Maskless Laser Etching of Alumina and Ceramic Substrates

1990 ◽  
Vol 201 ◽  
Author(s):  
Jamal Khan
Keyword(s):  
Laser Emission ◽  
Removal Rate ◽  
Computer Software ◽  
Substrate Material ◽  
Device Fabrication ◽  
Ceramic Substrates ◽  
Potential Applications ◽  
Laser Systems ◽  
Scan Speed ◽  
Maskless Patterning

AbstractMaskless patterning of alumina (A12O3) films of various thicknesses and ceramic (TiC-Al2O3) substrate material was accomplished by using pulsed excimer and Nd:YAG laser systems. Etched structure size was defined through the computer software which also controls the workpiece position and laser operating parameters. Etch profile, materials removal rate and surface roughness was found to be dependent on laser emission wavelength, fluence, pulse rate and relative scan speed. Smoother etching was obtained with the excimer lasers. The etch characteristics are compared with those of the polymeric and metallic materials. Various potential applications of this laser based etching process in microelectronic and micromagnetic device fabrication are identified.

Advanced Si-based Semiconductors for Energy and Photonic Applications

2009 ◽  
Vol 156-158 ◽  
pp. 77-84 ◽  
Author(s):  
J. Kouvetakis ◽  
Jose Menendez ◽  
John Tolle
Keyword(s):  
Precursor Chemistry ◽  
Group Iv ◽  
Device Fabrication ◽  
Interface Microstructure ◽  
Si Substrates ◽  
Group Iv Semiconductors ◽  
Dislocation Densities ◽  
Potential Applications ◽  
Molecular Mixtures ◽  
Lattice Matched

Group-IV semiconductors, including alloys incorporating Sn, have been grown on dimensionally dissimilar Si substrates using novel molecular hydride chemistries with tunable reactivities that enable low temperature, CMOS compatible integration via engineering of the interface microstructure. Here we focus on properties of three such Ge-based systems including: (1) device quality Ge layers with thicknesses >5m possessing dislocation densities <105/cm2 are formed using molecular mixtures of Ge2H6 and highly reactive (GeH3)2CH2 organometallic additives circumventing the classical Stranski-Krastanov growth mechanism, (2) metastable GeSn alloys are grown on Si via reactions of Ge2H6 and SnD4, and (3) ternary SiGeSn analogs are produced lattice-matched to Ge-buffered Si using admixtures of SiGeH6, SiGe2H8, SnD4, Ge2H6, and Si3H8. Optical experiments and prototype device fabrication demonstrate that the ternary SiGeSn system represents the first group-IV alloy with a tunable electronic structure at fixed lattice constant, effectively decoupling band gap and strain and eliminating the most important limitation in device designs based on group-IV materials. Doping at levels higher than 1019 cm-3 (both p and n-type) is achieved for all the above semiconductor systems using a similar precursor chemistry approach. Electrical and infrared optical experiments demonstrate that doped GeSn and SiGeSn have mobilities that compare or exceed that of bulk Ge. The potential applications of these materials, including micro- and optoelectronics as well as photovoltaics and thermoelectricity, are discussed.

Characterisation of the Femtosecond Laser Micro-Grooving Process for Germanium Substrates

2016 ◽  
Vol 874 ◽  
pp. 291-296 ◽  
Author(s):  
Lin Li ◽  
Jun Wang ◽  
Huai Zhong Li
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Material Removal ◽  
Removal Rate ◽  
High Quality ◽  
Scan Speed ◽  
Micro Grooving ◽  
Fs Laser ◽  
Selection Of ◽  
Germanium Substrates

An experimental study is reported to characterise the femtosecond (FS) laser grooving process for Germanium (Ge) substrates. The effects of process parameters, including laser fluence, pulse repetition rate and scan speed, on the groove characteristics, material removal rate (MRR) and heat affected zone (HAZ) size are discussed. It is shown that with properly selected process parameters, high quality micro-grooves can be obtained on Ge wafers. Recommendations are finally made on the selection of the most appropriate process parameters for FS micro-grooving of Ge substrates.

Mapping of Process-Induced Dopant Redistributions by Electron Holography

2004 ◽  
Vol 10 (4) ◽  
pp. 462-469 ◽  
Author(s):  
Wolf-Dieter Rau ◽  
Alexander Orchowski
Keyword(s):  
Semiconductor Device ◽  
Device Fabrication ◽  
Electron Holography ◽  
Dopant Diffusion ◽  
Fundamental Parameters ◽  
Device Processing ◽  
Device Structures ◽  
Before And After ◽  
Potential Applications ◽  
Junction Potential

