JP2010045385A - Surface emitting laser element and method of manufacturing the same, surface emitting laser array and wavelength multiplexing transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface emitting laser element which is easy to obtain the oscillation light of a single mode, oscillates at a low threshold current, and reduces a wavelength shift and the deterioration of an element caused by the distortion of an active layer. <P>SOLUTION: The surface emitting layer element includes a drive base and a surface emitting laser lower base. The drive base includes a first mirror layer 1, a deflection film 2 on which the first mirror layer 1 is arranged, a support substrate 4 arranged oppositely to the first mirror layer 1 on the deflection film 2 through a first air gap 3, and a pair of displacement control electrodes 5a, 5b provided on the deflection film 2 and the support substrate 4 in order to control a deflection amount. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a surface emitting laser element, a manufacturing method thereof, a surface emitting laser array, and a wavelength multiplexing transmission system.

  A surface emitting laser that can extract light perpendicular to the surface of a semiconductor substrate has the following advantages over a conventional edge emitting laser. That is, since the volume of the active layer can be reduced, it can be driven with a low threshold current and low power consumption. Further, since the mode volume of the resonator is small, modulation of several tens of GHz is possible, which is suitable for high-speed transmission. In addition, the spread angle of the emitted light is small and coupling to the optical fiber is easy. Further, the surface emitting laser does not require cleavage for production and has a small element area, and thus can be parallelized and formed into a two-dimensional high-density array.

  Because of these advantages, surface-emitting lasers are key in optical communication systems that require rapid increases in transmission speed and transmission capacity, optical interconnections between computers, chips, chips, and optical computing. It is actively researched and developed as a device.

  If the oscillation wavelength of this surface-emitting laser can be varied or stabilized, a large-capacity transmission with higher throughput becomes possible using a wavelength multiplexing method or the like. The following method has been proposed as a method for controlling the wavelength of a surface emitting laser. That is, the first method is to change the temperature of the active layer, the second method is to inject carriers and change the refractive index by the plasma effect, and the third method is to use the quantum confined Stark effect. It has been proposed to change the refractive index and, as a fourth method, to change the resonator length by changing the position of the external mirror.

  However, the first method requires an electronic circuit for coping with the drift of the threshold current in addition to the temperature control mechanism, and the configuration becomes complicated. Further, the second and third methods have a problem that the variable wavelength range is as small as 10 nm or less. In contrast, the fourth method can widen the variable wavelength range to several tens of nm.

  As a conventional example using the fourth method, Patent Literature 1, Patent Literature 2, and Patent Literature 3 are known.

  In Patent Document 1, a doubly-supported beam (bridge) that also serves as an external mirror and is laminated with a conductive film through which current flows is placed in a magnetic field applied from the outside, and is moved by the generated Lorentz force.

  However, in Patent Document 1, it is necessary to apply a magnetic field, and there is a problem that the element becomes large. Further, there is a problem that the current flowing through the driving stripe film becomes a heat generation source, the temperature of the laser element rises, and the laser characteristics deteriorate.

  In Patent Document 2, a cantilever (cantilever beam) also serving as an external mirror is moved by electrostatic force or a piezoelectric effect.

  However, the layer that is the main component of the cantilever needs to have high durability against repeated applied strains, and thus high homogeneity is necessary. There is a problem that it is difficult to give it sex. Moreover, there exists a problem that it becomes thick as the whole cantilever and becomes difficult to distort. Furthermore, in order to reduce the warpage in the initial state, it is necessary to reduce the internal stress of the multilayer film, and the manufacturing problems are great.

  Further, in Patent Document 3, a surface emitting laser body provided with an active layer and a mirror layer provided on one side of the active layer is provided on a flexible film (strained dielectric film), and an external layer composed of a dielectric multilayer film on a silicon substrate. A mirror is provided, a gap having a predetermined interval is provided between the external mirror and the flexible film, and the resonator length is changed by electrostatic force to change the oscillation wavelength.

  However, in Patent Document 3, since a flexible film is included in the resonance region of laser oscillation, the resonator length becomes equal to or greater than this film thickness (several μm), which facilitates multimode oscillation and increases the threshold current. There is a problem of becoming. Further, since the surface emitting laser substrate is connected to the flexible film, there is a problem that the active layer is distorted and the oscillation wavelength is shifted. There is also a problem that the element is likely to deteriorate.

  The present invention relates to a surface emitting laser element capable of easily obtaining single-mode oscillation light, oscillating at a low threshold current, and capable of reducing wavelength shift and element degradation due to distortion of an active layer, and a method for manufacturing the same. An object of the present invention is to provide a surface emitting laser array and a wavelength division multiplexing transmission system.

  In order to achieve the above object, an invention according to claim 1 includes a driving base and a surface emitting laser lower base, and the driving base includes a first mirror layer and a first mirror layer. A flexible film, a support substrate disposed on a side opposite to the first mirror layer of the flexible film via a first gap, and a flexible film and a support substrate for controlling a deflection amount. A surface-emitting laser lower base body on a semiconductor substrate, a second mirror layer made of a semiconductor multilayer reflector, a first spacer layer, an active layer, The second spacer layer and the current injection layer are laminated to form a laminated structure, and the surface emitting laser lower substrate and the drive substrate are formed of the surface of the laminated structure of the surface emitting laser lower substrate and the first structure. The surface of the mirror layer is arranged so as to face the second gap. It is characterized in that it is.

  According to a second aspect of the present invention, in the surface emitting laser element according to the first aspect, the flexible film is formed of silicon or silicon oxide.

  According to a third aspect of the present invention, in the surface emitting laser element according to the first aspect, the support substrate is formed of silicon or silicon oxide glass.

  According to a fourth aspect of the present invention, in the surface-emitting laser element according to the first aspect, the first mirror layer is a dielectric multilayer film reflecting mirror.

  According to a fifth aspect of the present invention, in the surface emitting laser element according to the first aspect, a displacement control conductive film is provided on the surface of the support substrate facing the flexible film through the first gap, and the displacement control conductive film is provided. The conductive film is characterized in that it is electrically connected to one displacement control electrode of the pair of displacement control electrodes.

  According to a sixth aspect of the present invention, in the surface emitting laser element according to any one of the first to fifth aspects, the laser beam on the surface opposite to the side on which the flexible film of the support substrate is provided. An optical element is provided on this path.

  According to a seventh aspect of the present invention, in the surface-emitting laser element according to any one of the first to sixth aspects, the active layer is formed of a GaInAs-based or GaInNAs-based material. It is said.

  The invention according to claim 8 has a drive base and a surface emitting laser lower base, wherein the drive base includes a first mirror layer, a flexible film in which the first mirror layer is disposed, and a flexure. A support substrate disposed on the opposite side of the film from the first mirror layer via a first gap, and a pair of displacement controls provided on the deflection film and the support substrate to control the amount of deflection The surface emitting laser lower substrate includes a second mirror layer made of a semiconductor multilayer reflector, a first spacer layer, an active layer, and a second spacer layer on a semiconductor substrate. And a current injection layer are laminated to form a surface emitting laser element formed as a layered structure, wherein the surface of the layered structure of the surface emitting laser lower substrate and the surface of the first mirror layer are So as to have the second gap so as to be opposed to each other. It is characterized in that connected by a laser lower substrate and the driving substrate direct bonding method.

  According to a ninth aspect of the present invention, in the method for manufacturing a surface emitting laser element according to the eighth aspect, the first mirror layer is a dielectric multilayer film reflecting mirror, and the dielectric multilayer film reflecting mirror is the flexible film. It is characterized in that it is formed by a film forming method.

