Shin-etsu Chemical Co., Ltd.

Shin-estu Chemical Co., Ltd.

Noriyasu Fukushima

Hiroki Yoshikawa

Hideo Kaneko

Yukio Inazuki

Satoshi Okazaki

An opaque area is formed in a sidewall portion of a susceptor by stacking a material that is transparent to flash light and a material that is opaque to the flash light to form the sidewall portion or coating a surface of the opaque material with the transparent material. A top surface of the opaque area in the sidewall portion of the susceptor is designed to have a predetermined positional relationship with a top surface of a substrate; the top surface of the opaque area is set at the same position as that of the top surface of the substrate or higher than the top surface of the substrate by a predetermined height. Thus, obliquely incident flash light is absorbed or irregularly reflected by the opaque quartz portion, surrounding an excavated portion of the susceptor.

Method of fabricating photomask blank

A photomask blank comprising a multilayer film including at least four layers of different compositions, wherein the interface between the layers is moderately graded in composition; a phase shift mask blank comprising a phase shift film of at least two layers including a surface layer of a composition based on a zirconium silicide compound and a substrate adjacent layer of a composition based on a molybdenum silicide compound, and a further layer between one layer and another layer of a different composition, the further layer having a composition moderately graded from that of the one layer to that of the other layer; a phase shift mask blank comprising a phase shift film including a plurality of layers containing a metal and silicon in different compositional ratios which are stacked in such order that a layer having a higher etching rate is on the substrate side and a layer having a lower etching rate is on the surface side. The invention provides a photomask blank, typically a phase shift mask blank, which satisfies optical properties such as transmittance, reflectance and refractive index at an exposure wavelength of interest, and has an etched pattern with a minimal line edge roughness, and a photomask, typically a phase shift mask obtained therefrom.

Photomask blank, photomask, and method of manufacture

A susceptor having the most basic structure has a three-layer structure including a first and a second transparent quartz part and an opaque quartz part sandwiched therebetween. For example, the opaque quartz part is made of 'foamed quartz'. In addition, the opacity of the opaque quartz part to flash light is determined to fall within an appropriate range based on the material or thickness of the opaque quartz part, taking into consideration the composition or thickness of a thin film formed on the substrate and various conditions concerning the energy of the irradiation light during flash light irradiation or the like. The stack structure may be composed of a stack of a plurality of opaque quartz layers having different opacities.

Fabrication method of photomask-blank

A photomask blank is prepared by forming a light-absorbing film on a transparent substrate, and irradiating the light-absorbing film with light from a flash lamp at an energy density of 3 to 40 J/cm. A photomask is prepared by forming a resist pattern on the photomask blank by photolithography, etching away those portions of the light-absorbing film which are not covered with the resist pattern, and removing the resist.

Preparation of photomask blank and photomask

There is disclosed a method of producing a phase shift mask blank wherein the method includes at least a step of forming one or more layers of phase shift films on a substrate by a sputtering method, and in the step, the phase shift films are formed by the sputtering method while simultaneously discharging plural targets having different compositions. Thereby, a phase shift mask blank having a desired composition and quality, in particular, having a phase shift film with few defects can be easily produced.

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Niigata, Japan

Noriyasu Fukushima