Surface emitting semiconductor laser

Abstract

A method of forming a conductive pattern such as an electrode on a compound semiconductor layer includes the steps of forming a first organic layer on the compound semiconductor layer, forming a second layer on the first organic layer, the second layer being resistant to plasma ashing, forming a pattern including a first aperture in the second layer, forming a second aperture in the first organic layer by the plasma ashing of the first organic layer using a mask of the pattern including the first aperture to expose the compound semiconductor layer in the second aperture, depositing a conductive layer over a region including the compound semiconductor layer exposed in the second aperture and the second layer, and forming the conductive pattern on the compound semiconductor layer by a lift-off process.

Description

[0001] This is a Division of application Ser. No. 10 / 629,777 filed Jul. 30, 2003. The disclosure of the prior applications is hereby incorporated by reference herein in its entirety.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a method of forming a conductive pattern such as electrodes on a compound semiconductor layer, and more particularly, to a method of forming a fine electrode pattern using a lift-off process. [0004] 2. Description of the Related Art [0005] In a technical field of an optical communication and optical recording, the demand of using a surface emitting semiconductor laser (Vertical Cavity Surface Emitting Laser Diode) has been increased because of facilitation of the two-dimensional light source array. The surface emitting semiconductor laser device is typically made of compound semiconductor layers such as GaAs, AlGaAs and so on, and generally the lift-off process is employed to form electrodes and wirings w...

AI Technical Summary

Benefits of technology

The present invention provides a method for forming a conductive pattern on a compound semiconductor layer without causing surface damage. This method allows for the formation of fine patterns of electrodes or wirings using a lift-off process. The invention also provides a method for manufacturing a surface emitting semiconductor laser with improved optical characteristics and a longer lifespan. The surface roughness of the compound semiconductor layer in at least a peripheral portion of the electrode is not more than 5 nm.

Problems solved by technology

The compound semiconductor layer, e.g. GaAs, has a surface that is chemically weak, and therefore the etching progressives clearly memorably and the life time of devices may be shortened by the surface damages caused by the etching and the performances may be affected by the damages.

Furthermore, when a p-side electrode which defines an emission window for the laser light is formed the contact layer such GaAs in the surface emitting semiconductor laser, the etching of a contact layer has an adverse effect on the optical characteristics or properties of the laser light.

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