JPH02103987A - Semiconductor laser-array device - Google Patents

Abstract

PURPOSE:To diffuse heat which is generated in an element into the outward lateral direction, to suppress the increase in temperature, to decrease interference to neighboring elements and to improve reliability by forming a semiconductor region at the outside of an outermost element in a laser array element having separated electrodes. CONSTITUTION:Grooves 30 extending from the side of an electrode to an active layer 4 are provided in multilayered growth layers 3 on a semiconductor substrate 2. Laser array elements 31 in the layer 3 are electrically separated. A semiconductor region 100 is formed at the outside of an outermost element 31a. A pattern electrode 8 is formed on a heat sink 7 and bonded to the electrode 6 and the elements 31 electrically and thermally through a brazing filler metal 9. A contact wire 10 is connected by compression to the region 100 so as to form electrical contact. Introduction of defects into the elements 31 is prevented. Heat generated in the outermost element 31a is diffused in the lateral direction through the semiconductor region in this way. The increase in temperature is suppressed, and thermal interference to neighboring elements is decreased. Thus the reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor laser array (hereinafter abbreviated as a laser array device) device that operates stably and has high reliability.

[Conventional technology]

Conventionally, applied optics (APPLIED
0PTICS) Vo 1.23. Nn, 24°pp46
13 (1984) is known. As shown in FIG. 3, a multilayer growth layer 13 is formed using GaAs 12 as a substrate and an active layer 14 made of AlGaAs as a material, and laser emitting points are placed at intervals of 150 μm.
A p-electrode 1 is formed on the multilayer growth N (between elements) to form a
A groove 30 is provided to separate the active layer 14 from the 6 side, so that each laser element 31 can be driven independently. Furthermore, a semiconductor laser array element (hereinafter abbreviated as laser array element) is also installed on the heat sink 17 side made of BeO.
In the same way as above, pattern electrode 1 is placed at intervals of 150 μm between centers.
8, and as shown in the figure, the electrodes of the laser array element and the electrodes of the heat sink 17 are aligned and bonded together using an In brazing material 19. Further, the contact point of the n-side electrode 15 with the contact wire 20 is formed on or near an arbitrary laser element.

[Problem to be solved by the invention]

However, in the conventional technology, the outermost laser elements and the laser elements near the outer side have poor heat dissipation because there is no place for heat to escape in the lateral direction, and the temperature rise due to heat generated during operation makes the operation unstable and reduces reliability. In addition, there is a possibility that thermal interference may be caused to other adjacent laser elements, leading to unstable operation or a decrease in reliability.

In addition, contacts on the common substrate side must be formed on or near the active region of the laser element, and some defects may be introduced during contact formation, causing a reduction in the reliability of the element.

The purpose of the present invention is to suppress the temperature rise of the outer laser elements of a laser array element, stabilize the operation, improve reliability, and prevent the laser elements from being damaged even when the contact wire is electrically connected to the electrode on the substrate side. An object of the present invention is to provide a highly reliable laser array device that does not deteriorate.

[Means to solve the problem]

The laser array device of the present invention has a multilayer growth layer containing an active layer on the same semiconductor substrate, and is provided with a plurality of laser elements in an array, which are electrically isolated from each other by grooves, and further comprises: A laser array element that has a semiconductor region wider than the spacing between the laser elements outside the light emitting point of at least one of the outermost laser elements, and a center spacing that is the same as that of the electrodes formed on each laser element of the laser array element. The heat sink has patterned electrodes that are electrically separated from each other, and the outermost electrode has an electrode area wider than the element spacing, and is electrically and thermally bonded using a brazing material with the separated electrodes facing each other. The structure is as follows.

[Effect]

The present invention has a structure in which a semiconductor region having a length equal to or longer than the laser element interval is formed further outside the outermost laser element of a laser array element having a separation electrode, and is fixed to a heat sink. Therefore, the heat generated in the outermost laser element is dissipated outward laterally through this semiconductor region, which suppresses the temperature rise of the element and improves reliability, while at the same time reducing thermal radiation to other adjacent elements. interference can be reduced.

In addition, electrically separating the outermost element and the outermost semiconductor region not only improves heat dissipation but also prevents leakage current in the outermost semiconductor region from flowing into the outermost laser element. can stabilize the operating current and avoid excessive temperature rise.

Furthermore, since electrical contacts on the common substrate side can be formed in the semiconductor region provided outside the outermost light emitting point of the laser array element, defects are not introduced into the laser element, and the laser array device Reliability can be improved.

