Chemical processes in the chemical mechanical polishing of copper

Steigerwald, Joseph M.; Murarka, S. P.; Gutmann, R.J.; Duquette, D. J.

doi:10.1016/0254-0584(95)01516-7

Cited by 190 publications

(136 citation statements)

References 16 publications

Supporting

Mentioning

132

Contrasting

Unclassified

Order By: Relevance

“…It was already shown that a combination of line width, pattern density, pad rigidity and the applied down pressure determine not only the material removal rate but also the amount of dishing and erosion. 5,6,[8][9][10][11] Also, for CMP of Cu lines with an oxide spacer, Lin et al5 modeled the effect of line width, pattern density, pad rigidity and applied down pressure on dishing and showed that the line width and the applied down pressure, but not pad rigidity or pattern density, have a more significant effect on dishing, and confirmed it experimentally. Indeed, it was also shown that the optimization of pressure settings during the polishing process can contribute to lower dishing.…”

mentioning

confidence: 94%

See 1 more Smart Citation

Ceria-Based Slurries for Non-Prestonian Removal of Silicon Dioxide Films

Korkmaz

Babu

2014

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

A slurry with a non-Prestonian dependence on the polishing pressure can help in minimizing dishing and erosion during shallow trench isolation chemical mechanical planarization. Here, we show that ceria-based slurries containing diallyldimethylammonium chloride (DADMAC) yield a non-Prestonian blanket film polish rate with a low threshold pressure (1-2 psi) when polishing plasma-enhanced chemical vapor (PECVD) tetraethylorthosilicate (TEOS) deposited oxide as well as thermal oxide films. The polishing mechanism of this non-Prestonian slurry was investigated by a series of experiments involving zeta potential measurements, thermogravimetric analysis (TGA) and UV-vis spectroscopy and it was shown that more DADMAC molecules are adsorbed on silica particles (as oxide film representatives) than on ceria particles and the binding strength between DADMAC and silica is much higher than that with ceria surface. Shallow trench isolation (STI) is an ubiquitous complimentary metal-oxide semiconductor isolation process technology. Deposition of an isolation stack that contains 3 to 10 nm thick 1,2 thermally grown pad oxide on top of a silicon substrate followed by the deposition of either plasma-enhanced chemical vapor deposition (PECVD) or low-pressure chemical vapor deposition (LPCVD) nitride layer (10 to 30 nm) 1 is the first step in the STI process. In the next step, active areas and isolation fields are determined by patterning the silicon nitride and silicon dioxide pad layers on the silicon substrate, followed by etching of trenches into the silicon substrate using the oxide/nitride stack as a mask. The trenches are then filled with oxide, employing high density plasma-enhanced chemical vapor deposition (PECVD) process using tetraethylorthosilicate (TEOS) as the source of silicon, because of its high gap-filling capacity. The deposited oxide not only fills the trenches but also generates an overfill, which needs to be removed. This is achieved through planarization of the oxide film topography by chemical mechanical planarization (CMP) using a slurry that produces a high oxide and very low nitride removal rates (RRs).In this STI process, major concerns include dishing within the oxide features resulting from over-polish as well as the erosion of the underlying nitride film and, in some cases, the details of the corner rounding near active areas. Therefore, optimization of the CMP process is crucial in order to achieve complete removal of the oxide on top of the nitride film with good planarity and uniformity and to avoid erosion and dishing during the CMP process. 3,4 One method that can be used to minimize dishing and erosion during STI CMP is to control the polishing performance by using a slurry that shows a non-Prestonian polishing behavior. Non-Prestonian behavior occurs when there is a non-linear relationship between applied polishing pressures and resulting polishing rates. Here we consider only the effect of pressure and not that of the rotational velocity on the blanket film polish rates.Several models were di...

show abstract

mentioning

confidence: 94%

mentioning

confidence: 99%

Ceria-Based Slurries for Non-Prestonian Removal of Silicon Dioxide Films

Korkmaz

Babu

2014

ECS J. Solid State Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Several kinds of oxidizing agents, such as H 2 O 2 [5,6,8], HNO 3 [7][8][9][10][11], Fe(NO 3 ) 3 [8,12], NaClO 3 [13] and KIO 3 [14], among others, have been used to form a passive film on a copper surface or to dissolve it into slurries. Although the oxidizing powers of these agents are known, the specific roles of these agents on Cu CMP were not as clear as that found in W CMP [1] or Al CMP [2][3][4]15].…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, Gutmann et al [7] indicated that a combination of oxidizing agent and complexing agent would help to obtain a high solubility and dissolution rate of the abraded material in Cu CMP. In the case of Cu CMP in NH 4 OH slurry, Steigerwald et al [11] pointed out that Cu 2+ ions were complexed with NH 3 and the polishing rate was enhanced. Citric acid is also known to be a chelating agent for Cu 2+ ions [16].…”

Section: Introductionmentioning

confidence: 99%

Effects of hydrogen peroxide and alumina on surface characteristics of copper chemical–mechanical polishing in citric acid slurries

Chen¹,

Tsai²

2004

Materials Chemistry and Physics

View full text Add to dashboard Cite

The roles of H 2 O 2 and alumina on the changes of metal removal rate, surface passivation and surface morphology in citric acid (CA) base slurry in simulated Cu chemical-mechanical polishing (CMP) was investigated. X-ray photoelectron spectroscopy (XPS) analysis indicated that H 2 O 2 assisted oxide formation while citric acid promoted anodic dissolution of copper in various slurries that contained 1 wt.% Al 2 O 3 . Atomic force microscopy (AFM) revealed that Al 2 O 3 abrasive particles modified the surface morphology by inducing surface deformation. The results of open circuit potential (OCP) and removal rate measurements clearly demonstrated that there existed a synergistic effect due to the chelating and oxidizing agents in Cu CMP.

show abstract

“…Therefore, several difficulties exist in the experiments, calculations, and analysis of the CMP process. Steigerwald et al provide a survey on the status of current CMP modeling [1]. They investigate different modeling assumptions and discuss the controversial treatment of physical effects.…”

Section: Introductionmentioning

confidence: 99%

Material removal mechanism of copper chemical mechanical polishing with different particle sizes based on quasi-continuum method

Zhu

et al. 2017

Friction

View full text Add to dashboard Cite

Abstract:In this paper, the material removal mechanism of copper chemical mechanical polishing was studied by the quasicontinuum method that integrated molecular dynamics and the finite element method. By analyzing the abrasive process of different particle sizes on single crystal copper, we investigated the internal material deformation, the formation of chips, the stress distribution, and the change of cutting force. Results showed that shear band deformation was generated along the cutting direction at approximately 45° inside the workpiece material. The deformation was accompanied by dislocations and sliding phenomena in the shear band region. Smaller abrasive particle size led to poor quality of the workpiece, while a larger particle size led to better quality. However, larger particle size resulted in greater plastic deformation and deeper residual stress inside the workpiece. Size change of abrasive particles had little effect on the tangential cutting force.

show abstract

Chemical processes in the chemical mechanical polishing of copper

Cited by 190 publications

References 16 publications

Ceria-Based Slurries for Non-Prestonian Removal of Silicon Dioxide Films

Ceria-Based Slurries for Non-Prestonian Removal of Silicon Dioxide Films

Effects of hydrogen peroxide and alumina on surface characteristics of copper chemical–mechanical polishing in citric acid slurries

Material removal mechanism of copper chemical mechanical polishing with different particle sizes based on quasi-continuum method

Contact Info

Product

Resources

About