JP2008218774A - Semiconductor oxidation apparatus, manufacturing method of surface emitting laser element using it, surface emitting laser array provided with surface emitting laser element manufactured by the same, optical transmitting system equipped with surface emitting laser element manufactured by the method or surface emitting laser array and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor oxidation apparatus where a size of a non-oxidizing region in a wafer can be made uniform. <P>SOLUTION: A heater 105 is arranged in a heating table 103. An outer peripheral part of a semiconductor test sample 140 placed on a test sample tray 107 is heated to 365°C in accordance with control from a control part 127, and an inner peripheral part of the semiconductor test sample 140 is heated to 370°C. A mass flow controller 113 supplies nitrogen gas to a vaporizer 114. A liquid mass flow controller 111 supplies water held by a water tank container 109 to the vaporizer 114. The vaporizer 114 vaporizes water from the liquid mass flow controller 111 and generates steam, and generated steam is supplied to a reaction container 101 through pipings 115 and 116, a bulb 120 and an introductory pipe 108 with nitrogen gas from the mass flow controller 113 as carrier gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor oxidation apparatus, a method of manufacturing a surface emitting laser element using the same, a surface emitting laser array including a surface emitting laser element manufactured by the manufacturing method, and a surface emitting laser element manufactured by the manufacturing method Alternatively, the present invention relates to an optical transmission system and an image forming apparatus including a surface emitting laser array.

  A surface emitting laser is an example of a semiconductor laser having a current confinement structure to increase current injection efficiency. This surface emitting laser emits light in a direction perpendicular to the substrate, and is more suitable for lower cost, lower power consumption, smaller size, and two-dimensional devices than an edge emitting semiconductor laser that emits light in a direction parallel to the substrate. In recent years, it has attracted particular attention because of its high performance.

  A surface emitting laser is expected as a light source for light transmission in a LAN (Local Area Network), between boards, in a board, between chips of an integrated circuit (LSI: Large Scale Integrated circuit), and in a chip of an integrated circuit. Surface emitting lasers are also being used as light sources for optical writing on optical disks such as printers or DVDs.

  In these surface emitting laser applications, the output light is often required to be single fundamental mode light. Typically, a light source for optical writing to a printer or a DVD (oscillation wavelength: 850 nm) and a light source of an optical transmission system using a fiber (oscillation wavelengths: 1.3 μm, 1.5 μm) can be mentioned.

  In the optical writing system, it is necessary to control a precise and complicated optical path for narrowing the output beam, and a light source having a single wavelength is required. In an optical transmission system, since the propagation speed in the fiber differs depending on the wavelength, a light source having a single wavelength is required to propagate the signal waveform without breaking it. As described above, the surface emitting laser used for these applications is required to be single fundamental mode light.

  A typical configuration of a surface emitting laser has a structure in which an n-type reflective layer, a first resonator spacer layer, an active layer, a second resonator spacer layer, and a p-type reflective layer are sequentially stacked on a substrate. A current confinement structure is provided in the p-type reflective layer in the vicinity of the active layer. This current confinement structure functions to confine current in the vicinity of the active layer when current is injected into the active layer. As the current confinement structure, a constriction structure in which an AlAs layer or an AlGaAs layer is selectively oxidized to partially insulate these layers is used (Patent Document 1). Hereinafter, these selectively oxidized layers are referred to as selectively oxidized Al (Ga) As layers.

In the current confinement structure, a semiconductor substrate or semiconductor sample including a circular trapezoidal or rectangular trapezoidal mesa structure is heat-treated in an atmosphere of high-temperature water vapor, and a selectively oxidized Al (Ga) As layer included in the mesa structure is a mesa structure. The current constriction portion made of Al _x O _y is formed by oxidizing from the side surface toward the center portion of the mesa structure and leaving the central portion. Since this Al _x O _y is electrically insulating, it restricts the current path to the non-oxidized region in the central portion. In the case of a surface emitting laser, the current confinement portion made of Al _x O _y has a refractive index smaller than that of the surrounding semiconductor layer, so that it also functions to confine light. For this reason, when the current confinement portion is used, excellent characteristics are obtained in that the current confinement efficiency of the semiconductor element is high and the threshold current is small.

  In order to obtain single fundamental transverse mode oscillation with a surface emitting laser, it is necessary to reduce the size of the constriction (for example, the constriction diameter) and increase the diffraction loss of the higher order mode. Specifically, it is necessary to narrow the size or diameter of one side of the constriction part to about 3 to 4 times the oscillation wavelength. For example, when the oscillation wavelength is 0.85 μm and 1.3 μm, the length of one side of the constricted portion needs to be about 4.0 μm and about 5.0 μm or less, respectively. Further, in mass production, it is required that the element characteristics such as light output are uniform, and the tolerance of the length of one side of the constricted portion needs to be ± 0.2 μm or less.

  FIG. 24 is a diagram showing a conventional semiconductor oxidation apparatus that performs an oxidation process. Conventionally, a semiconductor oxidation apparatus shown in FIG. 24 is known (Non-Patent Document 1). Referring to FIG. 24, semiconductor oxidation apparatus 900 includes a reaction vessel 901, a heating stage 902, a substrate holder 903, a heater 904, an introduction pipe 905, and an exhaust pipe 906.

  The heating stage 902 is disposed in the reaction vessel 901. The heater 904 is built in the heating stage 902. The substrate holder 903 is disposed on one main surface of the heating stage 902. The introduction pipe 905 is disposed above the heating stage 902. The exhaust pipe 906 is installed on the side surface of the reaction vessel 901.

  The heating stage 902 supports the substrate holder 903, and the substrate holder 903 supports the semiconductor sample 910. The heater 904 heats the semiconductor sample 910 via the heating stage 902 and the substrate holder 903. The introduction pipe 905 introduces water vapor at a predetermined temperature into the reaction vessel 901 using a carrier gas. The exhaust pipe 906 exhausts the carrier gas introduced into the reaction vessel 901.

  The semiconductor oxidation apparatus 900 has a semiconductor sample 910 in which a first resonator spacer layer, an active layer, a second resonator spacer layer, and a p-type reflective layer are etched in a mesa shape on a substrate holder 903, and a heater 904. Then, the semiconductor sample 910 is heated to a predetermined temperature (for example, about 400 ° C.), and further, water vapor is introduced into the reaction vessel 901 through the introduction tube 905, and the selected sample provided in the p-type reflective layer near the active layer The oxide layer is oxidized from around the mesa shape to form a current confinement portion in the p-type reflective layer.

