JPS61120486A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent errors in position alignment and to remove restrictions on integration density and an optical system, by arranging a semiconductor light emitting body formed in a monolithic structure so that the output directions of individual light beams are different. CONSTITUTION:On a GaAs substrate 11, a semiconductor light emitting element having a double heterostructure is formed. Thereafter, a fan pattern is formed by a photomask, and injecting regions 13a-13e are formed. Each otuput end surface and a resonance plane are shifted by angles theta1 and theta2 with respect to a main axis. Light emitting directions 12a-12e are different one another. At this time, the resonance planes are formed so that light is emitted from a point Po on the opposite side with respect to the output side. Thus, the excellent image forming state is obtained by a simple optical system, and erros in position alignment and restrictions on integration density and the optical system can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device in which a plurality of semiconductor light emitting bodies are monolithically formed.

[Conventional technology and problems]

Conventionally, when designing an optical scanning device using a plurality of semiconductor lasers or light emitting diodes (LEDs), as disclosed in JP-A-59-12'6, for example, the light emitting body is The light sources were arranged so that the emission directions of the lights crossed at one point Po, so that multiple scanning spots could be scanned against the surface to be scanned (not shown) while maintaining good imaging conditions. .

FIG. 7 shows a typical conventional example, and is a diagram of the optical system between the light source and the deflector, viewed from a direction perpendicular to the deflection scanning plane. 71a and 71b are semiconductor lasers,
Each laser is arranged on the mount 72 so that its light beam generating surface is parallel to the end surface of the mount 7z. Semiconductor laser 71a.

End face 72a of mount 72 where 71b is provided
, 72b are set as if the central rays ha, hb of the diverging beams from the respective lasers 71a, 71b had passed through the same point Po. In other words, semiconductor laser (7
1a, 71b), and draw normal lines to the end faces 72a and 72b, each normal line becomes Po
The end faces 72a and 72b are set such that the end faces 72a and 72b pass through. Further, when viewed from a direction parallel to the deflection scanning plane, the position on the mount 72 is such that the position where the center beams ha and hb of each semiconductor laser pass through point Po is slightly displaced in the direction perpendicular to the deflection scanning plane. The position of the semiconductor laser provided in is set. The above 20 points and a point P in a predetermined vicinity of the deflection/reflection surface 73 of the deflector are maintained in an optically conjugate relationship by the imaging/splash 4.

In this way, in order to arrange multiple semiconductor light emitters (for example, semiconductor lasers) so that their respective light emission directions are different, they must be aligned on the mount and configured into a hybrid structure, as shown in the example above. I needed to. For convenience, the term "array laser" will be used below to refer to a plurality of semiconductor light emitters, but in principle it also applies to light emitters such as LED arrays.

Furthermore, when using an array laser formed on a monolift, it is necessary to install some kind of optical system in front of the array laser. In an example disclosed in Japanese Patent Laid-Open No. 58-211735, a prism is placed in front of an array laser.

This is shown in FIG.

FIG. 8 shows a cross section of a prism when a semiconductor array laser has five light emitting parts.

81 has five light emitting parts (81a, 81b, 81C, 8
1d.

81e), and 82 is a prism. The central ray ha of the final luminous flux from the light emitting section 81a is refracted by the inclined surface 82a and bent as if it had passed through the PO. The central ray hb from the same
e is bent by the inclined surface 828 as if it had passed through Po. Note that the central ray ha from 81C passes through the plane 82C perpendicularly, and Po exists on the extension of this central ray hc. In this way, an inclined plane with a defined inclination angle corresponding to each light emitting part is provided,
The direction of the central ray of each light beam after exiting the prism 82 is controlled as if it were exiting from the PO. As described above, this PO is kept conjugate with a desired position P (not shown) near the deflection/reflection surface via the optical system.

Problems in this case include the precision and method of microfabrication of the prism 82, the alignment and bonding method between the prism 82 and the array laser 81, and the smaller the pitch of the array laser, the more difficult it becomes. In fact, it is almost impossible if the thickness is less than 100 μm.

