MOS device with extended drain region and manufacturing method thereof

Abstract

The invention discloses an MOS (Metal Oxide Semiconductor) device with an extended drain region and a manufacturing method of the MOS device. The MOS device comprises a substrate, an epitaxial layer and a grid electrode, the epitaxial layer is arranged on the substrate, the conduction type of the epitaxial layer is the same as that of the substrate, and a well region, a channel doping region, a drain region extension region, a drain region and a source region are formed in the epitaxial layer; the grid electrode is formed on the epitaxial layer; the channel doping region is located below the grid electrode, and the conduction type of the channel doping region is opposite to that of the epitaxial layer; the well region is located below the channel doping region and is in contact with the drain region extension region, and the conduction type of the well region is the same as that of the epitaxial layer; the conduction type of the source region is opposite to that of the substrate. According to the invention, the thermal process of processing is reduced, the process is simplified, the consistency of the device is improved, the hot carrier injection effect of the device is inhibited, the doping concentration of the drain region extension region is improved, the on-resistance of the device is further reduced, and the performance of the device is improved.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and in particular relates to a MOS device with an extended drain region and a manufacturing method thereof. Background technique [0002] figure 1 It is a schematic structural diagram of a traditional power application LDMOS device, wherein the conductivity type of the source region 13, the drift region 14 and the drain region 15 are the same, the conductivity type of the channel region under the gate region 11 is the same as that of the body region and the source region 13 is opposite, and the drift Region 14 increases the breakdown voltage of the LDMOS, thereby increasing the output power of the device. [0003] Traditional LDMOS devices, formed by ion implantation figure 1 The well region 17 of the well region, and through long-term high-temperature annealing, the body region diffuses laterally and contacts the drift region 14 to form the channel of the device. Long-term...

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Problems solved by technology

Long-term high-temperature annealing increases the thermal process of the device, reduces the consistency of the device, and at the same time causes the device junction to become deeper and increase the device capacitance

Traditional LDMOS devices are prone to hot carrier injection effects in high-voltage and high-current scenarios, and carriers enter the gate oxide layer 12 area, which aggravates the changes in device on-resistance, saturation current, threshold voltage, and breakdown voltage. changes, reducing device life

Moreover, as the doping concentration of the drift region 14 increases, the hot carrier effect intensifies

In order to improve the efficiency of the device, the designer hopes to increase the doping concentration of the drift region 14. The traditional LDMOS device is trapped by the hot carrier injection effect, which cannot reduce the on-resistance and improve the performance of the device.

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