We present and review dopant mapping examples in semiconductor device structures by electron holography and outline their potential applications for experimental investigation of two-dimensional (2D) dopant diffusion on the nanometer scale. We address the technical challenges of the method when applied to transistor structures with respect to quantification of the results in terms of the 2Dp–njunction potential and critically review experimental boundary conditions, accuracy, and potential pitfalls. By obtaining maps of the inner electrostatic potential before and after anneals typically used in device processing, we demonstrate how the “vertical” and “lateral” redistribution of boron during device fabrication can directly be revealed. Such data can be compared with the results of process simulation to extract the fundamental parameters for dopant diffusion in complex device structures.

scholarly journals Spectral Modulation of Optofluidic Coupled-Microdisk Lasers in Aqueous Media

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1439 ◽  
Author(s):  
Zhihe Guo ◽  
Haotian Wang ◽  
Chenming Zhao ◽  
Lin Chen ◽  
Sheng Liu ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Microfluidic Channel ◽  
Single Mode ◽  
Pump Light ◽  
Laser Spectrum ◽  
Spectral Modulation ◽  
Microcavity Laser ◽  
Potential Applications ◽  
Laser Systems ◽  
Doped Polymer

We present the spectral modulation of an optofluidic microdisk device and investigate the mechanism and characteristics of the microdisk laser in aqueous media. The optofluidic microdisk device combines a solid-state dye-doped polymer microdisk with a microfluidic channel device, whose optical field can interact with the aqueous media. Interesting phenomena, such as mode splitting and single-mode lasing in the laser spectrum, can be observed in two coupled microdisks under the pump laser. We modulated the spectra by changing the gap of the two coupled microdisks, the refractive indices of the aqueous media, and the position of a pump light, namely, selective pumping schemes. This optofluidic microlaser provides a method to modulate the laser spectra precisely and flexibly, which will help to further understand spectral properties of coupled microcavity laser systems and develop potential applications in photobiology and photomedicine.

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 ◽  
...  
Keyword(s):  
Material Removal Rate ◽  
Material Properties ◽  
Chemical Mechanical Polishing ◽  
Crystal Orientation ◽  
Material Removal ◽  
Removal Rate ◽  
Substrate Material ◽  
Mechanical Polishing ◽  
Sapphire Crystal ◽  
Research Objects

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.

scholarly journals On Electrical Discharge Machining of Non-Conductive Ceramics: A Review

Technologies ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 55 ◽  
Author(s):  
Marina Volosova ◽  
Anna Okunkova ◽  
Pavel Peretyagin ◽  
Yury A. Melnik ◽  
Natalya Kapustina
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Secondary Phase ◽  
Scientific Revolutions ◽  
Relevant Today ◽  
Potential Applications ◽  
Conductive Ceramics ◽  
3D Printed ◽  
Full Shift

The inability of ceramic and nanoceramic processing without expensive diamond tools and with a high-material-removal rate hampers the scope of its potential applications and does not allow humanity to make a full shift to the sixth technological paradigm associated with Kuhn scientific revolutions and Kondratieff’s waves and restrains the growth of the economy. The authors completed a review on the research state of ceramic and nanoceramic processing by electrical discharge machining, which is possibly solved by two principal approaches associated with the usage of standard commercially available machine tools. The first approach is related to the introduction of expensive secondary phase; the second approach proposes initiate processing by adding auxiliary electrodes in the form of coating, suspension, aerosol, or 3D-printed layer based on the components of silver, copper, or graphite in combination with an improved dielectric oil environment by introducing graphite or carbon nanoparticles, which is hugely relevant today.

Recent Progress of Electro-optic Polymers for Device Applications

1997 ◽  
Vol 488 ◽  
Author(s):  
Alex K-Y. Jen ◽  
Qing Yang ◽  
Seth R. Marder ◽  
Larry R. Dalton ◽  
Ching-Fong Shu
Keyword(s):  
Data Storage ◽  
High Speed ◽  
Stable State ◽  
Optical Data Storage ◽  
Device Fabrication ◽  
Optical Data ◽  
Material System ◽  
Electro Optic ◽  
Potential Applications ◽  
Device Applications

AbstractElectro-optic (E-O) polymers have drawn great interest in recent years because of their potential applications in photonics devices such as high speed modulators and switches, optical data storage and information processing1–2. In order to have suitable materials for device fabrication, it is essential to design and develop polymeric material systems (active and passive polymers) with matched refractive indices, large E-O coefficients, good temporal and photochemical stability3–8 The E-O response of an active polymer commonly arises from the electric field induced alignment of its second-order nonlinear optical (NLO) chromophore, either doped as a guest/host system or covalently bonded as a side-chain. Because of the strong interaction among the electric dipoles, the poled structure is in a meta-stable state; the poled NLO chromophores which possess large dipole moment will tend to relax back to the randomly oriented state. As a result, the stability of the poled structure strongly depends on the rigidity of the overall material system. As it might be expected, the continuous increases of the rigidity and Tg of poled polymers imposes constraints on the selection of suitable chromophores that can survive the hightemperature poling and processing conditions. To circumvent this problem, we have developed a series of chromophores that possess conformation-locked geometry and perfluoro-dicyanovinylsubstituted electron-accepting group which demonstrate both good thermal stabilty and nonlinearity. This paper provides a brief review of these highly efficient and thermally stable chromophores and polymers for device applications.

