SPLIT GATE-TYPE FLASH MEMORY DEVICE AND FABRICATING METHOD THEREOF

摘要

PURPOSE: A split gate-type flash memory device is provided to prevent reverse tunneling by changing the structure of the lower corner portion of a wordline that could generate reverse tunneling. CONSTITUTION: A semiconductor substrate(21) has an active region. A drain region(33b) and a source region(33s) are formed in the active region, separated from each other. An insulated floating gate(25) includes the first sidewall(25a) adjacent to a source region, the second sidewall(25b) confronting the first sidewall and an upper surface between the first and second sidewalls. The insulated floating gate is formed on a channel region between the drain region and the source region, adjacent to the source region. The surface of the floating gate is covered with a tip-open insulation layer(27) that exposes a tip corner where the second sidewall and the upper surface are adjacent to each other. The semiconductor substrate including the tip-open insulation layer is covered with a tunnel insulation layer(30) in direct contact with the exposed tip corner. The wordline(31) crosses the upper portion of the channel region between the drain region and the floating gate. The wordline extends to cover the tunnel insulation layer on the second sidewall and the tip corner.