scholarly journals Focused Ion Beam Milling of Single-Crystal Sapphire with A-, C-, and M-Orientations

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2871
Author(s):  
Qiuling Wen ◽  
Xinyu Wei ◽  
Feng Jiang ◽  
Jing Lu ◽  
Xipeng Xu
Keyword(s):  
Single Crystal ◽  
Surface Quality ◽  
Material Removal ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Crystal Orientations ◽  
Aluminum Ions ◽  
Single Crystal Sapphire

Sapphire substrates with different crystal orientations are widely used in optoelectronic applications. In this work, focused ion beam (FIB) milling of single-crystal sapphire with A-, C-, and M-orientations was performed. The material removal rate (MRR) and surface roughness (Sa) of sapphire with the three crystal orientations after FIB etching were derived. The experimental results show that: The MRR of A-plane sapphire is slightly higher than that of C-plane and M-plane sapphires; the Sa of A-plane sapphire after FIB treatment is the smallest among the three different crystal orientations. These results imply that A-plane sapphire allows easier material removal during FIB milling compared with C-plane and M-plane sapphires. Moreover, the surface quality of A-plane sapphire after FIB milling is better than that of C-plane and M-plane sapphires. The theoretical calculation results show that the removal energy of aluminum ions and oxygen ions per square nanometer on the outermost surface of A-plane sapphire is the smallest. This also implies that material is more easily removed from the surface of A-plane sapphire than the surface of C-plane and M-plane sapphires by FIB milling. In addition, it is also found that higher MRR leads to lower Sa and better surface quality of sapphire for FIB etching.

Roughness Effects During Focused Ion Beam Repair of X-Ray Masks with Polycrystalline Tungsten Absorbers

1992 ◽  
Vol 279 ◽  
Author(s):  
R. R. Kola ◽  
G. K. Celler ◽  
L R. Harriott
Keyword(s):  
Material Removal ◽  
Etch Rate ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Sidewall Roughness ◽  
X Ray ◽  
Polycrystalline Tungsten ◽  
Absorber Material ◽  
Defect Repair

ABSTRACTTungsten is emerging as the absorber material of choice for x-ray masks due to recent advances in the deposition of low stress films. For a practical technology, the masks must be free from defects. These defects may be in the form of excess or missing absorber. Finely focused ion beams have been used for defect repair on x-ray masks, both for removal of excess absorber material by physical sputtering and for addition of absorber material by ion-induced deposition. The eifect of ion channeling in polycrystalline tungsten films is spatially nonuniform material removal during sputtering. Different grains will have significantly different sputtering yields, depending on their orientation with respect to the direction of the ion beam. The repaired features then suffer from roughness on the bottoms and sidewalls of the sputter craters. We have investigated the use of XeF2 assisted sputtering with a 20 keV Ga+ focused ion beam to reduce this roughness. The chemical etching component of the material removal lessens the directional dependence and therefore the roughness during defect repair. It was also found that chromium etch rate was reduced in the presence of XeF2 gas while the etch rate of W was enhanced so that the removal rate of Cr is much less than that of W. We can take advantage of this etch selectivity by using a thin Cr layer under the W absorber as an etch stop layer to eliminate the roughness at the bottom of the features and a thin layer of Cr on top of the W as an etch mask for reducing the sidewall roughness.

A Study of the Solid-State Reaction for Polishing Sapphires

2012 ◽  
Vol 497 ◽  
pp. 195-199 ◽  
Author(s):  
Qian Fa Deng ◽  
Zhi Xiong Zhou ◽  
Zhao Zhong Zhou ◽  
Ju Long Yuan ◽  
Ji Cui Wang
Keyword(s):  
Solid State ◽  
Surface Quality ◽  
Material Removal Rate ◽  
Surface Finish ◽  
Solid State Reaction ◽  
Material Removal ◽  
Removal Rate ◽  
Substrate Material ◽  
Quality Requirements

As sapphire is an important substrate material, stringent surface quality requirements (i.e., surface finish and flatness) are required. In order to acquire the higher material removal rate and the better surface quality of sapphire, the solid state-reaction were introduced in this paper; abrasive of SiO2 and SiO2 with mixing the MgF2 power were compared to polish sapphire. The result showed that abrasive of SiO2 with mixing the MgF2 can obtain higher material removal rate and better surface quality. The result of the pr

Dry WEDM in Improving HS-WEDMed Surface Quality

2008 ◽  
Vol 392-394 ◽  
pp. 624-628 ◽  
Author(s):  
Tong Wang ◽  
Yu Mei Lu ◽  
Shuang Shuang Hao ◽  
Shu Qiang Xie ◽  
Xiao Cun Xu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Material Removal ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Dry Wedm ◽  
Finish Cut ◽  
The Relationship

This paper studies the surface quality of mould steel with high-speed wire electrical discharge machining (WEDM) method, which is conducted in gas to improve the accuracy of finish cut, and compares the surface quality in atmosphere and in emulsion dielectric. Experiment results showed that WEDM in atmosphere offers advantages such as better surface roughness and higher material removal rate. The relationship about winding speed and worktable feed on WEDMed surface quality in semi-finishing cut and finishing cut had been obtained. Morover, a new attemption was successful in applying dry WEDM in multiple cut to improve surface roughness.

