A process for the preparation of a flash memory component - and - flash memory device

摘要

A process for the preparation of a flash memory device, wherein the method comprises:a semiconductor substrate (10), is made available, on which a connection oxide layer (11) in a cells region is formed, a lower voltage gate oxide layer (11b) in a lower voltage field is formed, and a high voltage gate oxide layer (11c) is formed in a high-voltage field;Forming a first polycrystalline silicon layer (12) in the lower - and high voltage fields;Deposition of a connection nitride layer (13) on the overall structure including the first polycrystalline silicon layer (12);Forming a first trench by means of a partial structure of the connection nitride layer (13), the connection of oxide layer (11) and of the semiconductor substrate (10) in the cells region;Form the second and third trenches by means of a partial structure of the connection nitride layer (13), the connection of oxide layer (11) and of the semiconductor substrate (10) in the lower voltage fields and high voltage fields;Forming a field insulation layer (14), in order to fill the first to third trenches;Removal of the connection nitride layer (13);Forming a tunnel insulation layer (15) on the overall structure;Forming a floating gate (16a) by depositing and patterning..