JP4655674B2 - PHOTOELECTRIC CONVERSION DEVICE AND ITS MANUFACTURING METHOD, OPTICAL WAVEGUIDE MODULE, AND OPTICAL INFORMATION PROCESSING DEVICE - Google Patents

Description

  The present invention relates to a photoelectric conversion device, a manufacturing method thereof, an optical waveguide module, and an optical information processing device.

  Currently, signal propagation between semiconductor chips such as LSI (Large Scale Integrated Circuit) is all done by electrical signals via substrate wiring. However, with the recent increase in MPU functionality, the amount of data exchanged between chips has increased remarkably, and as a result, various high frequency problems have emerged. Typical examples thereof include RC signal delay, impedance mismatch, EMC / EMI, crosstalk, and the like.

  In order to solve the above problems, the mounting industry and others have so far taken the lead in solving various problems by using various methods such as wiring layout optimization and new material development.

  However, in recent years, the effects of optimization of the wiring layout and development of new materials have been hampered by physical limitations, and it is assumed that simple semiconductor chips will be mounted in order to realize further advanced system functionality in the future. It has become necessary to review the structure of the printed wiring board itself. In recent years, various drastic measures have been proposed to solve these problems, but the following are representative examples.

-Fine wiring bonding by multi-chip module (MCM) High-performance chip is mounted on a precision mounting substrate such as ceramic and silicon, and fine wiring bonding that cannot be formed on a motherboard (multilayer printed circuit board) is realized. As a result, the pitch of the wiring can be narrowed, and the amount of data exchange increases dramatically by widening the bus width.

-Sealing and integration of various semiconductor chips and electrical wiring bonding by integration Various semiconductor chips are two-dimensionally sealed and integrated using polyimide resin or the like, and fine wiring bonding is performed on the integrated substrate. As a result, the pitch of the wiring can be narrowed, and the amount of data exchange increases dramatically by widening the bus width.

-Three-dimensional bonding of semiconductor chips A through electrode is provided in various semiconductor chips, and each is bonded to form a laminated structure. Thereby, the connection between the different types of semiconductor chips is physically short-circuited, and as a result, problems such as signal delay are avoided. On the other hand, however, problems such as an increase in the amount of heat generated due to lamination and thermal stress between semiconductor chips occur.

  Furthermore, in order to realize high speed and large capacity of signal transmission / reception as described above, an optical transmission coupling technique using optical wiring has been developed (for example, see Non-Patent Document 1 and Non-Patent Document 2 described later). . The optical wiring can be applied to various places such as between electronic devices, between boards in an electronic device, or between chips in a board. For example, as shown in FIG. 4, for transmission of signals over a short distance such as between chips, an optical waveguide 51 is formed on a printed wiring board 50 on which the chips are mounted, and a light emitting element (for example, a surface emitting laser) is formed. The light signal-modulated by 52 is made incident on the optical waveguide 51, the incident light is guided through the optical waveguide 51, and the light emitted from the optical waveguide 51 is received by a light receiving element (for example, a photodiode) 53. In this way, an optical transmission / communication system using the optical waveguide 51 as a transmission path for signal-modulated laser light or the like can be constructed.

  Further, a lens base 59 provided with a lens portion 58 is joined to the light emitting element 52 and the light receiving element 53, whereby the emitted light from the light emitting element 52 is collimated and effectively supplied to the optical waveguide 51. The light emitted from the optical waveguide 51 can be collected and effectively received by the light receiving element 53.

