Experimental Investigation on the Roles of Chemical Corrosion and Mechanical Polishing on Copper CMP

Author(s):  
Jhy-Cherng Tsai ◽  
Yaw-Yi Shieh ◽  
Ming-Shih Tsai ◽  
Bau-Tong Dai

This paper is an experimental investigation on the roles of chemical corrosion and mechanical polishing of the chemical mechanical polishing (CMP) of wafers with copper film of 1,000 nm thickness. Three types of experiments are designed and conducted: chemical corrosion, mechanical polishing, and CMP with φ0.3μm Al2O3 as abrasives. The results showed that copper films after PVD and annealing sustain tensile stress that intensifies corrosion rate. In general, the stress of copper film increases at higher annealing temperature and the corrosion rate increases correspondingly though the relationship is weak. The polishing rate of pure mechanical polishing is about the same as that of pure chemical corrosion, but surface roughness of mechanical polishing and CMP are much better than that of chemical corrosion. Furthermore, the removal rate of mechanical polishing and chemical corrosion, about 2nm/min, are relatively low compared to that of CMP, about 30nm/min, it indicates that the removal mechanism of CMP is not simply a linear superposition of chemical corrosion and mechanical polishing. The strong interaction and the combined reaction of chemical corrosion and mechanical polishing need further investigation.

2010 ◽  
Vol 126-128 ◽  
pp. 316-319
Author(s):  
Jhy Cherng Tsai ◽  
Wei Ching Lin

Abrasive Free Polishing (AFP) is a polishing technology without abrasives and widely employed in copper-base semiconductor fabrications. This paper investigates the effect of passivants, added to the slurry, on the material removal rate (MRR) and the non-uniformity (NU) via experiments. Two kinds of passivants, Benzotriazole (BTA) and citric acid (CA) are added to the slurry for the experiments. Experimental results showed that the MRR increases when polishing pressure increases while NU decreases at the same time. Both MRR and NU tends to increase when rotational speed increases, though MRR and NU at 40 rpm are lower than that at 30 and 50 rpm in the slurry with CA. Experimental data also showed that AFP using the slurry with CA performs better than that with BTA.


2008 ◽  
Vol 373-374 ◽  
pp. 820-823
Author(s):  
Sheng Li Wang ◽  
Y.J. Yuan ◽  
Yu Ling Liu ◽  
X.H. Niu

Chemical mechanical polishing (CMP) of copper films in alkaline slurries was investigated. In the copper CMP, the slurry was made by adding colloidal silica abrasive to de-ionized water.The organic alkali was added to adjust the pH, H2O2 was used as an oxidizer.The effects of varying polishing temperature, polishing pressure, slurry flow rate, organic alkali concentration and oxidizer concentration on removal rate were investigated in order to determine the optimum conditions for those parameters. It is shown the chemical composition of the slurry was 2%~3% oxidizer concentration, 3% organic alkali concentration and proper amount surfactant is reasonable. The solid concentration of the polishing slurry was fixed at 20% by weight. The removal rate of copper could reach 700nm/min and the surface roughness after CMP was 0.49nm.


2008 ◽  
Vol 594 ◽  
pp. 181-186
Author(s):  
Jhy Cherng Tsai ◽  
Jin Fong Kao

In this paper, experiments are designed and conducted to investigate the effects of abrasive size for Chemical-Mechanical Polishing (CMP) of copper film under different additives in HNO3-based polishing slurries. Alumina modified colloidal silica 100S (φ26nm), 200S (φ40nm) and Al2O3 (φ90nm), are used as polishing abrasives in this study. Experiments showed the following results. (1) With citric acid as an additive to slurry, the removal rate (RR) of the CMP process increases with abrasive size. Surface quality, however, becomes worse at the same time. (2) With benzotriazole (BTA) as an additive, RR of the slurry with Al2O3 powder is slightly higher but it does not increase with the abrasive size in general. Surface quality tends to be worse at the same time though it is not as strong as that in the slurry with citric acid as the additive. (3) The size effect of abrasive on RR with citric acid as additive is stronger than that with BTA.


2021 ◽  
Author(s):  
Peng Zhang ◽  
Jingfang Yang ◽  
Huadong Qiu

Abstract Silicon carbide (SiC) has been a promising the-third-generation semiconductor power device material for high-power, high-temperature, substrate applications. It aims to improve the material removal rate (MRR), on the premise of ensuring the surface roughness requirements of the double-faced mechanical polishing of 6-inch SiC substrate. To obtain the relationship between any point on SiC substrate and polishing pads, the model about double-faced mechanical polishing has been built and the kinematics equations were created. Best optimized material removal rate parameters were obtained. MRR reached the maximum when speed rate of the outside ring gear to the inside sun gear m=-1, speed rate of lower plate to the inside sun gear n=5, SiC substrate distribution radius RB=75. The primary and secondary order of MRR (n>m>RB) was obtained. An accurate mathematical model of orthogonal rotary regression test of Tri-factor quadratic of MRR was established and the regression model was significant. Surface quality of SiC substrate was observed and characterized with SEM and AFM. It greatly provides a key guarantee for the next process of CMP, confirmed the importance of MRR to ultra-smooth polishing, and provides a guarantee for its application in semiconductor equipment and technology.


