Field effect transistor and its manufacturing method

Abstract

The invention relates to a field-effect tube and a fabrication method thereof. The fabrication method of the field-effect tube comprises the steps of providing a silicon-on-insulator (SOI) substrate,wherein the SOI substrate comprises a silicon substrate, a buried oxide layer and top-layer silicon which are sequentially arranged; forming a P-type low-doping region on the top-layer silicon; forming an N-type high-doping region on a surface of the P-type low-doping region; etching the N-type high-doping region and the P-type low-doping region so as to form a first groove in the surface of the N-type high-doping region and form two second grooves, penetrating through the N-type high-doping region, the P-type low-doping region and the buried oxide layer, extending to the silicon substrate andcommunicating the first groove, in the bottom of the first groove; forming grid oxide layers on inner walls of the first groove and the second grooves; removing the grid oxide layers at the bottoms of the second grooves; forming poly-silicon on surfaces of the grid oxide layers in the first groove and the second grooves and the silicon substrate; and forming dielectric layers, contact holes, drains and sources on the poly-silicon and the grid oxide layers.

Description

【Technical Field】 [0001] The present invention relates to the technical field of semiconductor manufacturing technology, in particular, to a field effect tube and a manufacturing method thereof. 【Background technique】 [0002] Field effect tubes are widely used in the field of switching power supplies. However, in the existing field effect transistors, because the gate is above the channel region, the channel region is only controlled by the gate above the channel region, and the bottom of the channel is affected by the gate. Very weak. The carriers from the source to the drain are sometimes not controlled by the gate, causing problems such as current leakage. In addition, for the conventional structure, the gate is on the same side as the source and drain. However, for packaging in some application fields, if the gate and source and drain are not on one side, it will be more troublesome for the field effect tube packaging. [Content of the invention] [0003] One of the object...

AI Technical Summary

Problems solved by technology

However, for packaging in some application fields, if it is required that the gate and source and drain are not on one side, the packaging of field effect transistors will be more troublesome.

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