Yung-Chun Weng

Fabricating Nanostructures by Atomic Force Microscopy

In this study, we used a conductive Atomic Force Microscopy (AFM) probe to fabricate nanostructures and nanopatterns on a silicon chip using nano-oxidation technology. The height of grown oxidized nanodots tends to increase as the piezoelectric loading in nano-oxidation increases, while the number of oxidized nanodots affects the height of oxidation. In terms of patterning, the height and width of nanodots tend to decrease as the probe scanning speed increases. Moreover, in this study, we used nano-oxidation to perform complex nanopatterning, and found that complex and well-defined nanopatterns could be fabricated on a scale of 1000 ×1000 nm2. The technology proposed in this study can directly define nanostructures without limitations of the wavelength of the light source and light diffraction. The technology has the advantages of low cost and great potential for development.

Development and Study of Applications Combining Nanopowder Imprint Lithography and Array-Type UV-Curing Technology for Micro-Lens Molding

This study developed creative imprinting technology, combining nano-imprint lithography and array-type UV-curing technology. It used nanopowders as the method to transmit imprint force, and integrated technical features, such as soft lithography, light-curing resistant and gas-assisted imprint technology, in order to study the development of technological processes of micro-lens array manufacturing, and mature the application and technology of nano-imprinting. According to research results, SUS 304 stainless steel sheet with a micro-hole array could be smoothly fabricated into an original micro-lens array mold upon gas-assisted micro-hot embossing. At the same time, a micro-lens array structure with a complementary external form could be precisely remolded and reproduced by PDMS. Complete molding of micro-lens could be effectively achieved by combining imprints of gas-assisted lithography developed in this study, and even UV-NIL. The effective imprinting area and reproducibility of transfer printing could be greatly improved when a micro-lens contacts perfectly with a substrate surface. Moreover, since PDMS soft molds have short remolding times, and are easily feathered during manufacturing, production costs could be effectively reduced through features such as, low surface free energy, resistant to adhering to the mold during imprinting, and collocation of gas-assisted nanopowder imprinting of micro-structural processes.

Electromagnetic Field-Aided Magnetic Soft Mold Reverse Imprinting Technology Applied in Microstructure Replication

This paper proposes an advanced microstructure embossing replication technology that combines an electromagnetic-field-aided magnetic soft mold and a reverse imprinting technology to replicate microstructure. The main advantage of this technology is low pressure, low cost, and quick and easy forming. The entire imprinting process can be completed at room temperature using a ultraviolet (UV) curing technique. This study applied a compound casting technique to fabricate a magnetic poly(dimethylsiloxane) (PDMS) soft mold, with an electromagnetic chuck for even imprinting pressure, and reverse imprinting molding technology. Microstructure cavity of the mold was fully filled with photoresist before imprint replication, and improved microstructure transfer ratio. Examination of the results showed that, the magnetic PDMS soft mold integrated electromagnetic-field-aided reverse imprinting process developed by this study, can successfully replicate microstructure at room temperature, low pressure, and avoid deformation and residual stress problems due to heating and cooling.

Development of Nanoparticle Fluid Imprinting Technology in Microstructure Manufacture

In this study, we look into an innovative technology that utilizes nanoparticles as a medium for imprinting. This technology integrates the advantages of soft lithography, photo-cure resist, and gas assisted imprinting. We try to produce ridge waveguides and microlens arrays by gas-assisted nanoparticle-based soft mould imprinting on photo-cure resists. It helps the application and technology of nano-imprinting becoming more sophisticated. We find that PDMS can be used to precisely replicate micro-to-nanometer level microstructures. Together with nanoparticles and well-proportioned gas pressure, we can construct a perfect shape of microstructures and achieve a conformal contact with the surface of base material. It increases the effective imprinting area significantly and improves the replication capability of the transfer. Meanwhile, the PDMS soft mould is easy for production and fast in replication, which reduces the cost remarkably. Furthermore, it has a low surface free energy and low viscosity to the resists. Integrating gas-assisted nanoparticle imprinting can be a great advantage in the process of microstructure.

Fabrication of Optical Waveguide Devices Using Electromagnetic Assisted Nanoimprinting

A creative technology was used in this research. Using the PDMS flexible mold magnetic powder method to transmit imprinting, and by combining the special characteristics of the soft lithography, polymethylmethacrylate (PMMA), and electromagnetic Plate uniform control pressing technology, researching the use of magnetic flexible mold imprinting technology to produce the optical waveguide devices, so as to allow the usage and the technology of micro hot embossing or nanoimprinting more mature.

