METAL-OXIDE-SEMICONDUCTOR DEVICE INCLUDING A BURIED LIGHTLY-DOPED DRAIN REGION

摘要

An MOS(Metal Oxide Semiconductor) device, a forming method thereof and an IC(Integrated Circuit) are provided to improve the performance in a high frequency range without remarkable increase of costs by restraining HCD(Hot Carrier Degradation) and capacitance between a gate and a drain using a shielding structure. A second conductive type source and drain region(106,108) are spaced apart from each other in a first conductive type semiconductor layer(104). A gate(110) is formed on the semiconductor layer. A second conductive type LDD(Lightly Doped Drain) region(114) is horizontally spaced apart from the drain region in the semiconductor layer. A first conductive type second LDD region(116) is formed in the LDD region. At this time, the second LDD region approximates to an upper surface of the semiconductor layer. The second LDD region is self-aligned with the gate and horizontally spaced apart from the gate. A shielding structure(130) for contacting electrically the source region is formed adjacent to the gate on the semiconductor layer.