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:
Mar. 23, 1999
Filed:
Mar. 27, 1997
Ming-Hua Liu, Taichung, TW;
Chuck Chen, Fenshan, TW;
United Microelectronics Corporation, Taipei, TW;
Abstract
A method of forming a self-aligned contact of a DRAM cell includes providing a substrate having a MOS transistor. The MOS transistor includes a gate and a source/drain region. A first insulating layer, a second insulating layer and a third insulating layer are formed over the surface of the substrate in succession. The third insulating layer is planarized. A contact window mask is formed above the third insulating layer. Using the contact window mask as a cover, the third insulating layer is removed using anisotropic dry etching and isotropic wet etching. Then, a portion of the second insulating layer and a portion of the first insulating layer are removed sequentially to expose the source/drain region so that a self-aligned contact is formed.