JPH03225883A - Semiconductor laser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Industrial field of application B. Overview of the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the problem F. Effect G. Example [I. Effect of the invention A. Industrial field of application The present invention has Semiconductor lasers, especially AiGaAs
It relates to a buried heterojunction type (BH type) semiconductor laser made of a compound semiconductor such as a semiconductor laser.

B. Summary of the Invention The present invention relates to a semiconductor laser, in which a striped mesa protrusion extending in the direction of the 011 crystal axis is formed on the main surface of the 100 crystal plane of a compound semiconductor of the first conductivity type, and a first conductive layer is formed on the main surface side. a cladding layer of a type, an active layer, and a first layer of a second conductivity type.
a cladding layer of a first conductivity type, an intermediate layer of a second conductivity type, a current blocking layer of a first conductivity type, and a second cladding layer of a second conductivity type are sequentially grown epitaxially,
A striped epitaxial growth layer is formed on the striped mesa protrusion in which a first conductivity type cladding layer, an active layer, and a second conductivity type first cladding layer are laminated separately from each other; A cladding layer of a first conductivity type, an active layer, a first cladding layer of a second conductivity type, an intermediate layer of a first conductivity type, and an intermediate layer of a second conductivity type epitaxially grown on the mesa groove on both sides of the mesa protrusion. An intermediate layer and a current blocking layer are separated on both sides by a mesa protrusion and a striped epitaxial growth layer, and a second current blocking layer of a second conductivity type is formed.
The cladding layer is formed entirely across the striped epitaxial growth layer so that both end faces of the active layer in the striped epitaxial growth layer abut within the end faces of the current blocking layer. The active layer serves as a light emitting operation region, and aims to reduce threshold current I and improve saturation of output characteristics.

C. Prior Art In order to fabricate a semiconductor laser having a low threshold current, a BH type structure is adopted in which a refractive index difference is formed in the lateral direction of the active layer, that is, on both sides perpendicular to the plane direction of the active layer. Moreover, it is desirable to provide blocking means for current confinement. In this type of BH type semiconductor laser, a procedure is generally adopted in which two or more independent epitaxial growth operations are performed, that is, an etching operation is performed after the first epitaxial growth operation, and then a second epitaxial growth operation is performed. However, in this case, problems such as surface oxidation occur between the box 1 and second epitaxial growth operations, which leads to a decrease in reliability and properties.

With the purpose of avoiding such reliability problems and further complicating workability, the present applicant previously proposed, for example, Japanese Patent Application Laid-Open No.
No. 183987, S D H made it possible to form all layers in one epitaxial growth.
(Separate Double) Ietero
proposed a JuncLion type semiconductor laser.

D Problems to be solved by the invention

Claims (1)

[Claims] A strip-shaped mesa protrusion extending in the direction of the 011 crystal axis of the main surface of the 100 crystal plane of the compound semiconductor of the first conductivity type is formed on the main surface side of the compound semiconductor of the first conductivity type. a cladding layer, an active layer, a first cladding layer of a second conductivity type, an intermediate layer of a first conductivity type, an intermediate layer of a second conductivity type, a current blocking layer of a first conductivity type, and a second conductivity type. A second conductivity type cladding layer is sequentially epitaxially grown on the striped mesa protrusion, and is separated from the others to form the first conductivity type cladding layer, the active layer, and the second conductivity type cladding layer.
A stripe-shaped epitaxial growth layer is formed in which a first cladding layer of a conductivity type is laminated, and the cladding layer of the first conductivity type epitaxially grown on the mesa groove on both sides of the mesa protrusion, the active layer, and the first cladding layer of the first conductivity type are formed. 2nd conductivity type 1st
cladding layer, the intermediate layer of the first conductivity type, and the second conductivity type intermediate layer.
A conductive type intermediate layer and the current blocking layer are formed on both sides of the mesa protrusion and the striped epitaxial growth layer, and the second conductive type second cladding layer is formed on the striped epitaxial growth layer. The striped epitaxial growth layer is formed entirely across the striped epitaxial growth layer so that both side end faces of the active layer in the striped epitaxial growth layer abut within the end faces of the current blocking layer, and the striped active layer in the striped epitaxial growth layer is formed in a light emitting operation region. semiconductor laser.