Chemical Mechanical Polishing of Transparent Nd:YAG Ceramics

2008 ◽  
Vol 375-376 ◽  
pp. 278-282 ◽  
Author(s):  
Jun Li ◽  
Yong Zhu ◽  
Chuang Tian Chen

Transparent Nd:YAG ceramics which are very hard and brittle materials, are very difficult to be polished. There are many micro scratches or damages on the surface after mechanical polishing with Al2O3. In order to remove micro scratches or damages, chemical mechanical polishing (CMP) was adopted to manufacture Nd:YAG ceramics. In the polishing experiment, Pellon and Chemcloth pads were utilized for chemical mechanical polishing of Nd:YAG ceramics. Colloidal SiO2 was selected as the polishing slurry in two different polishing environments, acidity and alkalinity. The surface roughness was determined by using atomic force microscope. In this study, four polishing experimental combinations that each combination contains one of the two pads and one of the two polishing environments were carried out in the optimum polishing condition. Then the high quality surface of transparent Nd:YAG ceramics with the best surface roughness of < 0.2 nm RMS and few micro scratches or damages is obtained by adopting CMP process with Chemcloth pad and colloidal SiO2 in acidic condition.

2018 ◽  
Author(s):  
Zewei Yuan ◽  
Kai Cheng ◽  
Yan He ◽  
Meng Zhang

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.


2010 ◽  
Vol 24 (15n16) ◽  
pp. 3005-3010 ◽  
Author(s):  
KAZUTOSHI KATAHIRA ◽  
HITOSHI OHMORI ◽  
MASAYOSHI MIZUTANI ◽  
JUN KOMOTORI

To investigate the possibility of developing a new surface modification method by the combined process of ELID grinding and high-temperature oxidization, we treated ELID finished specimens and polished specimens by high-temperature oxidization in the atmosphere and performed detailed analysis to determine how the treatment would change the specimen surfaces. The ELID-series showed high quality surface roughness and excellent tribological characteristics as compared with the polished-series. The improved surface properties of the ELID-series seem to result from formation of fine, uniform structures of spinel-type multiple oxides FeCr 2 O 4 and Cr 2 O 3 on the surface by high-temperature oxidization.


2021 ◽  
Vol 8 ◽  
Author(s):  
Bing Yan ◽  
Hongyu Liang ◽  
Yongfeng Liu ◽  
Weihua Liu ◽  
Wenhui Yuan ◽  
...  

Gallium antimonide (GaSb) is considered an ideal substrate for heterostructure growth via molecular beam epitaxy. A significant aspect that inhibits the widespread application of infrared plane-array detector growth on GaSb is the starting substrate surface quality. In this study, the chemical mechanical polishing of GaSb wafers is investigated by considering the effects of the polishing pad, polishing solution, polishing time and pH buffer on their surface morphology and roughness. The surface morphology and root mean square (RMS) roughness of the free-standing wafers are characterized using a white light interferometer, a laser interferometer and an atomic force microscope. X-ray tomography is employed to measure the surface crystalline quality and strain defects of the samples subjected to the polishing treatments. The results show that with the optimum polishing condition, the polished GaSb wafers demonstrate high-quality surfaces without haze, scratches or strain defect regions. The peak to valley value is 5.0 μm and the RMS roughness can be controlled at less than 0.13 nm. A buffer layer grown on the GaSb surface with molecular beam epitaxy is examined via atomic force microscopy and high-resolution X-ray diffraction, which show a low RMS roughness of 0.159 nm, a well-controlled two-dimensional growth mode and a full width half maximum of the Bragg diffraction peak of 14.2”, indicating high-quality GaSb wafers. Thus, this work provides useful guidelines for achieving GaSb wafers with high-quality surfaces that show significant promise for substrate applications.


2005 ◽  
Vol 71 (701) ◽  
pp. 280-285 ◽  
Author(s):  
Atsushi MIYOSHI ◽  
Koei MATSUKAWA ◽  
Hiroshi MATSUO ◽  
Tadayuki SAKAI ◽  
Masaru NOZUE

Author(s):  
Joo Hoon Choi ◽  
Yangro Lee ◽  
Louis E. DeMarco ◽  
Richard T. Leveille ◽  
Joseph A. Levert ◽  
...  

The feature sizes on Integrated Circuits (ICs) continue to decrease to provide higher device densities and smaller chip designs. To accomplish this, current fabrication and processing technology must be advanced to achieve these goals. In particular, Chemical Mechanical Polishing (CMP), which is used for planarization of wafers and logic circuit components during IC fabrication, can cause severe surface damage to components in the form of delamination or distortion of surface features. CMP utilizes polishing particles suspended between a polymeric pad and the substrate to be polished. To control the process with higher precision the fundamentals of friction between CMP surfaces need to be analyzed. To investigate the friction contributions of the polishing particles in the CMP process, individual CMP abrasive particles are modeled by a silica atomic force microscope (AFM) probe with a radius of curvature on the order of 200 nm that is utilized in a scanning probe microscope (SPM). Lateral forces are measured that occur in simulated polishing of silica substrates and polyurethane pad material in a liquid environment. Results are obtained as a function of pH and environment and are compared with macroscopic friction results obtained using a high precision tribometer with a glass ball.


2005 ◽  
Vol 483-485 ◽  
pp. 197-200 ◽  
Author(s):  
Hugues Mank ◽  
Catherine Moisson ◽  
Daniel Turover ◽  
Mark E. Twigg ◽  
Stephen E. Saddow

In this work, we have investigated the 3C-SiC re-growth on planarized 3C-SiC epitaxial layers, grown on (001)Si, after the application of a chemical mechanical polishing (CMP) process. A specific polishing process was developed for 3C-SiC to achieve a flat, high-quality surface. The interface between the deposited 3C-SiC and the polished 3C-SiC on Si film was studied by TEM characterization to determine if defects appear at this interface. It was observed that no additional defects were nucleated at the interface. The resulting re-grown film roughness, as a function of film thickness, was studied and is reported along with recommendations for future work.


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