CN101039014A

CN101039014A - Optical semiconductor device

Info

Publication number: CN101039014A
Application number: CN 200710005407
Authority: CN
Inventors: 吉川则之; 南尾匡纪; 石黑永孝; 中西秀行; 石田裕之; 富田佳宏; 福田敏行
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Nuvoton Technology Corp Japan
Priority date: 2006-03-15
Filing date: 2007-02-08
Publication date: 2007-09-19
Anticipated expiration: 2027-02-08
Also published as: CN101039014B; JP2007250739A

Abstract

The invention discloses an optical semiconductor device. The object is to provide an optical semiconductor device in which residual stress applied to a semiconductor laser chip is applied in a desired direction and within a certain range to improve the performance and reliability of the semiconductor laser and improve mass productivity. The optical semiconductor device 20 of the present invention includes a semiconductor laser chip 21 , a base 23 on which the semiconductor laser chip 21 is mounted, and a solder layer 24 sandwiched between the upper surface of the base 23 and the lower surface of the semiconductor laser chip 21 . The semiconductor laser chip is bent upward into a convex shape.

Description

Optical semiconductor device

Technical field

The present invention relates to optical semiconductor device, particularly be used in the high-performance optical semiconductor device in the photomagneto disk that can rewrite and optical communication of high-speed high capacity etc.

Background technology

In order to meet advanced information society, be in the means of communication of representative with the network, an urgent demand at a high speed, jumbo optical communication technology, in the device of the big capacity information that obtains as memory by using communication etc., an urgent demand more at a high speed, the jumbo photomagneto disk technology that rewrites.Under these circumstances, optical semiconductor devices such as semiconductor laser just become the main devices of optical communication technology and photomagneto disk technology, and requirement has higher performance in such optical semiconductor device, higher function reaches higher reliability.

The technology that semiconductor laser chip is connected on the base station is as the major technique that makes this optical semiconductor device high performance.The structure example that Figure 10 incites somebody to action optical semiconductor device in the past illustrates as an example.

Figure 10 is the figure that shows as the major part of the optical semiconductor device 10 of the light source of optical communication.Optical semiconductor device 10 comprises silicon substrate 3 and distributed feed-back N-type semiconductor N laser chip 1.Upper surface at silicon substrate 3 is formed with silicon dioxide film 5, is formed with electrode pattern 6 on silicon dioxide film 5.Electrode pattern 6 is provided with welding flux layer 7, and semiconductor laser chip 1 bonds together across welding flux layer 7 and electrode pattern 6.

Middle body at semiconductor laser chip 1 lower surface is formed with platform (mesa) portion 8, and welding flux layer 7 is applied in platform portion 8 part in addition of semiconductor laser chip 1 lower surface.That is, between platform portion 8 and silicon dioxide film 5, have gap 9.Have active layer 2 in platform portion 8, active layer 2 is for sending the layer of laser, is set at the leaning on the position of lower surface of semiconductor laser chip 1.

In optical semiconductor device 10, when semiconductor laser chip 1 was installed in silicon substrate 3, at first, the solder flux that will dissolve was arranged on the electrode pattern 6, secondly, semiconductor laser chip 1 was arranged on the solder flux that dissolves, and then, utilized cooling method to allow solder flux solidify.Here,, therefore when allowing solder flux cooling, curing, active layer 2 is produced distort, perhaps can produce residual stress at active layer 2 because the thermal coefficient of expansion of the thermal coefficient of expansion of semiconductor laser chip and silicon substrate is different usually.

But, as mentioned above, owing between platform portion 8 and silicon dioxide film 5, have the gap, so active layer 2 does not contact with welding flux layer 7.Can reduce the distortion of active layer 2 significantly, perhaps be reduced in the possibility that active layer 2 produces residual stress.The result is the action (for example, with reference to patent documentation 1) that distributed feed-back type optical semiconductor device 10 can carry out the single-mode under stable oscillation wavelength.

For example, the optical semiconductor device shown in the patent documentation 2 (not having diagram) is roughly the same with the structure of above-mentioned optical semiconductor device 10, but has the semiconductor laser chip that does not form platform portion.At this moment, also because the thermal coefficient of expansion of semiconductor laser chip is different with the thermal coefficient of expansion that the installation substrate that semiconductor laser chip uses is installed, therefore in generation residual stresss such as the active layers that is installed in the semiconductor laser chip after substrate is installed.This residual stress might make the characteristic instability of the diffraction lattice of active layer.But,, therefore can reduce the characteristic instability of the diffraction lattice of active layer, can obtain stable oscillating characteristic owing to have above-mentioned gap.

For example, following structure is disclosed in patent documentation 3, to seek to reduce above-mentioned residual stress, improve the laser characteristics when at high temperature making the semiconductor laser chip action and to improve the reliability of semiconductor device.Be provided with ditch with platform portion aspectant part in substrate top surface is installed, welding flux layer is set to strip along ditch.Because (platform portion periphery) is not provided with solder flux around the platform portion in the semiconductor laser chip lower surface, therefore can reduce above-mentioned residual stress.And, on the ratio platform portion periphery position in the outer part in the semiconductor laser chip lower surface, be provided with welding flux layer with the ditch almost parallel.The fusing point of this solder flux is higher than the fusing point that is set to the solder flux of strip along ditch.By this structure, semiconductor laser chip is connected electrically in installs on the substrate, can guarantee the thermal diffusivity that semicondcutor laser unit is higher simultaneously.(for example, with reference to patent documentation 3)

[patent documentation 1] spy opens the 2002-314184 communique

[patent documentation 2] spy opens flat 11-87849 communique

[patent documentation 3] spy opens the 2003-23200 communique

As mentioned above, if at the lower surface of semiconductor laser chip and install between the upper surface of substrate the gap is set, then can reduce the residual stress in the direction of the resonator end face that is parallel to semiconductor laser chip.But, in order to seek the higher performance of optical semiconductor device, higher reliability, preferably also to reduce the residual stress in the resonator direction of semiconductor laser chip.

