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:
Oct. 12, 1999
Filed:
May. 27, 1998
Jeng Gong, Hsinchu, TW;
Sheng-Hsing Yang, Hsinchu, TW;
United Microelectronics Corp., Taipei, TW;
Abstract
A method of forming high voltage device. A first type semiconductor having at least a gate formed thereon is provided. A first ion implantation with a second type dopant is performed to form a first diffusion region in the semiconductor substrate. An oxide layer is formed on the semiconductor substrate. A second ion implantation with the second type dopant is performed to form a second diffusion region within the first diffusion region. A silicon nitride layer is formed on the oxide layer, through which an opening penetrates to exposed the oxide layer. A third ion implantation with the second type dopant is performed using the silicon nitride layer as a mask to form a third diffusion region within the second diffusion region. Drive-in is performed to deepen the third diffusion region. The silicon nitride layer is removed. The exposed oxide layer is transformed into a field oxide layer. A fourth ion implantation with a first type dopant is performed to form a fourth diffusion region as a source/drain region within the second diffusion region under a surface between the field oxide layer and the gate.