High-voltage LDMOS device and manufacturing method thereof

Abstract

The invention provides a manufacturing method of a high-voltage LDMOS device. The manufacturing method comprises the following steps: performing well injection in a P-type substrate to form an N well and a P well; depositing an active area isolation layer in the P well, and etching the P well to form an active area groove; removing the active area isolation layer, and filling an insulating material in the active area groove; injecting N-type impurity ions into the active area by a first doping amount and a first doping energy; injecting N-type impurity ions into the active area by a second doping amount and a second doping energy to form a drift area; depositing and etching the high-voltage gate isolation layer; growing a high-voltage gate oxide layer in a high-voltage gate area, and removing the high-voltage gate isolation layer; and depositing and etching polysilicon above the high-voltage gate oxide layer. The invention also provides an LDMOS device prepared by the method. The invention can effectively combine the substrate drain current performance and the interface breakdown voltage of the LDMOS device.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a high-voltage LDMOS device and a manufacturing method thereof. Background technique [0002] 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 LDMOSFET (lateral double-diffused MOSFET). LDMOS is widely adopted in the industry because it is easier to be compatible with CMOS process. [0003] At present, a high voltage laterally diffused metal oxide semiconductor transistor (HV LDMOS, Highvoltage Laterally Diffused Metal Oxide semiconductor) is widely used in a driver chip of a thin film transistor liquid crystal display (TFT-LCD, Thin Film Transistor liquid crystal Display). HV LDMOS devices have been integrated in a standard 0.18um logic process. However, under the premise of improved integration and performance,...

AI Technical Summary

Problems solved by technology

However, if the doping dose in the drift region is increased, the performance of the substrate leakage current will eventually increase. Due to the increase in the concentration of the doped region, the electric field strength in the drift region will increase, and as a result, breakdown will occur more easily. The breakdown voltage performance of the device is not enough to load the working voltage of the device, and the entire device will be irreversibly damaged due to breakdown

[0014] To sum up, improving the substrate leakage current performance and obtaining the ideal interface breakdown voltage are actually contradictory, and it is easy to lose sight of the other in the integrated circuit manufacturing process

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