  According to a tenth aspect of the present invention, there is provided at least a second mirror layer made of a semiconductor multilayer reflector, a first spacer layer, an active layer, a second spacer layer, and a current on a semiconductor substrate. A step of laminating an injection layer, a sacrificial layer for forming a second gap, and a first mirror layer to form a laminated structure; and The step of forming a surface emitting laser lower substrate by etching up to the depth of the sacrificial layer, leaving the junction region, and a driving substrate by disposing a support substrate over the flexible film via a first gap A step of manufacturing, a step of bonding the surface of the flexible film and the surface of the first mirror layer left unetched, bonding the surface emitting laser lower substrate and the driving substrate, and the sacrificial layer Remove by etching to form second void It is characterized by having a step.

  The invention according to claim 11 is a surface emitting laser array in which a plurality of surface emitting laser elements according to any one of claims 1 to 7 are provided on the same support substrate.

  The invention described in claim 12 is a wavelength division multiplex transmission system in which the surface emitting laser element according to any one of claims 1 to 7 or the surface emitting laser array according to claim 11 is used. is there.

  According to the first to seventh aspects of the present invention, the driving base includes the surface emitting laser lower base, and the driving base is a deflection in which the first mirror layer and the first mirror layer are disposed. The film, the support substrate disposed on the opposite side of the flexible film to the first mirror layer via the first gap, and the flexible film and the support substrate for controlling the amount of deflection are provided. The surface-emitting laser lower base body has a pair of displacement control electrodes, and a surface-emitting laser lower base on a semiconductor substrate, a second mirror layer made of a semiconductor multilayer reflector, a first spacer layer, an active layer, Two spacer layers and a current injection layer are laminated to form a laminated structure. The surface emitting laser lower base and the driving base are formed by the surface of the surface emitting laser lower base and the first mirror. The surface of the layer is disposed so as to face the second gap. Since, the following effects (first, second effect) is obtained.

  That is, as a first effect, since a flexible film is not included between the two mirror layers, an extremely short resonator structure is possible. This makes it easy to obtain single resonance mode light emission (that is, there is no split of the wavelength peak of the oscillation light) and facilitates optical transmission. In addition, light confinement is improved and oscillation is performed with a low threshold current, which facilitates laser driving.

  Further, as a second effect, since the surface emitting laser lower substrate is hardly bent, wavelength shift due to distortion of the active layer can be prevented. Further, the deterioration of the element is reduced.

  As described above, according to the first to seventh aspects of the invention, it is easy to obtain single-mode oscillation light, oscillation is performed with a low threshold current, and wavelength shift and element degradation due to active layer distortion are reduced. It is possible to provide a surface emitting laser element that can be made to operate.

  In particular, according to the invention described in claim 2, in the surface-emitting laser device according to claim 1, the flexible film is formed of silicon or silicon oxide, and silicon and silicon oxide are formed with high quality, so that the film is formed. Unlike a strained film, a highly reliable flexible film can be obtained, and a surface emitting laser element can be manufactured with a high yield.

  According to a third aspect of the present invention, in the surface emitting laser element according to the first aspect, the support substrate is formed of silicon or silicon oxide glass, and the silicon oxide film is formed between silicon and silicon. Since silicon and silicon can be directly bonded to each other, a drive base can be easily formed with high accuracy. In addition, since silicon and silicon oxide glass are homogeneous, precise processing is possible, and a highly reliable drive base can be formed.

  According to a fifth aspect of the present invention, in the surface emitting laser element according to the first aspect, the displacement control conductive film is provided on the surface of the support substrate facing the flexible film through the first gap, and the displacement Since the control conductive film is electrically connected to one displacement control electrode of the pair of displacement control electrodes, the capacitance between the conductive regions that generate electrostatic force can be reduced, and high-speed displacement control can be performed. (High speed operation) becomes possible. In addition, since the displacement control voltage can be individually applied to each element, the elements can be arrayed.

  According to the invention described in claim 6, in the surface emitting laser element according to any one of claims 1 to 5, the surface of the support substrate opposite to the side where the flexible film is provided. An optical element is provided on the path of the laser beam. By providing optical elements such as a microlens, a diffractive lens, a mirror, and a waveguide on the surface of the support substrate, it is easy to increase the functionality and functionality of the element. Become.

  According to the invention of claim 7, in the surface emitting laser element according to any one of claims 1 to 6, the active layer is formed of a GaInAs-based or GaInNAs-based material, Since the GaInAs-based or GaInNAs-based surface emitting laser has a small variation in laser characteristics even when the temperature changes, wavelength control is further facilitated. In addition, since a GaInAs-based or GaInNAs-based surface emitting laser has a semiconductor multilayer film reflecting mirror with a small number of layers, it can be manufactured at low cost. In addition, since the GaInAs-based and GaInNAs-based surface emitting lasers transmit laser light through silicon, it is easy to increase the functionality and functionality of the device by coupling with an optical device provided on a silicon support substrate.

  According to the inventions of claims 8 and 9, the driving substrate and the surface emitting laser lower substrate are provided, and the driving substrate is provided with the first mirror layer and the first mirror layer. A flexible film, a support substrate disposed on a side opposite to the first mirror layer of the flexible film via a first gap, and a flexible film and a support substrate for controlling a deflection amount. A surface-emitting laser lower base body on a semiconductor substrate, a second mirror layer made of a semiconductor multilayer reflector, a first spacer layer, an active layer, A method of manufacturing a surface-emitting laser element in which a second spacer layer and a current injection layer are stacked to form a stacked structure, wherein the surface of the stacked structure of the surface-emitting laser lower substrate and the first The mirror layer is disposed so as to face the surface of the mirror layer so as to have the second gap. As described above, since the surface emitting laser lower substrate and the drive substrate are connected by a direct bonding method, the gap between the first mirror layer and the surface emitting laser lower substrate is easily formed with a predetermined interval. be able to.

  In particular, according to the invention described in claim 9, in the method for manufacturing the surface emitting laser element according to claim 8, the first mirror layer is a dielectric multilayer reflector, and the dielectric multilayer reflector is The first mirror layer is formed on the flexible film by a film forming method, and the first mirror layer is firmly connected to the flexible film, so that the first mirror layer having high durability against the deflection can be obtained.

  According to a tenth aspect of the present invention, on the semiconductor substrate, at least a second mirror layer composed of a semiconductor multilayer mirror, a first spacer layer, an active layer, and a second spacer layer are provided. A step of laminating a current injection layer, a sacrificial layer for forming a second gap, and a first mirror layer to form a laminated structure, and the laminated structure is divided into a region of a laser oscillation unit and a driving substrate. And a step of forming a surface emitting laser substrate by etching to a depth equal to or greater than the depth of the sacrificial layer, and a driving substrate by disposing a support substrate on the flexible film via a first gap. Bonding the surface of the flexible film and the surface of the first mirror layer left unetched to bond the surface-emitting laser substrate and the driving substrate; and Remove by etching to form a second void Since the sacrificial layer is removed after the surface emitting laser lower substrate including the first mirror layer is bonded to the driving substrate, the gap between the surface of the laminated structure and the surface of the first mirror layer is removed. Can be set more precisely. Therefore, it becomes easier to manufacture the surface emitting laser element.

  According to an eleventh aspect of the present invention, there is provided a surface in which a plurality of the surface emitting laser elements according to any one of the first to seventh aspects are provided on the same support substrate. Since each surface emitting laser element is a light emitting laser array and each oscillation wavelength is stable, it is easy to construct a highly reliable high density and large capacity optical transmission system.

  According to a twelfth aspect of the present invention, the surface-emitting laser element according to any one of the first to seventh aspects or the surface-emitting laser array according to the eleventh aspect is used. Since each surface emitting laser element has a stable oscillation wavelength, high-density and large-capacity wavelength multiplex transmission is possible with high reliability.

