Showing papers on "Lithography published in 1977"

X-ray lithography

Abstract: The advent of X-ray lithography as a natural compliment to electron beam pattern generation and photolithography seems to be filling a need in the fabrication of submicron devices. The X-ray technique, which is simple for single level devices, lags behind other lithographies in registration techniques. However, its proven high resolution capabilities is responsible for the increased interest in further development. At present a, variety of mask substrates are being evaluated with no one material exhibiting an overwhelming advantage. The type of substrate used is closely coupled to the permissable wavelength of the X-ray source. The X-rays used for lithography to date vary from Rh L (4A) up to CK (44A). Each wavelength shows a distinct advantage and disadvantage. For example, at short wavelengths substrates can be relatively massive but resists are less sensitive and high resolution masks have low contrasts. At longer wavelengths, resists are more sensitive and masks have higher contrast, but defects due to dust are more probable. The use of more than one X-ray source could fulfill the requirements imposed by mask making and device fabrication. High throughput for both masks and device require both foster resists and higher intensity X-ray sources.

Electro-lithography method

Abstract: An electro-lithography method suitable for forming a high resolution pattern in an electron sensitive resist material is disclosed. This technology permits the inexpensive high resolution reproduction of masks for use in integrated circuits and magnetic bubbles. The method involves the application of a pulsed, electric field to two parallel electrodes having an electron beam resist layer positioned on one of the electrodes and a mask positioned between the second electrode and the resist layer. The mask forms a gap having a thickness of 10 -4 m to 10 -5 m with the resist layer.

X-ray lithography

Abstract: X-ray lithographic systems as heretofore constructed include a low-attenuation chamber for propagating x-rays from a source toward a mask member that is positioned in close proximity to a resist-coated wafer Both the mask and the wafer are included in the chamber which typically is either filled with helium or evacuated to a pressure less than about 10-2 Torr In accordance with this invention, an x-ray lithographic system is constructed to enable establishment in the wafer-to-mask region of a controlled atmosphere that is separate and distinct from that maintained in the low-attenuation chamber In this way, an improved lithographic system with advantageous throughput and other characteristics is realized

X-ray lithography mask and method for manufacturing the same

Abstract: An x-ray lithography mask including a thick silicon peripheral rib with a window formed therein and a multi-layered membrane transparent to x-rays and visible light supported by the rib and covering the window. The membrane consists essentially of at least two silicon nitride layers and at least one silicon oxide layer sandwiched between the silicon nitride layers. The silicon nitride layers are preferably positioned at opposite surfaces of the multi-layered membrane.

Submicron patterning of surfaces

Abstract: A new process for providing submicron patterning of surfaces is presented. This processing technique, which the authors call the Iso-E process, is capable of producing submicron openings to the surface of materials using conventional photolithographic techniques and processing common to the semiconductor industry. This process can be used equally well with X-ray or electron-beam lithography to provide minimum geometry openings at minimum geometry spacings.

A Half-Micron Gate GaAs FET Fabricated by Chemical Dry Etching

Abstract: A new microfabrication method is devised to make a submicron gate GaAs FET's. Ordinary photolithographic techniques are applied to duplicate a one micron pattern on the photoresist film deposited on a thick metal layer. Controlled undercutting of the metal by chemical dry etching produces a submicron contact with the semiconductor, leaving a wide metal top surface. This process gives experimentally confirmed advantages for reproducibility, accurate duplication, easiest lithography and minimal parasitic resistance. Half-micron gate GaAe FET's are fabricated by using this technique combined with triple layer (n«-n-buffer) epitaxial growth. The maximum frequency of oscillation observed is as high as 80 GHz and the noise figure as low as 3 dB at 12 GHz. The new technology has not resulted in any adverse effects and the high frequency performance is improved in direct proportion to the gate length.

Invited: New Developments in Materials and Processing Aspects of Silicon Device Technology

Abstract: Recent developments in materials and processing aspects of silicon device technology are reviewed. Important advances in silicon materials, passivation, CVD processing, ion implantation and diffusion, metallization, device lithography, and packaging/assembly are discussed in relationship to the overall goals of semiconductor manufacturers. It is concluded that the most important developments include more highly controlled and better understood processes, simpler and more efficient processing equipment, and greatly advanced techniques in device lithography.

Processing-free type lithographic printing plate material

Abstract: A processing-free lithographic printing plate, which comprises a support having deposited thereon a composition containing germanium and sulfur and at least one of a metal or metal compound in a physically mixed state

Invited: X-Ray Lithography

Abstract: X-ray lithography has been used in the fabrication of surface-acoustic-wave, bubble-domain, and silicon MOS devices and is well suited for replicating sub-micrometer linewidth patterns. In order to be applied in the commercial exposure of silicon IC devices, however, high power sources, sensitive resists, distortion free masks, multiple mask alignment, and repeatability of local mask-to-wafer gap will be required. These items are discussed from the point-of-view of developing design criteria for an X-ray lithography system optimized for 1/2 µm linewidths, 1/10 µm superposition, and exposure times under 200. For linewidths below 1/2 µm, copper (λ=13.3 A) or carbon (λ=44.7 A) sources are preferred. Recent progress in using the copper radiation to replicate grating patterns with linewidths of the order of 1000 A with sharp vertical sidewall profiles are described.

Plate for lithography or offset printing

Abstract: A plate for lithography or offset printing comprising a flexible substrate and a water-resistant coating layer formed on the flexible substrate, said water-resistant coating layer being composed of a water-insoluble resin binder and an inorganic pigment dispersed in said binder, and the water-resistant coating layer including an oleophilic ink-supporting portion composed of particles consisting essentially of at least one member selected from triiron tetroxide and γ-type diiron trioxide, the particles being embedded in at least a part of the surface of the coating layer, and an etched hydrophilic ink-repelling portion composed of the inorganic pigment.

Lithography and microscopy with X-rays

Abstract: In this review of recent progress in lithography and microscopy by X-rays the authors show how X-ray lithography is used to replicate microcircuit patterns with dimensions below 1 mu m, and how these advances have improved the older technique of X-ray microradiography

Novel Microfabrication Process Without Lithography Using an Ion-Projection System

Abstract: An ion-projection system has been developed for a novel fabrication process without lithography for LSI-circuits based on silicon. The system is designed to meet the requirements of the new technology with sub-micrometer resolution over a chip size of 5 × 5 millimeters. A self-supporting metal-mask is illuminated by ions and imaged onto a wafer with a 10 x reduction in size. According to the thickness of the SiO2-layer the ion energy is defined and the “exposure” dose is chosen in such a way, that the damage in the exposed oxide is sufficient for a following (dry) preferential etching technique. This etching technique is based on the effect that exposed oxide is etched faster than unexposed oxide. The difference between the etching rates is a function of the damage and depends on the type of ion and its dose.