Resist

About: Resist is a research topic. Over the lifetime, 40991 publications have been published within this topic receiving 371548 citations.

Method of forming resist pattern and photomask therefor

Abstract: In a photomask for use in forming a resist pattern by projection exposure of a resist through the photomask, a phase shifter has a first edge part whose image is to be transferred and a second edge part whose image is not to be transferred. A light attenuator is provided to cover the first edge part. The light attenuator may include an array of opaque stripes arranged at a pitch of not more than the limit of resolution, i.e., 0.5×λ/NA, where λ represents the wavelength of light used for the projection exposure, and NA represents the numerical aperture of an optical system used for the projection exposure. In another embodiment, the light attenuator is formed to cover a shifter edge part in alignment with a line of a transmission mask. In a further embodiment, one or more light attenuators having different transparency are used to obtain lines of a resist pattern having different widths.

Micromachining in Plastics Using X-Ray Lithography for the Fabrication of Micro-Electrophoresis Devices

Abstract: Micromachining was performed in polymethylmethacrylate (PMMA) using X-ray lithography for the fabrication of miniaturized devices ( microchips ) for potential applications in chemical and genetic analyses. The devices were fabricated using two different techniques : transfer mask technology and a Kapton mask. For both processes, the channel topography was transferred (1:1) to the appropriate substrate via the use of an optical mask. In the case of the transfer mask technique, the PMMA substrate was coated with a positive photoresist and a thin Au/Cr plating base. Following UV exposure, the resist was developed and a thick overlayer (∼3 μm) of Au electroplated onto the PMMA substrate only where the resist was removed, which acted as an absorber of the X-rays. In the other technique, a Kapton film was used as the X-ray mask. In this case, the Kapton film was UV exposed using the optical mask to define the channel topography and following development of the resist, a thick Au overlayer (8 μm) was electrodeposited onto the Kapton sheet. The PMMA wafer during X-ray exposure was situated directly underneath the Kapton mask. In both cases, the PMMA wafer was exposed to soft X-rays and developed to remove the exposed PMMA. The resulting channels were found to be 20 μm in width (determined by optical mask) with channel depths of∼50 μm (determined by x-ray exposure time). In order to demonstrate the utility of this micromachining process, several components were fabricated in PMMA including capillary/chip connectors, injectors for fixed-volume sample introduction, separation channels for electrophoresis and integrated fiber optic fluorescence detectors. These components could be integrated into a single device to assemble a system appropriate for the rapid analysis of various targets.

High aspect ratio UV photolithography for electroplated structures

Abstract: This paper describes single and two layer processes to realize thick resist moulds (40 and 80 µm) with a good reproducibility. The patterning of a thick AZ 4562 photoresist layer is performed with standard photolithography equipment. Different problems related to thick photoresist patterning (edge bead, resist cracking, ...) are discussed and solutions are proposed. Side walls are characterized after nickel electrodeposition and mould dissolution in acetone. Results, process limitations and applications are presented.

Critical issues in 157 nm lithography

Abstract: Projection lithography at 157 nm is a candidate technology for the 100–70 nm generations, and possibly beyond. It would provide an evolutionary extension to the current primary photolithographic processes and components: excimer lasers, refractive optics, and transmissive masks. This article presents data on the transmission of optical materials at 157 nm, the performance of optical coatings, the issues that must be faced by photomasks, and the considerations related to engineering resists at this wavelength.

Focused ion beam lithography

Abstract: Lithography for microelectronics, that is, the exposure and development of resist, is already being carried out in research laboratories at dimensions well below 0.1 μm. In production the minimum dimensions are likely to approach 0.1 μm before the end of the decade. This review will examine the use of focused ion beams for ultrafine lithography. Minimum dimensions down to 0.015 μm have been reported as well as exposure of 0.25 μm thick resist with o.05 μm linewidth for the making of X-ray lithography masks. At this time there are only two techniques for writing original patterns (as opposed to replicating them) at 0.1 μm and below; electron beams and ion beams. Electron beams are at a mature state of development and have advantages in absence of shot noise and in fast deflection capability. Ion beams on the other hand have demonstrated absence of proximity effect and high resist sensitivity, i.e. potentially faster writing speed. The development of the gas field ion source promises hundredfold increase in current density of light ions (H2+, He …) in the beam focal spot. In addition, these light ion beams at high energy can be deflected at the speeds needed for lithography. Thus focused ion beam lithography is a serious candidate for future fine pattern writing.