As described above, the surface emitting laser is manufactured by selectively oxidizing a target oxide film in the p-type reflective layer using a semiconductor oxidation apparatus to form a current confinement portion in the p-type reflective layer.
US Pat. No. 5,493,577 Optical Alliance, April 2004, pp 42-46.

  However, when the above-described conventional semiconductor oxidation apparatus is used, the oxidation rate of the selective oxidation layer varies due to the distribution of the thickness of the selective oxidation layer in the wafer. As a result, the selective oxidation layer is selectively oxidized. There was a problem that the variation in the diameter of the non-oxidized region was larger than ± 5%.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a semiconductor oxidation apparatus capable of making the dimensions of non-oxidized regions in a wafer uniform.

  Another object of the present invention is to provide a method for manufacturing a surface emitting laser element capable of making the dimensions of non-oxidized regions in a wafer uniform.

  Furthermore, another object of the present invention is to provide a surface-emitting laser array including a surface-emitting laser element manufactured by a method for manufacturing a surface-emitting laser element capable of making the dimensions of non-oxidized regions in a wafer uniform. is there.

  Furthermore, another object of the present invention is to provide an optical transmission system including a surface emitting laser element or a surface emitting laser array manufactured by a method for manufacturing a surface emitting laser element capable of making the dimensions of a non-oxidized region in a wafer uniform. Is to provide.

  Furthermore, another object of the present invention is to provide an image forming apparatus including a surface emitting laser element or a surface emitting laser array manufactured by a method of manufacturing a surface emitting laser element capable of making the dimensions of non-oxidized regions in a wafer uniform. Is to provide.

  According to the present invention, the semiconductor oxidation apparatus includes a reaction vessel, a support base, a plurality of heating devices, a supply unit, and a control unit. The support base is installed in the reaction container and supports the sample. Each of the plurality of heating devices heats the sample via the support base. The supply unit supplies an oxidizing material into the reaction vessel. The control unit controls the plurality of heating devices to heat the sample to a suitable temperature that suppresses the distribution of the oxidation rate in the in-plane direction of the sample to a reference value or less.

  Preferably, the control unit controls the plurality of heating devices so as to heat the sample to a suitable temperature that cancels the distribution of the oxidation rate based on factors other than the temperature of the sample.

  Preferably, the plurality of heating devices are divided and arranged in a direction from the center of the support base toward the outer periphery.

  Preferably, the suitable temperature is determined so as to decrease relatively from the inner periphery to the outer periphery of the sample.

  Preferably, the suitable temperature is a temperature determined based on experimental results.

  Preferably, each of the plurality of heating devices is a resistance heater.

  Preferably, each of the plurality of heating devices is a lamp heater.

  According to the invention, the method of manufacturing the surface emitting laser element includes a first reflective layer comprising a semiconductor distributed black reflector, a first resonator spacer layer, an active layer, a second resonator spacer layer, and a semiconductor. A first step of sequentially laminating a second reflective layer comprising a distributed black reflector on a wafer; and a plurality of surface emitting laser elements by etching the active layer, the second resonator spacer layer, and the active layer into a mesa shape A second step of forming a wafer on the wafer, a third step of setting the wafer on a support base in the reaction vessel, a fourth step of supplying an oxidizing material into the reaction vessel, and a plurality of steps formed on the wafer And a fifth step of heating the wafer to a suitable temperature at which the distribution of oxidation rates in the plurality of selectively oxidized layers included in the plurality of second reflective layers of the surface emitting laser element is less than or equal to a reference value.

  Preferably, the fifth step heats the wafer to a suitable temperature that cancels the oxidation rate distribution based on factors other than the wafer temperature.

  Preferably, the suitable temperature is a temperature determined based on experimental results.

  Preferably, in the fifth step, the wafer is heated to a favorable temperature by a plurality of heating devices arranged in the radial direction of the wafer.

  Preferably, in the fifth step, the wafer is heated by a plurality of heating devices such that the temperature of the wafer relatively decreases as it goes from the inner periphery to the outer periphery of the wafer.

  Preferably, each of the plurality of heating devices is a resistance heater.

  Preferably, each of the plurality of heating devices is a lamp heater.

  Preferably, the active layer includes a GaInNAs-based material.

  Furthermore, according to the present invention, the surface emitting laser array includes a substrate and a plurality of surface emitting laser elements formed on the substrate. Each of the plurality of surface emitting laser elements is a surface emitting laser element manufactured by the method for manufacturing a surface emitting laser element according to any one of claims 7 to 13.

  Furthermore, according to this invention, the optical transmission system is a surface emitting laser element manufactured by the method for manufacturing a surface emitting laser element according to any one of claims 7 to 13, or the surface emitting laser element according to claim 14. A surface emitting laser array is provided as a light source.

  Furthermore, according to this invention, the image forming apparatus is a surface-emitting laser element manufactured by the method for manufacturing a surface-emitting laser element according to any one of claims 7 to 13, or the surface-emitting laser element according to claim 14. A surface emitting laser array is provided as a light source.

  In the present invention, the sample is oxidized by heating to a suitable temperature that suppresses the distribution of the oxidation rate in the in-plane direction of the sample to a reference value or less. That is, in the present invention, the sample is oxidized at a substantially uniform oxidation rate in the in-plane direction of the sample.

  Therefore, according to this invention, the dimension of the non-oxidized region in the sample can be made uniform.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a schematic diagram of a semiconductor oxidation apparatus according to Embodiment 1 of the present invention. Referring to FIG. 1, a semiconductor oxidation apparatus 100 according to Embodiment 1 of the present invention includes a reaction vessel 101, a base 102, a heating table 103, a rotating shaft 104, a heater 105, a temperature detector 106, and the like. , Sample tray 107, introduction pipe 108, water reservoir 109, pipes 110, 112, 115 to 117, 124, 126, liquid mass flow controller (LMFC) 111, and mass flow controller (MFC: Mass). Flow Controllers) 113 and 118, valves 119 to 121, an exhaust pipe 122, a water collector 123, an exhaust pump 125, and a control unit 127.

  The base 102 is disposed in the reaction vessel 101 and is fixed to one end of the rotating shaft 104. The heating table 103 is installed on the base 102. A part of the rotating shaft 104 is disposed in the reaction vessel 101 and is fixed to the bottom surface of the reaction vessel 101 so as to be rotatable in the direction of an arrow 128.

  The heater 105 is built in the base 102. The temperature detector 106 is disposed in the base 102 so that the tip is embedded in the heating table 103. The sample tray 107 is made of carbon and is disposed on one main surface of the heating table 103.

