The present invention is to provide a method for producing a semiconductor
laser diode (LD) with an enhanced ESD resistance. The method includes a
step for forming an aluminum film on a facet of the LD and a step for
forming an aluminum oxide film on the aluminum film. The underlying
aluminum film is oxidized during the formation of the aluminum oxide film
to form a double aluminum oxide layer. The ratio of the oxide composition
of the underlying aluminum oxide film is smaller than that of the upper
aluminum oxide film.