Optimization on Conventional Photolithography Process of 0.98 μm Gap Design for Micro Gap Biosensor Application

2015 ◽  
Vol 754-755 ◽  
pp. 524-529
Author(s):  
M. Zaki ◽  
Uda Hashim ◽  
Mohd Khairuddin Md Arshad ◽  
M. Nurfaiz ◽  
M.F.M. Fathil ◽  
...  
Keyword(s):  
Silicon Oxide ◽  
Uv Light ◽  
Poor Performance ◽  
Pattern Design ◽  
Wafer Substrate ◽  
Biosensor Application ◽  
Conventional Photolithography ◽  
Post Exposure Bake ◽  
Photolithography Process ◽  
Exact Design

.Pattern design transfer is the most crucial step in fabrication. Even a small mistake in fabrication can result in device damage or poor performance. To ensure the device performs perfectly, exact design and dimension pattern should be perfectly transferred onto wafer substrate. In this paper, optimization of conventional photolithography process of 0.98μm gap design for micro gap biosensor application is presented. The micro gap pattern on chrome mask is used and the effect of coating profile, UV light, and Post Exposure Bake (PEB) process are investigated. The conventional photolithography process (using a micro gap mask) starts after the silicon oxide, polysilicon and aluminium have been deposited on top of the substrate. Each set of experiment conducted by pairing the element investigated coating profile, UV light, and PEB, with the normal specification of photolithography process. It was observed that 0.98μm gap size can be achieved by choosing suitable process parameters i.e. thickness of coating profile, time and temperature used for UV light and PEB.

scholarly journals Area-Selective ZnO Thin Film Deposition on Variable Microgap Electrodes and Their Impact on UV Sensing

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Q. Humayun ◽  
M. Kashif ◽  
U. Hashim
Keyword(s):  
Thin Films ◽  
Uv Light ◽  
Sol Gel ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Dynamic Responses ◽  
X Ray Diffraction ◽  
Current Voltage ◽  
Conventional Photolithography ◽  
Photolithography Process

ZnO thin films were deposited on patterned gold electrodes using the sol-gel spin coating technique. Conventional photolithography process was used to obtain the variable microgaps of 30 and 43 μm in butterfly topology by using zero-gap chrome mask. The structural, morphological, and electrical properties of the deposited thin films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and Keithley SourceMeter, respectively. The current-voltage (I-V) characterization was performed to investigate the effect of UV light on the fabricated devices. The ZnO fabricated sensors showed a photo to dark current (Iph/Id) ratios of 6.26 for 30 μm and 5.28 for 43 μm gap electrodes spacing, respectively. Dynamic responses of both fabricated sensors were observed till 1V with good reproducibility. At the applied voltage of 1 V, the response time was observed to be 4.817 s and 3.704 s while the recovery time was observed to be 0.3738 s and 0.2891 s for 30 and 43 μm gaps, respectively. The signal detection at low operating voltages suggested that the fabricated sensors could be used for miniaturized devices with low power consumption.

scholarly journals Formation of MgO:LiNbO3 Domain-Inverted Gratings by Voltage Application under UV Light Irradiation at Room Temperature

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Masatoshi Fujimura ◽  
Toshiaki Suhara
Keyword(s):  
Nonlinear Optic ◽  
Room Temperature ◽  
Uv Light ◽  
Lateral Expansion ◽  
Cladding Layer ◽  
Uv Light Irradiation ◽  
Voltage Application ◽  
Formation Method ◽  
Domain Inversion ◽  
Photolithography Process

MgO:LiNbO3 is an attractive nonlinear-optic crystal for quasiphasematched (QPM) nonlinear-optic devices. This paper reports a new formation method of domain-inverted gratings for QPM in MgO:LiNbO3. Domain inversion of MgO:LiNbO3 by voltage application under UV light was characterized, and reduction of the voltage required for inversion was demonstrated. Results of voltage application under periodic UV light suggested that suppression of excess lateral expansion of the domain inverted regions on −Z surface was crucial for domain-inverted grating formation. Voltage application to a crystal with a photoconductive cladding layer under periodic UV light was proposed. The cladding layer suppressed the expansion, and the domain-inverted gratings with period of 18 μm and area of 25×5 mm2 were obtained. The formation method does not require the photolithography process and allows the formation by voltage application at room temperature, and therefore, is quite simple and productive.

