Dai Nippon Printing Co., Ltd.

Shu Shimada

Noriyuki Takahashi

Hiroko Tanaka

Hiroyuki Ishii

Hiroshi Mohri

Hideki Yamamoto

Nobuhito Toyama

Junji Fujikawa

Hiroyuki Nakajima

Tsuyoshi Amano

Masashi Ohtsuki

Kimio Ito

Nobuyuki Kanda

Akihiko Naitoh

Yuuichi Yoshida

Shiho Sasaki

Yusuke Shoji

An object of the present invention is to provide a method for managing a light exposure mask wherein: a mask inspection or a wafer inspection, in order to manage a contamination of a light exposure mask by a growing foreign matter, is not necessary; the method has general versatility regardless to the history of the mask; the method dose not increase time and cost for mask manufacturing and inspection; and the method is operated so that the mask can always be used in a clean state. Another object of the present invention is to provide a light exposure mask wherein a contamination by a growing foreign matter dose not occur. A method for managing a light exposure mask is characterized in that: calculating a sulfate ion adsorption amount on a surface of the light exposure mask, of after a elapse of a predetermined time, from a sulfate ion concentration actually measured in an environment of using the light exposure mask, a maximum amount of sulfate ions adsorbed on the surface of the light exposure mask, and a threshold value of an amount of sulfate ions present on the surface of the light exposure mask of which the foreign matter occurs on the surface of the light exposure mask; setting an usable period of the light exposure mask, which the foreign matter dose not occur; and using the light exposure mask while rewashing the light exposure mask before the usable period expires.

Method for managing light exposure mask and light exposure mask

The invention provides a gradated photomask for reducing photolithography steps and its fabrication process, which make use of a generally available photomask blank, prevents the reflectance of a light shield film from growing high, makes alignment easy during the formation of a semitransparent film, and enables the semi-transparent film on a light shield pattern with good step coverage. A photomask () comprises a mixture of a light shield area including a light shield film () having a desired pattern on a transparent substrate wherein a film forming the pattern is substantially opaque to photolithographic light, a semitransparent film () that transmits the photolithographic light at a desired transmittance, and the light shield film () and the semitransparent film () are stacked on the transparent substrate () in that order; a semi-transparent area wherein there is only the semitransparent film (); and a transmissive area there is neither the light shield film () nor the semitransparent film (), and is characterized in that the semitransparent film () has an antireflection function with respect to the photolithographic light.

Gradated photomask and its fabrication process

The present invention provides a method of cleaning a storage case to be used for storing or transporting mask substrates such as photomasks and photomask blanks, semiconductor substrates such as semiconductor wafers, pellicles, or the like. The present invention: facilitates a regular cleaning operation, can be used also for a storage case of a complicated shape, does not require a large scale equipment or an expensive equipment to facilitate an environmental countermeasure, and provides high cleaning effect. The method of cleaning a storage case polluted by adhesion of a foreign substance of an organic material, an ionic foreign substances or an ionic crystal foreign substance physically absorbed, comprises a step of placing the storage case still in air flow of cleaned air or an inert gas in a temperature range from room temperature to 80&#xb0; C. for desorbing and removing the foreign substance adhered to the storage case.

Method of cleaning storage case

The present invention provides a method for cleaning a photo mask without the need for removal of the pellicle mounted on the photo mask, without the large scale equipment for washing with a solution, with a small number of steps for cleaning and inspection, and without the increase of the production cost. The method for cleaning a photo mask with a pellicle mounted, in which the pellicle frame has a gas introducing hole and a gas discharging hole, comprises: a step of introducing a gaseous substituting substance from the gas introducing hole in a pellicle inner space surrounded by the photo mask and the pellicle, substituting foreign substances on the photo mask, and discharging the foreign substances from the gas discharging hole; and a step of irradiating an ultraviolet ray to the photo mask, while an air or a nitrogen gas or a rare gas is introduced from the gas introducing hole, for degrading the substituted substituting substance so as to be gaseous, and discharging the same from the gas discharging hole.

Method for cleaning photo mask

Growing community of inventors

Tokyo, Japan

Shu Shimada