Needs along with the height outputization of optical semiconductor device must make the resonator of semiconductor laser chip longer, and its result makes the length of semiconductor laser chip elongated.When the chip length of semiconductor laser chip is longer, must control the residual stress in the resonator direction of semiconductor laser chip.If do not control residual stress, for example photomagneto disk with high output semiconductor laser in, each optical semiconductor device in (lot) can present different polarisation ratios in batches, perhaps, burns difference in each optical semiconductor device of variation meeting in batches of operating current value at attached (burn-in) initial stage.And the difference of the polarisation ratio in and the different of variation of above-mentioned operating current value can become big in batches.In addition, polarisation is than one of key property of using semiconductor laser for photomagneto disk.

Summary of the invention

The present invention is the invention in view of the premises, and purpose is: the optical semiconductor device that the residual stress in a kind of resonator direction that can reduce light-emitting component is provided.

Optical semiconductor device of the present invention comprises light-emitting component, the articulamentum between the lower surface of upper surface that upper surface is installed the base station of light-emitting component and is clipped in base station and light-emitting component, and light-emitting component is bent into protruding shape up.

(effect of invention)

According to the present invention, can allow the residual stress that is applied to semiconductor laser chip be applied on the desirable direction and in certain scope.So, can provide a kind of Performance And Reliability that improves semiconductor laser, improve the optical semiconductor device of the property produced in batches.

The simple declaration of accompanying drawing

Fig. 1 is the summary structure chart that shows the optical semiconductor device in the first embodiment of the present invention, and Fig. 1 (a) is that Fig. 1 (b) is the profile of the IB-IB line shown in Fig. 1 (a) from the summary structure chart of the installment state of top optical semiconductor device.

Fig. 2 shows the ideograph of installment state of the semiconductor laser chip of the first embodiment of the present invention.

The serve as reasons phasor (phase diagram) of the solder flux that gold and tin constitutes of Fig. 3.

Fig. 4 is the figure that shows the relation of the bending of photosemiconductor chip and operating current value.

Fig. 5 is the summary structure chart that the solder flux of the optical semiconductor device in the second embodiment of the present invention connects, the summary structure chart of Fig. 5 (a) when solder flux is placed on the upper surface of sub-erecting bed (submount) unevenly, Fig. 5 (b) is the summary structure chart when the upper surface of sub-erecting bed is provided with recess.

Fig. 6 is the summary structure chart that shows the optical semiconductor device that is assembled in the metallic packaging body in the second embodiment of the present invention, Fig. 6 (a) is for showing the ideograph of inner primary structure, and Fig. 6 (b) is the ideograph from the inside primary structure of the direction of arrow shown in Fig. 6 (a).

Fig. 7 is the summary structure chart that shows the optical semiconductor device in the third embodiment of the present invention, and Fig. 7 (a) is for showing the ideograph of inner primary structure, and Fig. 7 (b) is the summary profile of the VIIB-VIIB line shown in Fig. 7 (a).

Fig. 8 is the summary structure chart that shows the optical semiconductor device in the fourth embodiment of the present invention, and Fig. 8 (a) is that Fig. 8 (b) is the profile of the VIIIB-VIIIB line shown in Fig. 8 (a) from the summary structure chart of the installment state of top optical semiconductor device.

Fig. 9 is the summary structure chart that shows the optical semiconductor device in the fifth embodiment of the present invention, and Fig. 9 (a) is that Fig. 9 (b) is the profile of the IXB-IXB line shown in Fig. 9 (a) from the summary structure chart of the installment state of top optical semiconductor device.

Figure 10 is the summary structure chart of optical semiconductor device in the past.

(simple declaration of symbol)

10,20,30,40,50,60,70,80-optical semiconductor device; 1,21,31,41,71,81-semiconductor laser chip (light-emitting component); 3,23,33,43-erecting bed (base station); 7,24,34,44-welding flux layer (articulamentum); The central portion of 24b-optical axis direction; The end of 24a, 24c-optical axis direction; The 43b-recess; The 75-component body; 76,86-jut; The 122-active layer.

Embodiment

Below, with reference to accompanying drawing the related optical semiconductor device of embodiments of the invention is illustrated.In addition, sometimes to the prosign omission explanation of mark in the accompanying drawings.

(first embodiment)

Fig. 1 (a) is the upper surface figure of structure of the optical semiconductor device 20 that shows first embodiment, and Fig. 1 (b) is the profile of the IB-IB line shown in Fig. 1 (a).