On the other hand, FIG. 9 shows an attempt to achieve the same effect with an optical system, that is, a relay optical system 98, with an array laser 91a,
This is an example in which a relay system 93 is interposed between a collimator lens 92 that collimates the light emitted from 91b and forms an image, and an image is formed on a polygon surface 94, and the image is formed on a polygon surface 94. An image is formed on a surface to be scanned (not shown).

The problem in this case is the optical path length, and the relay system itself is approximately 2
It becomes 0cm longer.

It is an object of the present invention to eliminate alignment errors and limitations on integration density caused by arranging semiconductor light emitters in a hybrid, and also to eliminate alignment errors and limitations in integration density caused by arranging semiconductor light emitters in a hybrid, as well as to avoid problems such as when using a monolithically formed array laser with a constant light emission direction. An object of the present invention is to provide a semiconductor device that makes it possible to avoid the complexity of an additional optical system.

[Means for solving problems]

A semiconductor device according to the present invention achieves the above object.
In a semiconductor device in which a plurality of semiconductor light emitters are monolithically formed, these semiconductor light emitters are formed such that the directions of light emitted from each of the semiconductor light emitters are different.

In addition, the expression "the direction of light emitted from each light emitting body is different" used in the following description does not mean that there is no set of light emitting bodies that emit light in the same direction, but in a broad sense, it means that there are two light emitting bodies that emit light in different directions. This means that there is one or more pairs.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

After forming a semiconductor light-emitting element, such as a double heterostructure, on the GaAs substrate 11', a fan-shaped pattern as illustrated is formed using a photomask. The respective light emitting end faces are at an angle of θ1. They are formed shifted by θ2. The opposing surfaces that form the entire Fabry Bellow resonance surface are similarly formed with a deviation of θ by θ2, so the resonance direction is θ1.
．． The light emission directions 12a to 12e are shifted by θ2, and accordingly, the light emission directions 12a to 12e are also different.

In this case, by forming mutual resonance surfaces as if the light were emitted from the vicinity of a point Po on the opposite side to the light emitting side, addition of the prism 82 (Fig. 8), the relay optical system 93 (Fig. 9), etc. No additional components are required. Then, it becomes possible to realize a light source that can obtain a good imaging state with an apparatus using a simple scanning optical system. In addition, 13a to 138 in the figure
indicates the current injection region.

The distance l between the array lasers and the deviation θ in their emission directions (
θ1. It is generally convenient for device design to use a constant value for θ2). That is, θl=θ2, but it does not necessarily have to be a constant value. The relationship between l and θ depends on the optical system used, especially the focal length of the collimator lens 92 shown in FIG. 9. That is, the distance between the collimator lens and Po is L
(Po) is approximately L when the distance between the collimator lens and the array laser is small compared to L (PO).
The relationship is (Pa)×θ=l. Note that θ is expressed in radians. For example, L (Po) is 13 dragons, /=100
When it is μm, θ is approximately 1 degree.

Fig. 2 shows a modification of the present invention, and Fig. 3 shows A-A in Fig. 2.
It is a sectional view seen from the A' line. Note that the case of FIG. 1 also has a substantially similar cross-sectional structure, and the manufacturing process will be described below with reference to these drawings.

First, n-type GaAs 32 + n-type A is deposited on a wafer of n-type GaAs substrate 31 by molecular beam epitaxy.
I! GaA633, non-doped GaAs 34,
P-type A I G'a A s35, P-type GaAs 36
After growing, a fan-shaped mask as shown in FIG. 1 or 2 is formed, and vertical processing is performed in an Ar and cJ2 mixed gas atmosphere by reactive ion etching.
The n-type AI GaAsia layer was excavated halfway down.

The photomask pattern is formed by repeating fan shapes in the vertical and horizontal directions as shown in FIG. 1 or 2.

Next, the entire surface was covered with an 8i0z sputter film, and 1aa to 1
The portion 3e or the portions 23a-23c were removed by etching and covered with a laminated electrode 37 of Cr and Au. The electrode 37 is the part 13a to 13e or the part 2aa to
The 23c portion was also separated using Photoringella fibrosis so that it could be driven independently.

An alloy electrode 38 of Au and Ge was formed on the back surface.

