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:
Jun. 10, 1997
Filed:
Dec. 22, 1995
Jun-Seok Lee, Seoul, KR;
Suk-Bin Han, Choongchungbook-Do, KR;
LG Semicon Co., Ltd., Cheongju, KR;
Abstract
A method for fabricating a highly reliable phase shift mask, comprising the steps of: forming a phase shifting film and a screen on a transparent substrate, in sequence; forming an impurity layer on the screen; diffusing the impurities of the impurity layer selectively into the screen; removing the regions of the screen which are free of impurities; and selectively removing the phase shifting film. By virtue of using inorganic resist for screen, the method can be executed at low temperatures and a distortion of mask substrate can be prevented. Next, the vertical side wall of the shifter can be accomplished with ease owing to the high etch selectivity of the screen. In addition, the shifter beneath the screen offsets the bad affect resulting from the topology of the shifter, improving the effect of phase shift.