| 摘要 |
PURPOSE: A fabrication method of MOSFETs(Metal Oxide Semiconductor Field Effect Transistors) is provided to improve an electrical characteristic by forming a bent insulation layer under a lower portion of a gate and in a partial portion of a channel. CONSTITUTION: After sequentially depositing a pad oxide(15) and a pad nitride(20) on a substrate(10), a trench(25) is formed by a masking etch. An insulating layer(30) and a polysilicon layer(35) are deposited to partially fill the trench and bent layers are then formed on the edge portions of the trench(25) by etching the polysilicon layer(35) and the insulating layer(30). An epitaxial silicon layer is filled into the trench(25) to enclose the bent layers. After depositing a gate oxide on the resultant structure, an ion implantation is performed in the trench(25). After depositing a gate conductive layer in the trench(25), an LDD(Lightly Doped Drain) regions are formed in active regions. After forming spacers on both sidewalls of the gate conductive layer, a source and a drain regions are formed by implanting heavily doped drain.
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