<title>Fabrication of optical surfaces with low subsurface damage using a float polishing process</title>

We have investigated polishing non-cubic crystal wafers using a unique dry polishing process. The wafers tested were GaN and SiC. Wafers of both GaN and SiC have surfaces terminated by different materials. Each of these surfaces will react differently when polished. For GaN the Ga (000–1) surface has a higher degree of chemical inertness than the nitrogen terminated surface (0001). To compensate for this difference in chemical inertness complex slurries and long polish times are used in chemo-mechanical polishing (CMP). Dry polishing equaled the surface finish and removal of subsurface damage of CMP in significantly reduced polishing times.

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The Assessment of Subsurface Damage in Ground Optics by Chemical Etching

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.679.149 ◽

2016 ◽

Vol 679 ◽

pp. 149-153

Author(s):

Hui Ye ◽

Wei Yang

Keyword(s):

Chemical Etching ◽

Damage Threshold ◽

Subsurface Damage ◽

Polishing Process ◽

Etching Technique ◽

Optical Elements ◽

The Past ◽

Laser Induced Damage ◽

Grinding And Polishing

Optical subsurface damage (SSD), generated from traditional grinding and polishing process, is prone to lower the laser-induced damage threshold (LIDT) of optical elements. Due to the fact that SSD elimination is on the premise of SSD evaluation, numerous SSD characterizing techniques have been proposed in the past few decades. In this paper, various SSD evaluations based on chemical etching technique are described and compared.

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Subsurface Damage in Polishing Process of Silicon Carbide Ceramic

Materials ◽

10.3390/ma11040506 ◽

2018 ◽

Vol 11 (4) ◽

pp. 506 ◽

Cited By ~ 8

Author(s):

Yan Gu ◽

Wenhui Zhu ◽

Jieqiong Lin ◽

Mingming Lu ◽

Mingshuo Kang

Keyword(s):

Silicon Carbide ◽

Subsurface Damage ◽

Polishing Process ◽

Silicon Carbide Ceramic

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Development and theoretical analysis of novel center-inlet computer-controlled polishing process for high-efficiency polishing of optical surfaces

Robotics and Computer-Integrated Manufacturing ◽

10.1016/j.rcim.2019.01.017 ◽

2019 ◽

Vol 59 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Bin Lin ◽

Xiang-Min Jiang ◽

Zhong-Chen Cao ◽

Tian Huang

Keyword(s):

Theoretical Analysis ◽

High Efficiency ◽

Polishing Process ◽

Optical Surfaces ◽

Computer Controlled

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Polishing process effect on the image of dispersed precipitates

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100112646 ◽

1984 ◽

Vol 42 ◽

pp. 534-535

Author(s):

C.T. Hu ◽

C.W. Allen

Keyword(s):

Matrix Material ◽

Specimen Preparation ◽

Second Phase ◽

Precipitate Particle ◽

Polishing Process ◽

Second Phase Particles ◽

The Matrix ◽

Surface Profiles ◽

Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

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An Improved Method for the Preparation and TEM Examination of Sharp Pointed Tips used in APFIM and STM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134107 ◽

1990 ◽

Vol 48 (2) ◽

pp. 102-103

Author(s):

E.A. Fischione ◽

P.E. Fischione ◽

J.J. Haugh ◽

M.G. Burke

Keyword(s):

Atom Probe ◽

Preparation Process ◽

Improved Method ◽

Ion Milling ◽

Polishing Process ◽

Probe Field ◽

Scanning Tunnelling ◽

Stm Tips ◽

Tunnelling Microscopy ◽

Ion Microscopy

A common requirement for both Atom Probe Field-Ion Microscopy (APFIM) and Scanning Tunnelling Microscopy (STM) is a sharp pointed tip for use as either the specimen (APFIM) or the probe (STM). Traditionally, tips have been prepared by either chemical or electropolishing techniques. Recently, ion-milling has been successfully employed in the production of APFIM tips [1]. Conventional electropolishing techniques are applicable to a wide variety of metals, but generally require careful manual adjustments during the polishing process and may also be time-consuming. In order to reduce the time and effort involved in the preparation process, a compact, self-contained polishing unit has been developed. This system is based upon the conventional two-stage electropolishing technique in which the specimen/tip blank is first locally thinned or “necked”, and subsequently electropolished until separation occurs.[2,3] The result of this process is the production of two APFIM or STM tips. A mechanized polishing unit that provides these functions while automatically maintaining alignment has been designed and developed.

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