Complete-abrasive-free process for copper damascene interconnection

Kondo, Seiichi; Sakuma, Noriyuki; Homma, Yoshio; Goto, Y.; Ohashi, N.; Yamaguchi, H.; Owada, N.

doi:10.1109/iitc.2000.854340

Cited by 13 publications

(6 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since such solutions show perfect stop-on-barrier characteristics, they enable extremely accurate fabrication. 11,12 Frictional force was measured, first, by increasing down force and, then, by decreasing it in the case of HS-C430, as shown in Fig. 10.…”

Section: Frictionalmentioning

confidence: 97%

See 1 more Smart Citation

Effects of Mechanical Parameters on CMP Characteristics Analyzed by Two-Dimensional Frictional-Force Measurement

Homma

Fukushima

Kondo

et al. 2003

J. Electrochem. Soc.

View full text Add to dashboard Cite

The effects of mechanical parameters on the characteristics of chemical mechanical polishing ͑CMP͒ were evaluated by directly measuring frictional force acting on a wafer in terms of two components, i.e., the tangential and axial components of the platen's rotation. It was found that, when the platen and the wafer were rotated at the same speed, the tangential component of the frictional force was dominant. Also, frictional force was in linear proportion with removal rate. Though frictional force increased in linear proportion to down force when mechanical-effect-dominant CMP for silicon ͑Si͒ or silicon dioxide (SiO 2 ) was carried out, it decreased gradually as platen rotational speed was increased. Copper ͑Cu͒ polishing using abrasive-free polishing solutions, a typical example of chemical-effect-dominant CMP, showed much more complex behavior. Namely, dependence of frictional force on down force and on platen rotational speed showed nonlinear characteristics. Even when a nonlinear characteristic slurry was used, it was found that removal rate and frictional force were almost linearly correlated. It can thus be considered that frictional force is a basic parameter to determine CMP characteristics. From these results, an experimental equation was proposed to describe CMP characteristics by modifying Preston's empirical equation.Chemical mechanical polishing ͑CMP͒ has come to be widely used in manufacturing ultralarge scale integrated circuits ͑ULSIs͒ for both insulator planarization and damascene processes. 1,2 Compared with other LSI manufacturing processes, CMP is unique in that the film removal utilizes mechanical energy as well as chemical reaction. The contribution of mechanical energy to CMP can be well understood by comparing CMP with dry etching, a typical manufacturing process, as shown in Table I. Though the analogy is not strict, the slurry used in CMP has, for example, a role similar to the process gas in dry etching. Moreover, the frictional force corresponds to plasma energy. The frictional force in CMP is thus an essential parameter for analyzing the CMP mechanism. To describe the contribution of mechanical parameters to CMP characteristics, Preston's empirical equation has mainly been used, while various models on chemical aspects have been proposed for glasses and metal polishing. 3-5 Discussions on the equation have been made, because the equation is not considered to be sufficient for describing the detail of the CMP mechanism.Mahajan et al. tried to measure frictional force during CMP by Si and tungsten square tips with water or diluted nitric acids. 6 They observed a constant or monotonous decrease in frictional force over time. Philipossian further investigated the effects of mechanical parameters on polishing, and they applied the results to a CMP simulation model. 7 Following these works, we have developed a new CMP system that can measure the frictional force accurately under actual CMP conditions. 8,9 This system is equipped with a stage to support the rotating wafer, which is mobile in...

show abstract

Section: Frictionalmentioning

confidence: 97%

“…As chemical-effect-dominant slurries, abrasive-free polishing solutions HS-C430 and HS-C430-A3 ͑properties listed in Table II; Hitachi Chemical Co.; mixed with 30% H 2 O 2 solution͒ were used for Cu polishing. 11,12 Alumina abrasive slurry QCTT1010 ͑Rodel Co., mixed with H 2 O 2 solution͒ was also used.…”

