Opnext Japan, Inc.

Kazunori Saitoh

Hiroshi Hamada

Susumu Sorimachi

Yutaka Inoue

Masato Hagimoto

An opto-semiconductor device. An opto-semiconductor element includes a semiconductor substrate, a multilayered semiconductor layer formed on a first surface of the semiconductor substrate and having a resonator, a first electrode with multiple conductive layers formed on the multilayered semiconductor layer, and a second electrode formed on a second surface of the semiconductor substrate. A support substrate has a first surface formed with a fixing portion having a conductive layer for fixing the first electrode connected thereto through a bonding material. Bonding material and conductive layers forming the first electrode react to form a reaction layer. The difference in thermal expansion coefficient between semiconductor substrate and support substrate is not more than &#xb1;50%. A second barrier metal layer not reactive with bonding material is formed inside the first electrode uppermost conductive layer, while uppermost layer reacts with the bonding material to form the reaction layer.

Opto-semiconductor devices

It is an objective to control the occurrence of the disorder of a far-field pattern and of an optical axial shift. A manufacturing method of a semiconductor laser device has the step for preparing a semiconductor substrate which has growth of a multi-layer including an active layer, the step for forming a mask over the growth of a multi-layer, and a step for forming a stripe-shaped ridge by dry etching and wet etching. A structure stacking a p-type AlGaInP layer, an etch-stop layer, a p-type AlGaInP layer, a p-type AlGaInP layer, a p-type GaAs layer, in order, over the active layer is taken in order to make the tailing part created in the dry etching process smaller by wet etching. The tailing part is composed of a p-type AlGaInP layer including a high mixed crystal ratio of aluminum. Therefore, the p-type AlGaInP layer is etched faster than the p-type AlGaInP layer during wet etching, so that the tailing part becomes smaller, the far-field pattern of the semiconductor laser device is not disordered, and the optical axis shift does not occur.

Manufacturing method of optical semiconductor device

A highly reliable optical semiconductor device insusceptible to degradation in the characteristics thereof. An n-type buffer layer, n-type first cladding layer, active layer, a p-type first layer of the second cladding layer, p-type etch-stop layer, p-type second layer of the second cladding layer, and p-type contact layer are formed an n-type semiconductor substrate. Two lengths of separation grooves are formed in parallel in such a way as to reach the underside of the p-type second layer of the second cladding layer from the top face of the contact layer, and a ridge is formed between the respective separation grooves. The ridge comprises a lower portion thereof, made up of the second layer of the second cladding layer, and a portion of the contact layer, corresponding to the ridge, made up of the contact layer. Side parts of the top face of the portion of the contact layer, corresponding to the ridge, facing the separation grooves, respectively, are turned to tilted faces, respectively, and a barrier metal layer is formed on top of the tilted faces. Portions extending from side faces of the lower portion of the ridge to run across the respective separation grooves are covered with an insulating film. Since the tilted faces are formed at the respective side parts of the top face of the portion of the contact layer, no stepping occurs to the barrier metal layer. Accordingly, Au of an Au layer formed outside of the barrier metal layer is prevented from being diffused into the portion of the contact layer, corresponding to the ridge, made of GaAs, through steeped parts of the barrier metal layer.

Growing community of inventors

Maruko, Japan

Kazunori Saitoh