Chrome Mask Design for Microfluidic Fabrication

2013 ◽  
Vol 795 ◽  
pp. 276-280 ◽  
Author(s):  
Veeradasan Perumal ◽  
U. Hashim
Keyword(s):  
Device Fabrication ◽  
Wafer Surface ◽  
Master Mold ◽  
Major Step ◽  
Mask Design ◽  
Alignment Mark ◽  
Conventional Photolithography ◽  
Photolithography Process ◽  
Resolution Requirements ◽  
Chrome Mask

This paper presents a simple and effective method to design chrome mask for microfludic fabrication. Microfluidic fabrication involves 9 major step and mainly depends on the master mold template formation by SU-8 photoresists using conventional photolithography process The chrome mask was design using AutoCAD software. Essentially, mask is a crucial element in a microfluidic fabrication in which resolution requirements and precise alignment are vital, each mask needs to be precisely aligned with original alignment mark. Otherwise, it cant successfully transfer the original pattern to the wafer surface causing microchannel formation failure. Thus, the initial design is compared with the fabricated chrome mask to achieved a better result during device fabrication.

Characterization of MEMS Materials Using Laser Micromachine

2015 ◽  
Vol 754-755 ◽  
pp. 612-616
Author(s):  
Shazlina Johari ◽  
Mazlee Mazalan ◽  
Yuvahraj Sridaran ◽  
Siti Rohaida Ahmad
Keyword(s):  
Laser Pulse ◽  
Pulse Rate ◽  
Laser Energy ◽  
Laser Micromachining ◽  
Operational Parameters ◽  
Conventional Photolithography ◽  
Energy Laser ◽  
Photolithography Process ◽  
Microfluidic Structure

Laser micromachining technique was used in this work to produce two different microfluidic structure on three MEMS materials namely silicon, SU-8 photoresist and polydimethylsiloxane (PDMS). The operational parameters of the machine ablation effects on the materials, which are the laser energy, laser pulse rate and the laser size were also investigated. We found that this technique is capable to produce typical MEMS structure similar as being produced using conventional photolithography process.

Observation of Paramagnetic Silicon Dangling Orbitals in Luminescent Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
F. C. Rong ◽  
E. H. Poindexter ◽  
J. F. Harvey ◽  
D. C. Morton ◽  
R. A. Lux ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Silicon Oxide ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Skeletal Structure ◽  
Planar Surface ◽  
Paramagnetic Resonance ◽  
Wafer Substrate ◽  
Electron Paramagnetic ◽  
Annealing Experiments

ABSTRACTWe have detected two dominant paramagnetic centers in porous silicon by electron paramagnetic resonance (EPR). One of them is isotropic, assigned to a defect in amorphous silicon oxide in the porous silicon layer. The other is anisotropic, and is very much like a Pb center at a planar Si/SiO2 interface. This EPR center is unambiguously identified as an •Si≡Si3 moiety, a silicon with dangling orbital, back-bonded to three silicon atoms, by 29 Si hyperfine structure (HFS) associated with the dangling orbital, and 29 Si superHFS from three neighboring silicon atoms, as similarly observed in the usual planar surface Pb structure. The dangling orbitals are highly localized and heavily p character. The disposition of dangling orbitals is evidence that the skeletal structure of luminescent porous silicon is crystalline and has a lattice which is aligned and continuous with the wafer substrate. The possibility that these centers are the major photoluminescent killers or quenchers is not supported by our hydrogen annealing experiments.

scholarly journals Skin-Compatible Amorphous Oxide Thin-Film-Transistors with a Stress-Released Elastic Architecture

2021 ◽  
Vol 11 (12) ◽  
pp. 5501
Author(s):  
Kyung-Tae Kim ◽  
Seung-Han Kang ◽  
Seung-Ji Nam ◽  
Chan-Yong Park ◽  
Jeong-Wan Jo ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Oxide Thin Film ◽  
Indium Gallium Zinc Oxide ◽  
Large Area ◽  
Element Analysis ◽  
Conventional Photolithography ◽  
Drain Bias ◽  
Fea Simulation ◽  
Photolithography Process

