Semiconductor structure and manufacture method thereof

Abstract

The invention discloses a semiconductor structure and a manufacture method thereof. The semiconductor structure comprises a first conductive substrate, a second conductive well area, a grid electrode structure, a second conductive diffusion source electrode, a second conductive diffusion drain electrode and a plurality of first conductive buried rings, wherein the second conductive well area is arranged on the first conductive substrate; the grid electrode structure comprises a first edge and a second edge; the first edge is arranged on the second conductive well area; the second conductive diffusion source electrode is arranged on the first conductive substrate at the outer side of the second edge; the second conductive diffusion drain electrode is arranged on the second conductive well area at the outer side of the first edge; the plurality of first conductive buried rings are transversally arranged and mutually separated in the second conductive well area, and the doping outlines of the first conductive buried rings are gradually reduced from the second conductive diffusion source electrode to the second conductive diffusion drain electrode. The semiconductor structure and the manufacture method thereof, which are provided by the embodiment of the invention, can simultaneously increase the breakdown voltage and decrease the on-resistance.

Description

technical field [0001] The invention relates to a semiconductor structure and a manufacturing method thereof, in particular to a double-diffused metal oxide semiconductor transistor and a manufacturing method thereof, so as to increase breakdown voltage and reduce on-resistance at the same time. Background technique [0002] In today's integrated circuit manufacturing process, a large number of devices such as controllers, memories, low-voltage operating elements, and high-voltage power elements have been integrated in a single chip, thus forming a single chip system. In order to cope with high voltage and current requirements, high voltage devices such as double-diffused metal oxide semiconductor (DMOS) transistors are usually used in power supply devices, which have low conduction when operating at high voltages. Resistance (on-resistance). In addition, other high-voltage devices such as laterally diffused metal oxide semiconductor transistors (Lateral double-diffused met...

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Problems solved by technology

However, it has been found that when the LDMOS with the above-mentioned structure is turned off, the electric field will be concentrated near the N+ type drain region 406, and the crowded electric field (or current crowding effect) will cause the breakdown voltage of the device to drop. , and at the same time reduce the switching speed of the component (switchingspeed)

On the other hand, although the method of reducing the doping concentration of the N-type well 413 to increase the degree of depletion can be used to increase the breakdown voltage, the on-resistance of the element will be increased accordingly.

According to the above, the current technology is still difficult to achieve high breakdown voltage and low on-resistance at the same time, so it is difficult to apply in ultra-high voltage (UHV) devices, so it is necessary to provide a semiconductor structure and its forming method to overcome Shortcomings of prior art

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