Field Effect Transistor, Edge Structure and Related Manufacturing Method

Abstract

A field effect transistor includes a transistor cell formed in an active cell region and an edge structure formed in an edge region. The edge structure includes a plurality of isolation units, and each isolation unit includes a first-type trench and a guard ring region under the bottom of the first-type trench. The sidewall and bottom of each first-type trench are covered with a dielectric layer, and filled with a first conductive spacer, a second conductive spacer, and an isolation dielectric between the first conductive spacer and the second conductive spacer. electrical layer. The edge structure can not only isolate the edge area from the effective cell area well, but also has reduced edge area area and manufacturing cost, and solves the problem of easy breakdown of groove-type isolation cells, and improves the reverse breakdown voltage and other job 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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