Transistor structure with double buried oxide layers and preparation method thereof

Abstract

The invention provides a transistor structure with double buried oxide layers and a preparation method of the transistor structure. The transistor structure sequentially comprises a top silicon layer,an active region and a shallow trench isolation region from top to bottom, wherein the active region comprises a grid electrode located above the top silicon layer, a grid dielectric layer, and a source electrode and a drain electrode which are located at the two transverse ends of the top silicon layer; a first buried oxide layer; a second silicon layer; a second buried oxide layer; a substratesilicon layer; a through hole which sequentially penetrates through the shallow trench isolation region and the first buried oxide layer, wherein an ohmic contact region is formed at the interface ofthe second silicon layer and the through hole through the particle injection or doping; a deep trench isolation region which is formed by sequentially penetrating through the shallow trench isolationregion, the first buried oxide layer and the second silicon layer; and a defect layer formed at an interface of the substrate silicon layer and the second buried oxide layer. According to the transistor structure provided by the invention, the relatively lower substrate loss and the harmonic noise can be realized, so that a device can realize the relatively higher radio frequency characteristics under severe conditions, and is integrated with a digital circuit and an analog circuit.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a transistor structure with a double-buried oxide layer and a preparation method thereof. Background technique [0002] SOI technology (the full name of SOI is Silicon-On-Insulator, that is, silicon on insulating substrate, which is to introduce a buried oxide layer between the top silicon and the back substrate) has low power consumption, high speed, and anti-latch-up And excellent radio frequency performance and other characteristics, while SOI technology has excellent radiation resistance performance, and is widely used in the aerospace field. SOI technology is generally divided into two kinds of partial depletion and full depletion technology. For partially depleted SOI technology, a high-resistance substrate, such as HR SOI or TR SOI substrate, can be used to improve the radio frequency characteristics of the device and reduce harmonic noise. The fully deplet...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a transistor structure with a double buried oxide layer and its preparation method, so as to solve the problem that the high-resistance substrate and the back gate voltage function cannot be shared in the prior art, so it is difficult to use the back gate voltage adjustment technology to realize high-performance radio frequency circuit problem

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