Browsing by Author "Wang, Yu-Sheng"

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A Study of Trimethylsilane (3MS) and Tetramethylsilane (4MS) Based alpha-SiCN:H/alpha-SiCO:H Diffusion Barrier Films
(2012-03-01)
Chen, Sheng-Wen
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Wang, Yu-Sheng
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Hu, Shao-Yu
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Lee, Wen-Hsi
;
Chi, Chieh-Cheng
Amorphous nitrogen-doped silicon carbide (alpha-SiCN:H) films have been used as a Cu penetration diffusion barrier and interconnect etch stop layer in the below 90-nanometer ultra-large scale integration (ULSI) manufacturing technology. In this study, the etching stop layers were deposited by using trimethylsilane (3MS) or tetramethylsilane (4MS) with ammonia by plasma-enhanced chemical vapor deposition (PECVD) followed by a procedure for tetra-ethoxyl silane (TEOS) oxide. The depth profile of Cu distribution examined by second ion mass spectroscopy (SIMs) showed that 3MS alpha-SiCN:H exhibited a better barrier performance than the 4MS film, which was revealed by the Cu signal. The FTIR spectra also showed the intensity of Si-CH3 stretch mode in the alpha-SiCN:H film deposited by 3MS was higher than that deposited by 4MS. A novel multi structure of oxygen-doped silicon carbide (SiC:O) substituted TEOS oxide capped on 4MS alpha-SiC:N film was also examined. In addition to this, the new multi etch stop layers can be deposited together with the same tool which can thus eliminate the effect of the vacuum break and accompanying environmental contamination.
A Study on the Plating and Wetting Ability of Ruthenium-Tungsten Multi-layers for Advanced Cu Metallization
(2016-01-01)
Kuo, Tai-Chen
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Su, Yin-Hsien
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Lee, Wen-Hsi
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Liao, Wei-Hsiang
;
Wang, Yu-Sheng
In this study, the plating and wetting ability of Cu/Ruthenium-Tungsten (RuW)/silicon oxide (SiO2) multi-layer stacks were investigated. RuW alloy films were prepared on a SiO2 layer by sputtering, followed by a deposition of a Cu thin film by electroplating. Scanning electron microscopy (SEM) top view images shows that Cu films can be electroplated on RuW, with smaller Cu nuclei size but in a more highly concentrated and uniform distribution than Cu films electroplated on Ta or TaN. The rate of Cu nucleation decreases and larger Cu clusters were formed on the RuW alloy films with increasing W content. Cu/RuW/SiO2 samples were annealed at 400 degrees C for 30 min and then characterized using SEM. There were fewer pin holes on the surface of a pure Cu/Ru stack compared to Cu/RuW multilayers. Cu/RuW/SiO2 multi-layers had fewer pin holes than Cu/Ta/SiO2 structures processed under similar conditions. The wetting angle, measured by SEM, of Cu on a RuW substrate (43 degrees) was still lower than that of Cu on a Ta substrate (123 degrees), which suggests that the adhesion strength of Cu onto RuW alloy is better than that onto Ta.
A study on the plating and wetting ability of ruthenium-tungsten multi-layers for advanced Cu metallization
(2016-08-16)
Kuo, Tai-Chen
;
Su, Yin-Hsien
;
Lee, Wen-Hsi
;
Liao, Wei-Hsiang
;
Wang, Yu-Sheng
In this study, the plating and wetting ability of Cu/Ruthenium-Tungsten (RuW)/silicon oxide (SiO2) multi-layer stacks were investigated. RuW alloy films were prepared on a SiO2 layer by sputtering, followed by a deposition of a Cu thin film by electro-plating. Scanning electron microscopy (SEM) top view images shows that Cu films can be electroplated on RuW, with smaller Cu nuclei size but in a more highly concentrated and uniform distribution than Cu films electroplated on Ta or TaN. The rate of Cu nucleation decreases and larger Cu clusters were formed on the RuW alloy films with increasing W content. Cu/RuW/SiO2 samples were annealed at 400 degrees C for 30 min and then characterized using SEM. There were fewer pin holes on the surface of a pure Cu/Ru stack compared to Cu/RuW multilayers. Cu/RuW/SiO2 multi -layers had fewer pin holes than Cu/Ta/SiO2 structures processed under similar conditions. The wetting angle, measured by SEM, of Cu on a RuW substrate (43) was still lower than that of Cu on a Ta substrate (123 degrees), which suggests that the adhesion strength of Cu onto RuW alloy is better than that onto Ta. Preliminary studies of Cu diffusion through 25 nm RuW layers at 650 degrees C showed no Cu penetration into the underlying Si in a Cu/RuW/Si multi-layer test structure. (C) 2016 Elsevier B.V. All rights reserved.
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.
Cleaning methodology of small residue defect with surfactant in copper chemical mechanical polishing post-cleaning
(2016-11-01)
Wei, Kuo-Hsiu
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Hung, Chi-Cheng
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Wang, Yu-Sheng
;
Liu, Chuan-Pu
;
Chen, Kei-Wei
Advanced semiconductor manufacturing technology has adopted an alkaline solution for copper (Cu) corrosion prevention instead of the traditional acidic solution in the post-cleaning process of copper chemical mechanical polishing. Low particle and residue removal efficiency has been an issue for this process. In this study, we investigated the formation of small residue defects and the cleaning mechanism to remove these defects. The results show it is insufficient to remove the small residue defects by using the traditional process parameter tuning. Adding some friction between the pad and the wafer surface allowed the defects to be effectively reduced. (C) 2016 Elsevier B.V. All rights reserved.