  The introduction pipe 108 is fixed to the upper surface of the reaction vessel 101 so that a part thereof is arranged in the reaction vessel 101 and one end thereof is arranged above the heating table 103. The one end of the introduction pipe 108 is wide.

  One end of the pipe 110 is immersed in water 130 held in the water reservoir 109, and the other end is connected to the vaporizer 114. The liquid mass flow controller 111 is disposed in the pipe 110.

  One end of the pipe 112 is connected to the vaporizer 114. The mass flow controller 113 is disposed in the pipe 112. The vaporizer 114 is connected to the pipes 110, 112, and 115. The pipe 115 has one end connected to the vaporizer 114 and the other end opened to the external space.

  The pipe 116 has one end connected to the introduction pipe 108 and the other end connected to the pipe 115. One end of the pipe 117 is connected to the pipe 116. The mass flow controller 118 is disposed in the pipe 117.

  The valve 119 is disposed in the pipe 115 in the vicinity of the other end of the pipe 115. The valve 120 is disposed in the pipe 116 between a connection part between the pipe 115 and the pipe 116 and a connection part between the pipe 116 and the pipe 117. The valve 121 is disposed in the pipe 117 in the vicinity of the connection portion between the pipe 116 and the pipe 117.

  The exhaust pipe 122 has one end connected to the side surface of the reaction vessel 101 and the other end arranged in the water collector 123. The pipe 124 has one end connected to the water collector 123 and the other end connected to the exhaust pump 125. The exhaust pump 125 is connected to the other end of the pipe 124 and one end of the pipe 126. One end of the pipe 126 is connected to the exhaust pump 125.

  The reaction vessel 101 accommodates a base 102, a heating table 103, a part of the rotating shaft 104, a sample tray 107, and a part of the introduction tube 108. The base 102 supports the heating table 103. The heating table 103 supports the sample tray 107.

  The rotation shaft 104 rotates the base 102 in the direction of the arrow 128 according to the control from the control unit 127. The heater 105 heats the semiconductor sample 140 via the heating table 103 and the sample tray 107 in accordance with control from the control unit 127.

The temperature detector 106 detects the temperature Ts of the heating table 103 and outputs the detected temperature Ts to the control unit 127. The sample tray 107 supports the semiconductor sample 140. The introduction pipe 108 introduces nitrogen gas (N ₂ ) and water vapor supplied through the valve 120 into the reaction vessel 101 and introduces nitrogen gas supplied through the valve 121 into the reaction vessel 101.

  The water reservoir 109 holds water 130. The pipe 110 supplies water pumped up from the water reservoir 109 by the liquid mass flow controller 111 to the vaporizer 114. The liquid mass flow controller 111 supplies water 130 stored in the water reservoir 109 to the vaporizer 114 via the pipe 110 in accordance with control from the control unit 127. The piping 112 supplies the nitrogen gas from the mass flow controller 113 to the vaporizer 114. The mass flow controller 113 sets the flow rate of nitrogen gas supplied from the other end of the pipe 112 to a predetermined flow rate and supplies it to the vaporizer 114 according to control from the control unit 127.

  The vaporizer 114 vaporizes the water supplied from the liquid mass flow controller 111 to generate water vapor, and the generated water vapor and the nitrogen gas supplied from the mass flow controller 113 via the pipes 115 and 116 and the valve 120. Supply to the introduction pipe 108.

  The pipe 115 discharges the water vapor and nitrogen gas supplied from the vaporizer 114 to the outside through the valve 119 or supplies them to the introduction pipe 108 through the pipe 116 and the valve 120.

  The pipe 116 supplies water vapor and nitrogen gas supplied through the pipe 115 and the valve 120 to the introduction pipe 108, and supplies nitrogen gas supplied through the pipe 117 and the valve 121 to the introduction pipe 108.

  The pipe 117 supplies the nitrogen gas supplied from the mass flow controller 118 to the pipe 116 via the valve 121. The mass flow controller 118 sets the flow rate of the nitrogen gas supplied from the other end of the pipe 117 to a predetermined flow rate and supplies it to the pipe 116.

  The valve 119 releases the nitrogen gas and water vapor supplied to the pipe 115 to the outside, or stops releasing the nitrogen gas and water vapor to the outside. The valve 120 supplies nitrogen gas and water vapor supplied from the pipe 115 toward the introduction pipe 108 or stops supplying nitrogen gas and water vapor toward the introduction pipe 108. The valve 121 supplies nitrogen gas to the pipe 116 or stops supplying nitrogen gas to the pipe 116.

  The exhaust pipe 122 supplies the nitrogen gas and water vapor in the reaction vessel 101 to the water collector 123. The water collector 123 collects water vapor out of the nitrogen gas and water vapor supplied from the exhaust pipe 122.

  The pipe 124 guides the nitrogen gas in the water collector 123 to the exhaust pump 125. The exhaust pump 125 exhausts the nitrogen gas in the water collector 123. The pipe 126 discharges nitrogen gas to the outside.

  The control unit 127 controls the heater 105 to heat the heating table 103 to a suitable temperature at which the distribution of the oxidation rate in the in-plane direction of the semiconductor sample 140 is equal to or less than the reference value by a method described later.

  The control unit 127 controls the liquid mass flow controller 111 so as to set the flow rate of water to a predetermined flow rate, and controls the mass flow controllers 113 and 118 so as to set the flow rate of nitrogen gas to a predetermined flow rate. Further, the control unit 127 controls opening and closing of the valves 119 to 121.

  The pipes 115 and 116, the introduction pipe 108, and the inner wall of the reaction vessel 101 are heated to a temperature at which water vapor is not liquefied.

  FIG. 2 is a plan view of the heating table 103 and the heater 105 shown in FIG. Referring to FIG. 2, heater 105 includes heaters 105A and 105B. Each of the heaters 105A and 105B is made of a ceramic heater. The heating table 103 has a substantially circular planar shape. The heaters 105A and 105B are arranged inside the heating table 103 in a substantially concentric shape. In this case, the heater 105A is disposed outside the heater 105B.

  As described above, the heater 105 includes the heater 105A disposed on the outer side and the heater 105B disposed on the inner side. Then, the heaters 105A and 105B heat the heating table 103 independently of each other in accordance with control from the control unit 127. Therefore, the control unit 127 independently sets the set temperature of the heating table 103 heated by the heater 105A and the set temperature of the heating table 103 heated by the heater 105B based on the temperature Ts received from the temperature detector 106. The heaters 105A and 105B are independently controlled so that the set temperature is set.