〔Example〕

FIG. 1 is a diagram showing a laser array device according to an embodiment of the present invention. The laser array element uses an n-type GaAs 2 as a substrate and a multilayer growth layer 3 made of AlGaAs as a material.
Grooves 30 extending from the p-electrode 6 side to the active layer 4 are formed in the multilayer growth layer 3 so that laser emission points 1 are formed at μm intervals, and the laser element is completely electrically isolated by the grooves 30. A laser element 31a of 300 μm is placed outside the light emitting point of the outermost laser element 31a at both ends, which is configured to have a plurality of laser elements on the substrate 2.
A semiconductor region 100 is provided with a length of m. Other semiconductor materials for the laser array element include a laser element made of AIGaInP with a GaAs substrate, a laser element made of InGaAsP with an InP substrate, and semiconductor conductivity types (p and n). ) may be reversed. On the heat sink 7 made of electrically insulating SiC, a pattern electrode 8 formed by laminating metals in the order of Ti, Pt, and Au is arranged with a center spacing of 100 μm and an electrode width of 6.
It is formed with a thickness of 0 μm.

As shown in the figure, the outermost pattern electrode 101 extends 300 μm outward from the position of the laser light emitting point. The laser array element and the heat sink 7 are electrically and thermally bonded by a Pb5n brazing material 9 with their separated electrodes facing each other to form a laser array device. Semiconductor region 1 outside the outermost light emitting point of the laser array element
A contact wire 10 made of Au is crimped onto 00 to form electrical contact. This prevents defects from being introduced into the laser element, thereby improving the reliability of the laser array element. Additionally, by providing a semiconductor region outside the outermost laser element and thermally bonding it to the heat sink, it promotes the dissipation of heat generated in the outermost laser element in the outward lateral direction, thereby reducing the temperature rise of the element. At the same time, thermal interference to other adjacent elements can be reduced. The brazing material may also be In or Sn. Further, the outermost semiconductor region is not limited to both sides of the laser array, but may be provided on either side of the laser array element.

FIG. 2 is a diagram showing another embodiment of the present invention. A groove is formed 50 μm outward from the light emitting point of the outermost element of the laser array element from the p-electrode 6 side to the active layer 4 between the elements, and the heat sink 7 and the pattern electrode corresponding to the groove are electrically connected. By separating the outermost laser element 31a and the semiconductor region 100 provided outside it,
are completely electrically isolated. This provides a structure in which leakage current generated in the outer semiconductor region does not flow into the laser element.

Note that the parts other than those described above, such as the multilayer growth layer 3, the laser element 31, and the bonding structure between the laser array element and the heat sink, are the same as in the previous embodiment.

〔Effect of the invention〕

The present invention promotes the dissipation of heat generated in the outermost laser element in the outward lateral direction, suppresses the temperature rise of the element, improves reliability, and at the same time reduces thermal interference with other adjacent elements. can do. In addition, leakage current flowing into the laser element can be suppressed, and excessive temperature rise can be suppressed. Further, electrical contacts on the common substrate side can be formed without introducing defects into the laser element, and the reliability of the laser array device can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing another embodiment of the present invention, and FIG. 3 is a diagram showing a conventional example. DESCRIPTION OF SYMBOLS 1... Luminous point, 2... GaAs substrate, 3... Multilayer growth layer, 4... Active layer, 5... N-side electrode, 6...
p electrode, 7-3 i C heat sink, 8-=Ti/P
t/Au pattern electrode, 9...Pb5n brazing material, 10
...Au contact wire 11...Light-emitting point, 1
2...GaAs substrate, 13...Multilayer growth layer, 14.
...active layer, 15...n-type electrode, 16...p electrode,
17...BeO heat sink, 18...pattern electrode, 19...In brazing material, 20...contact wire

Claims (1)

[Claims] A plurality of laser elements each having a multilayer growth layer including an active layer and electrically separated from each other by grooves are provided in an array on the same semiconductor substrate, and further, at least one of the outermost lasers of this laser array is provided. A laser array element that has a semiconductor region wider than the spacing between laser elements outside the light emitting point of the element, and a pattern that is electrically separated at the same center spacing as the electrodes formed on each laser element of the laser array element. A semiconductor laser having electrodes, and a heat sink whose outermost electrode has an electrode area wider than the element spacing, and the semiconductor laser is electrically and thermally bonded by a brazing material with the separated electrodes facing each other. Array device.