  Below, the manufacturing method of the photoelectric conversion apparatus which consists of the light emitting element 52 and the lens base | substrate 59 in which the lens part 58 was provided is demonstrated. First, as shown in FIGS. 5A and 5B, a light emitting element 52 is formed on a base 54 made of GaAs or the like, and a reinforcing material 55 is attached to the base 54. Next, as shown in FIG. 5C, the base 54 is thinned by grinding or etching so that the light emitting surface 56 of the light emitting element 52 is exposed. Next, as shown in FIG. 5D, a transparent support base 57 for reinforcement is bonded on the light emitting surface 56 side of the light emitting element 52, and the reinforcing material 55 is peeled off. Next, as shown in FIG. 5E, in order to make the signal light from the light emitting element 52 parallel and effectively enter the optical waveguide, the light emitting element 52 is inserted into the base 54 via a transparent support base 57. The lens base 59 provided with the lens portion 58 is joined at a position corresponding to the above. Note that the light receiving element 53 of FIG. 4 is formed in the same manner as the light emitting element 52 described above in order to collect the light emitted from the optical waveguide 51 and cause the light receiving element 53 to receive the light effectively. A lens base provided with a lens portion is joined to the base through a transparent support base (not shown). As described above, the photoelectric conversion device 60 according to the conventional example is manufactured.

Nikkei Electronics, “Encounter with Optical Wiring”, December 3, 2001, pages 122, 123, 124, 125, FIG. 4, FIG. 5, FIG. 6, FIG. NTT R & D, vol.48, no.3, pp.271-280 (1999)

  However, in the above-described conventional example, since the lens base 59 is attached to the base 54 via the transparent support base 57, the alignment accuracy between the light emitting element 52 or the light receiving element 53 and the lens portion 58 may be lowered.

  Further, since the thickness of the photoelectric conversion device 60 is the sum of the thicknesses of the base 54, the transparent support base 57, and the lens base 59, it is difficult to reduce the size and thickness. Further, since the transparent support base 57 and the lens base 59 are provided, there is a limit to further reducing the beam diameter of the emitted light from the light emitting element 52.

  The present invention has been made to solve the above-described problems, and its purpose is to improve the alignment accuracy between the photoelectric conversion element and the lens unit, and to reduce the size and thickness. An object of the present invention is to provide a possible photoelectric conversion device, a method for manufacturing the same, an optical waveguide module, and an optical information processing device.

That is, the present invention provides a photoelectric conversion element provided on the element substrate so that the light emitting surface or the light incident morphism surface is exposed, a lens portion corresponding to the photoelectric conversion element is a single lens body provided becomes, the lens body to the element substrate on the side of the light emitting surface or the light incident morphism surface is directly bonded, but according to the photoelectric conversion device.

Further, a step of providing a step of light-emitting surface or the light incident morphism surface is formed in the element substrate of the photoelectric conversion element so as to expose the lens portion corresponding to the photoelectric conversion elements into a single lens body, the light emitting in the side surface or the light incident morphism surface and a step of directly bonding said lens body to said element substrate, which relates to a method of manufacturing the photoelectric conversion device.

  The present invention also relates to an optical waveguide module comprising the photoelectric conversion device of the present invention and an optical waveguide section.

  Furthermore, the present invention relates to an optical information processing apparatus including the photoelectric conversion device according to the present invention, an optical waveguide unit, and a drive element that drives the photoelectric conversion element.

According to the present invention, in the device substrate on the side of the light emitting surface or the light incident morphism surface of the photoelectric conversion element, because bonding the single lens body of the lens portion is provided directly above prior As in the example, the alignment accuracy between the photoelectric conversion element and the lens portion can be improved as compared with the case where the element base and the lens base are bonded via the transparent support base.

  Moreover, since the thickness of the photoelectric conversion device of the present invention is the sum of the thicknesses of the element base and the lens base, it can be easily reduced in size and thickness as compared with the conventional example. Furthermore, since the thickness can be reduced, the degree of freedom in optical design increases, for example, the beam diameter of the emitted light from the light emitting element as the photoelectric conversion element can be further reduced.

  In addition, since the step of bonding the transparent support base in the conventional example can be reduced, the manufacturing process can be further simplified and the cost can be reduced.

  In the present invention, the photoelectric conversion element is preferably a light emitting element (for example, a surface emitting laser) or a light receiving element (for example, a photodiode), and the lens unit effectively converts the signal light from the light emitting element into parallel light. The light can be incident on the optical waveguide, or the light emitted from the optical waveguide can be condensed and effectively received by the light receiving element.

