Semiconductor device with superjunction structure and preparation method thereof

Abstract

The invention provides a semiconductor device with a super-junction structure. The semiconductor device comprises a cellular area. The cellular area comprises a second-conductive-type first body area, first-conductive-type guide pillars and second-conductive-type guide pillars. A preset distance is kept between each second-conductive-type guide pillar and the first body area above the second-conductive-type guide pillars. The second-conductive-type guide pillars are partially or totally separated from the first body area above the second-conductive-type guide pillars. Capacitance between a source electrode and a drain electrode can be effectively reduced, and furthermore switching loss of the semiconductor device is reduced. The semiconductor device further has functions of restraining minority-carrier injection, restraining minority-carrier extraction in a reverse recovery period, improving a reverse recovery characteristic and reducing loss and voltage oscillation in a reverse recovery period. Through controlling the connecting area between the second-conductive-type guide pillars in the cellular area and the first body area above the second-conductive-type guide pillars, semiconductor device breakdown in the cellular area can be ensured, and furthermore durability of the semiconductor device can be improved.

Description

technical field [0001] The invention belongs to the manufacturing field of semiconductor devices, and relates to a semiconductor device with a super junction structure and a preparation method thereof. Background technique [0002] Metal-Oxide-Semiconductor Field-Effect Transistor, referred to as Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), is a field-effect transistor (field- effect transistor). MOSFETs can be divided into N-type and P-type MOSFETs according to the polarity of their "channels", commonly known as NMOSFETs and PMOSFETs. A common N-type MOSFET uses a P-type silicon semiconductor material as the substrate, diffuses it to form an N-type region, covers the top surface with an insulating layer, and finally sets holes on the N-type region as electrodes. In order to improve the characteristics of certain parameters, such as increasing the operating current, increasing the operating voltage, reducing the on-resistance, and improving the switching cha...

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Problems solved by technology

[0009] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a semiconductor device with a super junction structure, which is used to solve the problem in the prior art that due to the second conductivity type guide pillars in the cell region passing through the second conductivity The type of body region is directly connected to the source electrode, which causes the capacitance between the source and the drain to increase, which in turn increases the switching loss of the semiconductor device, resulting in a large number of minority carrier injection and too fast reverse extraction, thus In the reverse recovery stage, it causes more loss and excessive voltage oscillation, and makes the breakdown voltage of the cell region too high, making the semiconductor device easy to break down at the terminal, resulting in the durability of the semiconductor device the problem of reduced

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