SEMICONDUCTOR DEVICE HAVING MULTIPLE ISOLATION STRUCTURE AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A semiconductor device having multiple isolation structure and a method for manufacturing the same are provided to be capable of obtaining high driving voltage, good device isolation ability and small device isolation area. CONSTITUTION: The first conductive type buried layer(60) is formed in a semiconductor substrate(50). The first conductive type epitaxial layer(62) is formed on the resultant structure. A device isolation structure(90) that defines a device region through the epitaxial layer and the substrate is disposed. A field oxide layer(70) is formed on the device region to define the first and second active region(a1,a2). A gate electrode(80) is formed on the first active region(a1). A source and drain region are formed in the first and second active region. At the time, the device isolation structure(90) further includes a lower isolation structure(58) and an upper isolation structure(68).