Chemical-Mechanical Polishing of Wafers with Copper Film by Nano-Scale Abrasives

2008 ◽  
Vol 594 ◽  
pp. 181-186
Author(s):  
Jhy Cherng Tsai ◽  
Jin Fong Kao
Keyword(s):  
Citric Acid ◽  
Size Effect ◽  
Surface Quality ◽  
Chemical Mechanical Polishing ◽  
Colloidal Silica ◽  
Removal Rate ◽  
Copper Film ◽  
Mechanical Polishing ◽  
Al2o3 Powder ◽  
Abrasive Size

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.

Effect of Process Parameters on Material Removal Rate in Chemical Mechanical Polishing of 6H-SiC(0001)

2008 ◽  
Vol 600-603 ◽  
pp. 831-834 ◽  
Author(s):  
Joon Ho An ◽  
Gi Sub Lee ◽  
Won Jae Lee ◽  
Byoung Chul Shin ◽  
Jung Doo Seo ◽  
...  
Keyword(s):  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Colloidal Silica ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Diamond Particles ◽  
Average Grain Size ◽  
Silica Slurry ◽  
Sic Wafer

2inch 6H-SiC (0001) wafers were sliced from the ingot grown by a conventional physical vapor transport (PVT) method using an abrasive multi-wire saw. While sliced SiC wafers lapped by a slurry with 1~9㎛ diamond particles had a mean height (Ra) value of 40nm, wafers after the final mechanical polishing using the slurry of 0.1㎛ diamond particles exhibited Ra of 4Å. In this study, we focused on investigation into the effect of the slurry type of chemical mechanical polishing (CMP) on the material removal rate of SiC materials and the change in surface roughness by adding abrasives and oxidizer to conventional KOH-based colloidal silica slurry. The nano-sized diamond slurry (average grain size of 25nm) added in KOH-based colloidal silica slurry resulted in a material removal rate (MRR) of 0.07mg/hr and the Ra of 1.811Å. The addition of oxidizer (NaOCl) in the nano-size diamond and KOH based colloidal silica slurry was proven to improve the CMP characteristics for SiC wafer, having a MRR of 0.3mg/hr and Ra of 1.087Å.

Study on Chemical Mechanical Polishing Technology of Copper

2008 ◽  
Vol 373-374 ◽  
pp. 820-823
Author(s):  
Sheng Li Wang ◽  
Y.J. Yuan ◽  
Yu Ling Liu ◽  
X.H. Niu
Keyword(s):  
Chemical Mechanical Polishing ◽  
Colloidal Silica ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Alkali Concentration ◽  
Copper Films ◽  
Optimum Conditions ◽  
Slurry Flow Rate ◽  
Polishing Pressure ◽  
Oxidizer Concentration

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.

Research on CMP Characteristics Attribute to Groove Size

2011 ◽  
Vol 189-193 ◽  
pp. 4112-4115 ◽  
Author(s):  
Yong Chang Guo ◽  
Young Kyun Lee ◽  
Hyun Seop Lee ◽  
Hae Do Jeong
Keyword(s):  
Size Effect ◽  
Friction Force ◽  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Experimental Results ◽  
Groove Width ◽  
Significant Difference

Groove pads are used quite widely in chemical mechanical polishing (CMP), and groove size plays an important role in CMP characteristics. This study focuses on the investigation of the groove size effect using X-Y groove pads which are different with pitch and width. The first experiment shows the size effect on the polishing characteristics including material removal rate (MRR), within wafer non-uniformity (WIWNU) on 4 inch oxide blanket wafers for 60 seconds. The second experiment verifies the reason why MRR and WIWNU are different, by the calculation of slurry duration time (SDT) resulting from the change of friction force. All experimental results indicated that a significant difference of slurry flow attributed to groove width and pitch has an impressive influence on friction force, finally the MRR and WIWNU are affected by the groove size.