A highly reliable reverse-trapezoid-structured polydimethylsiloxane (PDMS) is demonstrated to achieve mechanically enhanced amorphous indium-gallium-zinc oxide (a-IGZO) thin-film-transistors (TFTs) for skin-compatible electronics. Finite element analysis (FEA) simulation reveals that the stress within a-IGZO TFTs can be efficiently reduced compared to conventional substrates. Based on the results, a conventional photolithography process was employed to implement the reverse-trapezoid homogeneous structures using a negative photoresist (NPR). Simply accessible photolithography using NPR enabled high-resolution patterning and thus large-area scalable device architectures could be obtained. The a-IGZO TFTs on the reverse-trapezoid-structured PDMS exhibited a maximum saturation mobility of 6.06 cm2V−1s−1 under a drain bias voltage of 10 V with minimal strain stress. As a result, the proposed a-IGZO TFTs, including stress-released architecture, exhibited highly enhanced mechanical properties, showing saturation mobility variation within 12% under a strain of 15%, whereas conventional planar a-IGZO TFTs on PDMS showed mobility variation over 10% even under a 1% strain and failed to operate beyond a 2% strain.

A UV Direct-Write Approach for Formation of Embedded Structures in Photostructurable Glass-Ceramics

2000 ◽  
Vol 624 ◽  
Author(s):  
P.D. Fuqua ◽  
D.P. Taylor ◽  
H. Helvajian ◽  
W.W. Hansen ◽  
M.H. Abraham
Keyword(s):  
Uv Light ◽  
Glass Ceramics ◽  
Laser Exposure ◽  
Direct Write ◽  
Mems Devices ◽  
Embedded Structures ◽  
Trade Offs ◽  
Conventional Photolithography ◽  
Materials Used ◽  
Photostructurable Glass

ABSTRACTPhotostructurable glass-ceramics are a promising class of materials for MEMS devices. Previous work micromachining these materials used conventional photolithography equipment and masking techniques; however, we use direct-write CAM tools and a pulsed UV laser micromachining station for rapid prototyping and enhanced depth control. We have already used this class of materials to build components for MEMS thrusters, including fuel tanks and nozzles: structures that would prove difficult to build by standard microfabrication techniques.A series of experiments was performed to characterize process parameters and establish the processing trade-offs in the laser exposure step. The hypothesis that there exists a critical dose of UV light for the growth of an etchable crystalline phase was tested by exposing the material to a fluence gradient for a variety of pulse train lengths, and then processing as usual. By measuring the dimensions of the etched region, we were able to determine the dose. We found that the dose is proportional to the square of the per-pulse fluence. This has allowed us to create not only embedded structures, but also stacked embedded structures. This also implies that we can embed tubes and tunnels with a single exposure inside a monolithic glass sample. We feel that this technique has promise for a number of applications, including microfluidics.

Processing and Applications of "Oxide Nanoskin"

2006 ◽  
Vol 45 ◽  
pp. 660-667
Author(s):  
Atsushi Hozumi
Keyword(s):  
Growth Rate ◽  
Vacuum Ultraviolet ◽  
Silicon Oxide ◽  
Uv Light ◽  
Surface Acidity ◽  
Native Oxide ◽  
Self Assembled Monolayer ◽  
Polymer Substrates ◽  
Si Substrates ◽  
Pattern Resolution