  FIG. 3 is a cross-sectional view of the semiconductor sample 140 shown in FIG. Referring to FIG. 3, a semiconductor sample 140 is a sample manufactured by the following method. First, for example, a semiconductor multilayer film 142 including a selective oxidation layer 1421 made of Al (Ga) As is formed on a wafer 141 made of gallium arsenide (GaAs) by metal organic chemical vapor deposition (MOCVD). Alternatively, crystal growth is performed by molecular beam epitaxy (MBE: Molecular Beam Epitaxy), and a semiconductor sample 140 shown in FIG. Next, the semiconductor sample 140 is etched to produce a semiconductor sample 140 having a large number of semiconductor mesas (semiconductor pillars) 143 in which the sidewalls of the selectively oxidized layer 1421 are exposed (see FIG. 3B).

  The selectively oxidized layer 1421 crystal-grown on the wafer 141 has a film thickness distribution in the in-plane direction DR1 of the wafer 141, and the outer peripheral portion of the wafer 141 has a thicker film thickness or the outer peripheral portion of the wafer 141. In many cases, the film thickness decreases. Below, the case where a film thickness becomes thicker as the outer peripheral part of the wafer 141 is demonstrated.

  FIG. 4 is a diagram showing the relationship between the oxidation rate and the film thickness. In FIG. 4, the vertical axis represents the relative oxidation rate of the selective oxidation layer 1421 with the oxidation rate “1” when the thickness of the selective oxidation layer 1421 is 100 nm, and the horizontal axis represents the selective oxidation layer. 1421 represents the film thickness. When oxidation is performed using the semiconductor oxidation apparatus 100 shown in FIG. 1, the oxidation rate increases as the film thickness increases in the range up to about 50 nm, and becomes substantially constant in the film thickness of 50 nm or more.

  Thus, the oxidation rate of the selective oxidation layer 1421 greatly depends on the film thickness of the selective oxidation layer 1421. Then, when the selective oxidation layer 1421 on the wafer 141 is oxidized, the area of the oxidized region (= the area of the non-oxidized region) varies in the in-plane direction DR1 of the wafer 141. As a result, the area of the oxidized region increases toward the outer periphery of the wafer 141 (that is, the area of the non-oxidized region decreases toward the outer periphery of the wafer 141) and decreases toward the center of the wafer 141 (that is, non-oxidized). The area of the region increases toward the center of the wafer 141).

  FIG. 5 is a cross-sectional view showing the positional relationship between the semiconductor sample 140 and the heater 105. Referring to FIG. 5, as described above, heater 105 includes heater 105 </ b> A disposed on the outer peripheral portion and heater 105 </ b> B disposed on the central portion, and thus heater 105 </ b> A is disposed on the outer peripheral portion of semiconductor sample 140. The heaters 105 </ b> B are disposed corresponding to the central portion of the semiconductor sample 140.

  As described above, the oxidation rate of the semiconductor sample 142 varies depending on the film thickness of the selective oxidation layer 1421 and increases as the film thickness of the selective oxidation layer 1421 increases. The film becomes slower as the film thickness becomes thinner.

  Therefore, in order to suppress the variation in the oxidation rate due to the film thickness of the semiconductor sample 140 to a reference value or less, the control unit 127 relatively sets the set temperature of the heater 105A disposed corresponding to the outer peripheral portion of the semiconductor sample 140. The heaters 105A and 105B are independently controlled by setting the heater 105B, which is set to a low value, and the heater 105B disposed corresponding to the center of the semiconductor sample 140 is set to a relatively high temperature. That is, the control unit 127 independently controls the heaters 105A and 105B so that the heating table 103 is heated to a suitable temperature that cancels the variation in the oxidation rate due to the film thickness distribution of the selective oxidation layer 1421.

  FIG. 6 is a schematic cross-sectional view of a surface emitting laser element to be oxidized by the semiconductor oxidation apparatus 100 shown in FIG. Referring to FIG. 6, surface emitting laser element 10 includes substrate 1, reflection layers 2 and 6, resonator spacer layers 3 and 5, active layer 4, selective oxidation layer 7, contact layer 8, Insulating resin 9, p-side electrode 11, and n-side electrode 12 are provided.

The substrate 1 is made of n-type gallium arsenide (n-GaAs) having a (100) plane orientation. The reflection layer 2 is composed of [low refractive index layer 21 / high refractive index layer 22] having a period of 35.5 when the pair of the low refractive index layer 21 and the high refractive index layer 22 is defined as one period. It is formed. The low refractive index layer 21 is made of n-AlGaAs, and the high refractive index layer 22 is made of n-GaAs. Further, when the oscillation wavelength of the surface emitting laser element 10 is λ ₁ , each of the low refractive index layer 21 and the high refractive index layer 22 has a film thickness of λ ₁ / 4n (n is the refractive index of each semiconductor layer). Have.

  The resonator spacer layer 3 is made of GaAs and is formed on the reflective layer 2. The active layer 4 has a GaInNAs / GaAs triple quantum well structure with GaInNAs as a well layer and GaAs as a barrier layer, and is formed on the resonator spacer layer 3.

  The resonator spacer layer 5 is made of GaAs and is formed on the active layer 4. The reflection layer 6 is composed of [low refractive index layer 61 / high refractive index layer 62] having 28 periods when the pair of the low refractive index layer 61 and the high refractive index layer 62 is defined as one period. Formed. The low refractive index layer 61 is made of p-AlGaAs, and the high refractive index layer 62 is made of p-GaAs. Each of the low refractive index layer 61 and the high refractive index layer 62 has a film thickness of λ / 4n (n is the refractive index of each semiconductor layer).

  The selective oxidation layer 7 is made of 30 nm p-AlAs and is provided in the reflection layer 6. More specifically, the selective oxidation layer 7 is provided in the second period from the resonator spacer layer 5 side in the reflective layer 6. The selective oxidation layer 7 includes a non-oxidized region 7a and an oxidized region 7b.

  The contact layer 8 is made of p-GaAs and is formed on the reflective layer 6. The insulating resin 9 includes a principal surface of a part of the reflective layer 102 and end faces of the resonator spacer layer 3, the active layer 4, the resonator spacer layer 5, the reflective layer 6, the selective oxidation layer 7, and the contact layer 8. It is formed to cover.

  The p-side electrode 11 is formed on a part of the contact layer 8 and the insulating resin 9. The n-side electrode 12 is formed on the back surface of the substrate 1.

  Each of the reflection layers 2 and 6 constitutes a semiconductor distributed Bragg reflector that reflects the oscillation light oscillated in the active layer 4 by Bragg multiple reflection and confines it in the active layer 4.