Optical semiconductor device 20 comprises semiconductor laser chip (light-emitting component) 21, sub-erecting bed (base station) 23, welding flux layer (articulamentum) 24 and metal base station 2, shown in Fig. 1 (a).Semiconductor laser chip 21 is bonded in the upper surface 23a of sub-erecting bed 23 across welding flux layer 24, and sub-erecting bed 23 is bonded in the upper surface of metal base station 25 across no illustrated welding flux layer.In addition, sub-erecting bed 23 promptly can be made of silicon, also can by high heat sink material, thermal coefficient of expansion constitutes less than the material (carborundum and aluminium nitride etc.) of the thermal coefficient of expansion of semiconductor laser chip 21.And metal base station 25 is the part of no illustrated packaging body.

Below, semiconductor laser chip 21 and welding flux layer 24 are described in detail.

In semiconductor laser chip 21, penetrate laser 22 from active layer (not having diagram).Active layer be arranged on semiconductor laser chip 21, compare with upper surface 27, by on the position of lower surface 21a.Because laser 22 penetrates along the arrow shown in Fig. 1 (b), so the direction of this arrow becomes the resonator direction of semiconductor laser chip 21, the optical axis direction of the light that optical semiconductor device 20 sends.And, in the end face of semiconductor laser chip 21, be approximately perpendicular to the end face 21b that optical axis direction extends, the speculum that 21c becomes resonator.

And, semiconductor laser chip 21 is bent into the shape of projection up, shown in Fig. 1 (b), in other words, the central portion 27b that is bent into optical axis direction is only than both ends 27a, the 27c of the optical axis direction shape of outstanding Δ b1 up, in other words, being bent into the radius of curvature of drawing up is that r1, center angle are the arc of θ.When semiconductor laser chip 21 is bent into the shape of projection up like this, with semiconductor laser chip 21 decurvations for the projection shape the time compare, can be in a plurality of optical semiconductor devices 20 in batches, make initial stage characteristic (for example, the symmetry of the expanded-angle of polarisation ratio, laser and the linearity of electric current-light output characteristic) value with identical in the variation of the operating current value of burning the attached initial stage.Thereby, can seek high-performance and high reliability in the optical semiconductor device 20.

Welding flux layer 24 is filled in the gap between the upper surface 23a of the lower surface 21a of semiconductor laser chip 21 and sub-erecting bed 23.As mentioned above, because semiconductor laser chip 21 is bent into the shape of projection up, and the upper surface 23a of sub-erecting bed 23 is smooth surfaces, and therefore the gap at the both ends that are positioned at optical axis direction in above-mentioned gap is narrower than the gap of the central portion that is positioned at optical axis direction.The thickness that makes the central portion 24b that is positioned at optical axis direction in the welding flux layer 24 is littler narrow that part of than the thickness of the both ends 24a, the 24c that are positioned at optical axis direction.

And preferably welding flux layer 24 contains tin and gold, the temperature the when fusing point of welding flux layer 24 approaches to use semiconductor device (below, be called " temperature during use ").This is because when semiconductor laser chip 21 usefulness solder flux being connected sub-erecting bed 23, earlier semiconductor laser chip 21 is bonded on the solder flux that dissolves, allow the solder flux cooling curing again, if the temperature when allowing the fusing point of welding flux layer 24 approach to use can seek to reduce the stress that is produced when allowing solder flux solidify.And the temperature when allowing the fusing point of welding flux layer 24 approach to use preferably allows and contains more tin in the welding flux layer 24.Utilize phasor shown in Figure 3, its reason is illustrated.

Fig. 3 shows the phasor of tin and gold.The longitudinal axis of Fig. 3 shows the melting temperature of solder flux, shows the ratio of components of tin for gold with the transverse axis of figure.

When the many solder flux of Jin Bixi being dissolved and solidify, that is, when the solder flux that makes tin for the ratio of components discontented 50% of gold dissolves and solidifies, make this solder flux curing with 280 ℃, become and contain the golden eutectic solder flux that enriches.

And when the ratio of components that makes tin for gold be that about 90% solder flux dissolves and when solidifying, with 217 ℃ this solder flux solidified.As mentioned above, the temperature when approaching to use for the fusing point that makes solder flux is preferably used the solder flux that contains abundant tin.

In welding flux layer 24, tin is that the ratio of components of central portion 24b of optical axis direction is greater than the both ends 24a of optical axis direction, the ratio of components of 24c for the ratio of components of gold.When the manufacture method to optical semiconductor device 20 is illustrated, again this point is illustrated.

This case inventors have made the laser aid that penetrates red laser, and the initial stage characteristic of this laser is investigated.And, investigated the composition of welding flux layer 24.

At first, the semiconductor laser chip 21 to the laser aid of made is illustrated.Its material is that wavelength is the AlGaInP class material of 650nm band, and its maximum waveform light is output as 300mW, and its chip length is 1500 μ m, and its chip width is 300 μ m, and its chip thickness is 110 μ m.And the mean value of having prepared Δ b1 shown in Figure 1 is that the batch of 0.3 μ m and the mean value of Δ b1 shown in Figure 1 are the batch of 0.5 μ m for the mean value of the batch of-0.12 μ m, Δ b1 shown in Figure 1.And, respectively the initial stage operating current value that belongs to each a plurality of laser aid is in batches investigated.Fig. 4 shows this measurement result.The transverse axis of Fig. 4 is amount of bow Δ b1, is the operating current value with the longitudinal axis of figure.

