Method for introducing strain to channel and device manufactured by the same

Abstract

A method for introducing a strain into the channel of an MOS device and a device manufactured by the method are provided. The method includes providing a semiconductor substrate (202), forming a channel (203) on the semiconductor substrate, forming a first gate dielectric layer (204) on the channel, forming a polysilicon gate layer (206) on the first gate dielectric layer; doping or implanting a first element into the polysilicon gate layer, removing parts of the first gate dielectric layer and the polysilicon gate layer so as to form a first gate structure; forming source / drain extension regions (212) in the channel, forming sidewalls (207) along two sides of the first gate structure, forming a source and a drain (214) in the channel, and performing an annealing process so that the lattice of the polysilicon, doped or implanted with the first element, is changed during the high-temperature crystallization process, a first stress is created in the polysilicon gate layer and then introduced into the channel through the gate dielectric layer.

Description

technical field [0001] The invention relates to a method for introducing strain into a channel and a device made by the method. Background technique [0002] Theoretical and empirical studies have confirmed that when stress is applied to the channel of a transistor, the semiconductor lattice in the channel region is strained, and the carrier mobility of the transistor can be increased or decreased; however, it is also known that the electron and space Caves respond differently to the same type of strain. For example, compressive stress is applied in the longitudinal direction of current flow to cause compressive strain in the channel region, which is beneficial to improve hole mobility, but correspondingly reduces electron mobility. Applying tensile stress in the longitudinal direction leads to tensile strain in the channel region, which is beneficial to improve electron mobility, but correspondingly reduces hole mobility. With the continuous reduction of device feature si...

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Problems solved by technology

However, some of the above-mentioned methods of generating channel local strain and changing the type of channel stress require complex processes, and some are easy to introduce defects into the channel. On the other hand, with the continuous shrinking of device feature size, The induced strain effect is also weakening

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