A novel photochemical approach is presented to fabricate a silicon oxide (SiOx) layer, which we have named an “oxide nanoskin” (ONS), whose thickness is defined in the molecular-order of 1~3 nm. Through the chemisorption of a vapor phase organosilane and subsequent photooxidation using 172 nm vacuum ultraviolet (UV) light, an extremely flat SiOx layer without cracks or aggregates was formed on various polymer substrates. Owing to this ONS coating, the charge density and surface acidity of the polymer substrates became almost equal to those of a native oxide-covered Si (SiOx/Si) substrate. In addition, there was marked improvement in the durability of the hydrophilicity and in the micro-wear resistance of the polymer surfaces. Moreover, organosilane self-assembled monolayer (SAM) chemistry currently available for the treatment of inorganic glass and Si substrates could be similarly utilized. Well-ordered SAMs with a wide variety of terminal-end groups (e.g., trifluorocarbon or amino groups) could be fabricated even on inert polymer substrates, in a manner similar to their fabrication on SiOx/Si substrates. Furthermore, we demonstrated the site-selective deposition of metal oxide and metal films on polymer substrates using photolithographically micropatterned SAMs as microtemplates. Well-shaped microstructures were achieved only on the polymer substrates with the ONS layer. On the substrates without the ONS layer, pattern resolution degraded significantly and growth rate decreased, since both depended greatly on the SAM density and quality. Our ONS was very useful not only in forming highly ordered SAMs on the polymer substrates, but also in obtaining excellent pattern resolution, sufficient growth rate, and adhesion of the target materials.

Investigate the Reliable and Accurate Pattern Transfer of IDE Silver Electrode Coated with Zinc Oxide Microwire for Biosensor Application

2014 ◽  
Vol 925 ◽  
pp. 529-532
Author(s):  
R. Haarindra Prasad ◽  
Kai Long Foo ◽  
U. Hashim
Keyword(s):  
Zinc Oxide ◽  
Electronic Device ◽  
Uv Light ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Pattern Transfer ◽  
Zno Films ◽  
Oxide Material ◽  
Chemical Route ◽  
Biosensor Application

This paper illustrate a facile route to fabricate and develop zinc oxide microwire which acts as transducer for biosensor application. Pattern transfer process is conducted on the wafer substrate by using conventional photolithography process to form IDE electrode. The substrate is coated with positive photo-resist (PR) and exposed for UV light for 10 seconds. After development, the unexposed area is etched by using hydrochloric acid, HCI. In this study, zinc oxide material have become a remarkable choice for bio-sensing development due to large band gap and tailor for bio-molecular application. Zinc oxide solution was prepared through chemical route, that is by using sol-gel method. The coated ZnO films were annealed in furnace at 500°C for 2 hours. ZnO seed solution undergoes hydrothermal growth to synthesize ZnO microwires. ithThe substrate used for this study is p-type silicon wafer which is oxidized. SiO2 layer is used because it acts as an insulator which is very essential for an electronic device to avoid electrical leakage and improve electron mobility. Further investigation of morphological and electrical characterization is conducted through SEM and I-V test .Average size diameter of Zno microwire is 0.45μm and exhibit 900μA of current at 5V.

Photoenhanced Deposition of Silicon Oxide Thin Films Using an Internal Nitrogen Discharge Lamp

1986 ◽  
Vol 75 ◽  
Author(s):  
Paul A. Robertson ◽  
W. I. Milne
Keyword(s):  
Thin Films ◽  
Silicon Oxide ◽  
Uv Light ◽  
Single Crystal Silicon ◽  
Film Surface ◽  
Oxide Thin Films ◽  
Crystal Silicon ◽  
Discharge Lamp ◽  
Rf Glow Discharge ◽  
Nitrogen Discharge

AbstractThis paper describes the optical and electrical properties of silicon oxide thin films produced using a novel photoenhanced deposition technique. Since there is no damage to the growing film surface from energetic ions, this process has the potential to produce better semiconductor/insulator interfaces than those grown using conventional RF glow discharge techniques. The deposition system is comprised of a windowless nitrogen discharge lamp contained within the reaction vessel. This unified approach allows the low wavelength UV light from the lamp to couple directly into the reaction gases without attenuation by a window material or the need for mercury sensitisation. Thin films of silicon oxide have been deposited onto single crystal silicon wafer substrates from a nitrous oxide/monosilane reaction gas mixture. The deposition rate and physical properties of films produced in this way are comparable to those of high quality insulator films deposited by plasma enhanced CVD techniques. The results of electrical tests indicate that this material could be used as a low temperature deposited insulator for thin film devices.

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