Pretreatment method for SiGe selective epitaxial growth

Abstract

The invention provides a pretreatment method for SiGe selective epitaxial growth. The method comprises the following steps that: hydrogen plasma is introduced into a device in a reaction cavity; chemical reaction is carried out on a native oxide on the device and the hydrogen plasma and then steam is generated and is volatilized; and SiGe selective epitaxial growth is carried out on source / drain regions of the device. According to the above-mentioned technical scheme, etching on a side wall by the plasma during the pretreatment process can be avoided, so that the quality of SiGe film growth can be improved.

Description

technical field [0001] The invention belongs to the field of semiconductor integrated circuit manufacturing, and in particular relates to a pretreatment method before selective epitaxial growth of germanium and silicon, so as to avoid etching of side walls by plasma during the pretreatment process and improve the growth quality of germanium and silicon thin films. Background technique [0002] As the integration process technology enters the deep submicron process conditions, the conventional shrinking method encounters a series of problems centered on the short channel effect. For example, when the device is further scaled, the improvement of the mobility becomes the key to maintain the performance of the transistor as the current density increases. In recent years, since strain engineering technology (Strain Engineering) can be used in 45nm and below processes, by introducing local unidirectional tensile or compressive stress into the channel of MOSFET in the source / drain ...

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Problems solved by technology

[0018] see Figure 1D , therefore, using this pretreatment method, the silicon nitride sidewall will be etched, which in turn will cause a reduction in the critical dimension (CD) of the sidewall, which will affect the performance of some subsequent key devices

[0019] In summary, it is very important to perform pretreatment before the growth of SiGe by selective epitaxial technology, and it is necessary to find a solution to eliminate the etching of side walls by plasma in the current pretreatment process and the influence on the growth quality of SiGe thin films. There are still problems in the actual implementation process, and it is urgent to introduce new methods that can effectively improve the above defects, so as to solve a series of problems such as how to improve the short channel effect when strain engineering technology is used in the semiconductor integration process.

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