Cleaning methodology of small residue defect with surfactant in copper chemical mechanical polishing post-cleaning
(2016-11-01)
Wei, Kuo-Hsiu
;
Hung, Chi-Cheng
;
Wang, Yu-Sheng
;
Liu, Chuan-Pu
;
Chen, Kei-Wei
Advanced semiconductor manufacturing technology has adopted an alkaline solution for copper (Cu) corrosion prevention instead of the traditional acidic solution in the post-cleaning process of copper chemical mechanical polishing. Low particle and residue removal efficiency has been an issue for this process. In this study, we investigated the formation of small residue defects and the cleaning mechanism to remove these defects. The results show it is insufficient to remove the small residue defects by using the traditional process parameter tuning. Adding some friction between the pad and the wafer surface allowed the defects to be effectively reduced. (C) 2016 Elsevier B.V. All rights reserved.
Effect of tungsten incorporation in cobalt tungsten alloys as seedless diffusion barrier materials
(2017-03-05)
Su, Yin-Hsien
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Kuo, Tai-Chen
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Lee, Wen-Hsi
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Wang, Yu-Sheng
;
Hung, Chi-Cheng
With the increase in the aspect ratio of the interconnect features in integrated circuits, the direct electroplating of Cu on diffusion barrier without sputtered Cu seed layers is attracting more and more attention. In this study, direct electroplating of Cu onto sputtered CoW films with various W concentration in acidic CuSO4 solution is investigated. Also, the adhesion and anti-diffusion properties of the CoW thin films for Cu are explored. The results show that Cu films cannot be electrodeposited on thin Co layers due to corrosion of Co in the acidic bath. For CoW alloys, higher W concentration is found to be beneficial for suppressing corrosion of CoW films and also improving the thermal stability. However, on the surface of Cu/CoW films with high W concentration, Cu agglomeration and pin-holes were found after annealing, indicating poor adhesion between Cu and high W-content CoW alloys. In this study, CoW alloys with moderate W concentration around 50% are found to be a direct platable material which also demonstrates desirable adhesion and anti-diffusion characteristics for Cu interconnects application. (C) 2017 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.
Effects of (002) beta-Ta barrier on copper chemical mechanical polishing behavior
(2013-02-01)
Wang, Yu-Sheng
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Chen, Kei-Wei
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Cheng, Min-Yuan
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Lee, Wen-Hsi
;
Wang, Ying-Lang
This study proposes that the corrosion resistance of copper film correlates well with underlying barrier's orientation. To test the hypothesis, we performed X-ray diffraction, conducted copper removal rate experiments after chemical mechanical polishing, and tested static potentiodynamic polarization. The results all show that copper deposited on strongly (002) oriented beta-Ta barrier layer demonstrated better chemical resistance against surface reaction with the slurry for strong copper (111) orientation. The findings were consistent with the result of the chronoamperometric test at 0.3 V in which the more passive film formed on the composite film with (002) beta-Ta underlying barrier. (C) 2012 Elsevier B.V. All rights reserved.
Evaluating the sensitizing effect on the photocatalytic decoloration of dyes using anatase-TiO2
(2014-04-27)
Hsiao, Yu-Cheng
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Wu, Tsai-Fang
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Wang, Yu-Sheng
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Hu, Chi-Chang
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Huang, Chihpin
This work tries to clarify the contribution of the dye-sensitizing effect on the photocatalytic decoloration of dyes dissolved in aqueous media using an anatase TiO2 (A-TiO2) photocatalyst. The photocurrentvoltage (J-V) curves of a typical dye-sensitized solar cell (DSSC) with the A-TiO2 photoanodes adsorbed with various dyes, including methylene blue (MB), orange G (OG), rhodamine B (RhB), metanil yellow (MY), acid black 24 (AB24), and N719, are employed to demonstrate the sensitizing characteristics of dyes on A-TiO2. Unlike RhB, the MB, OG, MY, and AB24 cannot work as the photo-sensitizer on A-TiO2 from the J-V curves of DSSCs, reasonably due to the unmatched band position between dyes and A-TiO2. In the photocatalytic decoloration test of these dyes on A-TiO2 in aqueous media, dye adsorption onto A-TiO2 becomes the key factors affecting the photocatalytic decoloration rate because the generation of oxidants species (e.g., Oi(2)(-center dot), OH center dot or photo-excited holes) occurs on the A-TiO2 surface. The contribution of dye-sensitizing on the photocatalytic decoloration of RhB is negligible since the dye-sensitizing/electron-injection/dye-regeneration cycle cannot be completed in the degradation media while adsorbed RhB molecules are unstable when few photo-generated electrons have been injected into the conduction band of A-TiO2, probably leading to the decomposition of RhB. (C) 2013 Elsevier B.V. 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.