It is a figure which shows the structural example of the surface emitting laser element which concerns on this invention. It is a figure which shows the other structural example of the surface emitting laser element which concerns on this invention. It is a figure which shows the example of a manufacturing process of the surface emitting laser element of FIG. It is a figure which shows the example of a manufacturing process of the surface emitting laser element of this invention. It is a figure which shows the other example of a manufacturing process of the surface emitting laser element of this invention. It is a figure which shows the other example of a manufacturing process of the surface emitting laser element of this invention. It is a figure which shows the modification of the surface emitting laser element which concerns on this invention. It is a figure which shows the modification of the surface emitting laser element which concerns on this invention. It is a figure which shows the modification of the surface emitting laser element which concerns on this invention. It is a figure which shows the structural example of the parallel transmission system which couple | bonded the surface emitting laser array of this invention, and the silica-type fiber. It is a figure which shows the structural example of the parallel transmission system which couple | bonded the surface emitting laser array of this invention, and the silica-type fiber. It is a figure which shows the structural example of the wavelength multiplexing transmission system using the surface emitting laser array of this invention. 1 is a diagram illustrating a configuration example of a surface emitting laser element according to Example 1. FIG. 1 is a diagram illustrating a configuration example of a surface emitting laser element according to Example 1. FIG. 1 is a diagram illustrating a configuration example of a surface emitting laser element according to Example 1. FIG. 6 is a diagram illustrating a configuration example of a surface emitting laser element according to Example 2. FIG. 6 is a diagram illustrating a configuration example of a surface emitting laser element according to Example 3. FIG. 6 is a diagram illustrating a configuration example of a surface emitting laser element according to Example 4. FIG. It is a figure which shows the structural example of the wavelength multiplexing optical transmission system using the surface emitting laser array of Example 4. FIG. It is a figure which shows the structural example of the wavelength multiplexing optical transmission system using the surface emitting laser array of Example 4. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a surface emitting laser element according to the present invention. Referring to FIG. 1, this surface emitting laser element has a driving base and a surface emitting laser lower base, and a first mirror layer 1 and a first mirror layer 1 are arranged on the driving base. A flexible substrate 2, a support substrate 4 disposed on the opposite side of the flexible membrane 2 from the first mirror layer 1 via a first gap 3, and a flexible membrane 2 for controlling the amount of deflection A pair of displacement control electrodes 5 a and 5 b provided on the support substrate 4 are provided.

  The surface emitting laser lower substrate is formed on a semiconductor substrate 11 with a second mirror layer 12 made of a semiconductor multilayer mirror, a first spacer layer 14, an active layer 15, and a second spacer layer 16. The current injection layer 17 is laminated to form a laminated structure.

  The surface emitting laser lower substrate and the drive substrate are disposed so as to face each other so that the surface of the laminated structure of the surface emitting laser lower substrate and the surface of the first mirror layer 1 have the second gap 19. .

  Here, when the driving substrate is, for example, the support substrate 4 and the flexible film 2 are conductive, when the voltage is applied between the pair of displacement control electrodes 5a and 5b, the flexible substrate 2 and the support substrate 4 An electric field is generated between them, and it has a function of deflecting (distorting) the flexible film 2 by the electrostatic force between the flexible film 2 and the support substrate 4. The shape of the flexible film 2 may be a wide surface or may have a double-supported beam (bridge) or cantilever (cantilever) structure. In the above-described example, the flexible film 2 and the support substrate 4 are made conductive. However, when the flexible film 2 and the support substrate 4 are made of an insulating material, the flexible film 2 and the support substrate are used. 4, each of the displacement control conductive films is attached to each other, and each displacement control conductive film is connected to each of the displacement control electrodes 5a and 5b to generate an electrostatic force between the displacement control conductive films. The membrane 2 can be deflected with respect to the support substrate 4.

  In FIG. 2, the support substrate 4 is conductive, but when the flexible film 2 is insulative (and when the flexible film 2 has a cantilever structure), the support substrate 4 is displaced to the tip of the flexible film 2. A case is shown in which a control conductive film 20 is provided and this displacement control conductive film 20 is electrically connected to a displacement control electrode 5b provided in the flexible film 2. In this case, a pair of displacement controls is shown. When a voltage is applied to the electrodes 5 a and 5 b, an electrostatic force is generated between the conductive support substrate 4 and the displacement control conductive film 20 provided at the tip of the insulating flexible film 2. Can bend. That is, the deflection amount of the flexible film 2 can be controlled by the voltage applied to the pair of displacement control electrodes 5a and 5b.

In FIG. 1 (or FIG. 2), the first mirror layer 1 is a high-reflectivity dielectric multilayer reflector, a semiconductor multilayer reflector, a metal reflector, or a combination thereof. It is composed of a multilayer film reflecting mirror. In the case of a dielectric multilayer reflector, the first mirror layer 1 can be composed of ZrO ₂ / SiO ₂ , MgO / SiO ₂ , MgO / Si, Al ₂ O ₃ / MgF ₂ or the like. When the semiconductor multilayer mirror is used, the first mirror layer 1 is made of AlAs / GaAs, AlGaAs / GaAs, AlGaAs / GaAs, GaInP / GaAs, AlGaN / GaN, GaInAsP / InP, AlGaInAs / InP, or the like. it can. In the case where the first mirror layer 1 is composed of a metal reflecting mirror, the first mirror layer 1 can be composed of Au, Al, Pt, Pd, Ag, Ni, Cr, Ti, or an alloy thereof.

  Further, GaAs, InP, GaP, GaNAs, Si, Ge, or the like can be used for the semiconductor substrate 11 of the surface emitting laser lower base.

  The active layer 15 is formed of a GaInAs-based or GaInNAs-based material.

  Since the surface emitting laser element using a GaInAs-based or GaInNAs-based material for the active layer 15 is a long wavelength band having an oscillation wavelength of 0.9 μm or more, it is a quartz-based one having the smallest transmission loss in the 1.3 μm band or 1.5 μm band High consistency with fiber. Conventionally, as these lasers for wavelength bands, edge emitting lasers using GaInAsP formed on an InP substrate as an active layer are used, but the confinement of carriers in the active layer is weak and the temperature characteristics are poor. Furthermore, when a surface emitting laser having GaInAsP as an active layer is formed on this InP substrate, GaInAsP / InP, which is the best semiconductor multilayer reflector structure on the InP substrate, has a small refractive index difference and a high reflectance. It takes a lot of layers to get

  On the other hand, since a surface emitting laser using a GaInAs-based or GaInNAs-based material for the active layer 15 can be formed on a GaAs substrate, a wide band gap material can be selected as a layer around the active layer such as a spacer layer. Thus, a surface emitting laser with good carrier confinement and good temperature characteristics can be obtained. Further, since a surface emitting laser using a GaInAs-based or GaInNAs-based material for the active layer 15 can be formed on a GaAs substrate, an Al (Ga) As / GaAs semiconductor multilayer film having a large refractive index difference that can be formed on the GaAs substrate. A reflector can be used as a mirror layer. Therefore, a surface emitting laser having a semiconductor multilayer mirror having a small number of layers can be obtained.

  Examples of the GaInAs-based or GaInNAs-based materials include GaInAs, AlGaInAs, GaInAsP, AlGaInAsP, AlGaAs, AlGaAsP, GaInAsSb GaInNAs, GaNAs, AlGaInNAs, GaInNAsP, AlGaInNAsP, AlGaNAs, AlGaNAsP, and GaInNASb.

  More specifically, the active layer 15 includes GaInAsP / InP (1.3 μm band, 1.55 μm band), GaInNAs / GaAs (1.3 μm band, 1.55 μm band), GaInAs / GaAs (0.98 μm band). GaAlAs / GaAs (0.85 μm band), AlGaInP / GaAs (0.65 μm band), and the like can be used.

