Nanofabrication of DLC-dot Arrays by Room-temperature Curing Imprint-liftoff Method

2013 ◽  
Vol 1511 ◽  
Author(s):  
Shuji Kiyohara ◽  
Shohei Matta ◽  
Ippei Ishikawa ◽  
Hideto Tanoue ◽  
Hirofumi Takikawa ◽  
...  
Keyword(s):  
Room Temperature ◽  
Polished Glass ◽  
Aluminum Film ◽  
Mold Material ◽  
Ion Energy ◽  
Dlc Film ◽  
Oxygen Ion ◽  
Mask Material ◽  
Etching Selectivity ◽  
20 Nm

ABSTRACTAs an application to the nanoemitter, we investigated the nanofabrication of diamond-like carbon (DLC)-dot arrays by room-temperature curing imprint-liftoff (RTCIL) method using aluminum mask. The DLC film which has excellent properties similar to diamond properties was used as the patterning material. A polished glass like carbon (GC) was used as a mold material. The polysiloxane in the state of sticky liquid at room temperature and stable in air exhibits a negative-exposure characteristics. Therefore, the polysiloxane was used as electron beam (EB) resist and oxide mask material in EB lithography, and also used as RTC-imprint resist material. An aluminum was used as oxide metal mask material of liftoff. We have fabricated the GC mold of dot arrays with 5 µm-square and 500 nm-height. We carried out the RTCIL process using the GC mold under the following optimum imprint conditions: 0.5 MPa-imprinting pressure and 5 min- holding time. Aluminum film on the imprinted polysiloxane was prepared by vacuum evaporation method and its thickness is 20 nm. Finally, the polysiloxane patterns were removed with acetone and aluminum mask patterns were fabricated. We found that the maximum etching selectivity of aluminum film against DLC film was as high as 35, which was obtained under an ion energy of 400 eV. Then we processed the patterned aluminum on DLC film with an ECR oxygen ion shower. We fabricated DLC-dot arrays with 5 µm-square and 400 nm-height with an aspect ratio of 0.08.

Fabrication of Diamond Nanopit arrays by Room-temperature Curing Nanoimprint Lithography Using Glass-like Carbon Molds

2012 ◽  
Vol 1395 ◽  
Author(s):  
Shuji Kiyohara ◽  
Chigaya Ito ◽  
Ippei Ishikawa ◽  
Hirofumi Takikawa ◽  
Yoshio Taguchi ◽  
...  
Keyword(s):  
Diamond Film ◽  
Nanoimprint Lithography ◽  
Room Temperature ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Mold Material ◽  
Oxygen Ion ◽  
Mask Material ◽  
Chemical Vapor Deposited ◽  
Etching Selectivity

ABSTRACTWe have proposed the use of glass-like carbon (GC), as mold material because the 27-maximum etching selectivity of polysiloxane film against GC, which was approximately sixtimes larger than that of polysiloxane film against chemical vapor deposited (CVD) diamond film. We have investigated the fabrication of diamond nanopit arrays by room-temperature curing nanoimprint lithography (RTC-NIL) using GC mold, as applications to the emitter and the micro-gear. The polysiloxane has in the state of sticky liquid at room-temperature and negative-exposure characteristic. Therefore, the polysiloxane was used as RTC-imprint resist material, and also used as electron beam (EB) resist (oxide mask) material in EB lithography. We have fabricated the cylindrical GC nanodot mold with 500 nm-diameter, 600 nm-height and 2 μm-pitch. We carried out RTC-NIL using GC mold under the following optimum conditions: time from spin-coating to imprint of 1 min, imprinting pressure of 0.5 MPa and imprinting time of 5min. Then, we have processed the diamond film with an electron cyclotron resonance (ECR) oxygen ion shower. We have fabricated diamond nanopit array with 250 nm-depth and 500 nm-diameter. The diameter of diamond nanopit pattern was in good agreement with that of GC mold. Moreover, the depth of the diamond nanopit patterns fabricated by RTC-NIL using cylindrical GC mold was three times larger than that using conical diamond mold.

Fabrication of DLC-Based Micro-Gear Patterns by Room-Temperature Curing Nanoimprint Lithography Using Glass-Like Carbon Molds

2013 ◽  
Vol 1511 ◽  
Author(s):  
Shuji Kiyohara ◽  
Tomu Ikegaki ◽  
Chigaya Ito ◽  
Ippei Ishikawa ◽  
Hideto Tanoue ◽  
...  
Keyword(s):  
Diamond Film ◽  
Nanoimprint Lithography ◽  
Room Temperature ◽  
High Accuracy ◽  
Residual Layer ◽  
Mold Material ◽  
Etching Time ◽  
Optimum Conditions ◽  
Dlc Film ◽  
Etching Selectivity

