Photomask / Direct Write Lithography Documents

Related Articles

• Diffractive x-ray optics using production fabrication methods

  Zone plates are the key focusing element for many x-ray (7–20 keV) and soft x-ray (200–500 eV) applications, yet, production with electron-beam lithography poses obstacles to their widespread availability. In addition, fabrication processes to date have limited the studies of amplitude Bragg– Fresnel-type elements in the hard x-ray regime. We report new processes that couple 100 keV electron-beam lithography with established production methods to achieve two goals: (1) improving the overall yield and volume of ultrahigh-resolution soft x-ray zone plates and (2) applying deep silicon etching techniques to extend the state of the art in high aspect ratio Bragg–Fresnel optics required to create high efficiency focusing of high-energy x rays.
• Fabrication of 5-7 nm wide etched lines in silicon using 100 keV electron-beam lithography and polymethylmethacrylate resist

  The present limit of around 10 nm for the width of lines fabricated by e-beam lithography using polymethylmethacrylate (PMMA) resist on silicon substrates has been overcome. 5–7 nm wide etched lines in bulk Si substrates have been produced. A 65 nm thick layer of PMMA was exposed with an 80 kV electron beam of diameter smaller than 5 nm. After exposure the resist was developed in 3:7 cellosolve:methanol with ultrasonic agitation. The pattern in resist was transferred to the Si substrate with reactive ion etching. Lines of width varying between 5 and 7 nm were recorded using an S-900 scanning electron microscope which has a resolution of 0.7 nm.
• Fabrication of 30 nm gate length electrically variable shallow-junction metal–oxide–semiconductor field-effect transistors using a calixarene resist

  We have fabricated electrically variable shallow-junction metal–oxide–semiconductor field-effect transistors (EJ-MOSFETs) with an ultrafine gate for the first time. The gate length was reduced to 32 nm by using electron-beam lithography with a calixarene resist, which has an under 10 nm resolution with a sharp pattern edge. Moreover, normal transistor operation of 32 nm gate-length EJ-MOSFETs was confirmed.
• Preparation of Diamond Mold using Electron Beam Lithography for Application to Nanoimprint Lithography

  Diamond molds were fabricated by two types of fabrication processes, both of which use a conductive intermediate layer between the diamond surface and polymethylmethacrylate (PMMA) resist to prevent surface charge-up.
• 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.
• High-Resolution Electron-Beam Lithography and Its Application to MOS Devices

  A point electron-beam lithography system using a thermal field emitter (TFE) allows us to use a nanometer-level fine electron beam to investigate nano-fabrication techniques and minute devices. We developed an organic negative resist, called calixarene, which has low molecular weight of 972 and almost monodispersity. This resist shows a high resolution of about 10 nm when it is exposed to an electron-beam system of 50 kV using TFE. The newly developed resist has been applied in order to fabricate an EJ-MOSFET (electrically variable shallow junction metal-oxide-semiconductor field effect transistor). A 14-nm-gate-length EJ-MOSFET was fabricated by using a calixarene resist and an electron-beam exposure system, and showed MOS device performance.