LDMOS (Laterally Diffused Metal Oxide Semiconductor) field effect transistor and manufacturing method thereof

Abstract

The invention provides a LDMOS (Laterally Diffused Metal Oxide Semiconductor) field effect transistor and a manufacturing method of the LDMOS field effect transistor. The manufacturing method of the LDMOS field effect transistor comprises the following steps of: providing a semiconductor substrate; forming an opening on the surface of the semiconductor substrate; forming a mask pattern on the semiconductor substrate, wherein the mask pattern is at least exposed out of the opening; carrying out ion implantation by using the mask pattern as a mask so as to form a drain electrode gradual doped zone at the position of the opening, wherein the opening is surrounded by the drain electrode gradual doped zone and the drain electrode gradual doped zone comprises lateral parts positioned at both sides of the opening and a convex part positioned below the opening; and forming a drain zone in the drain electrode gradual doped zone. The drain electrode gradual zone between a drain electrode and a grid electrode of the LDMOS field effect transistor disclosed by the invention is the doped zone with the convex part toward the deep position of the substrate, and therefore, the electric potential of a drift region is changed along the convex part, so that the breakdown voltage is increased. In the manufacturing method of the LDMOS field effect transistor, a new photoetching mask plate is not increased, so that the process cost is not greatly increased.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an LDMOS (Lateral Double Diffusion Metal Oxide Semiconductor) field effect transistor and a manufacturing method thereof. Background technique [0002] In double-diffused MOS field-effect transistors (D-MOSFETs), the channel length is precisely controlled by using the difference in the junction depth of the two inversion impurity diffusions. DMOS has a similar structure to CMOS devices, and also has electrodes such as source, drain, and gate, but the breakdown voltage of the drain terminal is high. [0003] There are two main types of DMOS, vertical double-diffused metal oxide semiconductor field effect transistor VDMOSFET (vertical double-diffused MOSFET) and lateral double-diffused metal oxide semiconductor field effect transistor LDMOSFET (lateral double-diffused MOSFET). [0004] LDMOS is widely adopted due to its easier compatibility with CMOS processes. High-vol...

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Problems solved by technology

[0008] The greater the concentration of the drift region, the lower its resistivity

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