Tribological Aspects of Chemical Mechanical Polishing Diamond Surfaces

2011 ◽  
Vol 325 ◽  
pp. 464-469
Author(s):  
Zhu Ji Jin ◽  
Z.W. Yuan ◽  
Q. Li ◽  
K. Wang
Keyword(s):  
Chemical Mechanical Polishing ◽  
Small Area ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Energy ◽  
Mechanical Polishing ◽  
Measuring System ◽  
Diamond Surfaces ◽  
Frictional System ◽  
Polishing Pressure

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.

Study on Chemical Mechanical Polishing Removal Mechanism of Monocrystalline Silicon

2014 ◽  
Vol 538 ◽  
pp. 40-43
Author(s):  
Hong Wei Du ◽  
Yan Ni Chen
Keyword(s):  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Silicon Wafers ◽  
Monocrystalline Silicon ◽  
Mechanical Polishing ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Polishing Pressure

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.

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.

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.

Modeling of Polishing Regimes in Chemical Mechanical Polishing

2005 ◽  
Vol 867 ◽  
Author(s):  
Suresh B. Yeruva ◽  
Chang-Won Park ◽  
Brij M. Moudgil
Keyword(s):  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Operating Conditions ◽  
Comprehensive Model ◽  
Mechanical Effects ◽  
Microelectronic Devices ◽  
Asperity Distribution ◽  
Modification Of The Surface

AbstractChemical mechanical polishing (CMP) is widely used for local and global planarization of microelectronic devices. It has been demonstrated experimentally in the literature that the polishing performance is a result of the synergistic effect of both the chemicals and the particles involved in CMP. However, the fundamental mechanisms of material removal and the interactions of the chemical and mechanical effects are not well understood. A comprehensive model for CMP was developed taking into account both the chemical and mechanical effects for monodisperse slurries. The chemical aspect is attributed to the chemical modification of the surface layer due to slurry chemistry, whereas the mechanical aspect is introduced by indentation of particles into the modified layer and the substrate depending on the operating conditions. In this study, the model is extended to include the particle size and pad asperity distribution effects. The refined model not only predicts the overall removal rate but also the surface roughness of the polished wafer, which is an important factor in CMP. The predictions of the model show reasonable agreement with the experimental observations.

A Model for Optimizing Material Removal Rate in Low-Pressure CMP: Effects of Pad Porosity and Abrasive Concentration

2008 ◽  
Author(s):  
Dinc¸er Bozkaya ◽  
Sinan Mu¨ftu¨
Keyword(s):  
Material Removal Rate ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Applied Pressure ◽  
Low Pressure ◽  
Mechanical Polishing ◽  
Low K

The necessity to planarize ultra low-k (ULK) dielectrics [1], and the desire to reduce polishing defects leads to use of lower polishing pressures in chemical mechanical polishing (CMP). However, lowering the applied pressure also decreases the material removal rate (MRR), which causes the polishing time for each wafer to increase. The goal of this work is to investigate effects of pad porosity and abrasive concentration on the MRR.

Experimental Investigation on Wafer Polishing of Oxide and Copper Layers

2002 ◽  
Author(s):  
Jhy-Cherng Tsai
Keyword(s):  
Process Parameters ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Back Pressure ◽  
Copper Layer ◽  
Wafer Polishing ◽  
Critical Technology ◽  
And Performance ◽  
Polishing Pressure

