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 ◽  
...  

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.

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.


Author(s):  
Dinc¸er Bozkaya ◽  
Sinan Mu¨ftu¨

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.


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.


1994 ◽  
Vol 337 ◽  
Author(s):  
Rajeev Bajaj ◽  
Mukesh Desai ◽  
Rahul Jairath ◽  
Matthew Stell ◽  
Robert Tolles

ABSTRACTChemical mechanical polishing (CMP) technology has successfully met the stringent requirements of ultraplanarized surfaces in semiconductor manufacture. Commonly, polyurethane based pads have been used to achieve this level of planarization. Recent studies have shown that the material properties of polishing pads used in the CMP process strongly influence the ability to reduce topography. In addition, past work has shown that in the absence of pad regeneration, polishing rate drops dramatically with polishing time. This decrease in material removal rate is believed to coincide with deterioration of the pad surface due to “cold flow” and/or “caking” of the pad material. This study attempts to correlate the intrinsic polymer properties and cellular structure of the pad material to CMP process indices like polishing rate and planarity. For example, the drop off in removal rate as a function of time can be attributed to the mechanical response of polyurethanes under conditions of critical shear. Moreover, planarity achieved is a function of pad stiffness - which itself is dependant upon intrinsic polymer stiffness and cell density.


2011 ◽  
Vol 189-193 ◽  
pp. 4112-4115 ◽  
Author(s):  
Yong Chang Guo ◽  
Young Kyun Lee ◽  
Hyun Seop Lee ◽  
Hae Do Jeong

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.


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.


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