半导体装置及该半导体装置的制造方法;SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SEMICONDUCTOR DEVICE

摘要

若不由无机绝缘膜覆盖氧化物半导体层情况下进行热处理而使氧化物半导体层晶化，则因晶化而形成表面凹凸，可能会产生电特性的不均匀。藉由如下顺序进行步骤：在从刚形成氧化物半导体层之后直到在氧化物半导体层上形成包含氧化矽的无机绝缘膜之前的期间一次也不进行热处理，而是在基板上的氧化物半导体层上地形成第二绝缘膜之后进行热处理。此外，在包含氧化矽的无机绝缘膜中含有的氢密度为5×10 20 /cm 3 或以上，且氮密度为1×10 19 /cm 3 或以上。 If an oxide semiconductor layer is crystallized by heat treatment without being covered with an inorganic insulating film, surface unevenness and the like are formed due to the crystallization, which may cause variation in electrical characteristics. Steps are performed in the following order: a second insulating film is formed on an oxide semiconductor layer over a substrate and then heat treatment is performed, instead of performing heat treatment during a period immediately after formation of the oxide semiconductor layer and immediately before formation of an inorganic insulating film including silicon oxide on the oxide semiconductor layer. The density of hydrogen included in the inorganic insulating film including silicon oxide is 5 × 10 20 /cm 3 or more, and the density of nitrogen is 1 ×