Semiconductor on insulator (SOI) substrate, semiconductor device with SOI substrate and forming methods for SOI substrate and semiconductor device

Abstract

The invention provides a method for forming a semiconductor on insulator substrate and a structure of the semiconductor on insulator substrate. The method comprises the following steps of: A, providing a first semiconductor wafer, wherein the first semiconductor wafer comprises a first surface and a second surface which are opposite to each other; B, etching the first surface to ensure that at least two flat regions are formed on the first semiconductor wafer, wherein each flat region has a uniform thickness, and the flat regions totally have at least two kinds of the thicknesses; C, forming a first insulation layer on the first surface, wherein the first insulation layer covers the flat regions so as to form a flat surface; and D, bonding a second semiconductor wafer on the first insulation layer. By forming the semiconductor on insulator substrate which comprises two flat regions with at least two kinds of thicknesses, a partially-depleted semiconductor on insulator (PDSOI) device and a fully-depleted semiconductor on insulator (FDSOI) device are integrated on the same chip, and the performance of an integrated circuit can be enhanced conveniently.

Description

technical field [0001] The present invention relates to the field of semiconductor design and manufacture thereof, in particular to an SOI (Semiconductor on Insulator, semiconductor on insulator) substrate, a semiconductor device with the SOI substrate and a forming method thereof. Background technique [0002] With the continuous development of semiconductor technology, SOI technology is favored because it can significantly improve the performance of devices and integrated circuits. The so-called SOI technology means that a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) device is formed on a semiconductor thin film on an insulator. Such as figure 1 As shown, a typical SOI substrate includes a semiconductor substrate 10 (such as bulk silicon), an insulating layer 20 (such as buried oxide silicon oxide) and a semiconductor film 30 (such as active silicon) from bottom to top, wherein the active silicon layer Shallow trench isolation (STI) 40 may be embedded. [...

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Problems solved by technology

However, because it is difficult to achieve this integration based on existing SOI silicon wafers and processes, how to integrate PDSOI devices and FDSOI devices in the same chip is still one of the research hotspots in this field

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