Browsing by Author "Hung, Chi-Cheng"

Now showing 1 - 7 of 7

A Study on the Plating and Wetting Ability of Ruthenium-Tungsten Multi-layers for Advanced Cu Metallization
(2016-01-01)
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 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.
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.
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 bis-(3-sodiumsulfopropyl disulfide) byproducts on copper defects after chemical mechanical polishing
(2008-01-01)
Hung, Chi-Cheng
;
Lee, Wen-Hsi
;
Hu, Shao-Yu
;
Chang, Shih-Chieh
;
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 tungsten incorporation in cobalt tungsten alloys as seedless diffusion barrier materials
(2017-03-05)
Su, Yin-Hsien
;
Kuo, Tai-Chen
;
Lee, Wen-Hsi
;
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
;
Hung, Chi-Cheng
;
Wang, Yu-Sheng
;
Chang, Shih-Chieh
;
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.