Scarface was actually a nickname of Al Capone who was an Italian-American gangster.
Despite the title, Tony Montana is called Scarface only once throughout the movie, and in Spanish at that (Cara de cicatriz).
In the final shootout sequence, Al Pacino grabs the gun by the barrel. Although only blanks were used, his hand was badly burned, and production had to be shut down for a few weeks. The production used that time to film the final gun battle sequence from numerous angles using numerous cameras.
Video: Scarface al pacino
The word “yeyo” is used by Tony Montana (Al Pacino) as a slang word for cocaine. This word was not in the script, and was ad-libbed by Pacino during the first drug deal scene (chainsaw scene), and Brian De Palma liked it enough to keep using it throughout the film. Pacino learned the word while learning the Cuban accent.