The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 1995
Filed:
Nov. 19, 1993
Yukio Yasuda, Himeji, JP;
Akiyasu Yamaguchi, Himeji, JP;
Tatsushi Igarashi, Himeji, JP;
Yasuo Oonishi, Himeji, JP;
Kenzo Kai, Himeji, JP;
Masanori Sugihara, Himeji, JP;
Takashi Mori, Kawasaki, JP;
Akira Miyaji, Tokyo, JP;
Ushiodenki Kabushiki Kaisha, Tokyo, JP;
Kabushiki Kaisha Nikon, Tokyo, JP;
Abstract
A cadmium/inert gas discharge lamp of the short arc type, which suppresses an unnecessary emission upstream and downstream of the necessary emission spectra in a wavelength range of 210 to 230 nm, achieves a high efficiency of the emission spectra in the range 210 to 230 nm and can be used in very satisfactory manner for industrial applications. Also, a highly efficient projection exposure device through the incorporation of a cadmium/rare gas discharge lamp of the short arc type having good emission spectrum characteristics in the wavelength range 210 to 230 nm, which can transmit in projecting manner fine image patterns with a large depth of focus. The cadmium/rare gas discharge lamp of the short arc type is arranged within a temperature-regulated quartz bulb, and is provided with a pair of adjacently facing electrodes, together with inert gas selected from xenon, krypton, argon, neon or mixtures of them. Metal cadmium with a pressure of 14 to 200 kPa is encapsulated in the tube in a stationary lighting operation. The lamp is operated in such a way that J/P, i.e. the ratio between a discharge current in a stationary lighting operation J (A) and a cadmium pressure in a stationary lighting operation P (kPa) is in a range 0.13 to 15. Also, a projection exposure device, which has the above-described discharge lamp and a power supply for carrying out the lighting operation of the discharge lamp under the above-described condtions.