  Preferably, the lens portion is formed in advance on a transparent substrate, and the transparent substrate is directly attached to the element substrate as the lens substrate.

  It is also possible to form the lens portion on the transparent substrate at a position corresponding to the photoelectric conversion element after directly attaching a transparent substrate as the lens substrate to the element substrate.

Also, exposing the said light emitting surface or the light incident morphism surface is partially removed from the opposite side of the element substrate provided with a photoelectric conversion element and the element forming surface is preferred.

  Further, it is preferable that a land surface higher than the uppermost surface position of the lens portion is formed in a region other than the lens portion in the lens base. As a result, handling with a general device is possible without destroying the components of the photoelectric conversion device such as the lens unit.

  Furthermore, it is preferable that an alignment mark for aligning the optical axis between the photoelectric conversion element and the lens portion is provided on at least the element base of the element base and the lens base. As a result, higher-precision and easier alignment at the wafer level becomes possible.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

First Embodiment FIG. 1 is a schematic sectional view showing an example of a method for manufacturing a photoelectric conversion device according to the present invention in the order of steps.

  First, as shown in FIGS. 1A and 1B, a photoelectric conversion element 2 such as a light emitting element (for example, a surface emitting laser) or a light receiving element (for example, a photodiode) is formed on an element base 1 such as GaAs. The reinforcing material 3 is affixed to the element substrate 1. At this time, it is preferable that an alignment mark 4 for aligning the optical axis between the photoelectric conversion element 2 and the lens unit described later is provided on the element base 1 simultaneously with the formation of the photoelectric conversion element 2. As a result, higher-precision and easier alignment at the wafer level becomes possible. Any conventionally known method can be applied to the method for producing the photoelectric conversion element 2.

Next, as shown in FIG. 1C, the element substrate 1 provided with the photoelectric conversion element 2 is partially removed from the side opposite to the element formation surface by grinding or etching, so that the light of the photoelectric conversion element 2 is obtained. emitting surface or to expose the light input morphism surface 5, a thin type of the element substrate 1.

  Next, as shown in FIG. 1 (d), a transparent substrate (for example, a glass substrate) 7 on which a lens portion 6 is formed in advance is used as the lens substrate, and the transparent substrate 7 is bonded to an element substrate with an adhesive (not shown). Paste directly on 1. For the formation of the lens portion 6 on the transparent substrate 7, any conventionally known method can be applied.

  Here, instead of directly attaching the transparent substrate 7 on which the lens portion 6 is formed in advance to the element substrate 1, illustration is omitted, but after the transparent substrate 7 is directly attached to the element substrate 1, the photoelectric conversion element 2 is attached. It is also possible to form the lens portion 6 on the transparent substrate 7 at the corresponding position.

  Moreover, it is preferable to form a land surface 8 higher than the uppermost surface position of the lens unit 6 in a region other than the lens unit 6 in the transparent substrate 7 having the lens unit 6. Thereby, when handling the photoelectric conversion device according to the present invention, it is possible to handle it with a general device without destroying the photoelectric conversion device components such as the lens unit 6.

  Further, as shown in FIG. 1D and FIG. 2, an alignment mark 9 for aligning the optical axis between the photoelectric conversion element 2 and the lens unit 6 may be provided on the transparent base 7 in the same manner as the element base 1. preferable. As a result, higher-precision and easier alignment at the wafer level becomes possible.

  The signal light from the light emitting element as the photoelectric conversion element 2 can be collimated by the lens unit 6 and can be effectively incident on the optical waveguide unit (not shown), or emitted from the optical waveguide unit. The light can be condensed and effectively received by the light receiving element as the photoelectric conversion element 2.

  Then, after the transparent substrate 7 having the lens portion 6 is directly attached to the element substrate 1, the reinforcing material 3 is peeled off.

  As described above, the photoelectric conversion device 10 according to the present invention can be manufactured.