Polishing, in particular chemical-mechanical polishing (CMP), is a critical technology for the planarization of wafers. This paper investigates, via experiments, and compares the performance of CMP process with different process parameters for wafers with silicon-dioxide (SiO2) layer and for wafers with copper (Cu) layer. Polishing pressure (P), speed (V), and back pressure (BP) are used as process parameters in this study. Different pads and slurries are also experimented for copper layer as its properties are different from that of conventional oxide layer. Material removal rate (RR) and non-uniformity (NU) are used as indices to measure the performance. Experimental data on oxide layers show RR increases as P and V increase but NU gets worse at the same time. This condition can be improved, for both oxide and copper layers, with suitable BP. Experiments on copper CMP using slurry with abrasives show that RR increases with higher P and V. While NU gets worse with higher P, it can be reduced as V increases using a soft pad. Better NU can be obtained using soft pad though RR is lower in this case. For abrasive-free polishing of copper layer, RR, though relatively lower compared to CMP with regular slurry, is unstable using hard pad despite that NU becomes better at higher P. NU of polished wafer is best at certain pressure but becomes worse at low pressure for hard pad and at high P for soft pad. It is also observed that NU of AFP can be improved with BP and softer pad. Soft pad gives better polishing quality and performance though RR is lower than that using slurry with abrasives.

Investigation on Smoothing Silicon Carbide Wafer With a Combined Method of Mechanical Lapping and Photocatalysis Assisted Chemical Mechanical Polishing

2018 ◽  
Author(s):  
Zewei Yuan ◽  
Kai Cheng ◽  
Yan He ◽  
Meng Zhang
Keyword(s):  
Silicon Carbide ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Combined Method ◽  
Polishing Process ◽  
High Quality ◽  
Quality Surface ◽  
High Quality Surface

The high quality surface can exhibit the irreplaceable application of single crystal silicon carbide in the fields of optoelectronic devices, integrated circuits and semiconductor. However, high hardness and remarkable chemical inertness lead to great difficulty to the smoothing process of silicon carbide. Therefore, the research presented in this paper attempts to smooth silicon carbide wafer with photocatalysis assisted chemical mechanical polishing (PCMP) by using of the powerful oxidability of UV photo-excited hydroxyl radical on surface of nano-TiO2 particles. Mechanical lapping was using for rough polishing, and a material removal model was proposed for mechanical lapping to optimize the polishing process. Several photocatalysis assisted chemical mechanical polishing slurries were compared to achieve fine surface. The theoretical analysis and experimental results indicate that the material removal rate of lapping process decreases in index form with the decreasing of abrasive size, which corresponds with the model developed. After processed with mechanical lapping for 1.5 hours and subsequent photocatalysis assisted chemical mechanical polishing for 2 hours, the silicon carbide wafer obtains a high quality surface with the surface roughness at Ra 0.528 nm The material removal rate is 0.96 μm/h in fine polishing process, which is significantly influenced by factors such as ultraviolet irradiation, electron capture agent (H2O2) and acidic environment. This combined method can effectively reduce the surface roughness and improve the polishing efficiency on silicon carbide and other hard-inert materials.

scholarly journals Study on the Influence of Sapphire Crystal Orientation on Its Chemical Mechanical Polishing

2020 ◽  
Vol 10 (22) ◽  
pp. 8065
Author(s):  
Linlin Cao ◽  
Xiang Zhang ◽  
Julong Yuan ◽  
Luguang Guo ◽  
Teng Hong ◽  
...  
Keyword(s):  
Material Removal Rate ◽  
Material Properties ◽  
Chemical Mechanical Polishing ◽  
Crystal Orientation ◽  
Material Removal ◽  
Removal Rate ◽  
Substrate Material ◽  
Mechanical Polishing ◽  
Sapphire Crystal ◽  
Research Objects

Sapphire has been the most widely used substrate material in LEDs, and the demand for non-C-planes crystal is increasing. In this paper, four crystal planes of the A-, C-, M- and R-plane were selected as the research objects. Nanoindentation technology and chemical mechanical polishing technology were used to study the effect of anisotropy on material properties and processing results. The consequence showed that the C-plane was the easiest crystal plane to process with the material removal rate of 5.93 nm/min, while the R-plane was the most difficult with the material removal rate of 2.47 nm/min. Moreover, the research results have great guiding significance for the processing of sapphire with different crystal orientations.

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.

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