JPH0451073B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to a semiconductor device, and particularly to a semiconductor device that has excellent heat radiation and provides stable performance. [Background of the Invention] A semiconductor laser element, which is an example of a semiconductor device, is
Recently, it has been attracting attention especially in the field of optical communications. Other than the fact that the output level is lower than that of non-semiconductor light emitting devices, this has the following advantages: (1) Low power drive possible, (2) Direct modulation possible, (3) High efficiency possible, and (4) Long lifespan. (5)
This is based on the fact that it has various advantages such as being small and lightweight. For example, a semiconductor laser element is
It is made of semiconductor single crystal materials such as - group compounds such as GaAs, GaP, GaAlAs, InGaAsP, etc., and - group compounds such as PbSSe, PbSnTe, etc.
A forward current is passed through the Pn junction, and the injected carriers recombine to emit light. A portion of the light generated is returned to the light emitting region near the junction by a reflecting mirror, and this feedback light is Furthermore, by repeating the stimulated emission process that promotes carrier recombination and new light emission, it is attempted to lead to laser oscillation. In order to increase the efficiency of this type of semiconductor laser device, it is effective to lower the threshold current that leads to laser oscillation. It is necessary to effectively confine the stimulated emission light and promote the interaction between photons and carriers. However, even with such measures, the oscillation threshold current density still reaches 1 to 3 KA/cm ² when continuous oscillation is performed at room temperature, which naturally causes heat generation at the junction. As a result,
In order to stably oscillate a laser, it is necessary to efficiently cool the semiconductor laser substrate or to efficiently dissipate the heat generated in the semiconductor laser substrate. At the same time, due to the heat generation and cooling cycles associated with the operation and rest of the semiconductor laser element, the semiconductor laser base and the supporting member for mounting the base are bonded due to thermal strain due to the difference in the thermal expansion coefficients of both parts. This can lead to thermal fatigue failure at the interface, such as cracks in the adhesive layer. This type of adhesive layer also serves as a part of the main heat dissipation path of the semiconductor laser substrate and also serves as an electrical conductor area, which may cause the laser substrate itself to overheat and become unable to conduct electricity, thus preventing stable laser oscillation. It becomes difficult to continue. In order to overcome the above-mentioned problems, conventionally, as shown in FIG. 1, a diamond strip having excellent thermal conductivity and having a coefficient of thermal expansion approximately similar to that of the semiconductor laser substrate 2 was placed on a metal support member 1 made of copper or the like. A structure was adopted in which the semiconductor laser substrate 2 was bonded via an intermediate member 3 such as a piece. At this time, the semiconductor laser substrate 2
In order to facilitate optical coupling between the laser element and the light receiving element or the optical fiber cable relaying between the laser element and the light receiving element, the end portion 31 of the intermediate member 3 is
At the same time, in order to increase heat radiation efficiency, the pn junction 21, which is a heat source, is placed close to the heat radiation path and bonded using a brazing material. A metallized layer 32 is provided on the intermediate member 3 to maintain adhesive strength to the intermediate member 3 and at the same time provide wettability to the brazing material. The intermediate member 3 is generally brazed onto the metal support member 1 using a material such as a gold-based solder such as Au-Si, Au-Ge, or Au-Sn or a Pb-Sn-based solder. Further, the semiconductor laser base 2 includes a conductive path forming member 5, an electrode layer that enables electrical and mechanical connection between the member 5 and the semiconductor laser base 2, and an electrical and mechanical connection between the semiconductor laser base 2 and the intermediate member 3. An electrode layer is provided that provides wettability to the brazing material in order to make a positive connection. As the brazing material between the semiconductor laser substrate 2 and the intermediate member 3, a material of the same quality and type as the above-mentioned brazing material is used. Furthermore, in addition to the semiconductor laser base 2, a relay metal plate 6 for electrical connection to the conductive path forming member 5 is bonded on the intermediate member 3 in the same manner as the semiconductor laser base 2. Since the semiconductor laser substrate 2 usually has a pn junction formed by epitaxial growth or diffusion,
The light-emitting region is formed not at the center in the thickness direction of the substrate but at a portion extremely close to the surface. However, in order to increase the heat dissipation efficiency, it is necessary to
