Manufacturing method of flash memory device

• Main Authors: ZHU JINGRUN, LIU XIANZHOU, SHEN SIJIE
• Format: Patent
• Language: Chinese; English
• Published: 17.03.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention provides a manufacturing method of a flash memory device, which comprises the following steps of: removing a control gate layer exposed by an opening through a first etching process, and at the moment, forming a bulge at a vertex angle, close to a first side wall, of the control gate layer; removing the interlayer dielectric layer exposed by the protrusions and the openings through a second etching process, so as to enable the junction of the surface of the first side wall and the side wall of the control gate layer to be straight; forming a second side wall covering the surface of the first side wall and the side wall of the control gate layer; removing the floating gate layer exposed by the opening, and forming a word line in the opening; and removing the hard mask layer and the control gate layer, the interlayer dielectric layer and the floating gate layer below the hard mask layer to form a control gate and a floating gate. The protrusions formed in the first etching process are removed thro