  Since the GaInAs-based or GaInNAs-based surface emitting laser has a small fluctuation in laser characteristics even when the temperature changes, wavelength control is further facilitated. Further, a GaInAs-based or GaInNAs-based surface emitting laser has a semiconductor multilayer film reflecting mirror with a small number of layers, and can be manufactured at low cost. In addition, since a GaInAs-based or GaInNAs-based surface emitting laser transmits laser light through Si, it is easy to increase the functionality and functionality of the device by coupling with an optical device provided on a Si support substrate.

  In addition, the semiconductor multilayer reflector as the second mirror layer 12 is formed of AlAs / GaAs, AlGaAs / GaAs, AlGaAs / when the semiconductor substrate 11 is formed of GaAs, InP, GaP, GaNAs, Si, Ge, or the like. It is formed using a multilayer film such as GaAs, GaInP / GaAs, AlGaN / GaN, GaInAsP / InP, or AlGaInAs / InP.

  The spacer layers 14 and 16 are provided for transporting carriers to the active layer 15 and adjusting the resonator length, and are required to be transparent to the emitted light. Specifically, the spacer layers 14 and 16 are selected from GaAs, InP, GaInAsP, GaAlAs, AlGaInP, GaInP, and the like according to the material of the active layer 15.

  The current injection layer 17 is provided on the entire surface of the laminated structure of the surface emitting laser lower substrate or in a region excluding the light emitting region. The current injection layer 17 includes a highly conductive semiconductor layer / metal film, metal film, or the like. Can be used.

Further, it is desirable that the lower substrate of the surface emitting laser has a current confinement structure by providing an insulating layer made of Al _x O _y or the like and a high resistance region into which protons are implanted in the vicinity of the active layer 15.

  The surface emitting laser lower substrate can be manufactured by a film forming method such as MOCVD method or MBE method and a method of joining samples prepared by these methods. In some cases, a part of both substrates is etched or a spacer layer is provided to adjust the distance between the first gaps 3 before bonding, or both substrates are polished to improve surface smoothness.

  Further, the drive substrate and the surface emitting laser lower substrate are portions other than the deflection region of the flexible film 2, such as brazing, fusion, pressure welding (solid phase bonding) -room temperature interface bonding, anodic bonding, direct bonding, diffusion bonding, etc. Connected by Details of these joining methods are described in, for example, the literature “Masaki Esashi et al.,“ Micromachining and Micromechatronics ”Baifukan”.

  The case where the surface emitting laser lower substrate and the driving substrate are connected by a direct bonding method will be described. In direct bonding, smooth substrates are overlapped with each other in an air atmosphere, and bonding is generated by atomic force at the interface. After overlapping, heating is preferably performed to further strengthen the bonding at the interface. Bonding of a compound semiconductor substrate or film such as GaAs, GaAlAs, InP, or the like, a silicon substrate or film, a compound semiconductor substrate or film, and a silicon substrate or film is possible (for example, the document “Appl. Phys. Lett. ., 56 (1990) 11 "). In order to adjust the distance between the mirrors, a bonding spacer layer made of a compound semiconductor film, a silicon film, or a silicon oxide film may be provided at the bonding portion between the surface emitting laser lower substrate and the driving substrate. In the case of direct bonding, since the binder layer that can be formed at the interface is 10 nm or less, the gap between the first mirror layer 1 and the surface emitting laser lower substrate can be easily formed with a predetermined interval.

  Further, as a method for manufacturing the surface emitting laser element of the present invention, when the first mirror layer 1 is a dielectric multilayer film reflector, the dielectric multilayer film reflector is formed on the flexible film 2 by a film forming method. Thus, the first mirror layer 1 can be formed.

Specifically, a dielectric multilayer film reflecting mirror such as ZrO ₂ / SiO ₂ , MgO / SiO ₂ , MgO / Si, Al ₂ O ₃ / MgF ₂ or the like is formed on the flexible film 2 as the first mirror layer 1. It can be formed by a wire vapor deposition method, a resistance heating vapor deposition method, a sputtering method, or the like. In this method, since the first mirror layer 1 is firmly bonded to the flexure film 2, the mirror layer 1 having high durability against flexure (distortion) can be obtained.

  FIG. 3 is a diagram showing an example of a manufacturing process of the surface emitting laser element of the present invention. 3A to 3D are shown as longitudinal sectional views. Referring to FIG. 3, first, at least a second mirror layer 12 made of a semiconductor multilayer reflector, a first spacer layer 14, an active layer 15, and a second spacer layer 16 are formed on a semiconductor substrate 11. Then, the current injection layer 17, the gap forming sacrificial layer 18, and the first mirror layer 1 are laminated to form a laminated structure (FIG. 3A).

  Next, this stacked structure is removed by etching to a depth greater than or equal to the depth of the sacrificial layer 18, leaving the region of the laser oscillation portion and the drive substrate, thereby forming a surface emitting laser lower substrate (FIG. 3 ( b)).

  Next, the support substrate 4 is arranged at a predetermined interval on the flexible film 2 and the surface of the flexible film 2 to produce a drive base. Thereafter, the surface emitting laser lower substrate and the driving substrate are connected by bonding the surface of the flexible film 2 and the surface of the first mirror layer 1 remaining without being etched (FIG. 3C). .

  Next, the sacrificial layer 18 is removed by etching to form a second gap 19 (FIG. 3D). Thereby, the surface emitting laser element of FIG. 1 can be produced.

In the manufacturing process example of FIG. 3, when HF aqueous solution is used for etching, AlAs and SiO ₂ are compared with GaAs, AlGaAs, Al ₂ O ₃ , TiO ₂ , AlF ₃ , SrF ₂ , Si, SiN, and SiON. The etching rate is much higher. When AlAs and SiO ₂ are used as the material for the sacrificial layer 18 and an aqueous HF solution is used as an etching solution, the portion that comes into contact with the etching solution is GaAs, AlGaAs, Al ₂ O ₃ , TiO ₂ , AlF ₃ , SrF ₂ , Si, SiN, SiON, or the like. If it comprises with the material of this, the space | interval of the 2nd space | gap 19 can be formed between the surface of a laminated structure and the surface of the 1st mirror layer 1. FIG.

  In the example of the manufacturing process of FIG. 3, since the sacrificial layer 18 is removed after the surface emitting laser lower substrate including the first mirror layer 1 is bonded to the driving substrate, the surface of the laminated structure and the surface of the first mirror layer 1 are removed. The space | interval of the 2nd space | gap 19 between these can be set more precisely. Therefore, it becomes easier to manufacture the surface emitting laser element.

  When the support substrate 4 is, for example, insulative, a displacement control conductive film is provided on the surface of the support substrate 4 facing the flexible film 2 with a gap, and this displacement control conductive film is used as one displacement control. It can be electrically connected to an electrode, for example 5a.

Specifically, displacement control made of polycrystalline silicon, Ti, Mo, W, Ta and nitrides thereof, Al, Cu, Au, Pt, Pd or the like is provided on the surface of the support substrate 4 made of silicon or silicate glass. A conductive film can be provided. When the support substrate 4 is conductive, an insulating layer such as SiN, SiO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ can be provided between the conductive film and the support substrate 4. In such a configuration, when the laser beam is emitted to the driving substrate side, it is preferable to make a hole at a position where the emission beam of the conductive film passes. Capacitance between conductive regions that generate electrostatic force can be reduced, and high-speed displacement control is possible. In addition, since the displacement control voltage can be individually applied to each element, the elements can be arrayed.