  Further, the oxidized region 7b of the selective oxidation layer 7 restricts the injection path of the current injected through the p-side electrode 11 and the reflective layer 6 to the active layer 4 to the non-oxidized region 7a. Thus, the current injected into the active layer 4 does not spread in the in-plane direction of the surface emitting laser element 10, and the surface emitting laser element 10 can oscillate with a low threshold current.

  7 and 8 are first and second process diagrams showing a method of manufacturing the surface-emitting laser element 10 shown in FIG. 6, respectively. Referring to FIG. 7, first, reflection layer 2, resonator spacer layer 3, active layer 4, resonator spacer layer 5, reflection layer 6, selective oxidation layer 7 and contact layer 8 are formed on substrate 1 by using MOCVD. (= Wafer 141, the same applies hereinafter) The layers are sequentially stacked (see step (a) in FIG. 7).

  In this case, the selective oxidation layer 7 is formed on the high refractive index layer 22 after the low refractive index layer 21 and the high refractive index layer 22 in the first cycle of the reflective layer 6 are stacked on the resonator spacer layer 5. .

Further, n-AlGaAs of the reflective layer 2 is formed using trimethylaluminum (TMA), trimethylgallium (TMG), arsine (AsH ₃ ), and hydrogen selenide (H ₂ Se) as raw materials, and the n-GaAs of the reflective layer 2 is formed. Trimethylgallium (TMG), arsine (AsH ₃ ) and hydrogen selenide (H ₂ Se) are used as raw materials.

Further, GaAs of the resonator spacer layer 3 is formed using trimethyl gallium (TMG) and arsine (AsH ₃ ) as raw materials, and GaInNAs of the active layer 4 is formed of trimethyl gallium (TMG), trimethyl indium (TMI), dimethyl hydrazine (DMHy). And arsine (AsH ₃ ) as a raw material, and GaAs of the active layer 4 is formed from trimethyl gallium (TMG) and arsine (AsH ₃ ) as a raw material.

Further, GaAs for the resonator spacer layer 5 is formed using trimethyl gallium (TMG) and arsine (AsH ₃ ) as raw materials.

Further, p-AlGaAs of the reflective layer 6 is formed using trimethylaluminum (TMA), trimethylgallium (TMG), arsine (AsH ₃ ), and carbon tetrabromide (CBr ₄ ) as raw materials, and p-GaAs of the reflective layer 6 is formed. Trimethylgallium (TMG), arsine (AsH ₃ ) and carbon tetrabromide (CBr ₄ ) are used as raw materials.

Further, p-AlAs of the selective oxidation layer 7 is formed using trimethylaluminum (TMA), arsine (AsH ₃ ) and carbon tetrabromide (CBr ₄ ) as raw materials, and p-GaAs of the contact layer 8 is formed of trimethylgallium (TMG). , Arsine (AsH ₃ ) and carbon tetrabromide (CBr ₄ ).

  Thereafter, a resist is applied on the contact layer 8, and n (n is an integer of 2 or more) resist patterns 31, ..., 3m, ..., on the contact layer 8 using a semiconductor lithography technique. 3n (m is an integer satisfying 1 <m ≦ n) is formed (see step (b) in FIG. 7). In this case, each of the resist patterns 31, ..., 3m, ..., 3n has a circular shape with a diameter of 25 µm.

When the resist patterns 31,..., 3m,..., 3n are formed, the formed resist patterns 31,. ICP (Inductively) using chlorine gas (Cl ₂ ) around the low refractive index layer 21, the resonator spacer layer 3, the active layer 4, the resonator spacer layer 5, the reflective layer 6, the selective oxidation layer 7 and the contact layer 8. .., 3n are further removed (see step (c) in FIG. 7). As a result, n mesa structures 41 to 4n having the reflective layer 2 in common are formed on the substrate 1, and each of the n mesa structures 41 to 4n includes one low-layer constituting the reflective layer 2. The refractive index layer 21, the resonator spacer layer 3, the active layer 4, the resonator spacer layer 5, the reflective layer 6, the selective oxidation layer 7 and the contact layer 8 are exposed.

  In the present invention, the case where the etching bottom surface around the mesa structure is above the reflective layer 2 will be described in all configuration examples. However, the etching bottom surface is below the selective oxidation layer 7 in the reflective layer 6. If there is, the completed element functions as a surface emitting laser. Therefore, when the etching bottom surface is located below the reflective layer 6 deeper than the selective oxidation layer 7, the etching bottom surface is one of the two resonator spacer layers 3 and 5. In some cases, the etching spacer bottom surface is located in the reflective layer 2, and the etching bottom surface is located in the substrate 1.

  Next, referring to FIG. 8, after the step (c) shown in FIG. 7, the periphery of the n selective oxidation layers 7 on the substrate 1 is directed from the outer peripheral portion to the central portion using the semiconductor oxidation apparatus 100. Oxidized to form a non-oxidized region 7a and an oxidized region 7b in each selective oxide layer 7 (see FIG. 8D). Details of the oxidation of the selective oxidation layer 7 will be described later.

  Thereafter, the insulating resin 9 is applied to the entire sample by spin coating, and the insulating resin 9 on the region that becomes the light emitting portion is removed. Then, after forming the insulating resin 9, a resist pattern is formed on the region to be the light emitting portion, a p-side electrode material is formed on the entire surface of the sample by vapor deposition, and the p-side electrode material on the resist pattern is lifted off. By removing, the p-side electrode 11 is formed. Further, the back surface of the substrate 1 is polished, the n-side electrode 12 is formed on the back surface of the substrate 1, and further annealed to establish ohmic conduction between the p-side electrode 11 and the n-side electrode 12 (step (e) in FIG. 8). reference). As a result, n surface emitting laser elements 51,..., 5m,. Each of the surface emitting laser elements 51,..., 5m,.

  The oxidation of the selective oxidation layer 7 will be described in detail. When the step (c) shown in FIG. 7 is completed, the n mesa structures 41 to 4n shown in the step (c) of FIG. 7 (each stacked body includes the reflective layer 2, the resonator spacer layer 3, the active layer 4, A resonator spacer layer 5, a reflective layer 6, a selective oxidation layer 7 and a contact layer 8) are formed on a wafer 141 (= substrate 1). Then, the wafer 141 on which the n mesa structures 41 to 4n are formed is placed on the sample tray 107 as the semiconductor sample 140, and the sample tray 107 is placed on the heating table 103 in the reaction vessel 101.

