METHOD OF FORMING DUAL GATE OXIDE LAYER FOR MINIMIZING EFH STEP BY CONTROLLING GROWTH OF OXIDE LAYER BY SELECTIVE ION IMPLANTATION PROCESS

摘要

PURPOSE: A method for forming a dual gate oxide layer of a semiconductor device is provided to minimize an EFH(Effective Fox Height) step and prevent a short error such as a gate bridge by performing a selective ion implantation process to control growth of an oxide layer. CONSTITUTION: Isolation layers(102a,120d) are formed on a cell region and a peripheral region of a semiconductor substrate(100) to define an active region. A first gate oxide layer is formed on the active region. A photoresist layer is formed on the cell region. A gate oxide layer is etched by using the photoresist layer as a mask. Ions are implanted into the entire surface of the resultant structure in order to control growth of the isolation layer of the peripheral region. The implanted isolation layer is grown. A second gate oxide layer(108) which is thinner than the first gate oxide layer is formed on the peripheral region.