  In the surface emitting laser element shown in FIG. 1 (or FIG. 2), the first mirror layer 1 and the second mirror layer 12 form a resonator, and laser oscillation occurs. In this case, the oscillation wavelength varies depending on the distance between the first mirror layer 1 and the second mirror layer 12. That is, in the surface emitting laser element of FIG. 1 (or FIG. 2), the amount of deflection of the flexure film 2 is changed by adjusting the voltage applied between the pair of displacement control electrodes 5a and 5b. As the distance between 1 and 12 changes, the oscillation wavelength changes. The laser light may be emitted from the support substrate 4 side or may be emitted from the semiconductor substrate 11 side.

  The configuration of FIG. 1 (or FIG. 2) is different from the configuration of Patent Document 3 (Japanese Patent Laid-Open No. 11-17285) described above, and does not include a flexible film between the two mirror layers 1 and 12, and therefore has an extremely short resonance. A vessel structure becomes possible. For this reason, it becomes easy to obtain a single resonance mode of the longitudinal mode. Therefore, there is no splitting of the wavelength peak of the oscillation light, and optical transmission is facilitated. In addition, since the ratio of the active layer thickness to the resonator length is increased, light confinement is improved and oscillation is performed with a low threshold current, which facilitates laser driving.

  Further, since the lower substrate of the surface emitting laser is hardly bent, the wavelength shift due to the distortion of the active layer 15 does not occur, and the deterioration of the element is reduced.

  In the surface emitting laser element of FIG. 1 (or FIG. 2), silicon, silicon oxide, or the like can be used for the flexible film 2. When silicon is used for the flexible film 2, a single crystal silicon or polycrystalline silicon film is desirable because it has few defects. In addition, when silicon oxide is used for the flexible film, a film obtained by thermally oxidizing single crystal silicon or polycrystalline silicon or a film obtained by vapor phase growth at a high temperature is preferable because there are few defects.

  The support substrate 4 can be made of silicon or silicon oxide glass. When silicon is used for the support substrate 4, a single crystal silicon or polycrystalline silicon film is desirable because it has good homogeneity and is easy to process. Further, when silicon oxide glass is used for the support substrate 4, borosilicate glass, alkali glass, and quartz glass are desirable because they have good homogeneity and are easy to process.

The use of silicon or silicon oxide for the flexible film 2 and the use of silicon or silicon oxide glass for the support substrate 4 will be further described. Silicon or silicon oxide is a material used as a central material in micromachining technology, and stable microfabrication technology has been accumulated through etching, vapor deposition, polishing, bonding, and the like. For example, there are the following bonding techniques. That is, silicon and silicon can be directly bonded to each other via the SiO ₂ layer. Further, borosilicate glass or alkali glass containing alkali or alkaline earth ions can be anodically bonded to silicon. Quartz glass can be anodic bonded to silicon if a binder layer such as borosilicate glass, alkali glass, or In ₂ O ₃ is attached to the surface.

FIG. 4 shows a manufacturing process example of a surface emitting laser element using a driving base using these materials. FIGS. 4A to 4E are shown as vertical cross-sectional views. Referring to FIG. 4, first, boron-diffused silicon regions 32 are formed by diffusing high-concentration boron in the first silicon wafer (for removal) 31, and SiO 2 is formed on the surface of the second silicon wafer support substrate 33. _{A two-} thermal oxide film 34 is formed, and the first silicon wafer 31 and the second silicon wafer support substrate 33 are directly bonded to each other at the surface of the boron diffusion silicon region 32 and the surface of the thermal oxide film 34 (FIG. 4). (A)). Thereafter, silicon is removed using an anisotropic etching solution such as KOH, leaving only the boron diffusion silicon region 32 on the first silicon wafer 31 (FIG. 4B).

  Thereafter, the first mirror layer 35 is formed in a partial region of the boron diffusion silicon region 32, and then the boron diffusion silicon region 32 is etched to form a flexible film 32 (FIG. 4C). ).

  Thereafter, the surface emitting laser lower base 36 is bonded (FIG. 4D). Next, a part of the thermal oxide film 34 in contact with the boron diffusion silicon region (flexible film) 32 is removed with HF liquid, thereby forming a first gap 37 (FIG. 4E).

  Thereby, the surface emitting laser element of this invention is producible. In this surface emitting laser element, the resonator length can be changed by applying an electric field between the boron diffusion silicon region (flexible film) 32 and the second silicon wafer (support substrate) 33.

FIG. 5 shows another example of the manufacturing process of the surface emitting laser element of the present invention. Referring to FIG. 5, first, a recess 42 is formed on the surface of a second silicon wafer (support substrate) 41 by dry etching, and a SiO ₂ thermal oxide film is formed on the surface of the first silicon wafer (for removal) 43. 44 is formed, and the first silicon wafer 43 and the second silicon wafer 41 are directly bonded to each other at the surface having the recess 42 and the surface of the SiO ₂ thermal oxide film 44 (FIG. 5A).

Next, all the silicon of the first silicon wafer 43 is removed by KOH, the first mirror layer 45 is formed in a partial region of the SiO ₂ thermal oxide film 44 exposed on the surface, and the first mirror layer 45 One displacement control conductive film 46 is formed in the vicinity of the substrate (FIG. 5B).

Thereafter, the SiO ₂ thermal oxide film 44 is etched to form a flexible film 44, and then the surface emitting laser lower base body 47 is joined (FIG. 5C).

  Thereby, the surface emitting laser element of this invention is producible. In this surface emitting laser element, the resonator length can be changed by applying an electric field between the displacement control conductive film 46 and the second silicon wafer (supporting substrate) 41.

  FIG. 6 shows another example of manufacturing steps of the surface emitting laser element of the present invention. FIGS. 6A to 6C are shown as longitudinal sectional views. Referring to FIG. 6, first, a recess 52 is formed on the surface of a Pyrex plate (support substrate) 51 by dry etching, and a high-concentration boron is diffused in a silicon wafer (for removal) 53 to form a boron diffusion silicon region 54. Then, the Pyrex plate 51 and the silicon wafer 53 are anodically bonded with the surface provided with the recess 52 and the surface of the boron diffusion silicon region 54 (FIG. 6A). Thereafter, silicon is removed using an anisotropic etching solution such as KOH, leaving the boron diffusion silicon region 54 of the silicon wafer 53, a displacement control conductive film 55 is provided on the back surface of the Pyrex plate 51, and boron diffusion silicon is provided. The first mirror layer 56 is formed in a part of the region 54 (FIG. 6B). Thereafter, the boron diffusion silicon region 54 is etched to form it as a flexible film 54, and then the surface emitting laser lower substrate 57 is bonded (FIG. 6C).

  Thereby, the surface emitting laser element of this invention is producible. In this surface emitting laser element, the resonator length can be changed by applying an electric field between the boron diffusion silicon region (flexible film) 54 and the displacement control conductive film 55.

  Since silicon and silicon oxide are of high quality, unlike the formed flexible film, a highly reliable flexible film can be obtained and can be manufactured with high yield. Since the silicon and the silicon can be directly bonded to each other through the silicon oxide film, the driving base can be easily formed with high accuracy. In addition, since silicon and silicon oxide glass are homogeneous, precise processing is possible and a highly reliable drive base can be formed.

  FIG. 7 is a view showing a modification of the surface emitting laser element of the present invention. In the surface emitting laser element of the example of FIG. 7, an optical element 22 is provided on the laser beam path on the surface opposite to the surface to which the flexible film 2 of the support substrate 4 is bonded. In the example of FIG. 7, the optical element 22 is a microlens. However, the optical element 22 may be a diffractive lens as shown in FIG. 8, or may be a mirror and a waveguide as shown in FIG. good.

  In the surface emitting laser element shown in FIG. 7, FIG. 8, or FIG. Can be formed. These optical elements 22 can be easily manufactured by the above-described micromachining technology. By providing these optical elements 22 on the surface of the support substrate 4, it becomes easy to make the surface emitting laser element highly functional and multifunctional.

