Photomask

About: Photomask is a research topic. Over the lifetime, 7917 publications have been published within this topic receiving 54524 citations. The topic is also known as: photoreticle & reticle.

Method and apparatus of correcting design-patterned data, method of electron beam and optical exposure, method of fabricating semiconductor and photomask devices

Abstract: A method for correcting designed-pattern data obtained by data-processing a plurality of designed patterns, comprising the steps of (a) producing hierarchical-area-bitmapped bitmap data from a plurality of the designed-pattern data, (b) determining a line width of the designed pattern and a space width between said designed pattern and a designed pattern adjacent to said designed pattern, from said hierarchical-area-bitmapped bitmap data, and (c) correcting the designed-pattern data on the basis of the determined line width and the determined space width, for proximity effect correction and/or optical proximity effect correction.

Thermal oxide patterning method for compensating coating stress in silicon substrates.

Abstract: We introduce a novel method for correcting distortion in thin silicon substrates caused by coating stress. Thin substrates, such as lightweight mirrors for x-ray or optical imaging, and semiconductor wafers or flat panel substrates, are easily distorted by stress in thin film coatings. We report a new method for correcting stress-induced distortion in flat silicon substrates which utilizes a micro-patterned silicon oxide layer on the back side of the substrate. Due to the excellent lithographic precision of the patterning process, we demonstrate stress compensation control to a precision of ~0.2%. The proposed process is simple and inexpensive due to the relatively large pattern features on the photomask. The correction process has been tested on flat silicon wafers that were distorted by 30 nm-thick compressively-stressed coatings of chromium, achieving RMS surface height and slope error reductions of a factor of 68 and 50, respectively.

Understanding resolution limit of displacement Talbot lithography.

Abstract: Displacement Talbot lithography (DTL) is a new technique for patterning large areas with sub-micron periodic features with low cost. It has applications in fields that cannot justify the cost of deep-UV photolithography, such as plasmonics, photonic crystals, and metamaterials and competes with techniques, such as nanoimprint and laser interference lithography. It is based on the interference of coherent light through a periodically patterned photomask. However, the factors affecting the technique’s resolution limit are unknown. Through computer simulations, we show the mask parameter’s impact on the features’ size that can be achieved and describe the separate figures of merit that should be optimized for successful patterning. Both amplitude and phase masks are considered for hexagonal and square arrays of mask openings. For large pitches, amplitude masks are shown to give the best resolution; whereas, for small pitches, phase masks are superior because the required exposure time is shorter. We also show how small changes in the mask pitch can dramatically affect the resolution achievable. As a result, this study provides important information for choosing new masks for DTL for targeted applications.

Method and apparatus for producing scanning data used to produce a photomask

Abstract: The invention provides a method for generating scanning data used to control a photomask production system for producing a photomask for use in semiconductor production so as to produce a photomask having a pattern corrected in terms of the optical proximity effects wherein it is possible to perform data processing and data conversion associated with the correction in terms of the optical proximity effects without introducing significant rounding errors, and it is possible to make correction in terms of the optical proximity effects without increasing the time required to produce the photomask, and furthermore it is possible to easily deal with a change in the process condition such as the resist exposure condition. In the method for generating scanning data used to control the pattern exposing operation of a pattern exposure apparatus of the raster scanning type or of the vector scanning type so as to form a pattern on a photomask, wherein the pattern formed according to the above scanning data is corrected so that when a pattern is formed in a resist by exposing the resist to exposure light via the above-described pattern formed on the photomask, the deformation of the resultant pattern formed in the resist is minimized, the scanning data is generated by the process including the steps of: generating scanning data on the basis of mask data received from the outside; and correcting the scanning data produced in the previous step according to a predefined correction method thereby generating the corrected scanning data.

Photomask, its production and exposure method using the same

Abstract: PROBLEM TO BE SOLVED: To obtain a photomask that form accurate resist steps in a resist by considering the transmittance and phase difference between a semi- transmitting part and a transmitting part. SOLUTION: The phase difference between a semi-transmitting part 12 and a transmitting part 11 in a photomask 1 is set so as to inhibit interference between exposure light that passes through the semi-transmitting part 12 and exposure light that passes through the transmitting part 11. When exposure is carried out using the resultant photomask 1, a resist 5 with a resist hole 51 and resist steps 52 formed positively in a prescribed range (half region 22) is obtained.