SOI SEMICONDUCTOR DEVICE AND METHOD FOR FABRICATING THE SAME

摘要

PURPOSE: An SOI(Silicon On Insulator) semiconductor substrate and a method for fabricating the same are provided to prevent leakage current and short circuit between different conductive types of diode diffusion regions by extending an isolation layer to a sub silicon substrate having the diode diffusion region. CONSTITUTION: A surface silicon layer(320) is formed by depositing a buried oxide layer(310) on a p-type sub silicon substrate(300). A trench is formed on the surface silicon layer(320). An N-well(340) is formed within the sub silicon substrate(300). An isolation layer(330) is formed on an entire surface of the resultant. A gate is formed on the surface silicon layer(320). A predetermined part of the N well(340) is exposed by forming the first opening portion and the second opening portion penetrating the surface silicon layer(320) and the buried oxide layer(310). A P- diffusion region(360) is formed on the silicon layer(320) of both sides of the gate. The P- diffusion region(360) is formed on the N well(340) of a lower portion of the first opening portion. An N- diffusion region(370) is formed on the N well(340) of a lower portion of the second opening portion. A spacer(380) is formed on both sidewalls of the gate and the first and the second opening portions. A P+ diffusion region(390) is formed within the surface silicon layer(320) and the N well(340). An N+ diffusion region is formed on the N well(340). A silicide layer(410) and a contact wire(420) is formed on the gate, the source/drain, the P+ diffusion region(390), and the N+ diffusion region(400).