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. 01, 1999
Filed:
Feb. 05, 1997
Liang-Choo Hsia, Taipei, TW;
Thomas Chang, Taichung, TW;
Mosel Vitelic Inc., Hsinchu, TW;
Abstract
A method of fabricating single-side corrugated cylindrical capacitor of high density Dynamic Random Access Memory (DRAM) cells. The corrugated capacitor shape is achieved by depositing the thermal chemical vapor deposition (CVD) oxide and the plasma-enhanced CVD (PECVD) oxide alternating layers. Then, the thermal CVD oxide and the PECVD oxide layers are lateral etched by hydrofluoric acid (HF). Because hydrofluoric acid (HF) etches the thermal CVD oxide at a slower rate than etches the PECVD oxide, a cavity (undercut) is formed in each PECVD oxide layer. Therefore, the single-side corrugated shape capacitor surface is created that increases the surface area of the capacitor considerably. The cylindrical capacitor storage node of the DRAM capacitor of this method has much greater surface area so as to increase the capacitance value of the DRAM capacitor, that can achieve high packing density of the integrated circuit devices.