Fabrication of High Aspect Ratio TSV and Assembly With Fine-Pitch Low-Cost Solder Microbump for Si Interposer Technology With High-Density Interconnects

Yu, Aibing; Lau, John H.; Ho, Soon Wee; Kumar, Aditya; Hnin, Wai Yin; Lee, Wen Sheng; Jong, Ming Ching; Sekhar, Vasarla Nagendra; Kripesh, V.; Pinjala, D.; Chen, S.; Chan, Chien-Feng; Chao, Chun-Chieh; Chiu, Chi-Hsin; Huang, Chi Yen; Chen, C.

doi:10.1109/tcpmt.2011.2155655

Cited by 54 publications

(14 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Si was the initial material used for interposers because of its coefficient of thermal expansion (CTE) match to the Si chip and the familiarity of wafer fabrication facilities in Si processing. 1,2 Recently, glass has gained attention as a candidate interposer material. [3][4][5][6] The CTE of borosilicate glass, 3.2, is reasonably close to that of Si, 2.9, and a wide range of CTE's is available by changing the glass composition.…”

mentioning

confidence: 99%

“…[12][13][14] In the case of Si, through vias (TSV) have been generated by first filling vias as blind vias, then thinning the back side of the wafer by CMP until the bottoms of the filled vias are intersected, thereby producing filled TSVs 2 or by first sealing one end of the TSVs then filling them as blind vias. 1 In the case of glass, where through-holes may be formed directly into the glass without the need for mechanical thinning, it is our intent to develop Cu plating processes to fill these holes as TGVs (open on both ends) instead of as blind vias. The aforementioned plating methods for filling of blind vias do not work well when directly applied to filling of TGVs, and a different approach is needed.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Superconformal Filling of High Aspect Ratio through Glass Vias (TGV) for Interposer Applications Using TNBT and NTBC Additives

Ogutu

Fey

Dimitrov

2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

Cu superconformal filling of through glass vias (TGV) of aspect ratios (AR) 6:1 and 10:1 for glass interposer applications is achieved by DC electroplating in the presence of the additives tetranitroblue tetrazolium Cl − (TNBT) and nitroblue tetrazolium Cl − (NTBC) in acidic CuSO 4 / Cl − formulations. Filling takes place by the so-called 'butterfly' mechanism that nucleates hemispherical or X-shaped Cu plugs in the centers of TGV's while keeping the thickness on external surfaces low. Holes of AR 6:1 are filled in 3 h at 2.5 mA.cm −2 , using a bath composed of 40 ppm TNBT, 80 ppm Cl − , 0.88 M CuSO 4 , and 0.3 M CH 3 COOH under stagnant conditions. Increasing [TNBT] to 80 ppm and [Cl − ] to 120 ppm in the presence of 0.3 M CH 3 COOH allows filling of 10:1 AR holes in 12.5 h at 1.0 mA.cm −2 while maintaining thin surface plating. In the case of NTBC, 6:1 holes are filled in 4-5 h at 2.5-4.0 mA.cm −2 , and 10:1 holes are filled in 12-13 h at 1.0 to 1.5 mA.cm −2 in a slowly stirred bath containing 0.88 M CuSO 4 , 80 ppm Cl − , 0.6 M H 2 SO 4, and 45-50 ppm NTBC. Optimization of bath composition is necessary to avoid void-formation in the holes. Effects of composition on overvoltage and Cu surface topography are discussed.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Superconformal Filling of High Aspect Ratio through Glass Vias (TGV) for Interposer Applications Using TNBT and NTBC Additives

Ogutu

Fey

Dimitrov

2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…Methods have been developed for creating Cu-filled through vias (TSVs) in Si interposers based on (i) blind via plating followed by back side wafer thinning until the via barrel is reached, 1 or (ii) for small diameter holes, "bottom up" filling after blocking one end of the hole by plating at high current density (CD). 2 Recently, glass interposers (GIs) have been attracting increased interest because of their lower cost and certain performance advantages. [3][4][5][6][7] Due to its lower thermal conductivity compared to Si, it is even more important to fill holes in glass with Cu to improve heat dissipation, and it would be desirable to do so by less cumbersome means than used for TSVs.…”