  Thereafter, the control unit 127 controls the mass flow controller 118 to flow a predetermined flow rate of nitrogen gas into the reaction vessel 101 through the pipes 117 and 116, the valve 120, and the introduction pipe 108. Thereby, the inside of the reaction vessel 101 is replaced with nitrogen gas.

  Further, the control unit 127 controls the mass flow controller 113 to flow 5 SLM nitrogen gas to the vaporizer 114 via the pipe 112.

  Further, the control unit 127 controls the liquid mass flow controller 111 to pump 50 g / hr of water from the water reservoir 109 and supply it to the vaporizer 114.

  The vaporizer 114 vaporizes the water supplied from the liquid mass flow controller 111 to generate water vapor, transports the generated water vapor using the nitrogen gas supplied from the mass flow controller 113 as a carrier gas, and supplies the water vapor to the pipe 115. And is discharged out of the system through the valve 119.

  When these nitrogen gas and water vapor supply systems are in an equilibrium state, the control unit 127 closes the valve 121, opens the valve 120, and closes the valve 119. Thus, 50 g / hr of water vapor is transported by 5 SLM nitrogen gas and supplied to the reaction vessel 101.

  Next, the control unit 127 controls the heater 105A and the heater 105B so that the temperature of the heating table 103 near the heater 105A becomes 365 ° C., and the temperature of the heating table 103 near the heater 105B becomes 370 ° C. The heating table 103 is heated.

  Further, the control unit 127 controls the rotation shaft 104 so as to rotate at a predetermined rotation number, and the rotation shaft 104 rotates at a predetermined rotation number in the direction of the arrow 128 according to the control from the control unit 127.

  The outer peripheral portion of the heating table 103 is heated to 365 ° C., the central portion of the heating table 103 is heated to 370 ° C., and a state where 5 SLM nitrogen gas and 50 g / hr of water vapor are allowed to flow into the reaction vessel 101 is maintained for a predetermined time. To do.

  Thereby, the selective oxidation layer 7 made of AlAs is oxidized from the outer peripheral portion, and a non-oxidized region 7 a and an oxidized region 7 b are formed in the reflective layer 6.

  When a predetermined time elapses, the control unit 127 opens the valve 119, closes the valve 120, opens the valve 121, and controls the heaters 105A and 105B to stop heating.

  Then, the semiconductor sample 140 is rapidly cooled by the nitrogen gas supplied from the mass flow controller 118. Thereby, the oxidation of the selective oxidation layer 7 using the semiconductor oxidation apparatus 100 is completed.

  FIG. 9 is a plan view showing the oxidation process of the selective oxidation layer 7. FIG. 10 is a plan view and a cross-sectional view of the semiconductor sample 140. Since the mesa shape is a circular shape having a diameter of 25 μm, the resonator spacer layer 3, the active layer 4, the resonator spacer layer 5, the reflective layer 6, and the selective oxidation layer 7 are obtained when step (c) in FIG. 7 is completed. And the laminated body 50 which consists of the contact layer 8 has a circular shape whose diameter is 25 micrometers (refer (a) of FIG. 9).

  Then, when the selective oxidation layer 7 is oxidized using the semiconductor oxidation apparatus 100, the outer peripheral portion of the selective oxidation layer 7 is oxidized to form a non-oxidized region 7a and an oxidized region 7b (see FIG. 9B). ).

  Since the oxidation of the selective oxidation layer 7 using the semiconductor oxidation apparatus 100 is performed in a state where the plurality of mesa structures 41 to 4n are formed on the wafer 141, the diameter of the non-oxidized region 7a in the in-plane direction of the wafer 141. The distribution of was examined. A plurality of points were selected from each of the outer peripheral portion 141A and the inner peripheral portion 141B of the wafer 141, and the diameters of the non-oxidized regions 7a at the selected plurality of points were examined (see FIG. 10).

  As a result, the diameter of the non-oxidized region 7a was 4.0 μm on average, and the variation was ± 2% or less on average.

  Thus, by oxidizing the selective oxidation layer 7 using the semiconductor oxidation device 100, the variation in the diameter of the non-oxidized region 7a could be suppressed to a reference value (= ± 5%) or less. The variation of the diameter of the non-oxidized region 7a on average is ± 5% or less because the outer peripheral portion of the semiconductor sample 140 is heated to 365 ° C., and the central portion of the semiconductor sample 140 is heated to 370 ° C. This is because 7 was oxidized.

  The set temperature (= 365 ° C.) of the outer peripheral portion and the set temperature (= 370 ° C.) of the central portion are temperatures determined based on experimental results. For comparison, in the semiconductor oxidation apparatus 100, when the set temperature of the heaters 105A and 105B is both set to 370 ° C. and the selective oxidation layer 7 is oxidized, the non-oxidized region 7a has an average diameter of 4.2 μm. The variation in diameter was ± 10% on average. In the vicinity of the center of the wafer 141, the diameter of the non-oxidized region 7a is relatively long, and in the outer peripheral portion of the wafer 141, the diameter of the non-oxidized region 7a is relatively short.

  The diameter of the non-oxidized region 7a is relatively long near the center of the wafer 141 because the film thickness of the selective oxide film 7 (= AlAs) on which the crystal is grown is relatively thin near the center of the wafer 141. This is because the oxidation rate of the film 7 (= AlAs) is relatively slow, and the diameter of the non-oxidized region 7a is relatively short in the outer peripheral portion of the wafer 141. This is because the oxide layer 7 (= AlAs) is relatively thick and the selective oxide film 7 (= AlAs) has a relatively high oxidation rate (see FIGS. 4 and 10).

  Therefore, in order to slow down the oxidation rate of the selective oxide film 7 (= AlAs) at the outer peripheral portion of the wafer 141, the set temperature of the outer peripheral portion 141A of the wafer 141 is set higher than the set temperature (= 370 ° C.) of the central portion 141B of the wafer 141. The lower temperature was set to 365 ° C. As a result, as described above, the diameter of the non-oxidized region 7a was 4.0 μm on average, and the variation in diameter was ± 5% or less on average.

  Accordingly, the set temperature of the outer peripheral portion (= 365 ° C.) and the set temperature of the inner peripheral portion (= 370 ° C.) are temperatures determined based on experimental results.

  As described above, the selective oxidation layer 7 is oxidized by setting the set temperature of the outer peripheral portion 141A of the wafer 141 to a temperature (= 365 ° C.) lower than the set temperature (= 370 ° C.) of the inner peripheral portion 141B of the wafer 141. Thus, the diameter distribution of the non-oxidized region 7a on the wafer 141 can be suppressed to a reference value or less. This is because the oxidation rate of the selective oxidation layer 7 formed on the wafer 141 depends on the film thickness of the selective oxidation layer 7. This is because the outer peripheral portion 141A and the inner peripheral portion 141B of the wafer 141 are different.