According to this embodiment, the element substrate 1 on the side of the light emitting surface or the light incident morphism surface 5 of the photoelectric conversion element 2, since joining the single transparent substrate 7 in which the lens unit 6 is provided directly above As in the conventional example, the alignment accuracy between the photoelectric conversion element 2 and the lens portion 6 can be improved as compared with the case where the element base and the lens base are bonded via the transparent support base.

  Moreover, since the thickness of the photoelectric conversion device 10 according to the present invention is the sum of the thicknesses of the element substrate 1 and the transparent substrate 7, it is possible to easily realize a reduction in size and thickness as compared with the conventional example.

  Furthermore, since the thickness can be reduced, for example, the beam diameter of the emitted light from the light emitting element as the photoelectric conversion element 2 can be further reduced, and the degree of freedom in optical design is increased. Specifically, when it is desired to extract a parallel beam having a small diameter as much as possible from a surface emitting laser having an emission diameter of Φ10 μm and a radiation angle of 90 °, in the conventional example as shown in FIG. If the thickness of the lens base 59 is 100 μm, the thickness involved in the control of the beam diameter is 200 μm, so the minimum beam diameter is Φ410 μm. On the other hand, in the photoelectric conversion device 10 according to the present invention, when the thickness of the transparent substrate 7 is 100 μm, the thickness involved in the control of the beam diameter is as thin as only the thickness of the transparent substrate 7 is 100 μm. The diameter becomes 210 μm, and the beam diameter can be further reduced.

  In addition, since the step of bonding the transparent support base in the conventional example can be reduced, the manufacturing process can be further simplified and the cost can be reduced.

Second Embodiment FIG. 3 is a schematic sectional view of an example of an optical information processing apparatus according to the present invention. As shown in FIG. 3, an optical information processing apparatus 11 according to the present invention includes a photoelectric conversion apparatus 10 according to the present invention, an optical waveguide 12 as the optical waveguide unit, and a drive element 13 that drives the photoelectric conversion element 2. It consists of. In addition, the photoelectric conversion device 10 according to the present invention is mounted on the interposer 14 with the solder 15, and the driving element 13 is mounted on the surface of the interposer 14 opposite to the photoelectric conversion device 10. The photoelectric conversion elements 2 a and 2 b and the drive element 13 are electrically connected via the through electrode 16 of the interposer 14. Further, the optical waveguide 12 is mounted on the printed wiring board 17.

  The optical waveguide 12 as the optical waveguide section is not particularly limited, and a conventionally known one can be used. For example, the optical waveguide 12 includes clads 18a and 18b and a core layer 19 sandwiched between the clads 18a and 18b. In addition, each of the light incident part and the light emission part has a lens member 20. Furthermore, the light incident end face and the light exit end face of the optical waveguide 12 are formed on a 45 ° mirror surface.

  The mechanism of the optical information processing apparatus 11 according to the present invention is such that light (for example, laser light) that is signal-modulated by the light-emitting element 2a as the photoelectric conversion element is collimated by the lens unit 6. This signal light is further condensed by the lens member 20 formed at the light incident portion of the optical waveguide 12 and is effectively incident on the core layer 19 of the optical waveguide 12. The incident light is guided through the optical waveguide 12, converted into parallel light by the lens member 20 formed in the light emitting portion of the optical waveguide 12, and then emitted from the optical waveguide 12. The emitted light is collected by the lens unit 6 and is effectively received by the light receiving element 2b as the photoelectric conversion element. In this way, it is possible to construct an optical transmission / communication system using the optical waveguide 12 as a transmission path for signal-modulated laser light or the like.

  As mentioned above, although embodiment of this invention was described, the above-mentioned example can be variously modified based on the technical idea of this invention.

  For example, the shape of the lens portion is not particularly limited, and the example of the convex lens has been described above. However, a concave lens may of course be used.

  Moreover, although the example which uses the said optical waveguide as the said optical waveguide part was given and demonstrated, the optical fiber etc. are applicable, for example.

  The present invention is suitable for the above-described optical wiring system in which a signal is placed on a laser beam. However, the present invention can also be applied to a display or the like by selecting a light source or the like.

