Groove silicon carbide MPS diode structure and preparation method thereof

Abstract

The invention discloses a groove silicon carbide MPS diode structure and a preparation method thereof, and the structure comprises the components of silicon carbide ohmic contact metal which is located on a P + groove region and is matched with a groove; the silicon carbide Schottky contact metal is positioned above the silicon carbide epitaxial layer and the silicon carbide ohmic contact metal and is in groove fit with the silicon carbide epitaxial layer and the silicon carbide ohmic contact metal; a groove matching structure of the silicon carbide Schottky contact metal and the silicon carbide epitaxial layer interface Schottky contact region can effectively increase the area of the Schottky contact region, so that the forward conduction voltage drop of the device is effectively further reduced, and the current density of the device is increased; and the area of the ohmic contact region is increased by a groove-groove matching structure of the P + groove region and the ohmic contact region of the silicon carbide ohmic contact metal interface, so that higher current can pass through the device in a surge mode, and the anti-surge performance of the device is further improved.

Description

technical field [0001] The invention relates to a trench silicon carbide MPS diode structure and a preparation method, and belongs to the technical field of electronic components. Background technique [0002] Prior art silicon carbide MPS diodes (also called integrated PIN Schottky diodes) such as figure 1 As shown, its main structure includes: metal upper electrode 11; silicon carbide ohmic contact metal 12 under the metal upper electrode 11; silicon carbide P+ implantation region 13 under the ohmic contact metal, wherein the P+ implantation region 13 and the metal above it 12 The contact interface is an ohmic contact area; the silicon carbide N-type epitaxial layer 14 including the implanted region 13, wherein the contact interface between the silicon carbide epitaxial layer 14 and the metal upper electrode 11 is a Schottky contact area; Silicon carbide substrate 15, metal lower electrode 16 located under the silicon carbide epitaxial layer; its main structure is also di...

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Problems solved by technology

[0003] The disadvantage of the existing structure is that in the MPS structure of the planar structure, on the one hand, the area of ​​the ohmic contact area formed by the contact interface between the P+ implantation region 13 and the metal 12 above it is limited by the planar area, and there is a problem that the anti-surge capability of the device cannot be further improved; On the other hand, the area of ​​the Schottky contact region formed by the contact interface between the silicon carbide epitaxial layer 14 and the metal upper electrode 11 is limited by the planar area of ​​the chip and directly affects the forward conduction voltage drop when the device is in operation, so the forward conduction voltage of the device cannot be further reduced. drop problem

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