A kind of fce diode and its manufacturing method

Abstract

The invention discloses an FCE diode and a manufacturing method thereof. The FCE diode comprises: a drift layer; a P-type layer positioned on a first surface of the drift layer; an N-buffer layer positioned on a second surface of the drift layer; an N++ layer formed by implanting N-type ions into the N-buffer layer A doped layer, wherein the thickness of the N++ doped layer is less than the thickness of the N buffer layer; a plurality of N++ doped regions formed by etching the N++ doped layer and the trench between every two adjacent N++ doped regions , the bottom 10 of the groove contacts the N-buffer layer; the P++ doped region that is not in contact with the N++ doped region formed by implanting P-type ions into the N-buffer layer through the groove, wherein the thickness of the P++ doped region is less than N‑buffer thickness. Adopting the present invention can improve the contact effect of the P++ doped region while ensuring better soft recovery characteristics, thereby simultaneously reducing the contact resistance of the cathode surface of the FCE diode.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to an FCE diode and a manufacturing method thereof. Background technique [0002] Existing FRD (Fast recovery diode, fast recovery diode) such as figure 1 As shown, it includes a drift layer 101, a P-type layer 102 on the first surface of the drift layer 101, an N-buffer layer 103 on the second surface of the drift layer 101, and N-type ions are implanted into the N-buffer layer 103. And the formed N++ doped layer 104, the first metal layer 105 on the P-type layer 102 and the second metal layer 106 on the N++ doped layer 104, wherein the thickness of the N++ doped layer 104 is smaller than the N-buffer layer 103 thickness of. [0003] An ideal FRD must have the characteristics of low conduction voltage drop, low reverse recovery loss and high soft recovery factor. However, for figure 1 As shown in the FRD, if it has low turn-on voltage drop characteristics, it is r...

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Problems solved by technology

[0005] because figure 2 The N-type ions of the N++ doped layer 104 and the P-type ion concentrations of the P++ doped region 201 in the N++ doped layer 104 are all very high, so that the N-type ions of the N++ doped layer 104 and the P-type ions of the P++ doped region 201 are easily mixed in the P++ The impurity regions compensate each other, reducing the contact effect between the P++ doped region 201 and the second metal layer 106

If the concentration of N-type ions in the N++ doped layer 104 is reduced, the soft recovery characteristics of the FCE diode will be weakened

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