2009 ◽  
Vol 69-70 ◽  
pp. 98-102
Author(s):  
Ke Hua Zhang ◽  
Dong Hui Wen

The interaction between the tungsten steel surface and the polishing fluid & abrasive were discussed by AFM, SEM and XRD test in order to compare the chemical performances and mechanical action of the tungsten steel polishing in the paper. The chemical mechanical polishing (CMP) and the mechanical polishing (MP) was employed, respectively. The experiments results indicated that the CMP with a higher the materials removal ratio than by MP. Because a chemical corrosion effect implies that slurries with the highest removal rate have high dissolution rate, and have a lower the residual stress, however the surface took on wrinkling.


2007 ◽  
Vol 991 ◽  
Author(s):  
Patrick J. Andersen ◽  
Megan Frary

ABSTRACTNovel die-stacking schema using through-wafer vias may require thick electrodeposited copper and aggressive first-step chemical mechanical planarization (CMP). However, the effect of microstructural parameters, including surface orientation and grain size, on the CMP behavior of thick electrodeposited copper is not well understood. Here we explore the relationship be-tween the surface orientation of copper grains and local CMP removal parameters using electron backscatter diffraction and topography correlation techniques. In the present work, solid copper disks are studied which are annealed to produce samples with differing grain sizes. In addition, aggressive CMP is performed on copper films (30 μm) electrodeposited on silicon. At the bulk level, the slurry composition is found to have the greatest effect on the removal rate and surface roughness. At the microstructural level, the nature of the grain boundaries (e.g. coincidence site lattice (CSL) vs. non-CSL boundaries) is shown to impact the depth of grooving at the grain boundaries. A relationship between surface orientation and local removal rate is found.


2006 ◽  
Vol 128 (3) ◽  
pp. 445-459 ◽  
Author(s):  
Jen Fin Lin ◽  
Sheng-Chao Chen ◽  
Yu Long Ouyang ◽  
Ming Shih Tsai

An average Reynolds equation considering the effects of a pad’s annular grooves and surface roughness is developed in this study to examine mixed lubrication in the chemical mechanical polishing (CMP) of a copper-film silicon wafer. This equation is obtained on the basis of the principle that the pressure gradients and volume flow rates in the direction normal to the border of a groove and a plateau as well as on two sides of the border must be equal. The continuities of volume flow rates and hydrodynamic pressure on two sides of the border as well as in the direction normal to the border of a groove and a plateau are satisfied in order to develop this Reynolds equation. The removal rate model is obtained by taking the concentration of active abrasives in the slurry and the pad grooves into account. Theoretical results are also shown in order to investigate the effects of changing the groove depth and width on the removal rate and the nonuniformity of a copper-film wafer. The application of concentric grooves in general can lower the suction pressure (negative pressure) formed between the pad and the wafer, elevate the wear rate, and reduce the nonuniformity. However, the influences of the groove depth on wear rate and nonuniformity become insignificant when the depth is excessively large. The removal rate is reduced by increasing the groove width such that it finally approaches to the result of a nongrooved pad.


Author(s):  
Armin Schnider

This chapter summarizes current interpretations of all forms of confabulations discussed in the book and reviews the relationship between the four forms of memory-related confabulations. Experimental investigation has confirmed the dissociation between various types of false memories and considerably advanced the understanding of the mechanisms of some forms of confabulation, in particular behaviourally spontaneous confabulation and false statements in anosognosia. Overall, experimental evidence is scarce; many models have no controlled experimental basis or extend their proposed range of application well beyond the empirical evidence. The chapter concludes with a call for heightened respect of basic scientific standards in the research on confabulation.


2019 ◽  
Vol 8 ◽  
pp. 54-56
Author(s):  
Ashmita Dahal Chhetri

Advertisements have been used for many years to influence the buying behaviors of the consumers. Advertisements are helpful in creating the awareness and perception among the customers of a product. This particular research was conducted on the 100 young male and female who use different brands of product to check the influence of advertisement on their buying behavior while creating the awareness and building the perceptions. Correlation, regression and other statistical tools were used to identify the relationship between these variables. The results revealed that the relationship between media and consumer behavior is positive. The adve1tising impact on sales and there is positive and high degree relationship between advertising and consumer behavior. The impact on advertising of a product of electronic media is better than non-electronic media.


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