A kind of preparation method of semiconductor device

Abstract

The invention provides a preparation method of a semiconductor device. The preparation method comprises that a semiconductor substrate is provided, and an isolation structure is formed in the semiconductor substrate, and divides the semiconductor into an NMOS region and a PMOS region; a high k dielectric layer, a cover layer, a dummy grid layer and a hard mask layer are successively deposited on the semiconductor substrate successively; the high k dielectric layer, the cover layer, the dummy grid layer and the hard mask layer are patterned to form an NMOS virtual grid structure and a PMOS virtual grid structure; and residual cover layer and high k dielectric layer between the NMOS virtual grid structure and the PMOS virtual grid structure are removed by implementing a dry-etching stress proximity technology. According to the method provided by the invention, the residual cover layer and high k dielectric layer are completely removed via the dry-etching stress proximity technology, the carrier mobility is improved, bridging and short-circuit problems in the semiconductor device are effectively solved, and influence on the whole technical flow is reduced to the minimum.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a method for preparing a semiconductor device. Background technique [0002] With the development of semiconductor technology to the nanotechnology node, stress technology has been used in the CMOS process to improve the performance of semiconductor devices. The main factor affecting the performance of field effect transistors is the mobility of carriers, where the mobility of carriers will affect the magnitude of the current in the channel. The reduction in carrier mobility in field-effect transistors not only reduces the switching speed of the transistor, but also reduces the difference in resistance between on and off. Therefore, in the development of complementary metal-oxide-semiconductor field-effect transistors (CMOS), effectively improving carrier mobility has always been one of the key points in transistor structure design. [0003] Conventionally, in the CMOS d...

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Problems solved by technology

However, in the conventional SPT technology, it is still unable to solve the residual problem of the cover layer, so that the existence of bridging and short circuit problems in semiconductor devices cannot be avoided

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