  In addition, a surface emitting laser array can be configured by providing a plurality of the surface emitting laser elements of the present invention described above on the same support substrate.

  Such a surface emitting laser array can be manufactured by the following method. That is, a plurality of driving bases are collectively formed on a silicon wafer and a silicate glass plate, and a plurality of surface emitting laser lower bases are separately formed on a semiconductor substrate wafer. Next, as a first example, a surface emitting laser array is manufactured by bonding a surface provided with a driving base of a silicon wafer or a silicate glass plate and a surface provided with a surface emitting laser lower base of a semiconductor substrate wafer. be able to. Further, as a second example, a surface emitting laser array can be manufactured by bonding individually separated surface emitting laser lower substrates to each driving substrate on a silicon wafer and a silicate glass plate.

  10 and 11 show configuration examples of a parallel transmission system in which the surface emitting laser array of the present invention and a silica fiber are coupled. Since the surface emitting laser array of the present invention is single mode and each wavelength is stable, it is easy to construct a highly reliable transmission system having a plurality of light sources.

  A wavelength division multiplexing transmission system can be constructed using the above-described surface-emitting laser element of the present invention or the above-described surface-emitting laser array of the present invention.

  FIG. 12 shows a configuration example of a wavelength multiplexing transmission system using the surface emitting laser array of the present invention. In the wavelength division multiplexing transmission system of FIG. 12, a plurality of surface emitting laser elements having different oscillation wavelengths are arranged to form a surface emitting laser array, and each oscillation light from each surface emitting laser element of the surface emitting laser array is multiplexed. It is comprised so that it may couple | bond with one optical fiber through. In such a configuration, a large amount of signal can be transmitted with high throughput with a single fiber. As described above, the surface emitting laser array of the present invention is in a single mode and each oscillation wavelength is stable, so that it is possible to perform wavelength multiplexing multiplex transmission with high reliability and high density and large capacity.

  Next, examples of the present invention will be described.

Example 1
13, FIG. 14, and FIG. 15 are diagrams showing a configuration example of the surface emitting laser element according to the first embodiment. 13 is a side view, FIG. 14 is a front view, and FIG. 15 is a bottom view.

The surface emitting laser element of Example 1 is manufactured as follows. That is, first, a drive base is manufactured. As in the example described above, the driving substrate is first made 1 × 10 ²⁰ / cm ³ by solid phase diffusion to a depth of 2 μm from the surface of the first silicon wafer (not shown in FIGS. 13 to 15). Diffuse the concentration of boron. Further, a thermal oxide film (SiO ₂ thermal oxide film) 62 having a thickness of 1 μm is formed on the surface of the second silicon wafer support substrate 61. Then, the first silicon wafer and the second silicon wafer support substrate 61 are directly bonded in the atmosphere between the surface of the boron diffusion silicon region and the surface of the thermal oxide film 62. Then, it is heated to 1100 ° C. Then, using a KOH aqueous solution, the silicon is removed while leaving the boron diffusion silicon region on the first silicon wafer. Next, p-type polycrystalline silicon (poly-Si) is formed on the boron diffusion silicon region by a CVD method at a thickness of 3 μm, and then polycrystalline silicon (poly-Si) in a region of 60 μm × 200 μm is KOH. Remove with aqueous solution. The surface of polycrystalline silicon (poly-Si) in the remaining region is polished and smoothed to form a bonding spacer layer (poly-Si bonding spacer layer) 63.

Next, etching is performed by dry etching using CF ₄ so as to leave a region of 30 μm × 200 μm at the center of the boron-diffused silicon region of 60 μm × 200 μm, and the double-supported beam of the boron-diffused silicon region is bent (strained film) 64. Form as. Then, a first mirror layer 65 composed of 7 pairs of ZrO ₂ / SiO _{2 having} a width of 20 μm × 20 μm is formed at the center of the beam (flexible film) 64 by EB vapor deposition. In this way, a drive base can be produced.

Next, a surface emitting laser lower substrate is fabricated. That is, first, a second mirror layer 67 composed of 25 pairs of n-AlAs / n-GaAs, a first GaAs spacer layer 68, and three layers of GaInAs are formed on an n-GaAs (100) substrate 66 by MOCVD. And a multi-quantum well active layer 69 composed of two layers of GaAs, a second GaAs spacer layer 70, and a p ⁺ -GaAs current injection layer 71. Next, a current confinement structure 72 is produced by proton injection. In this way, a surface emitting laser lower substrate is produced.

Next, the drive substrate and the surface emitting laser lower substrate manufactured in this way are directly bonded in the atmosphere with the portion through which the oscillation light passes and the position of the first mirror layer 65 aligned. Then, heat to 200 ° C. Next, this sample is put in HF solution, and the periphery of the both ends of the boron diffusion silicon region and the underlying SiO ₂ oxide film are removed.

  Next, a displacement control electrode (not shown) of the drive base is provided on the back surface of the second silicon wafer support substrate 61. Further, a drive electrode (n-side drive electrode) 73 of the surface emitting laser element is formed on the back surface of the n-GaAs substrate 66. Further, a ground electrode 74 serving both as displacement control and laser driving is provided on a part of the outer periphery of the junction region of the p-type polycrystalline silicon (poly-Si) film.

In Example 1, the length of the gap between the first mirror layer 65 and the p ⁺ -current injection layer 71 is 0.450 μm. When a voltage of 0 to 8 V is applied between the both-end supported beam (flexible film) 64 in the boron diffusion silicon region and the second silicon wafer support substrate 61, the oscillation wavelength changes from 1.05 to 1.22 μm. To do. The oscillation light spectrum has a single peak.

  In the surface emitting laser element of Example 1, since the flexible film 64 is not included between the two mirror layers 65 and 67, an extremely short resonator structure is possible, and light emission in a single resonance mode can be obtained. it can. Further, by directly bonding the driving substrate and the surface emitting laser lower substrate, the gap between the first mirror layer 65 and the surface emitting laser lower substrate can be easily formed with a predetermined interval. In addition, since the silicon and silicon oxide and silicon and silicon oxide can be directly bonded, the driving base can be easily formed with high accuracy. Further, since the first mirror layer 65 is firmly bonded to the flexure film (strain film) 64, the mirror layer 65 having high durability against the flexure (strain) can be obtained. In addition, since the GaInAs surface emitting laser element has a small change in laser characteristics even when the temperature changes, wavelength control is further facilitated.

Example 2
FIG. 16 is a diagram illustrating a configuration example of the surface emitting laser element according to the second embodiment. The surface emitting laser element of Example 2 is manufactured as follows. That is, first, a drive base is manufactured. As in the example described above, the driving substrate is first boron having a concentration of 1 × 10 ²⁰ / cm ³ by solid phase diffusion to a depth of 2 μm from the surface of the first silicon wafer (not shown in FIG. 16). To diffuse. Further, a thermal oxide film (SiO ₂ thermal oxide film) 82 having a thickness of 1 μm is formed on the surface of the second silicon wafer support substrate 81. Then, the first silicon wafer and the second silicon wafer support substrate 81 are directly bonded in the atmosphere between the surface of the boron diffusion silicon region and the surface of the thermal oxide film 82. Then, it is heated to 1100 ° C. Then, using a KOH aqueous solution, the silicon is removed while leaving the boron diffusion silicon region on the first silicon wafer.

Next, a 30 μm × 120 μm cantilever (flexible film) 84 is formed in a boron diffused silicon region of 60 μm × 200 μm by dry etching using CF ₄ . Then, the surface of the boron diffusion silicon region is polished and smoothed. In this way, a drive base can be produced.