After achieving ohmic properties by thermal diffusion, each unit was separated by cleaving or cutting as shown in FIG. 1 or 2. Then, individual electrodes were taken out by wire bonding.

In the case of FIG. 2, an ohmic electrode is formed in the center by dry etching on all sides.

In this case, L(I'o)=lQm, 1=50μm1θ=
Good imaging conditions were obtained at 0.5 degrees.

FIG.
FIG. 3 is a cross-sectional view and a plan view when a laser is used.

When using a DBR laser, by arranging array lasers radially, laser light that spreads radially can be obtained.

The manufacturing method is the same as the normal DBR laser manufacturing method, and the only difference is that multiple lasers are arranged radially. First, a cladding layer 42. active layer 43
．． A cladding layer 44 is created.

Next, the cladding layer 4 corresponding to the plug reflection (DBR) part
4 is removed by etching to a thickness of several hundred nm, and a plurality of diffraction gratings 45 with a period of several hundred nm are formed radially (see FIG. 4 (bl)) on this by interference exposure.

Finally, an electrode 46 for current injection is formed on the upper surface of the cladding layer 44 corresponding to the active region along the direction in which the diffraction grating 45 is formed. The length of each part is several hundred microns for the DBR part.
m to several μm, the active part is several hundred μm, and the DBR and waveguide portion are several hundred μm.

In addition, D F B (Distributed Fee
When using a d Back ) laser, the objective can be achieved in almost the same way by arranging the array lasers radially.

The explanation so far has been about the case where the light emitting bodies are arranged in a one-dimensional manner and pass through one point Po, but even when the light emitters are arranged two-dimensionally, they are arranged so that each light emission direction passes through one point Po. By doing so, you can achieve the same goal. An example thereof is shown in FIG.

1 and 5 are perspective views showing another modification of the present invention using a two-dimensional array laser, and FIG. 6 is a sectional view of a portion of each laser shown in FIG. 5, that is, a light emitting section.

The creation method will be described below. First, n-type G a A
A reflective multilayer (n-type A I G a A
s and n-type Ga As) 62 is formed, and further n-type A/Ga Aθ, n-type Ga As
After forming, a protrusion 63 was formed by dry etching. Next, a P-type head region 64 is provided by diffusion of Zn, and Pn
A junction was formed. After forming an electrode 65 for current injection, the electrode was thinned to about 70 μm by lapping. In addition,
66 indicates an output end face. Next, an n-type ohmic electrode 67 was formed on the back surface, and the entire crystal was curved as shown in FIG. As a result, lasers with different emission directions were realized.

The array laser of the present invention with different emission directions uses not only a deflection optical system based on mechanical scanning as shown in FIG. It is also useful for systems (not shown).

〔Effect of the invention〕

As described above, the present invention makes it possible to collimate light emitted from many points by simply installing a plurality of semiconductor light emitting bodies so that their light emission directions are different when forming them into a monolithic structure. This has the effect of making it extremely effective as a light source for optical devices that use a scanning optical system to form and scan an image on a medium (such as a laser beam pre-reflector). This effect is even more pronounced when array lasers with different directions are used.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the structure of a light emitting body in a semiconductor device according to the present invention, FIG. 2 shows a modified example, FIG. 3 is a sectional view taken along the line AA' in FIG. 2, and FIG. al and (b) show an example using a DBR laser, and FIG. 5 is a cross-sectional view and a plan view, respectively, a perspective view showing another modified example using a two-dimensional array laser, and FIG. Figure 5 is a cross-sectional view of the configuration of a portion of each laser, Figure 7 is a conventional example in which lasers are arranged in a hybrid manner, and Figure 8 is a conventional example in which an array laser with a fixed emission direction and a prism are combined to have different emission directions. For example, Fig. 9 shows a conventional example in which an array laser whose emission direction is constant is corrected by an optical system.12a-12's 22a-22C...Light emission direction 31-36.41-44. 61-64... Semiconductor light emitter patent applicant Canon Co., Ltd. Figure 2

Claims (1)

[Claims] In a semiconductor device in which a plurality of semiconductor light emitters are monolithically formed, the semiconductor light emitters are formed such that the directions of light emitted from each of the semiconductor light emitters are different. Characteristic semiconductor devices.