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

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 600-603 ◽  
pp. 831-834 ◽  
Author(s):  
Joon Ho An ◽  
Gi Sub Lee ◽  
Won Jae Lee ◽  
Byoung Chul Shin ◽  
Jung Doo Seo ◽  
...  

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.


2014 ◽  
Vol 538 ◽  
pp. 40-43
Author(s):  
Hong Wei Du ◽  
Yan Ni Chen

In this paper, material removal mechanism of monocrystalline silicon by chemical etching with different solutions were studied to find effective oxidant and stabilizer. Material removal mechanism by mechanical loads was analyzed based on the measured acoustic signals in the scratching processes and the observation on the scratched surfaces of silicon wafers. The chemical mechanical polishing (CMP) processes of monocrystalline silicon wafers were analyzed in detail according to the observation and measurement of the polished surfaces with XRD. The results show that H2O2 is effective oxidant and KOH stabilizer. In a certain range, the higher concentration of oxidant, the higher material removal rate; the higher the polishing liquid PH value, the higher material removal rate. The polishing pressure is an important factor to obtain ultra-smooth surface without damage. Experimental results obtained silicon polishing pressure shall not exceed 42.5kPa.


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.


2011 ◽  
Vol 317-319 ◽  
pp. 29-33 ◽  
Author(s):  
Xiang Dong Yang ◽  
Xin Wei ◽  
Xiao Zhu Xie ◽  
Zhuo Chen ◽  
Wei Bo Zou

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.


1994 ◽  
Vol 337 ◽  
Author(s):  
Rahul Jairath ◽  
Mukesh Desai ◽  
Matt Stell ◽  
Robert Tolles ◽  
Debra Scherber-Brewer

ABSTRACTChemical mechanical polishing (CMP) is rapidly becoming the process of choice for planarizing dielectrics in very large scale integrated circuits. In addition, it is being used at an increasing rate in the removal of metals in order to define conducting levels. In the case of dielectric CMP, planarization ability is dictated by the mechanical aspects of polishing such as pad rigidity, polishing pressure and speed of the polishing platen, while inherent removal rate of the dielectric material is generally a function of the polishing chemistry. Polishing rate of both, dielectric and metallic films can be significantly increased by changing the nature of the dispersed abrasive in the slurry and that of the dispersing agent. However, such changes have profound implications to the surface quality, planarity, and cleaning of the polished surface. In addition, the polishing pad plays an important role in manufacturability of metal CMP processes. This work reviews the chemistry of polishing slurries containing silica, ceria and alumina abrasives for dielectric and metal CMP. Also, the contribution of the polishing pad to CMP processes is explained. The need for balancing the chemical and mechanical aspects of polishing in order to achieve overall planarization and pattern definition is demonstrated.


Author(s):  
Kailiang Zhang ◽  
Zhitang Song ◽  
Songlin Feng

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.


2006 ◽  
Vol 532-533 ◽  
pp. 233-236 ◽  
Author(s):  
Yu Hui Sun ◽  
Ren Ke Kang ◽  
Dong Ming Guo

The within-wafer non-uniformity (WIWNU) of material removal rate in chemical mechanical polishing (CMP) is important for IC manufacture. The non-uniform distributions of polishing pressure and the relative speed between the wafer and the polishing pad are main factors affecting the WIWNU. In this paper,based on the contact mechanics and the elastic plate theory, a compensate pressure computing model is presented, in which the effects of kinematic parameters are taken into acount. By modelling and calculating, the desired compensate back pressure distribution is obtained. In the last section the design of a schematic carrier with multi-zone, in which the compensate back pressure can be applied, is presented. The model and the design can be used for providing theoretical guide to the development of CMP equipments and selection of the kinematic variables in CMP process.


2011 ◽  
Vol 325 ◽  
pp. 464-469
Author(s):  
Zhu Ji Jin ◽  
Z.W. Yuan ◽  
Q. Li ◽  
K. Wang

Mechanical energy may initiate and accelerate chemical reaction in chemical mechanical polishing (CMP). To study the effect of mechanical energy on the chemical reactions, a special friction measuring system was designed in this paper. The system could measure the local friction to reduce the error caused by resultant force. The effects of rotational speed, polishing pressure and the concentration of oxidant on friction and material removal rate were investigated. The results showed that the system could accurately measure the friction of small area diamond film in CMP process. The frictional system was in a mixed lubrication state since the value of the friction coefficient located in the range of 0.060~0.065.


2010 ◽  
Vol 44-47 ◽  
pp. 3067-3071
Author(s):  
Sheng Li Wang ◽  
Zhen Xia Li ◽  
Hui Lai Mu ◽  
Yu Tian ◽  
Li Bing Yang

Chemical mechanical polishing (CMP) is the effective technology which obtains high accuracy surface of hard disk substrate with nickel-phosphorus (Ni-P) coating. The slurry is significant factor in hard disk substrate CMP. Colloidal silica-based alkaline slurry was prepared based on negative pressure vortex method. The effects of slurry parameters such as abrasive concentration, organic alkali concentration and oxidant concentration on material removal rate and surface characteristics were investigated. The experimental result indicated that the abrasive concentration was 20wt%, the slurry pH value was 11.2, the oxidant concentration was 15ml/L, improved surface roughness and polishing efficiency of hard disk substrates, a smooth surface was obtained and micro scratches could hardly be observed.


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