Radio frequency laterally diffused metal oxide semiconductor (LDMOS) device

Abstract

The invention discloses a radio frequency laterally diffused metal oxide semiconductor (LDMOS) device. The radio frequency LDMOS device comprises a light-doped epitaxial layer, wherein the light-doped epitaxial layer is arranged on a heavily-doped substrate, a drift region and a channel region of the LDMOS device are arranged in the light-doped epitaxial layer, the surface of the epitaxial layer where the drift region and the channel region are crossed is provided with a grid oxide layer and a poly-silicon grid, a drain region of the LDMOS device is further arranged in the drift region, a metal silicide covers the poly-silicon grid, a Z-shaped Faraday shielding ring covers the metal silicide and half covers the metal silicide above the poly-silicon grid, the lower end of the Z-shaped Faraday shielding ring covers the drift region near to the poly-silicon grid, the Faraday shielding ring is led out to a first metal layer via a contact hole, the first metal layer further crosses the part above the Faraday shielding ring to be connected with the contact hole of a channel leading-out region and an electric sink channel, and a drain is connected to a second metal layer through the contact hole. In the radio frequency LDMOS device, the leading-out mode of the Faraday shielding ring is changed, and the resistance of the Faraday shielding ring is reduced.

Description

Technical field [0001] The invention relates to the field of semiconductor integrated circuits, in particular to a radio frequency LDMOS device. Background technique [0002] Radio frequency LDMOS (RadioFrequencyLaterallyDiffusedMetalOxideSemiconductor, radio frequency lateral double diffused metal oxide semiconductor) is a radio frequency power device with high gain, high linearity, high withstand voltage and high output power widely used in radio and television transmitting base stations, mobile transmitting base stations, radars, etc. Common radio frequency RFLDMOS devices such as figure 1 As shown, it includes the following structures: source 7, drain 5, gate 11, channel 3, Faraday shield ring 10 and so on. The device is located in the epitaxial layer 2 grown on the heavily doped substrate 1. The drain end has a longer drift region 4 to obtain the required breakdown voltage. The channel 3 is formed by the self-aligned gate 11 at the edge of the source end. The P-type ion imp...

AI Technical Summary

Problems solved by technology

Due to the large resistance of the terminal of the Faraday shielding ring across the gate, it affects the response speed of the device, making it difficult to pass the linearity of the device.

However, if it is expected to reduce the resistance of the Faraday shielding ring by increasing the number of terminals of the Faraday shielding ring, it will cause uneven source current and affect the reliability of the device.

Images