Manufacturing method of semiconductor device

摘要

A transistor with superior electric characteristics is manufactured. An oxide insulating film is formed over a substrate, an oxide semiconductor film is formed over the oxide insulating film, heat treatment is then conducted at a temperature at which hydrogen contained in the oxide semiconductor film is desorbed and part of oxygen contained in the oxide insulating film is desorbed, then the heated oxide semiconductor film is etched into a predetermined shape to form an island-shaped oxide semiconductor film, a pair of electrodes is formed over the island-shaped oxide semiconductor film, a gate insulating film is formed over the pair of electrodes and the island-shaped oxide semiconductor film, and a gate electrode is formed over the gate insulating film.

主权项

1. A method for manufacturing a semiconductor device comprising the steps of:
forming an oxide insulating film over a substrate, wherein the oxide insulating film contains oxygen with a higher proportion than a proportion of oxygen in a stoichiometric composition; forming an oxide semiconductor film on and in contact with the oxide insulating film; reducing hydrogen concentration and oxygen vacancies in the oxide semiconductor film by performing a heat treatment; etching parts of the oxide semiconductor film to form an island-shaped oxide semiconductor film; forming a gate insulating film over the island-shaped oxide semiconductor film; and forming a gate electrode overlapping with the island-shaped oxide semiconductor film with the gate insulating film interposed therebetween, wherein an amount of oxygen desorbed from the oxide insulating film by the heat treatment is higher than or equal to 1.0×1020 atoms/cm3.