ABSTRACTThe fabrication of diamond-like carbon (DLC) micro-gear by room temperature curing nanoimprint lithography (RTC-NIL) using glass-like carbon (GC) molds as applications to the DLC-based medical MEMS (Micro Electronic Mechanical Systems) was investigated. The DLC film which has excellent properties similar to chemical vapor deposited (CVD) diamond films was used as the patterning material. We propose GC as mold material because GC has higher etching selectivity than a diamond film. The etching selectivity of polysiloxane film against a GC substrate is about 5 times as high as that of a diamond film. Therefore we fabricated the GC molds that have micro-gear patterns with 30 µm-tip diameter and 500 nm-tooth thickness. We carried out the RTC-NIL process using the GC micro-gear molds under the following optimum conditions. 1 min-time from spin-coating to imprint: t1, 0.5 MPa-imprinting pressure: P and 5 min-holding time: t2, and then the imprinted polysiloxane pattern on DLC film was processed with an electron cyclotron resonance (ECR) oxygen ion shower. However, we were not able to fabricate micro-gear patterns in high accuracy because of a remaining residual layer on the DLC film. Therefore we propose the removing process for the residual layer with trifluoromethane (CHF3) ion shower under the optimum conditions of 300 eV-ion energy and 4 min-etching time. As a result, we succeeded to fabricate concave DLC-based micro-gear patterns in high accuracy which has 30 µm-tip diameter and 1 µm-depth.

Fabrication of Diamond-Like Carbon Emitter Patterns by Room-Temperature Curing Nanoimprint Lithography with PDMS Molds Using Polysiloxane

MRS Advances ◽  
2016 ◽  
Vol 1 (16) ◽  
pp. 1075-1080 ◽  
Author(s):  
Shuji Kiyohara ◽  
Shogo Yoshida ◽  
Ippei Ishikawa ◽  
Toru Harigai ◽  
Hirofumi Takikawa ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Room Temperature ◽  
Electron Cyclotron Resonance ◽  
Mold Material ◽  
Etching Time ◽  
Diamond Like Carbon ◽  
Curing Time ◽  
Flat Panel Display ◽  
Ion Energy ◽  
Mask Material

ABSTRACTWe investigated the fabrication of diamond-like carbon (DLC) emitter patterns by room-temperature curing nanoimprint lithography (RTC-NIL) with polydimethylsiloxane (PDMS) molds using polysiloxane, as an application to the emitter for the next generation flat panel display.The DLC which has excellent properties similar to diamond properties was used as a pattern material. A PDMS was used as a mold material and fabricated by the following optimum conditions of the first curing time at RT for 36 h and the second curing time at the temperature of 150 °C for 15 mins. The polysiloxane is in the state of sticky liquid at RT and stable in air. Therefore, the polysiloxane was used the electron beam (EB) resist and oxide mask material in EB lithography, and also used as RT-imprint material.First, we fabricated the PDMS mold with pit array. Each dot is 5 µm-diameter and 400 nm-depth. We carried out the RTC-NIL process with PDMS molds using polysiloxane under the following optimum imprint conditions of 0.5 MPa-imprinting pressure, 1.5 min-the time between spin-coat and imprint, and 5 min-imprinting time. Next, the residual layer of imprinted polysiloxane pattern was 450 nm and then was removed with electron cyclotron resonance (ECR) trifluoromethane (CHF3) ion shower under the conditions of 300 eV-ion energy and 3 min-etching time. Then, we processed the imprinted polysiloxane patterns on the DLC film with an ECR oxygen (O2) ion shower under the conditions of 400 eV-ion energy and 12 min-etching time. As a result, we succeeded in fabricating convex DLC emitter patterns with high accuracy which has 5 µm-diameter and 500 nm-height.

Fabrication of Diamond-Like Carbon Microgears in Room-Temperature Curing Nanoimprint Lithography Using Ladder-Type Hydrogen Silsesquioxane

MRS Advances ◽  
2016 ◽  
Vol 1 (16) ◽  
pp. 1119-1124
Author(s):  
Shuji Kiyohara ◽  
Yuto Shimizu ◽  
Ippei Ishikawa ◽  
Toru Harigai ◽  
Hirofumi Takikawa ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Room Temperature ◽  
Electron Cyclotron Resonance ◽  
Sol Gel ◽  
Etching Time ◽  
Diamond Like Carbon ◽  
Pdms Mold ◽  
Hydrogen Silsesquioxane ◽  
Ion Energy ◽  
Mask Material

ABSTRACTWe investigated the fabrication of convex diamond-like carbon (DLC) based microgears in room-temperature curing nanoimprint lithography (RTC-NIL) using the ladder-type hydrogen silsesquioxane (HSQ), as an application for the medical micro electro mechanical system (MEMS). The HSQ which is an inorganic polymer of sol-gel system turns into a gel when exposed to air and has the siloxane bond. Therefore, the HSQ was used as RT-imprinting material, and also used as an oxide mask material in electron cyclotron resonance (ECR) oxygen (O2) ion shower etching. We fabricated the polydimethylsiloxane (PDMS) mold with concave microgear patterns which has 40, 50 and 60 μm-tip diameter and 300 nm-depth. We carried out the RTC-NIL process using the PDMS mold under the following optimum conditions of 0.10 MPa-imprinting pressure and 1.0 min-imprinting time. We found that the residual layer of imprinted HSQ microgear patterns was removed with ECR trifluoromethane (CHF3) ion shower under the following conditions of 300 eV-ion energy and 2.0 min-etching time, and then microgears of the HSQ on the DLC film were etched with ECR O2 ion shower under the following conditions of 400 eV-ion energy and 10 min-etching time. As a result, the convex DLC based microgears which have 40, 50 and 60 μm-tip diameter and 400 nm-height were fabricated with high accuracy in the new fabrication process of RTC-NIL.