As shown in Figure 4, be in the batch of-0.12 μ m at the mean value of amount of bow Δ b1, that is, when semiconductor laser chip 21 decurvations were the shape of projection, the operating current value was different greatly in each optical semiconductor device.And be in the batch of 0.3 μ m at the mean value of amount of bow Δ b1, the operating current value each optical semiconductor device 20,20 ... in be roughly fixed value.

And, the initial stage characteristic that to the mean value of amount of bow Δ b1 is the laser that sent of the semiconductor laser chip 21 in the batch of 0.3 μ m is investigated, the result of investigation be in batches a plurality of optical semiconductor devices 20,20 ... present roughly same initial stage characteristic value, the difference of the initial stage characteristic value in is less in batches.And, to a plurality of optical semiconductor devices 20,20 ... the initial stage characteristic value that is presented has carried out on average, the result of the mean value of the initial stage characteristic value of calculating represents that this mean value is comparatively ideal value, therefore infer if make laser aid, then can provide laser aid with high-performance and high reliability with this semiconductor laser chip 21.So preferably amount of bow Δ b1 is 0.3 μ m, and radius of curvature r1 is 900mm when being 0.3 μ m owing to amount of bow Δ b1, therefore learns that best radius of curvature r1 is more than 900mm.

And, be in the batch of 0.5 μ m at the mean value of amount of bow Δ b1, the maximum of Δ b1 is 1.0 μ m, radius of curvature is 281mm when Δ b1 is 1.0 μ m.Mean value at amount of bow Δ b1 is in the batch of 0.3 μ m, and radius of curvature is about 900mm.Therefore, learn that best semiconductor laser chip 21 is bent into the shape of projection up, and the radius of curvature of drawing is the above arc of 280mm, better is the shape that is bent into projection up, and the radius of curvature of drawing is the above arc of 900mm.

Here, by to laser radiation is measured, resolved to the light interference fringe that semiconductor laser chip obtains, calculated amount of bow Δ b1.Because the mensuration boundary of the light interference fringe of laser is 0.05 μ m, be the semiconductor laser chip 21 of 1500 μ m when being bent into protruding shape up therefore when making chip length, be limited to 6000mm on the radius of curvature.But, the chip length of semiconductor laser chip 21 is long more, and the upper limit of its radius of curvature is big more.So, be the semiconductor laser chip 21 of 3000 μ m when being bent into the shape of projection up making chip length, be limited to 22500mm on the radius of curvature.

And, semiconductor laser chip 21 is cut off, the result who measures amount of bow Δ b1 from its section shape is, can be in the batch of 0.02 μ m at the mean value of amount of bow Δ b1, makes the initial stage characteristic value of laser identical with the variation of the operating current value of burning the attached initial stage.When amount of bow Δ b1 is 0.02 μ m, chip length be 3000 μ m semiconductor laser chip 21 radius of curvature on be limited to 56250mm.From foregoing as can be known, preferably semiconductor laser chip 21 is bent into the shape of projection up, and the radius of curvature of drawing is the following arc of the above 56250mm of 280mm.

In sum, preferably semiconductor laser chip 21 is bent into the shape of projection up, and the radius of curvature of drawing is the following arc of the above 56250mm of 280mm, and better is the shape that is bent into projection up, and the radius of curvature of drawing is the above arc below 22500 of 280mm.

And this case inventors investigate welding flux layer 24 after above-mentioned off-test.The result of investigation is that the thickness of welding flux layer 24 is 4.8 μ m at the central portion 24b of optical axis direction, and is 3.8 μ m at the both ends of optical axis direction 24a, 24c.And, in welding flux layer 24, contain Jin Hexi.Can think that gold in the welding flux layer 24 derives from the part of dissolving in the Gold plated Layer that is formed on semiconductor laser chip 21, and the tin in the welding flux layer 24 derives from for semiconductor laser chip 21 is installed, and the tin solde layer when the tin solde layer of stanniferous is arranged on the upper surface 23a of sub-erecting bed 23 dissolve part.

This case inventors make the shape of semiconductor laser chip decurvation for projection again, and the initial stage characteristic of the laser that this semiconductor laser chip is sent is investigated.A plurality of optical semiconductor devices in the result learns in batches present different initial stage characteristics, and interior in batches is widely different, therefore are difficult to make in a large number laser aid.And, with decurvation is that the semiconductor laser chip of convex shape assembles, make the lamination-type optical semiconductor device, carried out burning attached to this lamination-type optical semiconductor device, the result is the variable quantity that changes since the mean value of initial stage operating current value and initial stage operating current value, and is bigger than the semiconductor laser chip that is bent into convex shape up.

And, even make semiconductor laser chip be bent into the shape of convex up, if but the discontented 250mm of its radius of curvature r1 is that situation more than the 250mm is compared with radius of curvature r1, also have very large stress and be applied to semiconductor laser chip, make the mean value of operating current value bigger.Because when the mean value of operating current value was big, when being installed in optical semiconductor device in the optical take-up apparatus, optical semiconductor device can send more heat, so the temperature of optical semiconductor device is risen significantly, so, not ideal.So preferably making radius of curvature r1 is more than the 250mm, and make semiconductor laser chip 21 be bent into the shape of projection up.

