Method of forming CMOS transistor
A method of forming CMOS transistor is disclosed. A CMOS transistor having a first active area and a second active area is provided. In order to maintain the concentration of the dopants in the second active area, according to the method of the present invention an ion implantation process is performed to form a lightly doped drain (LDD) in the second active area after an epitaxial layer is formed in the first active area. On the other hand, the ion implantation process is performed to form the respective LDD of the first active area and the second active area. After the epitaxial layer in the first active area is formed, another ion implantation process is performed to implant dopants into the LDD of the second active area again.
United Microelectronics Corp.
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inventional inventional inventional
Yao-Chin Yu-Ming Wen-Han Li-Shian Meng-Yi Shih-Jung Cheng-Tung Kun-Hsien Shyh-Fann
Cheng Lin Hung Jeng Wu Tu Huang Lee Ting