A gate structure of a semiconductor device and its manufacturing method

Abstract

The invention relates to a gate structure of a semiconductor device. The gate structure comprises a gate oxide layer, a field oxide structure and a poly-silicon split gate, wherein the gate oxide layer is arranged on a substrate, the field oxide structure is arranged on the gate oxide layer, the poly-silicon split gate is arranged on the gate oxide layer and the field oxide structure, the width of the field oxide structure is smaller than the distance of two surfaces, deviating from each other, between a first gate structure and a second gate structure, and greater than the distance between the first gate structure and the second gate structure, and the orthographic projection of an interval region between the first gate structure and the second gate structure on the field oxide structure is not beyond the edge of the field oxide structure. The invention also relates to a fabrication method for the gate structure of the semiconductor device. The fabrication method is compatible and consistent with the traditional fabrication methods of a power vertical double-diffusion metal oxide semiconductor field effect transistor (VDMOS) and an insulated gate bipolar transistor (IGBT) chip, the process difficulty and the photoetching frequency are not increased, the specific turn-on resistance, the gate charge Qg and the leakage current Idss are low, the reliability is high, the chip area is small, the production cost can be greatly reduced, and the fabrication method can be used for manufacturing the power VDMOS and the IGBT chip at a large scale, low cost and high reliability.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a gate structure of a semiconductor device, and also to a method for manufacturing the gate structure of a semiconductor device. Background technique [0002] Power VDMOS (Vertical Double Diffused Metal Oxide Semiconductor Field Effect Transistor) and power IGBT (Insulated Gate Bipolar Transistor) devices have a huge demand in the power drive market. They are used in people's daily life, industrial and agricultural production, national defense and aerospace technology It can be seen everywhere, but in today's increasingly fierce competition and increasing emphasis on production costs, power device manufacturers are facing tremendous pressure to produce high-performance devices and reduce production costs. Due to the wide polycrystalline gate of the existing power devices VDMOS and IGBT, the gate area of ​​the entire device is large, so the gate charge Qg is very large, ...

AI Technical Summary

Problems solved by technology

The problem with this method of reducing Qg is that it has a limited effect on reducing Qg. Although the frequency characteristics of the device have been improved, it still cannot meet the needs of high-frequency switching characteristics.

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