Next, a surface emitting laser lower substrate is fabricated. That is, first, a second mirror layer 86 composed of 25 pairs of n-AlAs / n-GaAs, a first GaAs spacer layer 87, and three GaInNAs layers are formed on an n-GaAs (100) substrate 85 by MOCVD. And a multi-quantum well active layer 88 made of two layers of GaAs, a second GaAs spacer layer 89, a p ⁺ -GaAs current injection layer 90, a p-AlAs sacrificial layer 91, and 18 pairs of p-AlGaAs / p-GaAs. A first mirror layer 92 is formed. Next, dry etching is performed so that the region of 60 μm × 200 μm of the laminated film remains in the post shape and reaches the p ⁺ -current injection layer 90. Next, the current confinement structure 93 is produced by proton injection. In this way, a surface emitting laser lower substrate is produced.

Next, the drive substrate and the surface emitting laser lower substrate thus manufactured are directly joined in the atmosphere with the post-shaped laminated film and the position near the tip of the cantilever (flexible film) 84 aligned. Then, heat to 400 ° C. Next, this sample is put in HF solution, and the p-AlAs sacrificial layer 91 and the periphery of the boron diffusion silicon region in the cantilever and the underlying SiO ₂ oxide film are removed. At this time, the p-AlAs layer at the junction is also etched to the inside by about 20 μm, but the laser characteristics are not greatly affected.

  Next, a displacement control electrode (not shown) of the drive base is provided on the back surface of the second silicon wafer support substrate 81. Further, a drive electrode (n-side drive electrode) 94 of the surface emitting laser element is formed on the back surface of the n-GaAs substrate 85. Further, a ground electrode for displacement control and laser driving is provided on a part of the outer periphery of the bonding region of the boron diffusion silicon region.

In Example 2, the length of the gap between the first mirror layer 92 and the p ⁺ -GaAs current injection layer 90 is 0.4 μm. When a voltage of 0 to 4 V is applied between the cantilever (flexible film) 84 in the boron diffusion silicon region and the second silicon wafer support substrate 81, the oscillation wavelength changes to 1.15 to 1.30 μm. To do. The oscillation light spectrum has a single peak.

  In the surface emitting laser element of Example 2, since the flexible film 84 is not included between the two mirror layers 92 and 86, an extremely short resonator structure is possible, and light emission in a single resonance mode can be obtained. it can. Further, by directly bonding the driving substrate and the surface emitting laser lower substrate, the gap between the first mirror layer 92 and the surface emitting laser lower substrate can be easily formed with a predetermined interval. In addition, since the sacrificial layer 91 is removed after the surface emitting laser lower substrate including the first mirror layer 92 is bonded to the driving substrate, the gap between the surface of the laminated film and the surface of the first mirror layer 92 is reduced. It can be set more precisely. Therefore, it becomes easier to manufacture the surface emitting laser element. Further, since silicon and silicon can be directly bonded, the drive base portion can be easily formed with high accuracy. In addition, since the GaInNAs-based surface emitting laser has a small change in laser characteristics even when the temperature changes, wavelength control is further facilitated.

Example 3
FIG. 17 is a diagram illustrating a configuration example of the surface emitting laser element according to the third embodiment. The surface emitting laser element of Example 3 is manufactured as follows. That is, first, a drive base is manufactured. Drive substrate, as in the example described above, first, to form a recess by dry etching with CF ₄ to the second silicon wafer depth 3μm an area of 60 [mu] m × 200 [mu] m on the surface of the supporting substrate 101 having a thickness of 250 [mu] m. A SiN insulating film 102 is formed on the etched bottom surface of the recess by plasma CVD, and a Ti displacement control conductive film 103 is formed by sputtering, and the center of these films 102 and 103 is removed by dry etching using Cl ₂ in a circle. . Next, a borosilicate glass 105 is formed on the surface of the second silicon wafer support substrate 101 by EB vapor deposition, and the borosilicate glass 105 is removed from the convex portion to 1 μm by polishing.

Further, boron having a concentration of 1 × 10 ²⁰ / cm ³ is diffused by solid phase diffusion to a depth of 2 μm from the surface of the first silicon wafer (not shown in FIG. 17). Then, the second silicon wafer supporting substrate 101 and the first silicon wafer are anodically bonded at 400 ° C. with the surface of the borosilicate glass 105 and the surface of the boron diffusion silicon region. Next, using a KOH aqueous solution, the silicon is removed while leaving the boron diffusion silicon region on the first silicon wafer.

Next, a 30 μm × 120 μm cantilever (flexible film) 104 is formed in a boron diffused silicon region of 60 μm × 200 μm by dry etching using CF ₄ . Then, the surface of the boron diffusion silicon region is polished and smoothed. In this way, a drive base can be produced.

  The manufacturing process of the surface emitting laser lower substrate is performed in the same manner as in Example 2, and the subsequent processes are also performed in the same manner as in Example 2 to manufacture the surface emitting laser element. In FIG. 17, the same reference numerals as those in FIG. 16 are assigned to the respective portions of the surface emitting laser lower substrate.

  In the surface-emitting laser device of Example 3 manufactured in this way, when a voltage of 0 to 4 V is applied between the cantilever (flexible film) 104 in the boron diffusion silicon region and the Ti displacement control conductive film 103, oscillation occurs. The wavelength changes from 1.15 to 1.30 μm. The oscillation light spectrum has a single peak.

  In the surface emitting laser element according to the third embodiment, since the flexible film 104 is not included between the two mirror layers 92 and 86, an extremely short resonator structure is possible, and light emission in a single resonance mode can be obtained. it can. Further, by anodically bonding the driving substrate and the surface emitting laser lower substrate, the gap between the first mirror layer 92 and the surface emitting laser lower substrate can be easily formed with a predetermined interval. In addition, since the sacrificial layer 91 is removed after the surface emitting laser lower substrate including the first mirror layer 92 is bonded to the driving substrate, the gap between the surface of the laminated film and the surface of the first mirror layer 92 is reduced. It can be set more precisely. Therefore, it becomes easier to manufacture the surface emitting laser element. Further, since the silicon and silicon oxide and silicon and silicon oxide can be directly bonded, the drive base portion can be easily formed with high accuracy. In addition, since the GaInNAs surface emitting laser element has a small change in laser characteristics even when the temperature changes, wavelength control is further facilitated. Moreover, in Example 3, the electrostatic capacitance between the electroconductive area | regions which generate | occur | produces an electrostatic force can be made small, and high-speed displacement control becomes possible. In addition, since the displacement control voltage can be individually applied to each surface emitting laser element, the elements can be arrayed.

Example 4
FIG. 18 is a diagram illustrating a configuration example of the surface emitting laser element according to the fourth embodiment. In FIG. 18, the same parts as those in FIG. In the surface emitting laser element of Example 4, the concave portion of the second silicon wafer support substrate 101 was formed after the step of removing the silicon while leaving the boron diffusion silicon region on the first silicon wafer using the KOH aqueous solution. The same process as in Example 3 except that a step of forming the microlens 120 by dry etching using CF ₄ by a gradation method in which the thickness of the photomask is changed is inserted into a portion where the laser beam on the opposite surface is emitted. In Example 4, a surface-emitting laser array in which four surface-emitting laser elements are arrayed in parallel at intervals of 300 μm in a one-dimensional manner on the driving base made of the second silicon wafer support substrate 101 is manufactured.

  In the surface emitting laser array of Example 4, a voltage is applied in the range of 0 to 4 V between the cantilever (flexible film) 104 in the boron diffusion silicon region of the four surface emitting laser elements and the Ti displacement control conductive film 103. When applied, the four surface emitting laser elements can be set to have oscillation wavelengths of 1.15, 1.20, 1.25, and 1.30 μm, respectively. The oscillation light spectrum of each surface emitting laser element has a single peak.

