Preparation method of Schottky diode and Schottky diode

Abstract

The invention provides a preparation method of a Schottky diode and a Schottky diode. The preparation method comprises the steps of sequentially forming an N type epitaxial layer and a first dielectric layer on an N type substrate; performing etching on the first dielectric layer and the N type epitaxial layer in sequence to respectively form a dielectric layer step on the N type epitaxial layer and a trench of the N type epitaxial layer; etching the N type epitaxial layer by taking the dielectric layer step as a mask so as to form an N type epitaxial layer step at the edge of the trench, andthus forming a stepped trench; forming a second dielectric layer in the stepped trench; filling an intrinsic silicon structure in the stepped trench in which the second dielectric layer is formed; andforming a metal electrode at the completion of filling of the intrinsic silicon structure. According to the technical scheme of the invention, the electric field intensity inside the device in the conduction process is reduced, the maximum electric field intensity value is significantly reduced in particular, and thus the Schottky barrier lowering effect of the device is effectively reduced, so that the reverse leakage current is reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for preparing a Schottky diode and a Schottky diode. Background technique [0002] In the related art, the structure of the trench Schottky diode is as follows figure 1 As shown, it specifically includes: N-type substrate 102, N-type epitaxial layer 104, dielectric layer trench 106, polysilicon 108 and metal electrode 110 filled in the dielectric layer trench. On the one hand, the electric field intensity is changed by the effect of electric field depletion Distribution, the maximum value of the electric field intensity is transferred from the Schottky junction position to the bottom 112 of the dielectric layer trench. On the other hand, the trench Schottky diode can also reduce the maximum value of the electric field intensity in the active region, thereby improving Reverse breakdown voltage, but the Schottky barrier effect is still obvious, and the...

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Problems solved by technology

[0002] In the related art, the structure of the trench Schottky diode is as follows figure 1 As shown, it specifically includes: N-type substrate 102, N-type epitaxial layer 104, dielectric layer trench 106, polysilicon 108 and metal electrode 110 filled in the dielectric layer trench. On the one hand, the electric field intensity is changed by the effect of electric field depletion Distribution, the maximum value of the electric field intensity is transferred from the Schottky junction position to the bottom 112 of the dielectric layer trench. On the other hand, the trench Schottky diode can also reduce the maximum value of the electric field intensity in the active region, thereby improving Reverse breakdown voltage, but the Schottky barrier effect is still obvious, and the reverse leakage current of the device is large

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