SOI NMOS ESD device and preparing method thereof

Abstract

The invention provides an SOI NMOS ESD device and a preparing method thereof. In a bulk silicon region, an ESD acceptor doping ion implantation region is formed on the bottom of a channel, being close to and making contact with the side edge of a drain region, and being far away from a source region and the surface of the bulk silicon region, and therefore the ESD acceptor doping ion implantation region can be applied to an SOI device; the ESD acceptor doping ion implantation region located at the position can guide ESD trigger currents to flow through the bulk silicon region, the depth range of the bulk silicon region is larger than that of the drain region, the effect of electrostatic discharge is improved, and breakdown voltage of the drain region is decreased.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an SOI NMOS ESD device and a method for preparing the SOI NMOS ESD device. Background technique [0002] As semiconductor device technology continues to enter submicron and deep submicron, the reliability of electrostatic discharge protection (ESD) devices is becoming more and more important. In order to overcome the problem of decreased electrostatic discharge protection (ESD) capability brought about by the LDD structure, electrostatic discharge (ESD) ion implantation (ESD implant) technology is used to improve the electrostatic discharge (ESD) protection capability of NMOSESD devices, which is carried out under the drain The ESD acceptor dopant ion implantation reduces the breakdown voltage of the drain, which can improve the electrostatic protection capability of the NMOS ESD device. Usually, the ESD acceptor doping ion implantation uses boron for ion doping. Boron i...

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Problems solved by technology

However, the above ESD acceptor doping ion implantation process is not suitable for SOI NMOS ESD devices

This is because the drain region of the SOI device is completely implanted with N+, and there is no space for ESD acceptor dopant ion implantation under the drain region, such as figure 2 Shown is a schematic structural diagram of an existing SOI NMOS device, wherein 00 represents the bottom silicon layer of the SOI substrate, 200 represents the intermediate dielectric layer of the SOI substrate, 201 represents the bulk silicon region, 202 represents the gate, and 203 represents the drain Pole, 204 represents the source, it can be seen that the drain 203 region is directly in contact with the intermediate dielectric layer below it, so that the ESD acceptor doping ion implantation region cannot be formed under the drain 203 region, therefore, an ESD is formed in the device This method of ion-implanted regions will no longer be applicable in SOINMOS ESD devices

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