METHOD OF MANUFACTURING A NAND FLASH MEMORY DEVICE

• Main Author: JANG, PHIL SOON
• Format: Patent
• Language: English
• Published: 06.09.2007
• Subjects: ELECTRICITY

A method for fabricating a NAND-type flash memory device is provided to improve interference effect while enabling shrink of a device by preventing both lateral surfaces of the upper part of an insulation layer from being partially lost while using an amorphous carbon layer as a hard mask layer instead of a nitride layer. After an amorphous carbon layer, a hard mask layer and a photoresist pattern are sequentially formed on a semiconductor substrate(100), the hard mask layer, the amorphous carbon layer and a part of the semiconductor substrate are etched to form a trench by using the photoresist pattern as a mask. After the photoresist pattern is removed and a part of the lateral surface of the amorphous carbon layer are removed, an insulation layer is formed on the resultant structure to bury the trench. After the insulation layer is polished until the upper part of the amorphous carbon layer is exposed, an isolation layer(110) is formed and the amorphous carbon layer is removed. After a cleaning process is performed to remove a part of both lateral surfaces of the upper part of the isolation layer, a gate oxide layer(112) and a polysilicon layer(114) are formed. The polysilicon layer is planarized. The amorphous carbon layer can be made of the same component as the photoresist layer.