Semiconductor device and method for forming semiconductor device

Abstract

The invention discloses a semiconductor device and a forming method of the semiconductor device. The forming method of the semiconductor device comprises the following steps: providing a semiconductor substrate, wherein a liner oxide layer and a hard mask layer are formed on the surface of the semiconductor substrate, and the hard mask layer is positioned on the surface of the liner oxide layer; etching the liner oxide layer and the semiconductor substrate of a part of thickness in sequence to form a first channel; laterally etching back a part of hard mask layer on the two sides of the first channel; forming a first isolation layer for filling the first channel; etching back to remove the liner oxide layer and the first isolation layer of a part of thickness until the top of the first isolation layer is lower than the surface of the semiconductor substrate to form a second channel; forming an epitaxial layer on the surface and the side wall of the semiconductor substrate in the second channel, wherein the epitaxial layer and the semiconductor substrate are made of the same material. The formed semiconductor device has larger active region width, and the drive current of the semiconductor device is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a semiconductor device and a method for forming the semiconductor device. Background technique [0002] The development direction of semiconductor integrated circuits is to increase density and reduce components. Therefore, in the manufacture of integrated circuits, isolation structures are an important technology. The components formed on the semiconductor substrate must be isolated from other components. With the advancement of semiconductor manufacturing technology, the shallow trench isolation (STI: Shallow Trench Isolation) method has replaced the isolation method used in the traditional semiconductor device manufacturing, such as local oxidation method (LOCOS) and other isolation methods. [0003] Compared with other isolation methods, the shallow trench isolation method has many advantages, mainly including: the shallow trench isolation method can obtain a narrow...

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Problems solved by technology

However, when the shallow trench width of the shallow trench isolation structure is narrowed, it will cause other negative effects, such as increasing the difficulty of filling the shallow trench isolation structure (gap-filling)

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