Photomask / Direct Write Lithography Documents

Related Articles

• Cu Single Damascene Interconnects with Plasma-polymerized Organic Polymers (k=2.6) for High-speed, 0.1µm CMOS devices

  For high-speed CMOS devices, triple-layered Cu single damascene interconnects (SDI) with Cu-via plugs are fabricated in hybrid dielectric films of plasma-polymerized divinylsiloxan benzocyclobuten film (p-BCB: k=2.6) and p-CVD SiO2. No degradation of 0.1µm MOSFETs is observed after the full interconnect integration through MOCVD-Cu filling and pad-scanning, local-CMP for Cu polish. The stacked Cu-pads in the high modulus p-BCB film (19Gpa) withstand sever mechanical impact during Al wire bonding. The 0.08µm CMOS transmitter, which consists of 32:8 pre-multiplexer (MUX), 8B10B encoder, 10:1 MUX and DATA driver, is obtained successfully to generate high-speed serial signals up to 6Gb/s. This fabrication process is a key to obtain the high speed CMOS devices with low-k/Cu interconnects.
• Nanobeam process system: An ultrahigh vacuum electron beam lithography system with 3 nm probe size

  We have constructed a "nanobeam process system" which is applicable to high resolution electron beam lithography using inorganic resists and is also compatible with electron beam induced surface reaction. It is a 50 kV electron beam lithography system with a gas introducible ultrahigh vacuum sample chamber using a double chamber stage system which isolates stage mechanisms from the sample chamber. The probe size measured with a knife edge method was 2.8 nm, where the probe current was 127 pA. The base pressure of the sample chamber was 3.5X10-7 Pa after baking. The pressure of the gun chamber did not vary at all and the pressure rise of the mechanism chamber was 3X10-6 Pa when the pressure of the sample chamber increased to 1X10-3 Pa during N2 gas introduction. Standard deviations of stitching and overlay accuracy were 14 and 18 nm, respectively. Line patterns with a width of about 5 nm and a pitch of 15 nm were delineated in SiO2 when used as a high resolution resist.
• High-purity, ultrahigh-resolution calixarene electron-beam negative resist

  Calixarene is a promising high-resolution negative electron-beam resist having a resolution of the order of 10 nm because of its low molecular weight. We have made a purified calixarene resist containing metal contaminants whose concentrations are measured in parts per billion and which therefore do not degrade the performance of silicon-based electron devices. The purity of the calixarene itself was also improved and we obtained high-purity calix[6]arene and high-purity calix[7]arene, both of which contain the main component, which is more than 95% of all the calixarene present. The resolution of both purified calixarene resists is almost the same as that of the unpurified calixarene, but the sensitivity of calix[7]arene is higher than that of calix[6]arene because its molecular weight is higher.
• Nanofabrication of subwavelength, binary, high-efficiency diffractive optical elements in GaAs

  A single-etch-step process for the fabrication of high-efficiency diffractive optical elements is presented. The technique uses subwavelength surface relief structures to create a material with an effective index of refraction determined by the fill factor of the binary pattern. Fabrication is performed using electron beam lithography and reactive-ion-beam etching on bulk GaAs, but the process is applicable to any material for which well-controlled etches exist. In this work, we designed and fabricated a blazed transmission grating for operation at 975 nm. The blazed grating exhibits a diffraction efficiency into the first order of 85% of the transmitted power,
• Novel high-yield trilayer resist process for 0.1 µm T-gate fabrication

  By utilizing a novel ZEP/PMGI/ZEP trilayer resist process, GaInAs/AlInAs T-gate modulation-doped field effect transistors on InP with 0.1 µm gate lengths have been demonstrated. The trilayer resist requires only a single exposure. An overhang structure for liftoff, with a 0.1 µm footprint, is created by a sequence of infinitely selective developments for each layer. Linewidths as narrow as 65 nm have been obtained.
• Application of X-ray Mask Fabrication Technologies to High Resolution, Large Diameter Ta Fresnel Zone Plates

  The resolution of Fresnel zone plate (FZP) as X-ray lens is determined by the width of outer-most zone, and the diameter of condenser lens is desirable to be large so that bright x-ray beam is available in x-ray optical systems. As the diameter of FZPs with nm resolution reported so far is small, typically less than 0.2mm, FZPs cannot be used as effective condenser lens.