When as mentioned above, when welding flux layer 24 was installed in base station with semiconductor laser chip 21, residual stress was applied on certain direction and in certain scope on the semiconductor laser chip 21 (particularly active layer).But if shown in Fig. 1 (b), when semiconductor laser chip 21 was bent into up the shape of projection, the initial stage characteristic value in can making in batches all was same initial stage characteristic value roughly, can make the variation of operating current value at attached initial stage of burning identical.Though for its concrete reason and unclear, this case inventors think like this.That is, this is that the part that approaches active layer among the lower surface 21a of semiconductor laser chip 21 produce to be shunk because when making semiconductor laser chip 21 be bent into the shape of projection up, thereby can suppress the event of difference of the gain etc. of optical axis direction.

Secondly, show the manufacture method of the related optical semiconductor device of present embodiment 20.Semiconductor laser chip 21 usefulness solder flux are installed in the upper surface 23a of sub-erecting bed 23 with this manufacture method.Below, the method that semiconductor laser chip 21 is installed with solder flux is illustrated.

At first, the upper surface 23a at sub-erecting bed 23 is provided with solder flux.

Secondly, the sub-erecting bed 23 that is provided with solder flux side and below thereof is heated from it, solder flux is dissolved.Then, clamp (hold) semiconductor laser chip 21, be pressed on the solder flux that dissolves with the vacuum tweezer (vacuum tweezer) of heating.Method can utilize solder flux semiconductor laser chip 21 to be installed in the upper surface 23a of sub-erecting bed 23 by this.

Then, stop heating, allow solder flux solidify from the below.

At this moment, because the lower surface 21a of semiconductor laser chip 21 is than upper surface 27 cooling earlier, so laser chip is bent into the shape of projection up.Here, the thermal coefficient of expansion of best sub-erecting bed 23 is more slightly bigger than the thermal coefficient of expansion of semiconductor laser chip 21.This be because if the thermal coefficient of expansion of sub-erecting bed 23 greater than the words of the thermal coefficient of expansion of semiconductor laser chip 21, then compare during less than the thermal coefficient of expansion of semiconductor laser chip 21 with the thermal coefficient of expansion of sub-erecting bed 23, it is big that the contraction of sub-erecting bed 23 becomes, and can suppress semiconductor laser chip 21 decurvations is the event of convex shape.

And, because as mentioned above, make semiconductor laser chip 21 be bent into the shape of projection up, so the gap between the upper surface 23a of the lower surface 21a of semiconductor laser chip 21 and sub-erecting bed 23 is that the gap of central portion of optical axis direction is greater than the gap at the both ends of optical axis direction.Thereby the solder flux that dissolves moves to the central portion of optical axis direction respectively from the both ends of optical axis direction, has filled this gap.At this moment, because the fusing point of gold is higher than the fusing point of tin, mainly be that tin moves to the central portion of optical axis direction from the both ends of optical axis direction therefore.The result is a tin for the ratio of gold is that the ratio of the central portion 24b of optical axis direction is higher than the both ends 24a of optical axis direction, the ratio of 24c.In addition, inventors' usefulness X line microanalysis method (micro analysis) (below, be called the XMA method) tin in the welding flux layer 24 is investigated for the ratio of gold, determined that this ratio is that the ratio of central portion 24b of optical axis direction is greater than the both ends 24a of optical axis direction, the ratio of 24c.

In addition, because the tin of the central portion 24b of optical axis direction is more than the both ends 24a of optical axis direction, the tin of 24c, so the fusing point of the solder flux of the central portion 24b of optical axis direction is lower than the fusing point of solder flux of both ends 24a, the 24c of optical axis direction.Thereby, when allowing solder flux solidify, at first be that the solder flux of both ends 24a, the 24c of optical axis direction solidifies, be the solder flux of the central portion 24b of optical axis direction solidifies then.Make semiconductor laser chip 21 be bent into the shape of projection up.

(second embodiment)

Show to Fig. 5 pattern the appearance that solder flux is placed on the upper surface 33a of sub-erecting bed 33.Fig. 5 (a) shows the figure of an example in the present embodiment for pattern ground, Fig. 5 (b) be pattern show the figure of another example in the present embodiment.

In the second embodiment of the present invention, can make the tin containing ratio of the central portion of optical axis direction be higher than above-mentioned first embodiment.Particular content is as follows.

In Fig. 5 (a), though the upper surface 33a of sub-erecting bed 33 is smooth, the solder flux of upper surface 33a that is placed on sub-erecting bed 33 is inhomogeneous.Specifically, the solder flux of the central portion 34a of the optical axis direction among the upper surface 33a of sub-erecting bed 33 and to clip the solder flux of

circumference

34b, 34c of this central portion 34a more than the solder flux of other parts.So, can make the tin of central portion 34a of optical axis direction abundanter.

In Fig. 5 (b), be formed with

recess

43b, 43b, 43b at the upper surface 43a of sub-erecting bed 43.Specifically, the central portion of the optical axis direction in the upper surface 43a of sub-erecting bed 43 and the circumference that clips this central portion are formed with

recess

43b, 43b, 43b.When putting solder flux at such upper surface 43a, when forming uniform welding flux layer 44, be formed with the part of

recess

43b, 43b, 43b and compare with the part that does not form

recess

43b, 43b, 43b, can be placed with more solder flux.So, can make the tin of central portion 44a of optical axis direction more than the both ends 44b of optical axis direction, the tin of 44c.