  Therefore, if the thickness of the selective oxidation layer 7 formed on the wafer 141 is relatively thin at the outer peripheral portion 141A of the wafer 141 and relatively thick at the inner peripheral portion of the wafer 141, the setting of the outer peripheral portion 141A of the wafer 141 is performed. The temperature is set relatively higher than the set temperature of the inner peripheral portion 141B of the wafer 141 so that the selective oxidation layer 7 is oxidized.

  That is, in the present invention, the wafer 141 (that is, the semiconductor sample 140) is heated to a suitable temperature that cancels the oxidation rate distribution based on the film thickness distribution of the selective oxidation layer 7, and the selective oxidation layer 7 is oxidized.

  Actually, in addition to the thickness of the selective oxidation layer 7, the oxidation rate of the selective oxidation layer 7 varies depending on the composition of the semiconductor material constituting the selective oxidation layer 7. AlAs has a higher oxidation rate than AlGaAs because the amount of Al is higher than that of AlGaAs. Therefore, it is sufficient that the selective oxidation layer 7 is made of AlAs in the entire region of the wafer 141. However, when the amount of Al is different in the wafer 141, the distribution of the oxidation rate due to the composition occurs.

  In the present invention, as described above, the set temperatures of the heaters 105A and 105B are set to the same temperature, and after checking the variation in the diameter of the non-oxidized region 7a, the set temperature of the heaters 105A and 105B is set so as to cancel the variation. The selective oxidation layer 7 is oxidized by setting independently.

  Therefore, in general, according to the present invention, the semiconductor sample 140 is set to a suitable temperature that cancels the oxidation rate distribution (= variation) of the selective oxidation layer 7 based on factors (film thickness, composition, etc.) other than the temperature of the semiconductor sample 140. Is heated to oxidize the selective oxidation layer 7.

  FIG. 11 is another schematic cross-sectional view of the surface emitting laser element to be oxidized by the semiconductor oxidation apparatus 100 shown in FIG. The surface emitting laser element 10A shown in FIG. 11 may be the surface emitting laser element to be oxidized by the semiconductor oxidation apparatus 100.

  Referring to FIG. 11, surface emitting laser element 10 </ b> A is the same as surface emitting laser element 10 except that selective oxidation layer 7 of surface emitting laser element 10 shown in FIG. 6 is replaced with selective oxidation layer 71. It is.

The selective oxidation layer 71 has a thickness of 30 nm and is made of p-Al _x Ga _1-x As (0.9 ≦ x <1). The selective oxidation layer 71 has a non-oxidized region 71a and an oxidized region 71b. The oxidized region 71b performs the same function as the oxidized region 7b described above.

The surface emitting laser element 10A is manufactured according to steps (a) to (e) shown in FIGS. In the step (a) shown in FIG. 7, the selective oxidation layer 71 is formed using trimethylaluminum (TMA), trimethylgallium (TMG), arsine (AsH ₃ ), and carbon tetrabromide (CBr ₄ ) as raw materials. . Further, in the step (d) shown in FIG. 8, the selective oxidation layer 71 is oxidized by the above-described method using the semiconductor oxidation apparatus 100, and the non-oxidized region 71 a and the oxidized region 71 b are formed in the reflective layer 6.

  When the selective oxidation layer 71 was oxidized using the semiconductor oxidation apparatus 100, the diameter of the non-oxidized region 71a was 3.8 μm on average, and the variation in diameter was ± 5% or less on average.

The selective oxidation layer 7 of the surface emitting laser element 10 described above is made of p-AlAs, and the selective oxidation layer 71 of the surface emitting laser element 10A is p-Al _x Ga _1-x As (0.9 ≦ x <1). Therefore, the selective oxidation layer of the surface emitting laser element to be oxidized by the semiconductor oxidation apparatus 100 is made of p-Al _x Ga _1-x As (0.9 ≦ x ≦ 1), preferably p− consisting _{al x Ga 1-x As (} 0.95 ≦ x ≦ 1). This is because if the amount of Al increases, the oxidation rate of the selective oxidation layers 7 and 71 will increase moderately, and a constriction structure can be created under realistic conditions.

  FIG. 12 is a schematic cross-sectional view of an edge-emitting laser element to be oxidized by the semiconductor oxidation apparatus 100 shown in FIG. The surface emitting laser element to be oxidized by the semiconductor oxidation apparatus 100 may be an edge emitting laser element 10B shown in FIG.

  Referring to FIG. 12, edge emitting laser element 10B includes substrate 51, cladding layers 52 and 57, guide layers 53 and 55, active layer 54, selective oxidation layer 56, upper electrode 58, and lower electrode. 59.

The substrate 51 is made of n-GaAs having a (100) plane orientation. The clad layer 52 is made of n-Al _0.8 Ga _0.2 As and is formed on the substrate 51. The guide layer 53 is made of GaAs and is formed on the cladding layer 52.

The active layer 54 has a GaInNAs / GaAs double quantum well structure using GaInNAs as a well layer and GaAs as a barrier layer, and is formed on the guide layer 53. The guide layer 55 is made of GaAs and is formed on the active layer 54. The selective oxidation layer 56 is made of Al _x Ga _1-x As (0.95 ≦ x ≦ 1) and is formed on the guide layer 55. The selective oxidation layer 56 includes a non-oxidized region 56a and an oxidized region 56b.

  The clad layer 57 is made of p-AlGaAs and is formed on the selective oxide layer 56. The upper electrode 58 is formed on the cladding layer 57, and the lower electrode 58 is formed on the back surface of the substrate 51.

  In the edge-emitting laser device 10B, the guide layer 53, the active layer 54, the guide layer 55, the selective oxidation layer 56, and the cladding layer 57 have a stripe shape. The stripe shape has a length in the direction perpendicular to the paper surface in FIG. 12 of 300 μm and a length in the direction parallel to the paper surface of 30 μm.

The edge-emitting laser element 10B is manufactured according to steps (a) to (e) shown in FIGS. First, a cladding layer 52 made of n-Al _0.8 Ga _0.2 As, a guide layer 53 made of GaAs, and a GaInNAs / GaAs double quantum well structure on a substrate 51 made of n-GaAs by MOCVD or MBE. A stacked layer in which an active layer 54 made of GaAs, a guide layer 55 made of GaAs, a selective oxidation layer 56 made of Al _x Ga _1-x As, and a cladding layer 57 made of p-Al _0.8 Ga _0.2 As are sequentially grown. A film is formed.

