Patent ID: 6197608
Filing Date: 2001-03-06
Classification: G03F,H01S

Abstract:
A method for fabricating an electro-absorption modulated laser device in which a laser diode and an optical modulator are formed on a substrate by continuous epitaxial growth comprising:(a) forming a mask for forming a selective diffraction grating and selective area growth, the mask comprising, on the substrate, a pattern for forming the selective diffraction grating which is formed to correspond to the modulator region and a pattern for the selective area growth which allows the selective area growth to be carried out in the laser diode region of a stripe shape wherein trench regions are formed between the stripe type pattern and the inserted portion of the island type pattern to have a predetermined depth;(b) forming the selective diffraction grating on the substrate of the laser diode region by using the mask for forming the selective diffraction grating and the selective area growth;(c) removing the pattern for forming the selective diffraction grating from the mask for forming the selective diffraction grating and selective area growth, and forming a mask for the selective area growth which is composed of the selective area growth pattern only;(d) growing epitaxial layers for laser oscillation and optical modulation on the substrate of the laser diode region and the modulator region wherein the selective area growth is performed by growing the epitaxial layers on the diffraction grating in the laser diode region fast than epitaxial growth in the modulator region;(e) etching both edge of the epitaxial layers to form a mesa structure, and forming current blocking layers on the etched portions;(f) forming a cap layer on the mesa structure and the current blocking layers; and(g) depositing electrode metal on the epitaxial layers, and forming a trench by region by performing etching for electrically isolating the laser diode and the modulator from each other,wherein the patter for forming the selective diffraction grating is formed to be an island type patter in which the region other than the portion of the pattern inserted between the selective area growth pattern is larger than the modulator region andwherein the selective area growth pattern is formed in a stripe shape.