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.

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.

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.

Optical Band Gap of Diamond-Like Carbon Films as a Function of RF Substrate Bias

1989 ◽  
Vol 162 ◽  
Author(s):  
P. W. Pastel ◽  
W. J. Varhue
Keyword(s):  
Band Gap ◽  
Cyclotron Resonance ◽  
Optical Band Gap ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Substrate Bias ◽  
Ion Energy ◽  
Resonance Plasma

ABSTRACTDiamond-like carbon films have been deposited with a low temperature 2.45 GHz electron cyclotron resonance plasma enhanced chemical vapor deposition system. The bombarding ion energy was independently controlled with a RF bias to the substrate. The production rate of reactant species and the impinging ion energy are decoupled with this system. The optical band gap decreased from 2.7 to 1.2 eV as substrate bias was increased from 0 to -140 V.

Diamond Nanopit Arrays Fabricated by Room-Temperature Nanoimprinting using Diamond Molds

2011 ◽  
Vol 1282 ◽  
Author(s):  
Shuji Kiyohara ◽  
Masaya Kumagai ◽  
Yoshio Taguchi ◽  
Yoshinari Sugiyama ◽  
Yukiko Omata ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Room Temperature ◽  
Electron Cyclotron Resonance ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Ion Beam Etching ◽  
Minimum Diameter ◽  
Oxygen Ion ◽  
Pressure Time ◽  
Chemical Vapor Deposited

ABSTRACTWe have investigated the nanopatterning of chemical vapor deposited (CVD) diamond films in room-temperature nanoimprint lithography (RT-NIL), using a diamond nanodot mold. We have proposed the use of polysiloxane as an electron beam (EB) mask and RT-imprint resist materials. The diamond molds of cylinder dot using the RT-NIL process were fabricated with polysiloxane oxide mask in EB lithography technology. The dot in minimum diameter is 500 nm. The pitch between the dots is 2 μm, and dot has a height of about 600 nm. It was found that the optimum imprinting conditions for the RT-NIL : time from spin-coating to imprinting t1 of 1 min , pressure time t2 of 5 min, imprinting pressure P of 0.5 MPa. The imprint depth obtained after the press under their conditions was 500 nm. We carried out the RT-NIL process for the fabrication of diamond nanopit arrays, using the diamond nanodot molds that we developed. The resulting diamond nanopit arrays with 500 nm-diameter and 200 nm-depth after the electron cyclotron resonance (ECR) oxygen ion beam etching were fabricated. The diameter of diamond nanopit arrays was in good agreement with that of the diamond nanodot mold.

Hydrogenation and Defect Creation in GaAs-Based Devices During High Density Plasma Processing

1998 ◽  
Vol 510 ◽  
Author(s):  
T. Maeda ◽  
J. W. Lee ◽  
C. R. Abernathy ◽  
S. J. Pearton ◽  
F. Ren ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Inductively Coupled Plasma ◽  
Electron Cyclotron Resonance ◽  
Field Effect Transistors ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Source Power ◽  
Ion Energy ◽  
Inductively Coupled ◽  
Self Bias

AbstractThe effects of Inductively Coupled Plasma (ICP) and Electron Cyclotron Resonance (ECR) H2 plasmas on GaAs metal semiconductor field effect transistors (MESFETs), high electron mobility transistors (HEMTs) and heterojunction bipolar transistors (HBTs) have been measured as a function of ion flux, ion energy and process pressure. The chemical effects of hydrogenation have been compared to direct physical bombardment by Ar plasmas under the same conditions. Si dopant passivation in MESFETs and HEMTs and C base-dopant passivation in HBTs produces much larger changes in sheet resistance, breakdown voltage and device gain or transconductance than Ar ion bombardment and suggests that H2-containing plasma chemistries (CH4/H2 for semiconductor etching, SiH4 for dielectric deposition, CHF3 for dielectric etching) should be avoided, or at least the exposure of the surface minimized. In some cases the device degradation is less for higher source power conditions, due to the suppression of cathode dc self-bias and hence ion energy.

Fabrication of Micro-OLEDs by Room-temperature Curing Nanocontact-print Lithography Using DLC Molds

2012 ◽  
Vol 1511 ◽  
Author(s):  
Ippei Ishikawa ◽  
Keisuke Sakurai ◽  
Shuji Kiyohara ◽  
Taisuke Okuno ◽  
Hideto Tanoue ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Nanoimprint Lithography ◽  
Room Temperature ◽  
Hole Transport ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Insulating Layer ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Ito Glass

ABSTRACTThe microfabrication technologiesfor organic light-emitting devices (OLEDs) are essential to the fabrication of the next generation of light-emitting devices. The micro-OLEDs fabricated by room-temperature curing nanoimprint lithography (RTC-NIL) using diamond molds have been investigated. However, light emissions from 10 μm-square-dot OLEDs fabricated by the RTC-NIL method have not been uniform. Therefore, we proposed the fabrication of micro-OLEDs by room-temperature curing nanocontact-print lithography (RTC-NCL) using the diamond-like carbon (DLC) mold. The DLC molds used in RTC-NCL were fabricated by an electron cyclotron resonance (ECR) oxygen ion shower with polysiloxane oxide mask in electron beam (EB) lithography technology. The mold patterns are square and rectangle dots which has 10 µm-width, 10 µm-width and50 µm-length, respectively. The height of the patterns is 500 nm. The DLC molds were used to form the insulating layer of polysiloxane in RTC-NCL. We carried out the RTC-NCL process using the DLC mold under the following optimum conditions: 0.1 MPa-pressure for coating DLC mold with polysiloxane film, 2.1 MPa-pressure for transferring polysiloxane from DLC mold pattern to indium tin oxide (ITO) glass substrate. We deposited N, N'-Diphenyl -N, N'-di (m-tolyl)benzidine (TPD) [40 nm-thickness] as hole transport layer / Tris(8-quinolinolato)aluminum (Alq3) [40 nm-thickness] as electron transport layer / Al [200 nm-thickness] as cathode on ITO glass substrateas anode in this order. We succeeded in formation of the insulating layer with square and rectangle dots which has 10 µm-width,10 µm-width and 50 µm-length, and operation of micro-OLEDs by RTC-NIL using DLC molds.

Large Area Surface Treatment by Ion Beam Technology

1996 ◽  
Vol 438 ◽  
Author(s):  
R. L. C. Wu ◽  
W. Lanter
Keyword(s):  
Ion Beam ◽  
High Vacuum ◽  
Polycrystalline Diamond ◽  
Carbon Films ◽  
Ultra High Vacuum ◽  
Diamond Like Carbon ◽  
Chemical Compositions ◽  
Rf Power ◽  
Large Area ◽  
Ion Energy

AbstractAn ultra high vacuum ion beam system, consisting of a 20 cm diameter Rf excilted (13.56 MHz) ion gun and a four-axis substrate scanner, has been used to modify large surfaces (up to 1000 cm2) of various materials, including; infrared windows, silicon nitride, polycrystalline diamond, 304 and 316 stainless steels, 440C and M50 steels, aluminum alloys, and polycarbonates; by depositing different chemical compositions of diamond-like carbon films. The influences of ion energy, Rf power, gas composition (H2/CH4 , Ar/CH4 and O2/CH4/H2), on the diamond-like carbon characteristics has been studied. Particular attention was focused on adhesion, environmental effects, IR(3–12 μm) transmission, coefficient of friction, and wear factors under spacelike environments of diamond-like carbon films on various substrates. A quadrupole mass spectrometer was utilized to monitor the ion beam composition for quality control and process optimization.

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