Semiconductor device manufacturing: process – Making device or circuit emissive of nonelectrical signal – Groove formation
Utility Patent
1999-01-29
2001-01-02
Niebling, John F. (Department: 2812)
Semiconductor device manufacturing: process
Making device or circuit emissive of nonelectrical signal
Groove formation
C438S022000, C438S042000
Utility Patent
active
06168964
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor light emitting device, for example, a semiconductor laser, and a method of fabricating the same.
In a semiconductor light emitting device such as a semiconductor laser, it is desired that a light emitting at an end surface of an optical resonator is composed of an optical mirror surface. In general, such an end surface of an optical resonator is formed of a cleavage crystal plane. In the case where an end surface of an optical resonator is formed of a cleavage crystal plane, generally, a semiconductor substrate is first prepared in which a plurality of stripe-like resonators each being equivalent to several semiconductor light emitting devices are formed in parallel to each other. Then, the semiconductor substrate is cleaved along planes crossing the lengthwise direction of the stripe-like optical resonators into a plurality of semiconductor bars each having a width corresponding to a length of a resonator of a semiconductor laser chip to be finally obtained, wherein the cleavage surface is taken as the end surface of the resonator of the semiconductor device finally obtained. A protective film or an optical film having a specific reflectance is formed on each side surface of the semiconductor bar, wherein each side surface constitutes an end surface of the resonator. Then, the semiconductor bar is cut along lines between respective stripes to form semiconductor laser chips.
However, the above method has a problem since that the worker must handle a plurality of semiconductor bars after one semiconductor substrate is divided into multiple semiconductor bars; the handling thereof is laborious, resulting in degraded productivity on a large scale.
It is proposed that a method in constructing an end surface of a resonator is formed via an etched surface. This method does not require additional work for forming end surfaces of resonators by the above cleavage; that is, additional work for preparing semiconductor bars. As a result, according to this method, the worker can almost handle a semiconductor substrate equivalent to several semiconductor lasers as it is substantially up to the sizing step for forming semiconductor laser chips, thereby increasing productivity on a larger scale.
In the method using etching a problem occurs in that the etched surface is not necessarily smooth in the obtaining of a semiconductor laser. A so-called “facet degradation” is increased, to thus reduce luminous efficiency and lower service life.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a semiconductor light emitting device such as a semiconductor laser suitable for mass-production, in which a desirable end surface of a resonator of the device is formed using an etching process, and a method of fabricating the semiconductor light emitting device.
To achieve the above object, according to a first aspect of the present invention, there is provided a semiconductor light emitting device, including: semiconductor layers formed on a base body for constructing a plurality of semiconductor light emitting devices, stripe-like grooves formed in the semiconductor layers formed on the base body in the direction from a front surface of the semiconductor layers to the base body and a semiconductor film formed in the grooves by epitaxial growth, wherein a side surface of each of the grooves, forms an end surface of a resonator of each of the semiconductor light emitting devices is a crystal plane being later in expitaxial growth rate than a bottom surface of the groove.
According to a second aspect of the present invention, there is provided a method of fabricating a semiconductor light emitting device including the steps of: forming semiconductor layers on a base body for constructing a plurality of semiconductor light emitting devices, grooving the semiconductor layers formed on the base body in a selected direction from a front surface of the semiconductor layers to the base body to form stripe-like grooves, and forming a semiconductor film in the grooves by epitaxial growth wherein a side surface of each of the grooves forms an end surface of a resonator of each of the semiconductor light emitting devices is a crystal plane having a lower expitaxial growth rate than a bottom surface of the groove.
According to the present invention, surfaces of resonators of semiconductor light emitting devices are formed by grooving a semiconductor substrate having semiconductor layers constituting a plurality of semiconductor light emitting devices. As a result, the method of the present invention makes it possible to simply fabricate a semiconductor light emitting device.
Further, according to the present invention, by epitaxial growth of a semiconductor film in each groove, a flat, smooth surface is formed on a side surface of the groove. The reason for this is as follows: namely, according to the present invention, the side surface of the groove is basically formed of a plane having a lower epitaxial growth rate (hereinafter, such a plane is referred to simply as a specific crystal plane). When a semiconductor film is formed on each side surface of the groove by epitaxial growth, even if the side surface does not become smooth and contains a different crystal plane in addition to the specific crystal plane, the epitaxial growth proceeds for the different crystal plane. Also, if the epitaxial growth involves generation of the specific crystal plane, the epitaxial growth is apparently stopped at the specific crystal plane. As a result, since the end surface of the resonator is formed of only the specific crystal plane, the end surface is formed as a very smooth plane at an atomic level. This makes it possible to reduce the facet degradation, to improve luminous efficiency and stability, and to increase service life.
REFERENCES:
patent: 4522662 (1985-06-01), Bradbury et al.
patent: 5171706 (1992-12-01), Matsumoto et al.
patent: 5180685 (1993-01-01), Yamamoto et al.
patent: 5514619 (1996-05-01), Wakabayashi et al.
patent: 5604761 (1997-02-01), Seki et al.
patent: 5824453 (1998-10-01), Kim et al.
patent: 6030894 (2000-02-01), Hada et al.
Kananen Ronald P.
Niebling John F.
Rader Fishman & Grauer
Simkovic Viktor
Sony Corporation
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