Ion Induced Mixing of AlGaAs/GaAs Superlattices

1987 ◽  
Vol 93 ◽  
Author(s):  
T. Venkatesan ◽  
S. A. Schwarz ◽  
P. Mei ◽  
H. W. Yoon
Keyword(s):  
Thermal Stability ◽  
Process Parameters ◽  
Alloy Composition ◽  
Device Fabrication ◽  
Crystalline Quality ◽  
Good Crystalline Quality ◽  
Potential Applications ◽  
Mixed Layers ◽  
High Degree ◽  
Thermal Stability Of

ABSTRACTSubsequent to the implantation of certain ions, the thermal stability of AlGaAs/GaAs superlattices can be reduced, enabling mixing of the layers at temperatures where they would otherwise be stable. The mixed layers have intermediate alloy composition and are of good crystalline quality. As a result this process is of great value in device fabrication where a high degree of vertical and lateral bandgap control is desirable. This paper reviews our work in understanding the mechanism of diffusion, its dependence on varilous process parameters, and potential applications in device fabrication.

Analysis of Substrates for Single Emitter Laser Diodes

2003 ◽  
Vol 125 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Tapani M. Alander ◽  
Pekka A. Heino ◽  
Eero O. Ristolainen
Keyword(s):  
Thermal Performance ◽  
System Integration ◽  
Large Scale ◽  
Mechanical Performance ◽  
Laser Diodes ◽  
Substrate Material ◽  
Ceramic Substrates ◽  
Large Scale Integration ◽  
Semiconductor Laser Diodes ◽  
Scale Integration

Electrically conductive substrates (i.e., metals) are often used in the mounting of semiconductor laser diodes. While metals offer a good electrical and thermal performance, they restrict the system integration due to lack of signal routing capability. Since the implementations utilizing laser diodes have become more common, the integration level has also become an important factor in these products. Mounting of lasers on insulative substrates is the key to large-scale integration. Organic boards form the de facto standard of insulative substrates; however, their use with lasers is impossible due to low thermal conductivity. Ceramics, however, offer nearly the same thermal performance as metals but as electrically insulative materials also provide the foundation for high integration levels. In this study the effects of three different ceramic substrates on the stresses within diode lasers was evaluated. Finite element method was used to calculate the mounting induced straining and the thermal performance of the substrate. The same procedure was employed to examine the optimum metallization thickness for the ceramic substrates. The results present how greatly the substrate material can affect the very delicate laser diode. The ceramic substrates, though having nearly the same properties, exhibited clearly distinctive behavior and a great difference in thermal and mechanical performance.

scholarly journals Mesoporous bimetallic Fe/Co as highly active heterogeneous Fenton catalyst for the degradation of tetracycline hydrochlorides

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Junchao Li ◽  
Xuhua Li ◽  
Jindong Han ◽  
Fansheng Meng ◽  
Jinyuan Jiang ◽  
...  
Keyword(s):  
Bimetallic Catalyst ◽  
Removal Rate ◽  
Catalytic Efficiency ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Operating Parameters ◽  
Co Catalyst ◽  
Highly Active ◽  
Fenton Catalyst ◽  
Potential Applications

Abstract Mesoporous bimetallic Fe/Co was prepared as a Fenton-like catalyst to degrade the tetracycline hydrochlorides (TC). The nanocasting strategy with KIT-6 as a hard template was carried out to synthesize the mesoporous bimetallic catalyst. The mesoporous bimetallic Fe/Co catalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms, and Brunauer-Emmett-Teller (BET) method. The results showed that the catalyst has significant nanofeatures; the surface area, pore size, and particle size were 113.8 m2g−1, 4 nm, and 10 nm, respectively. In addition, the effects of the operating parameters, such as the iron-to-cobalt ratio, pH, H2O2, and initial TC concentrations on its catalytic performance were investigated. The best operating parameters were as follows: iron-to-cobalt ratio = 2:1 to 1:1, pH = 5–9, H2O2: 30 mmol, initial TC less than 30 mg/L. Furthermore, the mesoporous bimetallic Fe/Co showed a good performance for degrading TC, achieving a removal rate of 86% of TC after 3 h under the reaction conditions of H2O2 = 30 mmol, mesoporous bimetallic Fe/Co = 0.6 g/L, TC = 30 mg/L, pH = 7.0, and temperature = 25.5 °C. The mesoporous bimetallic Fe/Co catalyst shows good stability and reusability. This work demonstrated that mesoporous bimetallic Fe/Co has excellent catalytic efficiency, smaller amounts of leached ions, and wider pH range, which enhance its potential applications.

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