Semiconductor device and manufacturing method thereof

摘要

An object of the invention is to form an insulating film having favorable insulation and planarity. An insulating film is formed by performing heat treatment a resin containing a siloxane polymer after application, in an atmosphere including an inert gas as its main component and having an oxygen concentration of 5% or less and a water concentration of 1% or less. Preferably, an oxygen concentration is 1% or less and a water concentration is 0.1% or less. The resin containing a siloxane polymer includes a methyl group and a phenyl group. Further, the inert gas is nitrogen.