Method of manufacturing semiconductor device, method of processing substrate, and substrate processing apparatus

A method of manufacturing a semiconductor device, comprising:

• forming a layer containing a predetermined element on a substrate by supplying a source gas containing the predetermined element into a process vessel accommodating the substrate and exhausting the source gas from the process vessel under a condition where a chemical vapor deposition (CVD) reaction is caused;
• changing the layer containing the predetermined element into a nitride layer by supplying a nitrogen-containing gas into the process vessel and exhausting the nitrogen-containing gas from the process vessel, wherein an inside of the process vessel is heated and a pressure of the inside of the process vessel is lower than an atmospheric pressure;
• forming a nitride film having a predetermined film thickness on the substrate by alternately repeating forming the layer containing the predetermined element and changing the layer containing the predetermined element into the nitride layer;
• and
• purging the inside of the process vessel by supplying an inert gas into the process vessel and exhausting the inert gas from the process vessel between forming the layer containing the predetermined element and changing the layer containing the predetermined element into the nitride layer,
• wherein, in forming the layer containing the predetermined element, the source gas is supplied toward the substrate through a nozzle disposed at a side of the substrate, and one of an inert gas and a hydrogen-containing gas is supplied together with the source gas through the nozzle toward the substrate such that a flow velocity of the source gas flowing parallel to a surface of the substrate is greater than that of the inert gas flowing parallel to the surface of the substrate in purging the inside of the process vessel.