scholarly journals Structural and Enhanced Optical Properties of Stabilized γ‒Bi2O3 Nanoparticles: Effect of Oxygen Ion Vacancies

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1023 ◽  
Author(s):  
Ashish Chhaganlal Gandhi ◽  
Chia-Liang Cheng ◽  
Sheng Yun Wu
Keyword(s):  
Room Temperature ◽  
Excess Oxygen ◽  
Ambient Atmosphere ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Band Emission ◽  
Oxygen Ion ◽  
Integrated Intensity ◽  
Effect Of Oxygen

We report the synthesis of room temperature (RT) stabilized γ–Bi2O3 nanoparticles (NPs) at the expense of metallic Bi NPs through annealing in an ambient atmosphere. RT stability of the metastable γ–Bi2O3 NPs is confirmed using synchrotron radiation powder X-ray diffraction and Raman spectroscopy. γ–Bi2O3 NPs exhibited a strong red-band emission peaking at ~701 nm, covering 81% integrated intensity of photoluminescence spectra. Our findings suggest that the RT stabilization and enhanced red-band emission of γ‒Bi2O3 is mediated by excess oxygen ion vacancies generated at the octahedral O(2) sites during the annealing process.

Reduction of EUV resist damage by neutral beam etching

2021 ◽  
Author(s):  
Gyo Wun Kim ◽  
Won Jun Chang ◽  
Ji Eun Kang ◽  
Hee Ju Kim ◽  
Geun Young Yeom
Keyword(s):  
Radiation Damage ◽  
Light Source ◽  
Ion Beam ◽  
Critical Dimension ◽  
Neutral Beam ◽  
Etch Depth ◽  
Etching Selectivity ◽  
193 Nm ◽  
20 Nm ◽  
Neutral Beam Etching

Abstract Even though EUV lithography has the advantage of implenting a finer pattern compared to ArF immersion lithography due to the use of 13.5 nm instead of 193 nm as the wavelengh of the light source, due to the low energy of EUV light source, EUV resist has a thinner thickness than conventional ArF resist. EUV resist having such a thin thickness is more vulnerable to radiation damage received during the etching because of its low etch resistance and also tends to have a problem of low etch selectivity. In this study, the radiation damage to EUV resist during etching of hardmask materials such as Si3N4, SiO2, etc. using CF4 gas was compared between neutral beam etching (NBE) and ion beam etching (IBE). When NBE was used, after the etching of 20 nm thick EUV resist, the line edge roughness (LER) increase and the critical dimension (CD) change of EUV resist were reduced by ~ 1/3 and ~ 1/2, respectively, compared to those by IBE. Also, at that EUV etch depth, the RMS(root mean square) surface roughness value of EUV resist etched by NBE was ~2/3 compared to that by IBE on the average. It was also confirmed that the etching selectivity between SiO2, Si3N4, etc. and EUV resist was higher for NBE compared to IBE. The less damage to the EUV resist and the higher etch selectivity of materials such as Si3N4 and SiO2 over EUV resist for NBE compared to IBE are believed to be related to the no potential energy released by the neutralization of the ions during the etching for NBE.

ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Characterization ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

A Facile Fynthesis of ZnS Nanostructures via Liquid-Solid Reactions

2014 ◽  
Vol 979 ◽  
pp. 184-187
Author(s):  
Weerachon Phoohinkong ◽  
Thitinat Sukonket ◽  
Udomsak Kitthawee
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Inorganic Salts ◽  
Chloride Salt ◽  
X Ray ◽  
Commercial Grade ◽  
Transmission Electron ◽  
Salt Addition ◽  
20 Nm ◽  
Scanning Electron

Zinc sulfide (ZnS) nanostructures are important materials for many technologies such as sensors, infrared windows, transistors, LED displays, and solar cells. However, many methods of synthesizing ZnS nanostructures are complex and require expensive equipment. In this study, a liquid-solid chemical reaction without surfactant was used to synthesize ZnS at room temperature. In addition, commercial grade zinc oxide (ZnO) particles were used as a precursor. The effect of the addition of acids and inorganic salts were investigated. The products were characterized by field emission scanning electron microscopy (FESEM) coupled with energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The results show that the nanoparticles of ZnS were obtained in hydrochloric acid and acetic acid addition. The diameters were in the range of 10 to 20 nm and 50 to 100 nm, respectively. In the case of a sodium chloride salt addition, a ZnS structure was obtained with a particle size of approximately 5 nm and a flake-like morphology.

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