Two-Step Chemical Mechanical Polishing of Sapphire Substrate

Zhang, Zefang; Liu, Weili; Zhang, Song; Hu, Xiaokai

doi:10.1149/1.3410116

Cited by 49 publications

(31 citation statements)

References 20 publications

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“…However, it might be difficult to meet these two requirements simultaneously using only one type of slurry in a single-step polishing process [49]. Therefore, in order to quickly remove the mechanically damaged layer and to realize satisfactory surface quality of AISI 52100 steel substrate, a two-step polishing process is proposed.…”

Section: Effectiveness Of the Cmp Slurriesmentioning

confidence: 99%

Chemical mechanical polishing of steel substrate using colloidal silica-based slurries

Jiang

Luo

2015

Applied Surface Science

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Section: Effectiveness Of the Cmp Slurriesmentioning

confidence: 99%

Chemical mechanical polishing of steel substrate using colloidal silica-based slurries

Jiang

Luo

2015

Applied Surface Science

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“…The sapphire removal rate (RR) was measured using the same method as reported by previous research. 5,6 The RR was the average of at least three polish runs of 10 min duration each. Fig.…”

Section: Methodsmentioning

confidence: 99%

The Effect of pH on Sapphire Chemical Mechanical Polishing

Yan

Zhang

Guo

et al. 2015

ECS J. Solid State Sci. Technol.

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In this paper, the effect of pH on sapphire chemical mechanical polishing (CMP) was investigated. The sapphire removal rate increased with ascending pH until 8. To investigate the electrostatic force between colloidal silica abrasive and sapphire surface, the zeta potential of sapphire surface and colloidal silica abrasive were studied. The sapphires immersed into the slurry containing 20 wt% colloidal silica were observed with scanning electron microscopy (SEM). For further insights into the mechanism of sapphire CMP with different pH values, particle size of the colloidal silica was used to analyze the mechanical function. Finally, the chemical actions between sapphire (Al 2 O 3 ) and colloidal silica (SiO 2 ) during sapphire CMP as a function of pH value were discussed.Sapphire, which is a single crystal form of α-alumina (corundum), is an important ceramic material widely used in a range of applications such as optics, electronics and temperature sensing. 1 In manufacturing light-emitting diode (LED), sapphire is widely applied as the substrate of gallium and indium nitride films. The development of LED technology leads to an exponential increase in device efficiency and light output over the past thirty years, which promotes the LEDs to become the light source of choice for virtually all applications. All of the applications request sapphire high removal rate, no damaged near-surface layer and surface defects and a low working surface roughness. To achieve these surface quality of sapphire, the chemical mechanical polishing (CMP) of sapphire plays a significant role.Some researchers have investigated sapphire CMP. Zhu et al. 1,2 used alumina slurry to polish sapphire (0001) wafers. It was admitted the fact of a coupling effect of the chemo-mechanical reaction between the sapphire and alumina accelerated the material removal. Silica slurries were mostly used as the ultimate polish run because they can produce the required surface quality. Liu et al. 3 provided the silica-based slurry containing a chelating agent to polish sapphire. The results showed that the removal rate was 9.96∼18 μm/h and the surface roughness was 0.1∼0.3 nm. Zhang and colleagues investigated the process parameters effect on sapphire CMP using silica-based slurry. Wang et al. 4 achieved a MRR of 5 μm/h (approximate 83.3 nm/min) but the surface quality was not mentioned. However, there is still a dearth of detailed research on the effect of pH on sapphire CMP.In this paper, we investigated the effect of pH on sapphire CMP using slurry only containing colloidal silica. The removal rate of sapphire reached maximum at pH 8 and the CMP mechanism of the sapphire at this pH was analyzed with mechanical abrasion of the abrasive abrasion and the chemical action of the chemical agent. The effect of pH on mean particle size of colloidal silica indicated that an increase of the mean particle size of colloidal silica contributed little to the sapphire removal rate. The chemical actions between sapphire and colloidal silica resulted in accelerating inc...

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“…7(b) indicates that 100 µm-thick substrates should be sufficient to enable received power levels at the waveguide output close to the -15 dBm target. Processes to either thin down to the required thickness [45,46] or completely remove [47,48] the sapphire substrate have been demonstrated. Alternatively, the use of advanced assembly methods such as transfer printing [16,49], can enable the placement of the µLEDs directly onto the waveguide facets producing an effective "zero" distance between the waveguide input and µLED source.…”

Section: A Butt-couplingmentioning

confidence: 99%

Ultra-Low Cost High-Density Two-Dimensional Visible-Light Optical Interconnects

Bamiedakis

McKendry

Xie

et al. 2019

J. Lightwave Technol.

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Visible light communications has attracted considerable interest in recent years owing to the ability of lowcost light emitting diodes (LEDs) to act both as illumination sources and data transmitters with moderate data transmission rates. In this article we propose the formation of ultra-low cost visible light integrated optical links by interfacing dense micropixelated LED arrays with matching multi-layered multimode polymer waveguide arrays. The combination of these two optical technologies can offer relatively high aggregate data densities ≥ 0.5 Tb/s/mm 2 using very low cost components that can be directly interfaced with CMOS electronics and integrated onto standard PCBs. Here, we present the basic system design and report the first proof-of-principle demonstration of such a visible light system employing 4×4 µLED arrays on a pitch matching fourlayered waveguide array samples. Different interconnection topologies and light coupling schemes are investigated and their performance in terms of loss and crosstalk is compared. Data transmission of 2.5 Gb/s with a BER within the forward-error correction threshold of 3.8×10 -3 is achieved over a single µLEDwaveguide channel using PAM-4 modulation and equalization. The results presented here demonstrate the potential of such ultra-low cost visible light optical interconnects.

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Two-Step Chemical Mechanical Polishing of Sapphire Substrate

Cited by 49 publications

References 20 publications

Chemical mechanical polishing of steel substrate using colloidal silica-based slurries

Chemical mechanical polishing of steel substrate using colloidal silica-based slurries

The Effect of pH on Sapphire Chemical Mechanical Polishing

Ultra-Low Cost High-Density Two-Dimensional Visible-Light Optical Interconnects

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