A Novel Magnetic Nickel Mold Combined Nano-Particle Fluid Electromagnetism Imprinting on Replicating Microstructures

This study proposes a novel technology using nano-particle fluid electromagnetism to control the direct hot imprint resist of nickel mold. combining the present gas-assisted nanoparticle hot imprint molding technology, electroforming technology, and self-designed heatable electromagnetic plate for even control and progressive pressuring technology, this study used electromagnetic nickel mold direct hot imprint to replicate micro structures, in order to make the molding technology and application of micro nanoimprint more mature. This study first used gas-assisted nanoparticle hot embossing method to replicate structures of microlens of original silicon molds on PC, so as to obtain complementary structural patterns. This PC film with structures of microlens is cast into nickel molds by electroforming. This nickel mold was used as the mold for magnetic embossing to imprint hot plastic PMMA.The result showed that through gas-assisted nanoparticle hot embossing molding, casting and component magnetic PDMS soft mold casting, molds of high costs and complicated production process can be massively replicated, and the replication precision is good. Hot gas embossing PDMS film and the surface of base materials can achieve even pressure and conformal contact, thus significantly improving the effective imprint area and imprintability. Through electroforming, casting duration of magnetic nickel molds can be shortened and costs can be effectively lowered. Moreover, electromagnetic plate was used to evenly control the direct hot pressure imprint resist, which is an advantage of the production process of micro structures.

Fabrication of Ridge Waveguide Microstructure Using Vacuum-assisted Micromolding Technology

Limited by light source wavelength and light diffraction, nanostructure fabrication is tough, but it needs multiple special and expensive processes (e.g.: E-beam). The common problems are complex and slow processing, expensive manufacturing equipment and material, and it is very unsuitable for mass production; therefore, it’s of utmost importance to develop a nanoscale, high resolution and cost efficient next generation semiconductor process. This study integrated PDMS soft mold, photo resist(SU-8 2035) and vacuum pumping equipment, as well as researched and developed a vacuum-assisted photo resistant microstructure filling technique, and combined soft mold to fabricate waveguide microstructure. Conformal contact was obtained between PDMS soft mold and substrate surface, with low surface free energy, and resistance of sticking to resist in filling.Vacuum equipment was used to enable compact and complete resistant filling, and it can not only greatly increase the effective filling area, but, without residue after filling. There is no need for post treatment removing of the residual layer; it can well lower cost and reduce process time, so that the microstructure component manufacturing technique and application can be more mature.

Fabrication of Microlens Arrays by Using Nano-Particle Fluid Imprinting Technology

In this study, we look into an innovative technology which utilizes nano-particles as a medium for imprinting. This technology integrates the advantages of soft lithography, photo-cure resist, and gas assisted imprinting. We try to produce micro-lens arrays by gas-assisted nano-particles based soft mould imprinting on photo-cure resists. It helps the application and technology of nano-imprinting becoming more sophisticated. We find that PDMS can be used to precisely replicate micro-to-nano-meter level micro-structures. Together with nano-particles and well-proportioned gas pressure, we can construct a perfect shape of micro-structures and achieve a conformal contact with the surface of base material. It increases the effective imprinting area significantly and improves the replication capability of the transfer. Meanwhile, the PDMS soft mould is easy for production and fast in replication, which reduces the cost remarkably. Furthermore, it has a low surface free energy and low viscosity to the resists. Integrating gas assisted nano-particles imprinting can be a great advantage in the process of micro-structure.

Automatic Positioning Device Design for the Operation Platform of Nano-indentation

In this paper, we try to measure the differences among the indentations of single crystal bulks under different rotation angles by nanoindentation test. Besides, we also give a design of positioning device for the nanoindentation measuring system. It is driven by stepping motors and relevant circuits for controlling the rotations of the wafer supporting platform. The drive circuit is connected with microprocessors. The rotation angle of the platform can be adjusted by instructions so that the system can be used to carry out nanoindentation tests in different angles for more precise mechanical properties data of the nanoindentation materials.

Gas-Assisted Nanoparticle Fluid Magnetic Imprinting Technology in Micro-Lens Manufacture and the Application of Projection Lithography

Traditionally, making light-blocking micro-lens arrays requires not only precise positioning, but also a lot of time and cost. In this study, we try to utilize some innovative technologies. New molds are based on stainless steel plates penetrated by micro-aperture arrays. Together with gas-assisted nanoparticle fluid magnetic imprinting technology, a semi-sphere lens can be shaped by utilizing the properties of surface tension of the plastic film. It can be used to produce the plastic micro-lens array that is capable of light-blocking directly as projection lens. Using optical diffusion film, Fresnel lens, and single mask in centimeter level, we can construct a projection lithography system with micro-lens array. This brand new process technology simplifies the manufacture of micro-lens array with light-blocking capability to just one step. It cuts required time significantly and reduces the cost and pollution remarkably. Finally, we successfully generated some micrometer level pattern arrays on the photoresist layer through the exposal and developing process of this micro-lens array based projection lithography system.