JPH04139628A - Optical semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a device in which the precision of the relative positional relation of components is high by forming all of the relative positional relation of the semiconductor laser chip, the detector for detecting a signal, and the hologram of the components on a silicon substrate by using the technique of photolithography. CONSTITUTION:Light emitted from the semiconductor laser chip 1 is reflected by a V-grooved reflector mirror 6, and is emitted upward. The emitted light is collected on a disk 3 by a lens 2, and the reflected light from this desk 3 is diffracted by the hologram 8, and is collected to a photodetector 9. Through this configuration, the relative positional relation of the V-grooved reflector mirror 6, the bonding position of the semiconductor laser chip 1, the photodetector 9, and the hologram 8 can be controlled in a 1mum unit by using the technique of the photolithography, and the device in which the precision of the relational position relation of the components is high can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical semiconductor device for a hologram optical pickup used in an optical disk device, etc., and a method for manufacturing the same.

2. Description of the Related Art In recent years, as optical pickups have become smaller, lighter, and cheaper, signal detection systems using holograms have been attracting attention.

A conventional hologram optical pickup is shown in FIG. The laser beam emitted from the semiconductor laser chip 21 passes through the lens 2
After being focused on the disk 23 by the light beam 2, the light beam is reflected and separated by the hologram 24 on the way back, and is focused on the upper number of the signal detection detector 25.

Problems to be Solved by the Invention However, the above conventional configuration has the following problems.

In order to obtain a stable signal at 1 ra, it is necessary to control the positional relationship of the optical axis of the light emitted from the semiconductor laser chip, the detection detector pattern, and the hologram pattern with an accuracy of 1 μm. . but,
With the conventional configuration consisting of independent parts as shown in Figure 2, it is extremely difficult to control such precise positional relationships, and there is also the possibility of positional deviation due to deformation of the storage container due to temperature changes, etc. It's also big.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an optical semiconductor device in which the mutual positional relationship of component parts is highly accurate, and a method for manufacturing the same.

Means for Solving the Problems In order to achieve this object, the optical semiconductor device of the present invention has a silicon substrate whose main surface is a (100) plane, and whose side surface formed on the first main surface is a (111) plane. a V-shaped groove, a second main surface formed parallel to the first main surface from an intermediate part of one side surface of the groove, and a laser beam on the second main surface of the groove. , a hologram formed on the surface of a transparent film provided on the silicon substrate, and diffraction from the hologram on the first main surface. It has a configuration including a light receiving element installed at a position to receive light.

Effect: With the above configuration, the positional relationships of the components (semiconductor laser chip, signal detection detector, hologram) can all be controlled with an accuracy of 1 μm on the silicon substrate by using photolithography technology.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

In addition, lens 2. The relationship between the disk 3 and the laser beam is the same as the conventional example shown in FIG. 2, and is omitted here.

FIG. 1 is a sectional view of an optical semiconductor device according to an embodiment of the present invention. A V-shaped groove (hereinafter referred to as a groove reflection mirror) 6 is formed on the first principal surface 5a of a silicon (Si) substrate 4 by etching. By anisotropic etching using an etching solution made of an aqueous potassium hydroxide solution, it is possible to easily form an optically flat V-groove reflecting mirror 6 having a (111) plane. A semiconductor laser chip 1 is bonded facing this V-groove reflection mirror 6. The surface to which the semiconductor laser chip 1 is bonded is a second surface 5b parallel to the main surface, which is formed by slightly etching the main surface in advance so that the center of the emitted laser beam hits the groove reflection mirror 6. The substrate 81 to which the semiconductor laser chip 1 is bonded is coated with resin as a transparent film 7 that transmits the semiconductor laser light.

A hologram 8 is formed on the surface of this transparent film 7 using photolithography technology.

Further, a photodetector 9 is formed on the Si substrate 4.

The operation of the optical semiconductor device of the present invention configured as described above will be explained. The light emitted from the semiconductor laser chip 1 is reflected by the groove reflection mirror 6 and emitted upward. The emitted light is focused onto a disk 3 by a lens 2, and the reflected light from the disk 3 is diffracted by a hologram 8 and focused onto a photodetector 9.

81 The mutual positional relationship between the ■groove reflecting mirror 6 formed on the substrate 4, the bonding position of the semiconductor laser chip 1, the photodetector 9, and the hologram 8 can be controlled in units of 1 μm using photolithography technology. .

In this embodiment, an optical pickup using only one hologram 8 has been described, but if two holograms 8 are used,
Transparent film 7 is also used in optical pickup using more than one surface.
Exactly the same effect can be obtained by using two or more layers of.

Furthermore, in this embodiment, the transparent film 7 forming the hologram 8 is
Although the case where resin is applied has been described above, the same effect can be obtained even if a silicon oxide film formed on the 81 substrate 4 is used as the transparent film 7.

Effects of the Invention As described above, the present invention provides a flat surface for installing a semiconductor laser element, a V-groove reflecting mirror for reflecting laser light, a hologram, and a light receiving element, and is capable of semiconductor processing centered on photolithography technology. By forming the optical semiconductor device on a silicon substrate using technology, it is possible to realize an optical semiconductor device for a holographic optical pickup used in optical disk devices, etc., and a method for manufacturing the same, in which the mutual positional relationship of these components is highly accurate. .

[Brief explanation of drawings]

FIG. 1 is a sectional view of an optical semiconductor device used in a hologram optical pickup according to an embodiment of the present invention, and FIG. 2 is a partially sectional front view of a conventional hologram optical pickup. DESCRIPTION OF SYMBOLS 1... Semiconductor laser chip (semiconductor laser element), 4... Silicon substrate, 5a... First main surface, 5b... Second main surface Face, 6...
- V-groove reflecting mirror (V-shaped groove), 7...Transparent film, 8...Hologram, 9...Photodetector (light receiving element).

Claims (2)

[Claims] (1) A V-shaped groove whose side surfaces are (111) planes formed in a first principal surface of a silicon substrate whose principal plane is (100) planes, and - a second main surface formed parallel to the first main surface; a semiconductor laser element installed on the second main surface in a direction in which laser light is irradiated onto the other side surface of the groove; An optical semiconductor device comprising: a hologram formed on a surface of a transparent film provided on a silicon substrate; and a light receiving element installed on the first main surface at a position to receive diffracted light from the hologram. (2) forming a V-shaped groove whose side surfaces are (111) planes on the first main surface of the silicon substrate whose main surface is (100) planes; forming a second main surface parallel to the first main surface; and installing a semiconductor laser element on the second main surface in a direction in which the other side of the groove is irradiated with laser light. , forming a transparent film on the silicon substrate, forming a hologram on the surface of the transparent film, and placing a light receiving element on the first main surface at a position to receive diffracted light from the hologram. A method for manufacturing an optical semiconductor device, which includes a step of installing an optical semiconductor device.