LDMOS capable of lowering LDMOS on resistance and increasing breakdown voltage in on state

Abstract

A laterally double-diffused metal-oxide-semiconductor field effect transistor, comprising: a semiconductor substrate (200), located in a body area (201) for said semiconductor substrate (200); a drift region (204), located in said semiconductor substrate (200); a source region (205) and a body lead-out region (202) located in the body region (201) and separated from the drift region (204); a field region (208) and a drain region (206) located in the drift region (204); and a gate electrode located on the surface of the semiconductor substrate (200), partially covering the body region (201), the drift region (204) and the field region (208). The field region (208) and drain region (206) are separate one from the other by a certain distance. In the present semiconductor component, while the original dimensions of the drift region (204) remain unchanged, the dimensions of the field region (208) of the drift region (204) near the drain end are shortened, changing the drift region, which originally was wholly a field region, into one section of field region and one section of active region, thus reducing LDMOS on-resistance, while at the same time increasing on-state breakdown voltage.

Description

technical field [0001] The invention relates to the technical field of lateral double diffused metal oxide semiconductor field effect transistors (Lateral Double Diffused MOSFET, LDMOS), in particular to an LDMOS device structure that reduces the on-resistance and simultaneously increases the on-state breakdown voltage. Background technique [0002] With the continuous development of semiconductor technology, lateral double-diffused metal-oxide-semiconductor field-effect transistor (LDMOS) devices are widely used in mobile phones, especially in cellular phones, due to their good short-channel characteristics. With the continuous increase of the mobile communication market (especially the cellular communication market), the manufacturing process of LDMOS devices is becoming more and more mature. As a power switching device, LDMOS has the characteristics of relatively high working voltage, simple process, and easy process compatibility with low-voltage CMOS circuits. It includ...

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Problems solved by technology

In the prior art, in order to obtain a smaller on-resistance, the size of the drift region is made small. When the LDMOS is working under high-voltage conditions, the depletion layer in the drift region extends to the drain, and it is easy to expand to a high concentration in the drain region. The lead-out end (such as n+), thus forming a large electric field at the boundary of the high-concentration lead-out end, it is easy to cause breakdown due to impact ionization caused by the large electric field, that is, the breakdown voltage in the on state is low

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