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.

DUV laser lithography for photomask fabrication

Abstract: In the recent past significant work has been done to isolate and characterize suitable single layer Chemically Amplified Resist (CAR) systems for DUV printing applicable to photomask fabrication. This work is complicated by the inherent instability of most DUV CAR systems, particularly in air, showing unacceptable CD degradation over the normal photomask write time in today’s DUV mask pattern generators. The high reflectivity of most photomask substrates at DUV wavelengths, creating unacceptable standing waves in the photo resist profile, further compounds this problem. A single layer CAR system suitable for 90nm technology node mask fabrication with DUV printing has been characterized and optimized. Results of this optimization in terms of relevant mask making parameters will be detailed. Furthermore, comparison of the properties of this resist system to other commercially available systems, including FEP-171, will be shown. The pattern fidelity of DUV laser generated masks has been studied in considerable detail. A demonstration of the capabilities of the Etec Systems ALTA 4300 will be shown. The pattern fidelity achieved will be compared/contrasted to that achieved with today’s leading edge 50KeV vector scan e-beam systems. Advanced methods for modulating the DUV printed patterns’ fidelity will be detailed. Finally, the cost and cycle time implications of inserting the DUV laser pattern generator into the mask manufacturing flow will be discussed.

Photomask pattern position correcting method, and position corrected photomask

Abstract: PROBLEM TO BE SOLVED: To provide a photomask pattern position correcting method which corrects an error of a position of a random mask pattern of a photomask which cannot be corrected conventionally, using a simple and effective method, and to provide a pattern position corrected photomask. SOLUTION: The pattern position correcting method for a photomask where a pattern is formed on a principal surface of a transparent substrate, measures a pattern position of the photomask to calculate an amount of displacement from a pattern design position, uses a pattern position in which the amount of displacement exceeds a predetermined allowable value as a target of position correction to radiate femtosecond laser in the vicinity of the pattern position of the correction target and form a cavity inside the transparent substrate, and corrects the amount of displacement using stress caused by the cavity forming. COPYRIGHT: (C)2010,JPO&INPIT

Method of fabricating a fine structure electrode

Abstract: A fine structure T-shaped electrode is fabricated using a phase shift method. A photoresist layer is formed on a semiconductor substrate and the photoresist layer is exposed to an exposure light having a first wavelength through a photomask which has a desired pattern of a base shifting layer whereby the phase of the exposure light is shifted by 180 degrees. The photoresist layer is then exposed to another exposure light having a second wavelength that is different from the first wavelength through the photomask. The photoresist is developed to form a T-shaped resist cavity and a metal layer is deposited over the resist layer formed on the semiconductor substrate. All the metal layer is removed except for the areas covering the T-shaped photoresist pattern. The T-shaped electrode is also formed by disposing a photoresist layer on a semiconductor substrate. The photoresist is exposed to an exposure light through a photomask which has a desired pattern of a phase shift layer whereby the phase of the exposure light is reversed and the light blocking layer to block the exposure light are formed at a certain fixed distance from and in parallel with the edge of said phase shifting layer pattern and are also formed inside as well as outside of the phase shifting layer pattern. The photoresist is developed to form a T-shaped photoresist cavity. A metal layer is deposited over the photoresist pattern formed on the semiconductor substrate. All of the metal layer is then removed except for the areas covering the T-shaped photoresist pattern.

Glass substrate for photomask, and method for producing the same

Abstract: PROBLEM TO BE SOLVED: To provide a glass substrate having such a shape as to ensure high flatness of its exposure face and photomask holding face in exposure through a photomask as a silica glass substrate for a photomask used in a photolithographic process important to the production of IC, etc. SOLUTION: The glass substrate for the photomask is obtained by subjecting a glass substrate with a patterned light shielding film on the surface to local plasma etching in such a way that the flatness of the exposure face of the glass substrate in exposure becomes 0.04-2.2 nm per 1 cm 2 area of the exposure face. COPYRIGHT: (C)2002,JPO

Micro-structures

Abstract: Three-dimensional micrometer-scale structures can be prepared from an acid hardening photoresist by the use of a special photomask. Positive-mode structures have surface relief features while the negative mode produces tunnels, chambers, and cantilever beams. The resist chemistry and process are versatile and can be tailored to specific applications. Exploratory work in preparing microstructures is described and possible applications are proposed. >