Semiconductor device with improved breakdown voltage and high current capacity

Abstract

To improve the avalanche resistance of an entire element by improving the avalanche resistance of the peripheral part of the element in a super junction semiconductor element. A drain drift part has a first parallel pn structure constituted by alternately and repeatedly bonding a first n-type region and a first p-type region at a pitch P1. The periphery of the drain drift part is the fringe of an element comprising a second parallel pn structure. The fringe of the element continuing to the first parallel pn structure is constituted by alternately and repeatedly bonding a second n-type region and a second p-type region at the pitch P1. Impurity concentrations of the first and the second parallel pn structures are almost equal to each other. A third parallel pn structure formed at a surface layer region of the fringe of the element is constituted by alternately and repeatedly bonding a third n-type region and a third p-type region having the higher impurity concentration than that of the third n-type region at a pitch P2 smaller than the P1. The impurity concentration of the third parallel pn structure is lower than those of the first and the second parallel pn structures.

Description

technical field

[0001] The present invention relates to a high withstand voltage and large current capacitor applicable to active elements such as MOSFET (insulated gate electric field effect transistor), IGBT (insulated gate bipolar transistor), and bipolar transistor, or passive elements such as diodes. vertical power semiconductor components. Background technique

[0002] Generally, semiconductor elements are classified into: a lateral element having electrodes formed on one side; and a vertical element having electrodes on both sides. The direction in which the drift current flows in the ON state of the vertical semiconductor element is the same as the direction in which the depletion layer grows due to the reverse bias voltage in the OFF state. In the usual planar n-channel vertical MOSFET, the high resistance n - The drift layer portion operates as a region where a drift current flows in the vertical direction when in the ON state. Therefore, if the n - When the cu...

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