Since the structure is such that the surface on which the pn junction is formed is brazed onto the above-mentioned intermediate member 3, the following problems arise. The first problem is that the optical path of the laser light emitting part is cut off by the soldering of the semiconductor laser base 2, and the second problem is that the laser light emitting part is not made to have an ideal reflective surface. Since the pn junction is formed with an open wall and the pn junction is exposed, the junction is short-circuited by the brazing filler metal. The cause of such a problem is that the brazing material is discharged to the end of the bonded portion between the semiconductor laser substrate 2 and the intermediate member 3, and the brazing material bulges up. [Object of the Invention] An object of the present invention is to improve the above-mentioned problems and provide a semiconductor device having a structure that allows semiconductor devices with stable performance to be manufactured with a high yield. [Summary of the Invention] To summarize the present invention, the present invention relates to a semiconductor device, in which an intermediate member made of an inorganic insulator or an inorganic semiconductor and a semiconductor element are placed on a metal support member via a metallized layer. In the semiconductor device that is sequentially mounted on the intermediate member, a portion of the metallized layer between the intermediate member and the semiconductor element is also located on a portion of at least one side surface of the intermediate member, and the metallized layer is located on at least one side surface of the intermediate member. , the intermediate member and the semiconductor element have side surfaces that are substantially coplanar with the metallized layer located on the side surfaces, and are each bonded using a brazing material. To explain the various materials and layer configurations used in the semiconductor device of the present invention with specific examples, the intermediate member is made from the group consisting of SiC, Al ₂ O ₃ , AlN, BeO, Si ₃ N ₄ , MgO and C. A ceramic made of at least one selected material or a semiconductor made of at least one material selected from the group consisting of Si, Ge and SiC, wherein the metallized layer is in contact with the ceramic or semiconductor, Cr, Ti, Al, Mo,
a first layer made of one material selected from the group consisting of Ni, W and Ag, and in contact with the first layer;
Cr, Ti, Al, Mo, Ni, Cu, Ag, Pd, Pt and
a second layer made of one material selected from the group consisting of Au; and a second layer made of one material selected from the group consisting of Au;
A third layer made of one material selected from the group consisting of Pt is sequentially laminated. [Examples of the Invention] The present invention will be described in detail below using Examples. FIG. 2 shows a semiconductor laser device according to an embodiment of the present invention. In the figure, the same or equivalent parts as in FIG. 1 are denoted by the same reference numerals as in FIG. 1, and detailed description thereof will be omitted. In FIG. 2, a semiconductor laser substrate 2 (0.3
mm×0.3 mm×thickness 0.1 mm) are bonded via an intermediate member 3 made of a SiC strip. This SiC strip is
It is 0.8 mm x 1.6 mm x 0.3 mm thick, and has a Cr-Ni-Au multilayer metallization layer 3 formed by vapor deposition on both main surfaces.
2, and a homogeneous metallization layer 33 extending from the metallization layer 32 is provided on a side surface 31 substantially perpendicular to the two main surfaces. The semiconductor laser substrate 2 is die-bonded onto the intermediate member 3 using Au--Sn solder. The main surface of the semiconductor laser substrate 2 is provided with an electrode layer whose uppermost layer is an Au layer. Moreover, the intermediate member 3 is placed on the support member 1.
Bonded using Pb-Sn solder material. The conductive path forming member 5 is made of an Au wire with a diameter of 30 μm, and is connected from the upper electrode layer of the semiconductor laser body 2 to other conductive members by thermocompression bonding, while other electrical areas on the lower side of the semiconductor laser body 2 are It is connected to other conductive members by the conductive path forming member 5 via the gold-plated copper relay plate 6. The important point here is that a metallized layer 33 is provided on the side surface 31 of the intermediate member 3 extending from the metallized layer 32 to provide wettability to the brazing material between the semiconductor laser substrate 2 and the intermediate member 3. This is what is being done. With this structure, the brazing material protrudes from the edge of the semiconductor laser substrate 2 and then flows out onto the metallized layer 33 and hangs down, so that it does not bulge at the edge. Therefore, there is no possibility that the optical path of the laser beam emitting section is interrupted or the pn junction is electrically shorted. To quantitatively illustrate this effect, when the conventional structure shown in Figure 1 is adopted, the optical path changes, breaks and
While the failure rate due to pn junction short circuit was approximately 5%, the failure rate was reduced to 0.05% or less when the structure shown in FIG. 2 of the present invention was adopted. In addition, in the conventional structure, consideration was given to reducing the amount of brazing filler metal used in order to reduce the swelling at the end of the filler metal between the semiconductor laser substrate 2 and the intermediate member 3, but this has the opposite effect on the semiconductor laser substrate 2 and the intermediate member 3. This induces incomplete adhesion between the laser body 2 and the intermediate member 3. However, in the structure of the present invention, there is no need to reduce the amount of brazing filler metal so that the above-mentioned adhesion is completely achieved. For example, in the case of the structure shown in FIG. 1, the proportion of thermal resistance between the semiconductor laser substrate 2 and the support member 1 of 0.5° C./W or more was as high as 5% or more, whereas the structure shown in FIG. In terms of structure, it was lower at around 0.05%. Table 1 also shows the composition of the material for the intermediate member 3 applied to the semiconductor laser device of other embodiments of the present invention, the portion corresponding to the metallized layer 33 when it is made into a composite layer, and the metal forming the portion corresponding to the solder 4. It is.

