Shield gate groove type semiconductor device and manufacturing method thereof

Abstract

The invention relates to the technical field of semiconductor integrated circuit manufacturing, in particular to a shield gate groove type semiconductor device and a manufacturing method thereof. The device comprises a substrate layer, wherein a plurality of first grooves are formed in the substrate layer; a second groove is formed between every two adjacent first grooves; the first grooves extend downwards from the upper surface of the substrate layer by a first depth; the second grooves extend downwards from the upper surface of the substrate layer by a second depth; the second depth is smaller than the first depth; shielding electrodes and first gate electrodes are formed in the first grooves, and oxide layers are arranged between the shielding electrodes and the first gate electrodes, between the shielding electrodes and the side walls of the first grooves and between the first gate electrodes and the side wall of the first grooves to realize isolation of the above parts; second gate electrodes are formed in the second grooves, and oxide layers are arranged between the second gate electrodes and the side walls of the second grooves to isolate the second gate electrodes and the side walls of the second grooves; and source structures are formed on the upper layers of the parts, located between adjacent first grooves and second grooves, of the substrate layer. The method is used for manufacturing the device.

Description

technical field [0001] The present application relates to the technical field of semiconductor integrated circuit manufacturing, in particular to a shielded gate trench type semiconductor device and a manufacturing method thereof. Background technique [0002] Power semiconductor devices are the core devices of electric energy / power processing, mainly used for electric energy transformation and circuit control of high-power electric equipment. Operation plays a key role. [0003] In the past three decades, power devices have achieved leapfrog development, especially power metal oxide semiconductor field effect transistors (Metal Oxide Semiconductor Field Effect Transistor, MOSFET). The conduction loss and switching loss must be effectively reduced. At present, the device with the smallest switching loss among medium and low voltage power devices is the shielded gate power MOSFET. The Miller capacitance of this device is very small, so the switching speed of the device is ex...

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Problems solved by technology

[0004] However, in related technologies, there is a large tradeoff between the breakdown voltage and on-resistance of the shielded gate power MOSFET, that is, if the device is to have a higher breakdown voltage, the on-resistance will increase. Part of the breakdown voltage is sacrificed to make the device have a lower on-resistance

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