It is a schematic sectional drawing which shows an example of the manufacturing method of the photoelectric conversion apparatus based on this invention by 1st Embodiment in process order. FIG. 2 is a schematic plan view showing an example of the transparent substrate provided with the lens portion constituting the photoelectric conversion device according to the present invention. It is a schematic sectional drawing which shows an example of the optical information processing apparatus based on this invention by 2nd Embodiment. It is a schematic sectional drawing of an example of the optical wiring system by a prior art example. It is a schematic sectional drawing which shows the manufacturing method of a photoelectric conversion apparatus similarly to process order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Element base | substrate, 2 ... Photoelectric conversion element, 2a ... Light emitting element, 2b ... Light receiving element, 3 ... Reinforcing material,
4,9 ... alignment marks, 5 ... light-emitting surface or the light incident morphism surface, 6 ... lens portion,
7 ... Transparent substrate, 8 ... Land surface, 10 ... Photoelectric conversion device, 11 ... Optical information processing device,
12 ... Optical waveguide, 13 ... Drive element, 14 ... Interposer, 15 ... Solder,
16 ... Penetration electrode, 17 ... Printed wiring board, 18a, 18b ... Cladding, 19 ... Core layer,
20 ... Lens member

Claims (10)

So as to be exposed on the side opposite to the light emitting surface or the light incident morphism surface element formation surface, a photoelectric conversion element provided through the semiconductor layer in the thickness direction from the element formation surface, the photoelectric conversion consists of a lens substrate lens unit corresponding is provided in the element, the lens body is bonded directly to said semiconductor layer on the side of the light emitting surface or the light incident morphism surface, and said semiconductor layer from said device forming surface The photoelectric conversion device and the lens unit are aligned on the optical axis by an alignment mark that is exposed in the same direction as the light emitting surface or the light incident surface. . The photoelectric conversion apparatus according to claim 1, wherein an alignment mark for aligning an optical axis between the photoelectric conversion element and the lens unit is provided on the lens base at a position corresponding to the alignment mark.   2. The photoelectric conversion device according to claim 1, wherein a level position of a land surface other than the lens unit in the lens base is higher than a top surface position of the lens unit. Wherein the step of forming a photoelectric conversion element halfway depth in the thickness direction of the semiconductor substrate from the element formation surface, and forming an alignment mark from the element formation surface to the semiconductor substrate halfway depth in the thickness direction, said semiconductor substrate The semiconductor layer is processed into a thinned semiconductor layer that is partially removed from the surface opposite to the element forming surface in the thickness direction, and the light emitting surface or light incident surface of the photoelectric conversion element and the alignment mark are combined with the semiconductor layer. bonding directly exposing the same surface, a step of providing a lens portion corresponding to the photoelectric conversion element to the lens body, the lens body in the semiconductor layer in the exposed side of the light emitting surface or the light incident morphism surface from production of steps and, a step of aligning the optical axis and the lens unit and the photoelectric conversion element by the alignment mark exposed in the photoelectric conversion device for Law. 5. The method of manufacturing a photoelectric conversion device according to claim 4, wherein an alignment mark for aligning an optical axis between the photoelectric conversion element and the lens unit is formed on the lens base at a position corresponding to the alignment mark. The method for manufacturing a photoelectric conversion device according to claim 4, wherein the lens portion is formed in advance on a transparent substrate, and the transparent substrate is directly attached to the semiconductor layer as the lens substrate. 5. The method for manufacturing a photoelectric conversion device according to claim 4, wherein after the transparent base as the lens base is directly attached to the semiconductor layer , the lens portion is formed on the transparent base at a position corresponding to the photoelectric conversion element. .   The manufacturing method of the photoelectric conversion device according to claim 4, wherein a land surface higher than an uppermost surface position of the lens portion is formed in a region other than the lens portion in the lens base.   An optical waveguide module comprising the photoelectric conversion device according to claim 1 and an optical waveguide unit.   An optical information processing apparatus comprising the photoelectric conversion device according to claim 1, an optical waveguide unit, and a drive element that drives the photoelectric conversion element.

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