Therefore as mentioned above, in Fig. 5 (a) and Fig. 5 (b), owing to can make semiconductor laser chip be bent into the shape of projection up, can make the residual stress that is applied to semiconductor laser chip be applied on certain direction and in certain scope.Thereby, can make the initial stage characteristic value of interior in batches a plurality of optical semiconductor devices identical, and can make the variation of the operating current value of burning the attached initial stage identical.

Fig. 6 shows and utilizes in the structure shown in Fig. 5 (a) after solder flux loads onto semiconductor laser chip 31, more sub-erecting bed 33 is bonded in the structure chart of the optical semiconductor device 50 that forms in the metallic packaging body.Fig. 6 (a) is the ideograph of the internal structure that shows the state optical semiconductor device 50 down after the cover of optical semiconductor device 50 (not having diagram) taken off, and Fig. 6 (b) is the ideograph of the internal structure when showing from the direction of arrow optical semiconductor device 50 shown in Fig. 6 (a).In addition, though semiconductor laser chip 31 is not bent into the shape of projection up in Fig. 6 (b), is actually and is bent into the shape of projection up.

Semiconductor laser chip 31 is bent into up under the state of convex shape and is installed on the sub-erecting bed 33, utilizes fusing point to be lower than the solder flux of the fusing point of welding flux layer 24, should be installed on the metal derby 52 by sub-erecting bed 33.Metal derby 52 forms as one with metallic packaging body 53, and

electrode terminal

54a, 54b, 54c are formed on metallic packaging body 53 respectively.Electrode terminal 54b is connected electrically on the metallic packaging body 53, is the earth terminal of optical semiconductor device 50.And the electrode terminal of electrode terminal 54a for using to optical semiconductor device 50 injection currents applies positive voltage from electrode terminal 54a to electrode terminal 54b (earth terminal).This electrode terminal 54a links together by conductivity electric wire 55 and semiconductor laser chip 31.

This case inventors investigate the uniformity of the initial stage characteristic of optical semiconductor device shown in Figure 6 50 and the variation of the operating current value at attached initial stage of burning.Specifically,

electrode terminal

54a, 54b are electrically connected, have injected electric current to semiconductor laser chip 31.Making optical semiconductor device 50 export wavelength is laser 56 that 650nm is with, that waveform light is output as 250mW.Because the residual stress that is applied to semiconductor laser chip 31 is applied on certain direction and in certain scope, therefore in batches a plurality of semiconductor lasers in present identical initial stage characteristic value, and burn the operating current value at attached initial stage and present uniform variation.

(the 3rd embodiment)

Fig. 7 shows the summary structure chart of structure of the optical semiconductor device 60 of the third embodiment of the present invention.Fig. 7 (a) is for showing the ideograph of the state after the cover (not having diagram) that will be installed in the packaging body top of optical semiconductor device 60 takes off, and Fig. 7 (b) is the profile of the VIIB-VIIB line shown in Fig. 7 (a).

Optical semiconductor device 60 shown in Fig. 7 (a) is such light integrating device, comprising: semiconductor laser chip 21, photo detector 62, the treatment circuit (not having diagram) that is subjected to light signal, speculum 63, diffraction lattice (not having diagram), photo detector chip 64, packaging body 65, silicon substrate 66 and

electrode terminal

67,67 ...In this optical semiconductor device 60, photo detector chip 64 is set on the silicon substrate 66, photo detector 62 and be bonded on the photo detector chip 64 by solder flux by the signal processing circuit of light signal.And photo detector chip 64 is bonded on the packaging body 65 by conductive paste.

Action to optical semiconductor device 60 is illustrated.At first, to the

electrode terminal

67,67 of packaging body 65 ... after the injection current, semiconductor laser chip 21 drives, and penetrates laser 69.This laser 69 is parallel to the surface of (L1 shown in Fig. 7 (b)) photo detector chip 64 and penetrates, and in pip 68 reflections of speculum 63, (L2 shown in Fig. 7 (b)) is vertical upward penetrates, that is, penetrate from optical semiconductor device 60.The laser 69 that penetrates from optical semiconductor device 60 turns back to optical semiconductor device 60 after having read the signal on the photomagneto disk, be bonded in diffraction lattice (the not having diagram) branch on the packaging body top of packaging body 65, is received by photo detector 61.The light signal of 61 pairs of receptions of photo detector amplifies and computing, and the light signal after amplification and the computing is input in the treatment circuit that is subjected to light signal.

This case inventors to

electrode terminal

67,67 ... behind the injection current, it is laser 69 that 650nm is with, that waveform light is output as 300mW that optical semiconductor device 60 has been exported wavelength.Because the residual stress that is applied to semiconductor laser chip 21 is applied on certain direction and in certain scope, therefore a plurality of semiconductor lasers in batches present identical initial stage characteristic value, and the operating current value of burning the attached initial stage presents identical variation.

Though the optical semiconductor device 60 shown in Fig. 7 (a) has been omitted detailed explanation, shown in Fig. 7 (b), semiconductor laser chip 21 is bent into the shape of projection up.And welding flux layer 24 is that the thickness of central portion 24b of optical axis direction is bigger than the thickness of both ends 24a, the 24c of optical axis direction, and the tin of the central portion 24b of optical axis direction is more than the both ends 24a of optical axis direction, the tin of 24c.

(the 4th embodiment)

Fig. 8 is the structure chart that shows the related optical semiconductor device of the fourth embodiment of the present invention 70, and Fig. 8 (a) is its upper surface figure, and Fig. 8 (b) is the profile of the VIIIB-VIIIB line shown in Fig. 8 (a).

