology nodes. (C) 2014 American Vacuum Society.
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.
Impact of plasma treatment on structure and electrical properties of porous low dielectric constant SiCOH material
(2013-10-01)
Cheng, Yi-Lung
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Huang, Jun-Fu
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Chang, Yu-Min
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Leu, Jihperng
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材料科學與工程學系
Low dielectric constant (low-k) porous films are needed for advanced technologies to improve signal propagation. The integration of porous low-k films faces more severe challenges due to the presence of porosity. Plasma treatments have been considered to be critical steps to impact the low-k films' properties. In this study, the effect of various H-2/He plasma treatments on the porous low-k dielectrics deposited by plasma enhanced chemical vapor deposition was investigated. All the plasma treatments resulted in the formation of a thin and dense layer on the surface of the porous low-k films. Additionally, the properties of this top dense layer are modified and changed for the standard H-2/He plasma treatment, leading to a degraded electrical and reliability performance. However, H-2/He plasma-treated low-k dielectric by the remote plasma method shows a better electrical and reliability performance. As a result, the remote plasma treatment on the porous low-k dielectrics appears to be a promising method in the future interlayer dielectrics application. (C) 2012 Elsevier B.V. All rights reserved.
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.
Pulsed Electrodeposition of CuInSe2 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
;
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.
The influence of abrasive particle size in copper chemical mechanical planarization
(2013-09-01)
Wei, Kuo-Hsiu
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Wang, Yu-Sheng
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Liu, Chuan-Pu
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Chen, Kei-Wei
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Wang, Ying-Lang
There are many kinds of commercial slurries used in Cu CMP. Major components include an oxidizing agent, complexing agents, inhibitors, and abrasives. We analyze the abrasive particle size by TEM and light scattering. Cu CMP polishing mechanism is also discussed under different particle size distribution. The complexing agent transportation will be the rate determining step when a small abrasive is insufficient, but the copper hydroxide removal rate will determine the overall polishing rate when the amount of smaller particles is enough. (C) 2012 Elsevier B.V. All rights reserved.