Analysis of the Main Parameters in the Chemical Mechanical Polishing Process

2011 ◽  
Vol 317-319 ◽  
pp. 29-33 ◽  
Author(s):  
Xiang Dong Yang ◽  
Xin Wei ◽  
Xiao Zhu Xie ◽  
Zhuo Chen ◽  
Wei Bo Zou
Keyword(s):  
Surface Quality ◽  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Rotation Speed ◽  
Removal Rate ◽  
Surface Damage ◽  
Mechanical Polishing ◽  
Technological Parameters ◽  
Polishing Pressure

This paper studies the chemical mechanical polishing (CMP) of the wafer's material such as stainless steel, monocrystalline silicon etc, and analyzes how the technological parameters’ impact on the final wafer’s surface material removal rate, surface quality and surface damage like the polishing pad’s speed and the wafer speed, polishing pressure and polishing time.The results show that: when the difference between the polishing pad's rotation speed and the wafer's rotation speed is small and their directions are the same , then the material removal rate of the wafer is larger.when the polishing pressure is selected between 5 to 6.5 kPa, the wafer surface's damage is smaller.The polishing time also play a very important role and affect the surface quality and surface damage of the wafer after polishing.

Chemical Mechanical Polishing Slurry for Tungsten in ULSI With Large Particle Size Colloidal Silica Nano-Abrasive

2005 ◽  
Author(s):  
Kailiang Zhang ◽  
Zhitang Song ◽  
Songlin Feng
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Zeta Potential ◽  
Chemical Mechanical Polishing ◽  
Large Particle ◽  
Colloidal Silica ◽  
Removal Rate ◽  
Silica Sol ◽  
Mechanical Polishing ◽  
Large Particle Size

Silica sol nano-abrasives with large particle are prepared and characterized by TEM, PCS and Zeta potential in this paper. Results show that the silica sol nano-abrasives about 100nm are of higher stability (Zeta potential: −65mV) and narrow distribution of particle size. And then alkali CMP slurries for tungsten containing self-made silica sol nano-abrasives are prepared and applied. CMP results show that the removal rate has been improved to 367nm/min and the RMS of surface roughness has been reduced from 4.4nm to 0.80nm. In sum, one kind of alkali slurry containing 100nm silica sol for tungsten CMP is studied.

Analysis of the Tribological Mechanisms Arising in the Chemical Mechanical Polishing of Copper-Film Wafers When Using a Pad With Concentric Grooves

2006 ◽  
Vol 128 (3) ◽  
pp. 445-459 ◽  
Author(s):  
Jen Fin Lin ◽  
Sheng-Chao Chen ◽  
Yu Long Ouyang ◽  
Ming Shih Tsai
Keyword(s):  
Wear Rate ◽  
Chemical Mechanical Polishing ◽  
Reynolds Equation ◽  
Removal Rate ◽  
Copper Film ◽  
Groove Depth ◽  
Volume Flow ◽  
Mechanical Polishing ◽  
Flow Rates ◽  
Two Sides

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.

Effect of Citric Acid in Chemical Mechanical Polishing (CMP) for Lithium Tantalate (LiTaO3) Wafer

2016 ◽  
Vol 1136 ◽  
pp. 305-310 ◽  
Author(s):  
Hyun Seop Lee
Keyword(s):  
Citric Acid ◽  
Integrated Circuits ◽  
Chemical Mechanical Polishing ◽  
Removal Rate ◽  
High Surface ◽  
Lithium Tantalate ◽  
Mechanical Polishing ◽  
High Surface Quality ◽  
Force Microscopy ◽  
Atomic Force

Lithium tantalate (LiTaO3) has piezoelectric, electro-optical and nonlinear optical characteristics, and a wide transparency range going from ultraviolet to infrared. It is desirable that LiTaO3 wafer was a smooth surface in order to function with good quality. Chemical mechanical polishing (CMP) has been used to planarize integrated circuits (ICs) or obtain a high surface quality of the substrates. This paper investigates the effect of citric acid as an additive in the slurry for LiTaO3 CMP. The roughness of the wafers was measured by an atomic force microscopy (AFM, XE-100) after polishing. The slurry, which contains citric acid as an additive, has a higher material removal rate and friction force than a slurry without an additive. After polishing, the surface roughness of the LiTaO3 wafer can be reduced down to 1.7Å of Ra.

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