In the related optical semiconductor device 70 of present embodiment, semiconductor laser chip 71 has component body 75 and jut 76,76.Component body 75 is bent into the shape of projection up, and the radius of curvature of drawing is that r2 and center angle are the arc of θ 2, is the described semiconductor laser chip 21 of above-mentioned first embodiment.And end face 75b, the 75c of semiconductor laser chip 71 becomes the speculum of resonator respectively.

Each jut 76 is arranged on the circumference of the upper surface of component body 75, and shown in Fig. 8 (a), the short side direction that is set in the limit of the upper surface of composed component body 75 extends.In the present embodiment, owing to laser 22 penetrates along the long side direction in the limit of the upper surface of composed component body 75, so each jut 76 extends along the direction that is approximately perpendicular to optical axis direction in the limit of the upper surface of composed component body 75.And the part of the upper surface 76a of each jut 76 is present on the part of the bending the most up in the semiconductor laser chip 21.

And preferably each jut 76 is by gold-plated formation, is that material more than the pyroconductivity of component body constitutes by pyroconductivity preferably.And the length that is preferably formed as to the left and right directions among Fig. 8 is 100 μ m, and the depth among Fig. 8 is 300 μ m, and thickness is 5 μ m.

In the present embodiment, also the same with above-mentioned first embodiment, having prepared the mean value of amount of bow Δ b2 is that the batch of 0.3 μ m and the mean value of amount of bow Δ b2 are the batch of 0.5 μ m for the batch of-0.12 μ m, the mean value of amount of bow Δ b2, and, respectively the initial stage operating current value that belongs to each a plurality of optical semiconductor device is in batches investigated.Obtained the same result with above-mentioned first embodiment.

And, optical semiconductor device 70 shown in Fig. 8 (a) and Fig. 8 (b) is installed in the metallic packaging body, made device shown in Figure 7, variation to the initial stage characteristic and the operating current value at attached initial stage of burning is investigated, and the result is that the variation of initial stage characteristic value and operating current value is identical in batches.

Secondly, show the manufacture method of the optical semiconductor device 70 of present embodiment.

Secondly, for example, allow flat chuck (collet) touch the

jut

76,76 of semiconductor laser chip 71, clamp semiconductor laser chip 71.

Then, allowing flat chuck touch under the state of

jut

76,76 of semiconductor laser chip 71 the heated flat chuck.Simultaneously, add heater erecting bed 23 from the below, entire semiconductor chip 71 is heated.Because solder flux dissolves because of this heating, so semiconductor laser chip 71 is pressed on the solder flux that dissolves.

Then, stop to allow solder flux solidify to the heating of flat chuck and from the heating of below antithetical phrase erecting bed 23.

At this moment, the path that the heat of semiconductor laser chip 71 is escaped has two, from semiconductor laser chip 71 via welding flux layer 24, to first path that sub-erecting bed 23 is escaped; With from semiconductor laser chip 71 via

jut

76,76, to second path that flat chuck is escaped.Here, because the both ends of the optical axis direction in the semiconductor laser chip 71 are different with the central portion of optical axis direction, a part touches air, so cooling rate is very fast.The both ends of the semiconductor laser chip 71 of optical axis direction are than early cooling of central portion of the semiconductor laser chip 71 of optical axis direction.And, because solder flux when solidifying, shrink, so both ends quilt erecting bed 23 laybacks of the semiconductor laser chip 71 of optical axis direction is stretched.Can think that the result makes semiconductor laser chip 71 be bent into the shape of projection up.

As mentioned above, the phenomenon that solder flux solidifies to central portion 24b successively from both ends 24a, the 24c of optical axis direction is comparatively remarkable when using the solder flux that is made of gold and tin.In addition, this case inventors analyze welding flux layer 24 with the XMA method, and the ratio of having determined tin is the ratio height of tin of both

ends

24a, 24c of ratio optical axis direction of tin of the central portion 24b of optical axis direction.

(the 5th embodiment)

Fig. 9 shows the summary structure chart of the related optical semiconductor device of the fifth embodiment of the present invention 80.Fig. 9 (a) is that Fig. 9 (b) is the profile of the IXB-IXB line shown in Fig. 9 (a) from the summary structure chart of the optical semiconductor device 80 of top present embodiment.

In the present embodiment, the same with above-mentioned first embodiment shown in Fig. 9 (b), semiconductor laser chip 81 is bent into the shape of projection up, specifically, is bent into the shape of projection up, and the radius of curvature of drawing is that r3, center angle are the arc of θ 3.

And in the present embodiment, shown in Fig. 9 (a) and Fig. 9 (b), semiconductor laser chip 81 has component body 75 and jut 86,86.But

jut

86,86 is separately positioned on the position by the central authorities of the upper surface of semiconductor laser chip 81 than above-mentioned the 4th embodiment.So, main substrate is being cut, make simultaneously a plurality of

optical semiconductor devices

80,80 ... the time, compare with above-mentioned the 4th embodiment, more easily cutting.

In addition, as mentioned above, this case inventors also confirm the performance of the related optical semiconductor device 80 of present embodiment, here, its detailed content are omitted.

