Field effect transistor, marginal structure and relative manufacture method

Abstract

The invention provides a field effect transistor, a marginal structure used for the field effect transistor and manufacture methods of the field effect transistor and the marginal structure. The field effect transistor comprises a transistor unit formed in an effective unit region and the marginal structure formed in a marginal region. The marginal structure comprises a plurality of groove-type isolation units which are sequentially distributed from inner side to outer side of the marginal region, wherein the starting groove-type isolation unit nearest to the inner side of the marginal region divides a body region of the field effect transistor into an effective body region and a suspension body region in electricity suspension, the starting groove-type isolation unit is connected with a grid region of the transistor unit in an electric coupling mode, and other groove-type isolation units are in electric suspension. The marginal region can not only well isolate the marginal region from the effective unit region so as to protect the transistor unit in the effective unit region against being influenced by carriers of the marginal region, but also solve the problem that the starting groove-type isolation unit is prone to breakdown, and has relatively high reverse breakdown voltage and good operation stability.

Description

technical field [0001] Embodiments of the present disclosure relate to semiconductor devices, particularly but not limited to field effect transistors and methods of manufacturing the same. Background technique [0002] Semiconductor devices such as Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Junction Field Effect Transistor (JFET) and Double Diffused Metal Oxide Semiconductor Field Effect Transistor (DMOS) have been widely used in the electronics industry. In some applications, such as power switches for switching voltage converters, field effect transistors should have good current handling capabilities, low on-resistance Rds ON , higher breakdown voltage BV and good safety and durability. [0003] Field effect transistors such as MOSFETs, JFETs, DMOSs, etc. are usually fabricated on a semiconductor substrate and have an active cell area and an edge area. The effective cell area includes at least one field effect transistor unit, has a gate area, a source...

AI Technical Summary

Problems solved by technology

Therefore, the existence of the strong electric field region on the left side of the leftmost trench type isolation unit 109 will cause the reverse breakdown voltage of the field effect transistor 10 to drift or decrease, which cannot meet the expected design requirements.

In addition, during use, the leftmost trench isolation unit 109 of the field effect transistor 10 may repeatedly withstand a strong voltage for a long time, so the reliability and durability will also be reduced, affecting the service life of the field effect transistor 10

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