Method for forming oxide semiconductor film and method for manufacturing semiconductor device

Abstract

An oxide semiconductor film is formed over a substrate. A sacrifice film is formed to such a thickness that the local maximum of the concentration distribution of an injected substance injected into the oxide semiconductor film in the depth direction of the oxide semiconductor film is located in a region from an interface between the substrate and the oxide semiconductor film to a surface of the oxide semiconductor film. Oxygen ions are injected as the injected substance into the oxide semiconductor film through the sacrifice film at such an acceleration voltage that the local maximum of the concentration distribution of the injected substance in the depth direction of the oxide semiconductor film is located in the region, and then the sacrifice film is removed. Further, a semiconductor device is manufactured using the oxide semiconductor film.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a method for forming an oxide semiconductor film or an insulating film, and to a method for manufacturing a semiconductor device with the use of the oxide semiconductor film or the insulating film.[0003]Note that a semiconductor device in this specification refers to general devices which can function by utilizing semiconductor characteristics; for example, a semiconductor element such as a transistor, a semiconductor circuit including a semiconductor element, an electro-optical device such as a display device, and an electronic device are all semiconductor devices.[0004]2. Description of the Related Art[0005]Transistors used for most flat panel displays typified by a liquid crystal display device and a light-emitting display device are formed using silicon semiconductors such as amorphous silicon, single crystal silicon, and polycrystalline silicon provided over glass substrates. Furthe...

AI Technical Summary

Benefits of technology

The patent text describes a method for manufacturing a semiconductor device with favorable electrical characteristics. The method involves forming a sacrifice film using a material that is different from the material used to form the main film, which makes it easier to remove the sacrifice film during the manufacturing process. This sacrifice film helps to reduce impurities and allows for the uniform injection of oxygen ions into the oxide semiconductor film, resulting in a transistor with better electrical characteristics. Additionally, the method includes the use of an ion implantation method or ion doping method to inject oxygen ions into the oxide semiconductor film while forming a sacrifice film to remove impurities. Overall, this method provides a way to manufacture a semiconductor device with improved performance.

Problems solved by technology

However, in an oxide semiconductor, charge is generated owing to an oxygen vacancy caused therein.

Consequently, the lowering of the acceleration voltage for oxygen ion injection leads to a non-uniform concentration of the injected oxygen ions in the depth direction of the oxide semiconductor, and thus, oxygen vacancies might not be sufficiently filled.

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