Epitaxial structure capable of lowering switch-on resistance of super-junction device and manufacturing method

Abstract

The invention provides an epitaxial structure capable of lowering switch-on resistance of a super-junction device and a manufacturing method. In the section view plane of the epitaxial structure, a plurality of first conductive type injection regions are connected to form a first conductive type column in a direction from a first conductive type epitaxial layer to the depth direction of a first conductive type heavily doped substrate; a plurality of second conductive type injection regions are connected to form a second conductive type column; the first conductive type column and the second conductive type column are distributed alternately in parallel to jointly form a super-junction structure; and the width of the first conductive type injection regions is X, and the width of the secondconductive type injection regions is Y, wherein 2Y+X is less than L. By changing the width of each mask plate and by further enabling an N type injection region and a P type injection region to be spaced at a certain width, the problem existing diffusion and compounding between an N type column and a P type column of a small-sized super-junction device can be solved, the impurity injection concentration of the N type epitaxial layer can be improved, and the device switch-on resistance RSP can be further improved.

Description

technical field [0001] The invention relates to an epitaxial structure of the on-resistance of a super-junction device, in particular to an epitaxial structure and a manufacturing method capable of reducing the on-resistance of a super-junction device, and belongs to the field of MOSFET technology. Background technique [0002] At present, in the field of superjunction-superjunction design and manufacturing, in order to pursue lower and lower on-resistance-RSP, the size of the device unit-cellpitch is constantly being reduced. When the pitch is large (such as 16um), the reduction of the pitch is indeed It can bring lower and lower RSP, but when the cellpitch is further reduced (for example, below 8um), the reduction of the cellpitch cannot bring about a lower RSP, and may even cause an increase in RSP, because the device size is reduced to After a certain degree, after the P / N implantation of each layer of EPI in the superjunction undergoes thermal annealing, the diffusion a...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the shortcomings of existing super-junction devices on the basis of proposing an epitaxial structure and manufacturing method that can reduce the on-resistance of super-junction devices. A certain width from the P-type implanted region can effectively solve the problem of diffusion and recombination between the N-type pillar and the P-type pillar of the small-sized super-junction device, increase the impurity implantation concentration of the N-type epitaxial layer, and then increase the on-resistance RSP of the device

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