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

Abstract

The invention relates to a method for introducing strain to a channel of a MOS (Metal Oxide Semiconductor) device and a device manufactured by the method. The method comprises the following steps of: providing a semiconductor substrate; forming a channel on the semiconductor substrate; forming a first grid dielectric layer on the channel; forming a polycrystalline silicon grid electrode layer on the first grid dielectric layer; doping or injecting a first element in the polycrystalline silicon grid electrode layer; removing parts of the first grid dielectric layer and the polycrystalline silicon grid electrode layer so as to form a first grid electrode structure; forming a source drain extending zone in the channel; forming side walls on both sides of the first grid electrode structure; forming a source drain electrode in the channel; and annealing so that polycrystalline silicon doped or injected with the first element generates crystal lattice variation in a high-temperature crystallization process, thus generating first strain in the polycrystalline silicon grid electrode layer, and introducing the first stress to the channel through a grid medium layer. The method has stronger process flexibility, simpler process complication and no additional process cost.

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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