Impact of slurry pH on material removal rate and surface quality of polished fused silica

Optifab 2017 ◽  
2017 ◽  
Author(s):  
Cedric Maunier ◽  
Melanie Redien ◽  
Bertrand Remy ◽  
Jérôme Néauport ◽  
Karine Poliakoff-Leriche
Keyword(s):  
Surface Quality ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Fused Silica

Grindability of Single Crystal Sapphire in Medical Use and the Scheme of Forming Highly Precise Spherical Heads

2011 ◽  
Vol 496 ◽  
pp. 13-18
Author(s):  
Otar Mgaloblishvili ◽  
Rauli Turmanidze ◽  
David Butskhrikidze ◽  
Mariam Beridze
Keyword(s):  
Surface Layer ◽  
Low Temperature ◽  
Single Crystal ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Precision Grinding ◽  
Hip Joints ◽  
Grinding Conditions ◽  
Single Crystal Sapphire

The scale of influence of the single crystal sapphire crystallographic plane orientation and grinding conditions on the material removal rate, surface finish and the state of sub-surface layer have been studied under Low-Temperature Precision Grinding (LPG). The schemes of forming partial spherical heads for human hip joints endoprostheses are considered and elaborated. The possible versions of forming the spherical heads of endoprosthesis based on the novelties in kinematics and the mode of material removal are discussed.

Anisotropic Lapping of Single Crystal Sapphire

2010 ◽  
Vol 102-104 ◽  
pp. 502-505
Author(s):  
Ping Zhou ◽  
Peng Fei Gao ◽  
Wei Fang Wang ◽  
Dong Hui Wen
Keyword(s):  
Fracture Toughness ◽  
Surface Roughness ◽  
Elastic Modulus ◽  
Single Crystal ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Orientation ◽  
Experimental Results ◽  
Single Crystal Sapphire

Lapping processes of single crystal sapphire are investigated in relation to crystallo- graphic orientation, the influence of the crystal anisotropism under different lapping liquid concentration, loading forces on materials removal rate and roughness in sapphire lapping is discussed. C-plane(0001),M-plane ( ),R-plane ( ),A-plane ( ) sapphire wafers were used for lapping experiments, experimental results show that Surface roughness is depend on the fracture toughness, surface orientation with higher fracture toughness such as C-plane would get better roughness during lapping, material removal rate of R-plane is the lowest in four planes, it is for elastic modulus and fracture toughness of R-plane are less than other three planes.

Study on Dry WEDMed Surface Quality of Mould Steel

2008 ◽  
Vol 375-376 ◽  
pp. 416-420 ◽  
Author(s):  
Tong Wang ◽  
Xin Fu Zhang ◽  
Xue Fang Zhao
Keyword(s):  
Surface Quality ◽  
Electrical Discharge ◽  
Material Removal ◽  
High Speed ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Finish Cut ◽  
Straightness Error ◽  
Discharge Gap

This paper studies the surface quality of tool steel with high-speed wire electrical discharge machining (WEDM) method, which is conducted in gas to improve the accuracy of finish cut, and compares the surface quality in atmosphere and in emulsion dielectric. Experiment results showed that WEDM in atmosphere offers advantages such as better straightness and higher material removal rate. With the growth of wire winding speed, the removal rate and straightness error will increase significantly either in atmosphere or in liquid. Along with the feed increasing, the discharge gap lengthes decrease successively under the both media conditions, and the straightness is obviously improved in atmosphere. Regardless of the use of atmosphere or emulsion, an optimum feed will exist, which makes the roughness the lowest and the removal rate the highest.

A Preliminary Study on Machinability of Polymethylmethacrylate (PMMA)/Multi-Walled Carbon Nanotube (MWCNT) Nanocomposites in Focused Ion Beam Micromachining

2011 ◽  
Author(s):  
Pengfei Li ◽  
Wei Xue ◽  
Dave Dae-Wook Kim ◽  
Young-Bin Park
Keyword(s):  
Carbon Nanotube ◽  
Material Removal Rate ◽  
Soft Lithography ◽  
Material Removal ◽  
Focused Ion Beam ◽  
Removal Rate ◽  
Ion Beam ◽  
Input Current ◽  
Multi Walled Carbon Nanotube ◽  
Solution Casting Method

This experimental study investigated the machinability of polymethylmethacrylate (PMMA)/multi-walled carbon nanotube (MWCNT) nanocomposites with 20 wt% MWCNTs in focused ion beam (FIB) micromachining. PMMA/MWCNT nanocomposites were fabricated using a solution casting method, in which PMMA and MWCNTs were dispersed in a solvent by ultrasonication. Microscale rectangular pockets were created on the PMMA/MWCNT nanocomposites to study the material removal mechanism in FIB. Effects of FIB input current and the ion beam overlap parameter (overlap %) on the material removal rate and geometric accuracy were studied. It was observed that the material removal rate increased with increasing input current and decreasing overlap %. Soft lithography was used to translate the ion-milled pockets on PMMA/MWCNT nanocomposites into microscale posts on polydimethylsiloxane (PDMS) for accurate measurement of the pocket geometries. A Scanning Electron Microscope (SEM) was used to investigate the characteristics of the micromachined features, nanocomposite surfaces, and replicated PDMS patterns. Our results demonstrated an effective method to produce microscale patterns on MWCNT-based nanocomposites.

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