[Table] First layer in contact with SiC, second layer in contact with first layer
The layer, the second layer, and the third layer in contact with the solder were formed by vapor deposition in various combinations shown in the table. Even in this case, exactly the same effect as in the above embodiment was obtained. Also, as an intermediate member, the coefficient of thermal expansion is 4.5×
When using AlN, which is 10 ^-6 /℃, and 3.5×
10 ^-6 /℃ using SiC, the amount of thermal resistance change (with respect to the initial value) between the semiconductor laser substrate 2 and the support member 1 when thermal stress is applied to the semiconductor device, and the laser beam Table 2 shows the amount of change in output (relative to the initial value).

〔Effect of the invention〕

As described above, according to the present invention, it is possible to manufacture a semiconductor device with high performance and stability at a high yield.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining a conventional semiconductor device, Figure 2 is a diagram explaining a conventional semiconductor device.
The figure is a diagram for explaining a semiconductor device according to an embodiment of the present invention, and FIG. 3 is a diagram for explaining a method for manufacturing a semiconductor device according to an embodiment of the present invention. 1... Metal support member, 2... Semiconductor laser base, 3
...Intermediate member, 5...Conducting path constituent member, 6...Relay metal plate, 31...End portion, 32, 33...Metalized layer.

Claims (1)

[Scope of Claims] 1. A semiconductor device in which an intermediate member made of an inorganic insulator or an inorganic semiconductor and a semiconductor element are sequentially mounted on a metal supporting member with a metallized layer interposed therebetween, in which the intermediate member and the semiconductor element are sequentially mounted on a metal supporting member. A portion of said metallized layer between said at least one of said intermediate members
The metal support member is also located on a part of the side surface of the
the intermediate member and the semiconductor element have a side surface that is substantially coplanar with a metallization layer located on the side surface;
A semiconductor device characterized in that each of the semiconductor devices is bonded using a brazing material. 2 The intermediate member is made of SiC, Al ₂ O ₃ , AlN, BeO,
Ceramics made of at least one material selected from the group consisting of Si ₃ N ₄ , MgO and C, or Si;
A semiconductor made of at least one material selected from the group consisting of Ge and SiC, wherein the metallized layer is in contact with the ceramic or semiconductor, Cr,
A first layer made of one material selected from the group consisting of Ti, Al, Mo, Ni, W and Ag, and Cr, Ti, Al, Mo, Ni, Cu, Ag in contact with the first layer. ，
a second layer made of one material selected from the group consisting of Pd, Pt and Au, and in contact with the second layer;
2. The semiconductor device according to claim 1, further comprising a third layer made of one material selected from the group consisting of Ag, Au, and Pt.