Ferdinand de Saussure was a Swiss linguist credited with the beginning of Semiotic study along with other founding father, Charles Sanders Pierce.
Saussure is perhaps better known for his study in linguistics. His studies included vowels in early Indo-European language. He taught several different studies such general linguistics and Sanskrit at the University of Geneva. This understanding of the symbolism in language extended to his understanding of semiotics, and specifically, signs.
Saussure separated himself from other researchers and philosophers with how he considered signs. To him, there was no meaning to anything unless it had someone to glean meaning from it. Inherently, signs, and therefore semiotics, are not until society decides they are.
Saussure's greatest addition to the field of semiotics was his model to discuss the creation of the sign. A sign is only a sign because of two other influences. An object can possibly convey meaning, but only does when the signifier, a meaning or understanding of the sign, is interpreted by the mind of the signified. Without these three actions co-existing, objects would be entirely alien, without any meaning.
http://www.learn.columbia.edu/saussure/ Discussion of Saussure's semiotics model, with example sign explanations.
Salwen, Michael B. & Stacks, Don W. An Integrated Approach to Communication Theory and Research (2nd ed.). New York, NY: Routledge.