Promptly, with wavelength is that the AlGaInP class material that 650nm is with is used as semiconductor laser chip 81, make the optical semiconductor device 80 of output red laser, the reliability of its initial stage characteristic and optical semiconductor device 80 and the relation of amount of bow Δ b3 are investigated, obtained the roughly the same result of result who is obtained with above-mentioned first embodiment.

And, optical semiconductor device 80 shown in Fig. 9 (a) and Fig. 9 (b) is installed in the metallic packaging body, made device shown in Figure 7, variation to the initial stage characteristic and the operating current value at attached initial stage of burning is investigated, and the result is that the variation of initial stage characteristic value and operating current value is identical in batches.

(other embodiment)

Above-mentioned first to the 5th embodiment also can be following structure.

With wavelength be the AlGaAs based semiconductor laser device of 780nm band and AlGaInP based semiconductor laser device that wavelength is the 650nm band as optical semiconductor device in addition explanation, so long as can be used in high output semiconductor laser aid in the rewriting type photomagneto disk, also can use blue laser device and ultraviolet laser device.And, also can will send the device of multiwavelength laser such as two wavelength lasers and three-wavelength laser as optical semiconductor device.

Semiconductor laser chip can form monolithic, also can be that a plurality of chip hybrid are installed together.And semiconductor laser chip is an example of light-emitting component, also can replace semiconductor laser chip with end face light-emitting diode (led) chip.

Each jut is made of gold, also can constitutes by the pyroconductivity of pyroconductivity and light-emitting component roughly the same metal and semiconductor.And each jut also can be to form by the material of processing light-emitting component.When the laser chip that with wavelength is the AlGaInP based semiconductor formation of 650nm band was used as semiconductor laser chip, sub-erecting bed was made of GaAs.Therefore, also can carry out etching, form jut the substrate that constitutes by GaAs.

(utilizing on the industry possibility)

The invention provides that a kind of that the residual stress that is applied on the semiconductor laser chip is applied to is desired Direction on and in certain scope, improve the Performance And Reliability of semiconductor laser, improve in batches Productive optical semiconductor device, useful to the equipment of optical communication and photomagneto disk and system etc.

Claims

1. An optical semiconductor device, characterized in that:

Including: light emitting element,

a base, the above-mentioned light-emitting element is mounted on the upper surface, and

a connection layer sandwiched between the upper surface of the above-mentioned base and the lower surface of the above-mentioned light-emitting element;

The above-mentioned light-emitting element is bent upward in a convex shape.

2. The optical semiconductor device according to claim 1, characterized in that:

The above-mentioned light-emitting element is curved such that the radius of curvature is not less than 250 mm and not more than 22500 mm.

3. The optical semiconductor device according to claim 1, characterized in that:

The above connection layer contains gold and tin.

4. The optical semiconductor device according to claim 3, characterized in that:

The light emitting element emits light propagating substantially parallel to the upper surface of the base;

The ratio of tin to gold in the above-mentioned connection layer is that the ratio of the central portion of the light emitted by the light-emitting element in the direction of the optical axis is higher than the ratio of the end portions in the direction of the optical axis;

In the central portion in the direction of the optical axis, tin exists more than gold.

5. The optical semiconductor device according to claim 3, characterized in that:

The content of tin in the connection layer is greater than the content of gold in the connection layer in terms of weight ratio.

6. The optical semiconductor device according to claim 3, characterized in that:

The thickness of the above-mentioned connection layer is that the thickness of the central part in the direction of the optical axis of the light emitted by the above-mentioned light-emitting element is greater than the thickness of the end part in the direction of the optical axis;

In the center portion in the optical axis direction, tin exists more than gold.

7. The optical semiconductor device according to claim 3, characterized in that:

A recess is formed at the center of the upper surface of the base;

The connection layer is disposed on a part of the upper surface of the base platform where the recess is not formed, and fills the recess;

The ratio of tin to gold is such that the ratio inside the concave portion is higher than the ratio of the portion of the upper surface of the base where the concave portion is not formed.

8. The optical semiconductor device according to claim 1, characterized in that:

The above-mentioned light-emitting element has a plate-shaped element body bent upward into a convex shape, and a protrusion provided on the peripheral portion of the upper surface of the element body;

At least a part of the upper surface of the protrusion is present on the upper surface of the uppermost part of the element body.

9. The optical semiconductor device according to claim 8, characterized in that:

The above-mentioned element body, viewed from above, is rectangular;

The protruding portion extends in a direction substantially perpendicular to an optical axis direction of light emitted from the element body.

10. The optical semiconductor device according to claim 8, characterized in that:

The thermal conductivity of the protrusion is higher than the thermal conductivity of the element body.

11. The optical semiconductor device according to claim 1, characterized in that:

The above base is a silicon substrate.

12. The optical semiconductor device according to claim 11, characterized in that:

At least one of a light-receiving element, a circuit element, and a reflector is mounted on the upper surface of the silicon substrate.

13. The optical semiconductor device according to claim 1, characterized in that:

The above-mentioned submount is made of metal or semiconductor whose heat dissipation property is higher than that of the light-emitting element.

14. The optical semiconductor device according to claim 1, characterized in that:

An active layer that emits light is formed at a position closer to the lower surface than the upper surface inside the light emitting element.

15. The optical semiconductor device according to claim 1 or 8, characterized in that:

The above-mentioned light-emitting element is a semiconductor laser chip or an end-emitting light-emitting diode chip.