Provided are a method of generating plasma and a method of fabricating a semiconductor device including the method, which may improve selectivity in an etching process and minimize damage to layers. The method of generating plasma includes generating first plasma by supplying at least one first process gas into a first remote plasma source (RPS) and applying first energy having a first power at a first duty ratio, and generating second plasma by supplying at least one second process gas into a second RPS and applying second energy having a second power at a second duty ratio.