Section: Rr ϭ Kpv ͓1͔mentioning

confidence: 99%

Effects of Mechanical Parameters on CMP Characteristics Analyzed by Two-Dimensional Frictional-Force Measurement

Homma

Fukushima

Kondo

et al. 2003

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…Accordingly, we have developed a complete abrasive-free process for Cu damascene interconnection by using a combination of new Cu-AFP (abrasive-free polishing) and barrier-metal dry etching. 10 Experimental AFP conditions.-The new polishing solution comprises only chemical agents such as oxidizer, etchant, and corrosion inhibitor, but it does not contain abrasives. It is, therefore, transparent as shown in Fig.…”

mentioning

confidence: 99%

Abrasive-Free Polishing for Copper Damascene Interconnection

Kondo

Sakuma

Homma

et al. 2000

J. Electrochem. Soc.

View full text Add to dashboard Cite

A complete abrasive‐free process for fabricating copper damascene interconnection has been developed. The process is a combination of newly developed abrasive‐free polishing (AFP) of Cu and dry etching of a barrier metal layer. A new aqueous chemical polishing solution and a polyurethane polishing pad produce complete stop‐on‐barrier characteristics of Cu polishing. The AFP provides a very clean, scratch‐free, anticorrosive polished surface, and the total depth of erosion and dishing is reduced to less than one fifth of that produced by conventional slurries, even after 100% overpolishing. The barrier metal is successfully dry etched by using SF6 gas at a high selectivity ratio (more than 10) of barrier metal to SiO2 . It was found that the developed AFP significantly reduces both Cu line resistance and its deviation. Moreover, AFP can also contribute to cost reduction of chemical mechanical polishing and help solve environmental problems related to waste slurries. © 2000 The Electrochemical Society. All rights reserved.

show abstract

“…For a given set of process conditions, there exists an optimal thickness at which the resistance range is minimized. Abrasive-free slurries have also been investigated in an attempt to reduce dishing and erosion [7], [8]. However, the non-Prestonian polish behavior with these slurries resulted in uncleared copper in the field region outside the trenches [9].…”

Section: Introductionmentioning

confidence: 99%

Electrical characterization of the copper cmp process and derivation of metal layout rules

Lakshminarayanan¹,

Wright²,

Pallinti³

2003

IEEE Trans. Semicond. Manufact.

View full text Add to dashboard Cite

Design rules were developed for the layout of copper Damascene interconnect layers to minimize the within-die resistance variation. The impact of various layout configurations on the metal sheet resistance was characterized using two different test vehicles. An increase in resistance was observed on wide lines and high pattern densities due to dishing and dielectric erosion, respectively. In addition to the above, narrow lines were severely impacted by the presence of wide adjacent features in close proximity. The pattern interaction distance for copper chemical-mechanical planarization (CMP) was calculated by analyzing the resistance variation at the edge of a density or width transition. In this work, the interaction distance was found to be on the order of 25 m (as opposed to a few millimeters for oxide CMP). From these results, a window of about 50 to 60 m was found to be necessary to obtain the effective pattern density for copper CMP. The resistance of the upper metal level was a strong function of the underlying layer density. Hence, multilevel pattern dependencies have to be considered when modeling and predicting the line resistance on a real design. However, unlike oxide polish, pattern density alone is insufficient to predict the final copper thickness. Width-dependent spacing rules are necessary to prevent clustering of features (narrow lines very close to wide buses) and avoid regions of very low density.

show abstract

Complete-abrasive-free process for copper damascene interconnection

Cited by 13 publications

References 2 publications

Effects of Mechanical Parameters on CMP Characteristics Analyzed by Two-Dimensional Frictional-Force Measurement

Effects of Mechanical Parameters on CMP Characteristics Analyzed by Two-Dimensional Frictional-Force Measurement

Abrasive-Free Polishing for Copper Damascene Interconnection

Electrical characterization of the copper cmp process and derivation of metal layout rules

Contact Info

Product

Resources

About