  Thus, in the surface emitting laser array (surface emitting laser element) of Example 4, since the flexible film 104 is not included between the two mirror layers 92 and 86, an extremely short resonator structure is possible, Single resonance mode light emission can be obtained. Further, by anodically bonding the driving substrate and the surface emitting laser lower substrate, the gap between the first mirror layer 92 and the surface emitting laser lower substrate can be easily formed with a predetermined interval. In addition, since the sacrificial layer 91 is removed after the surface emitting laser lower substrate including the first mirror layer 92 is bonded to the driving substrate, the gap between the surface of the laminated film and the surface of the first mirror layer 92 is reduced. It can be set more precisely. Therefore, it becomes easier to manufacture the surface emitting laser element. Further, since silicon and silicon oxide can be anodic bonded, the drive base portion can be easily formed with high accuracy. In addition, since the GaInNAs surface emitting laser element has a small change in laser characteristics even when the temperature changes, wavelength control is further facilitated. In Example 4, since the voltage control electrode is individually provided for each surface emitting laser element, the capacitance of the electrode can be reduced, and high-speed displacement control is possible. In addition, since the displacement control voltage can be individually applied to each surface emitting laser element, the elements can be arrayed. Further, by providing the microlens 120 on the surface of the support substrate 101, it becomes easy to increase the functionality and functionality of the element.

  19 and 20 are diagrams showing a configuration example of a wavelength division multiplexing optical transmission system using the surface emitting laser array of the fourth embodiment. FIG. 20 is a diagram showing the relationship between the four surface emitting laser elements of the surface emitting laser array in FIG. 19 and the optical fiber. As shown in FIGS. 19 and 20, the laser light from the four surface emitting laser elements of the surface emitting laser array of Example 4 is divided into an optical fiber (multimode fiber) and light at the tip of the microlens of each surface emitting laser element. When coupled and wavelength multiplexed using a single mode fiber of 500 m via a multiplexer, a throughput of 2.5 Gbps × 4 can be obtained with a single fiber.

The present invention can be used for an optical communication system, between computers, between chips, in-chip optical interconnection, optical computing, and the like.

DESCRIPTION OF SYMBOLS 1 1st mirror layer 2 Deflection layer 3 1st space | gap 4 Support substrate 5a, 5b Displacement control electrode 11 Semiconductor substrate 12 2nd mirror layer 14 1st spacer layer 15 Active layer 16 2nd spacer layer 17 Current injection Layer 18 Sacrificial layer 19 Second gap 20 Displacement control conductive film 22 Optical element 31 First silicon wafer 32 Boron diffusion silicon region 33 Second silicon wafer support substrate 34 Thermal oxide film 35 First mirror layer 36 Surface emission Laser lower substrate 41 Second silicon wafer support substrate 43 First silicon wafer 44 Thermal oxide film 45 First mirror layer 46 Displacement control conductive film 47 Surface emitting laser lower substrate 51 Pyrex plate 53 Silicon wafer 54 Boron diffusion silicon region 55 Displacement control conductive film 56 First mirror layer 57 Surface emitting laser lower substrate 61 Second Silicon wafer support substrate 62 Thermal oxide film 63 Bonded spacer layer 64 Deflection film 65 First mirror layer 66 GaAs substrate 67 Second mirror layer 68 First spacer layer 69 Active layer 70 Second spacer layer 71 Current injection layer 72 Current confinement structure 73 Drive electrode 74 Ground electrode 81 Second silicon wafer support substrate 82 Thermal oxide film 84 Deflection film 92 First mirror layer 85 GaAs substrate 86 Second mirror layer 87 First spacer layer 88 Active layer 89 First Two spacer layers 90 Current injection layer 93 Current confinement structure 91 Sacrificial layer 94 Drive electrode 101 Second silicon wafer support substrate 102 SiN insulating film 103 Displacement control conductive film 104 Deflection film 120 Microlens

Japanese Patent Laid-Open No. 10-27943 JP-A-9-270556 Japanese Patent Laid-Open No. 11-17285

Claims (12)

The driving substrate has a surface emitting laser lower substrate, and the driving substrate is opposite to the first mirror layer, the flexible film on which the first mirror layer is disposed, and the first mirror layer of the flexible film. And a pair of displacement control electrodes provided on the flexible film and the support substrate for controlling the amount of deflection, and surface emission. The laser lower base is formed by laminating a second mirror layer composed of a semiconductor multilayer mirror, a first spacer layer, an active layer, a second spacer layer, and a current injection layer on a semiconductor substrate. The surface emitting laser lower substrate and the drive substrate are opposed to each other so that the surface of the surface emitting laser lower substrate and the surface of the first mirror layer have a second gap. A surface emitting laser element characterized by being arranged as described above. 2. The surface emitting laser element according to claim 1, wherein the flexible film is made of silicon or silicon oxide. 2. The surface emitting laser element according to claim 1, wherein the support substrate is made of silicon or silicon oxide glass. 2. The surface emitting laser element according to claim 1, wherein the first mirror layer is a dielectric multilayer reflector. 2. The surface-emitting laser element according to claim 1, wherein a displacement control conductive film is provided on the surface of the support substrate facing the flexible film with the first gap interposed therebetween, and the displacement control conductive film is formed of a pair of displacement control electrodes. A surface-emitting laser element characterized by being electrically connected to one of the displacement control electrodes. 6. The surface emitting laser element according to claim 1, wherein an optical element is provided on a path of laser light on a surface opposite to a side on which the flexible film of the support substrate is provided. A surface emitting laser element characterized by comprising: 7. The surface emitting laser element according to claim 1, wherein the active layer is made of a GaInAs-based or GaInNAs-based material. The driving substrate has a surface emitting laser lower substrate, and the driving substrate is opposite to the first mirror layer, the flexible film on which the first mirror layer is disposed, and the first mirror layer of the flexible film. And a pair of displacement control electrodes provided on the flexible film and the support substrate for controlling the amount of deflection, and surface emission. The laser lower base is formed by laminating a second mirror layer composed of a semiconductor multilayer mirror, a first spacer layer, an active layer, a second spacer layer, and a current injection layer on a semiconductor substrate. A method of manufacturing a surface emitting laser element formed as a laminated structure, wherein the surface of the laminated structure of the surface emitting laser lower base and the surface of the first mirror layer are opposed to each other so as to have a second gap. The surface emitting laser lower base and the drive base The method for manufacturing a surface-emitting laser element, characterized in that to connect by preparative direct bonding method. 9. The method for manufacturing a surface emitting laser element according to claim 8, wherein the first mirror layer is a dielectric multilayer film reflecting mirror, and the dielectric multilayer film reflecting mirror is formed on the flexible film by a film forming method. A method for manufacturing a surface-emitting laser element, which is characterized. On the semiconductor substrate, at least a second mirror layer made of a semiconductor multilayer mirror, a first spacer layer, an active layer, a second spacer layer, a current injection layer, and a second gap are formed. A step of laminating a sacrificial layer and a first mirror layer to form a laminated structure, and leaving the laminated structure in a sacrificial layer leaving a region of the laser oscillation portion and a junction region of the drive base Removing by etching to a depth equal to or greater than the depth of the surface, forming a surface emitting laser lower substrate, disposing a support substrate on the flexible film with a first gap interposed therebetween, producing a driving substrate, and the surface of the flexible film; A step of bonding the surface of the first mirror layer remaining without being etched to bond the surface emitting laser lower substrate and the driving substrate, and removing the sacrificial layer by etching to form a second gap. And having a process of The method for manufacturing a surface-emitting laser element. A surface-emitting laser array, wherein a plurality of surface-emitting laser elements according to any one of claims 1 to 7 are provided on the same support substrate. A wavelength division multiplex transmission system, wherein the surface-emitting laser element according to any one of claims 1 to 7 or the surface-emitting laser array according to claim 11 is used.

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