Semiconductor structure and method of forming the same

Abstract

A semiconductor structure and a forming method thereof, the semiconductor structure comprising: a gate structure on a substrate, extending parallel to a surface of the substrate and transversely to a direction of extension of the gate structure; a drain on one side of the gate structure; a first drift region on the same side of the gate structure as the drain, a projection of the first drift region in the substrate covering a projection of the drain in the substrate; and a second drift region on an end of the gate structure close to the drain, the first drift region and the second drift region being spaced apart in the transverse direction, the second drift region having a higher ion doping concentration than the first drift region. In the embodiment, the projection of the first drift region in the substrate covers the projection of the drain in the substrate, so the first drift region bears a higher voltage drop of the drain, making the breakdown voltage of the LDMOS higher; and because the second drift region has a higher ion doping concentration than the first drift region, the on-resistance of the first drift region is smaller, making the on-current of the LDMOS larger.

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