mentioning

confidence: 99%

Superconformal Filling of Through Vias in Glass Interposers

Ogutu

Fey

Dimitrov

2014

ECS Electrochemistry Letters

View full text Add to dashboard Cite

The additive tetranitroblue tetrazolium chloride (TNBT) has been applied successfully in this work to superconformal filling (SCF) of through-vias with an aspect ratio (AR) of 6 in glass interposers (TGVs). The TGVs were initially coated with thin conformal Cu using an earlier developed hybrid method. Optimization of plating parameters and bath composition led to SCF of these TGVs in only 3 h at a current density of 2.5 mA/cm 2 in a stagnant bath containing 0.88M CuSO 4 , 40 ppm TNBT, 40 ppm Cl − , 0.1M CH 3 COOH, and 0.6M Na 2 SO 4 . This is the shortest reported filling time for this AR using DC plating and a single-additive system. © 2014 The Electrochemical Society. [DOI: 10.1149/2.0081408eel] All rights reserved.Manuscript submitted April 28, 2014; revised manuscript received May 28, 2014. Published June 19, 2014 The increase in interconnection density in electronic packaging has led to the addition of interposers to package structures with Si being the interposer material of choice. Methods have been developed for creating Cu-filled through vias (TSVs) in Si interposers based on (i) blind via plating followed by back side wafer thinning until the via barrel is reached, 1 or (ii) for small diameter holes, "bottom up" filling after blocking one end of the hole by plating at high current density (CD).2 Recently, glass interposers (GIs) have been attracting increased interest because of their lower cost and certain performance advantages.3-7 Due to its lower thermal conductivity compared to Si, it is even more important to fill holes in glass with Cu to improve heat dissipation, and it would be desirable to do so by less cumbersome means than used for TSVs. W.P. Dow has reported successful super conformal filling (SCF) of through-vias (TVs) in printed circuit boards (PCBs) having aspect ratios (AR) of about 1.5 to 2.5 using DC plating and formulations containing the single organic additives tetranitroblue tetrazolium chloride (TNBT) or nitrotetratetrazolium blue chloride (NTBC) and Cl − ions. [8][9][10][11] These bulky cationic additives and their reduction products, e.g. diformazan derivatives, formed at typical Cu electroplating potentials, adsorb on Cl − covered Cu surfaces and inhibit further Cu deposition.10,11 Establishment of a concentration gradient of these inhibitors leads to a substantially faster plating rate at the middles of the vias than at their entrances or on the flat surfaces. [8][9][10][11] Thickening plating eventually forms a blockage at the centers of the holes transforming them into two blind vias. [8][9][10][11] In cross section this blockage sometimes has the appearance of a "butterfly", from which the term butterfly plating originates. [8][9][10][11][12] Continued plating under certain conditions uniformly fills the two resulting blind vias without development of voids, while plating thickness on the surface, where additive inhibition is most effective, is kept relatively low. 8,9,11,12 To date, the shortest time reported in the literature to fill TVs of 6:1 AR (in Si) using this app...

show abstract

“…One of the advantages of the bottom-up TSV approach is the ability to avoid seams or voids during via filling [28, 29]. Furthermore, the bottom-up process is suitable for via last scheme.…”

Section: Tsv Fillingmentioning

confidence: 99%

Three-Dimensional Integrated Circuit (3D IC) Key Technology: Through-Silicon Via (TSV)

2017

View full text Add to dashboard Cite

3D integration with through-silicon via (TSV) is a promising candidate to perform system-level integration with smaller package size, higher interconnection density, and better performance. TSV fabrication is the key technology to permit communications between various strata of the 3D integration system. TSV fabrication steps, such as etching, isolation, metallization processes, and related failure modes, as well as other characterizations are discussed in this invited review paper.

show abstract

Fabrication of High Aspect Ratio TSV and Assembly With Fine-Pitch Low-Cost Solder Microbump for Si Interposer Technology With High-Density Interconnects

Cited by 54 publications

References 15 publications

Superconformal Filling of High Aspect Ratio through Glass Vias (TGV) for Interposer Applications Using TNBT and NTBC Additives

Superconformal Filling of High Aspect Ratio through Glass Vias (TGV) for Interposer Applications Using TNBT and NTBC Additives

Superconformal Filling of Through Vias in Glass Interposers

Three-Dimensional Integrated Circuit (3D IC) Key Technology: Through-Silicon Via (TSV)

Contact Info

Product

Resources

About