  The laminated film is removed by dry etching or wet etching, leaving the stripe portion and reaching the cladding layer 52. Next, the selective oxidation layer 56 is oxidized by the above-described method using the semiconductor oxidation apparatus 100, and the non-oxidized region 56a and the oxidized region 56b are formed in the vicinity of the active layer 54.

  In the edge-emitting laser element 10B, the non-oxidized region 56a has a stripe shape. Therefore, the evaluation of the size of the non-oxidized region 56a when the selective oxidation layer 56 is oxidized using the semiconductor oxidation device 100 is performed on the paper surface in FIG. The length (= width) in the direction parallel to is used.

  As a result, when the selective oxidation layer 56 was oxidized using the semiconductor oxidation device 100, the width of the non-oxidized region 56a was 4.8 μm on average, and the variation in diameter was ± 5% or less on average.

  As described above, by oxidizing the selective oxidation layers 7, 56, 71 using the semiconductor oxidation apparatus 100 shown in FIG. 1, the dimensional distribution of the non-oxidized regions 7a, 56a, 71a is the reference value (= ± 5%). A plurality of surface emitting laser elements 10, 10A and end surface emitting laser elements 10B, which can be suppressed to the following and the non-oxidized regions 7a, 56a, 71a are uniform in size, can be fabricated on the wafer 141. As a result, the yield of the surface emitting laser elements 10 and 10A and the edge emitting laser element 10B can be increased.

  In the above description, the heater 105 is composed of the two heaters 105A and 105B. However, the present invention is not limited to this, and the heater 105 includes a plurality of heaters arranged substantially concentrically. Also good.

[Embodiment 2]
FIG. 13 is a schematic diagram of a semiconductor oxidation apparatus according to the second embodiment. Referring to FIG. 13, a semiconductor oxidation apparatus 200 according to the second embodiment includes a reaction vessel 201, a base 202, a heating table 203, a lamp 204, a temperature detector 205, a sample tray 206, and an introduction tube. 207, water reservoir 208, pipes 209, 211, 214 to 216, 223, 225, liquid mass flow controller 210, mass flow controllers 212, 217, vaporizer 213, valves 218 to 220, and exhaust pipe 221 , A water collector 222, an exhaust pump 224, and a control unit 226.

  The base 202 is mainly made of stainless steel and is disposed in the reaction vessel 201. The heating table 203 is made of carbon and installed on the base 202. The lamp 204 is disposed in the base 202 so as to be in contact with the heating table 203. The temperature detector 205 is disposed in the base 202 so that the tip is embedded in the heating table 203. The sample tray 206 is made of carbon and is disposed on one main surface of the heating table 203.

  The introduction pipe 207 is fixed to the upper surface of the reaction vessel 201 so that a part thereof is arranged in the reaction vessel 201 and one end thereof is arranged above the heating table 203. The one end of the introduction pipe 207 is wide.

  One end of the pipe 209 is immersed in the water 230 held in the water reservoir 208, and the other end is connected to the vaporizer 213. The liquid mass flow controller 210 is disposed in the pipe 210.

  One end of the pipe 211 is connected to the vaporizer 213. The mass flow controller 212 is disposed in the pipe 211. The vaporizer 213 is connected to the pipes 209, 211, and 214. The pipe 214 has one end connected to the vaporizer 213 and the other end opened to the external space.

  The pipe 215 has one end connected to the introduction pipe 207 and the other end connected to the pipe 214. One end of the pipe 216 is connected to the pipe 215. The mass flow controller 217 is disposed in the pipe 216.

  The valve 218 is disposed in the pipe 214 in the vicinity of the other end of the pipe 214. The valve 219 is disposed in the pipe 215 between a connection part between the pipe 214 and the pipe 215 and a connection part between the pipe 215 and the pipe 216.

  The valve 220 is disposed in the pipe 216 in the vicinity of the connection portion between the pipe 215 and the pipe 216. The exhaust pipe 221 has one end connected to the side surface of the reaction vessel 201 and the other end inserted into the water collector 222.

  The pipe 223 has one end connected to the water collector 222 and the other end connected to the exhaust pump 224. The pipe 225 has one end connected to the exhaust pump 224 and the other end opened to the external space.

  The reaction vessel 201 accommodates a part of the base 202, the heating table 203, the lamp 204, the temperature detector 205, the sample tray 206, and the introduction tube 207. The heating table 203 supports the sample tray 206. The lamp 204 heats the semiconductor sample 240 via the heating table 203 and the sample tray 206 in accordance with control from the control unit 226.

  The temperature detector 205 detects the temperature Ts of the heating table 203 and outputs the detected temperature Ts to the control unit 226. The sample tray 206 supports the semiconductor sample 240. The introduction pipe 207 introduces the nitrogen gas and water vapor supplied through the valve 219 into the reaction vessel 201 and introduces the nitrogen gas supplied through the valve 220 into the reaction vessel 201.

  The water reservoir 208 holds water 230. The pipe 209 supplies the water pumped up from the water reservoir 208 by the liquid mass flow controller 210 to the vaporizer 213.

  The liquid mass flow controller 210 supplies the water stored in the water reservoir 208 to the vaporizer 213 via the pipe 209 in accordance with control from the control unit 226. The pipe 211 supplies nitrogen gas from the mass flow controller 212 to the vaporizer 213. The mass flow controller 212 sets the flow rate of the nitrogen gas supplied from the other end of the pipe 211 to a predetermined flow rate and supplies it to the vaporizer 213 according to the control from the control unit 226.

  The vaporizer 213 vaporizes the water supplied from the liquid mass flow controller 210 to generate water vapor, and the generated water vapor and nitrogen gas supplied from the mass flow controller 212 are connected via the pipes 214 and 215 and the valve 219. Supply to the introduction pipe 207.

  The pipe 214 discharges the water vapor and nitrogen gas supplied from the vaporizer 213 to the outside through the valve 218 or supplies them to the introduction pipe 207 through the pipe 215 and the valve 219.

  The pipe 215 supplies the water vapor and nitrogen gas supplied via the pipe 214 and the valve 219 to the introduction pipe 207, and supplies the nitrogen gas supplied via the pipe 216 and the valve 220 to the introduction pipe 207.

  The pipe 216 supplies the nitrogen gas supplied from the mass flow controller 217 to the pipe 215 via the valve 220. The mass flow controller 217 sets the flow rate of the nitrogen gas supplied from the other end of the pipe 216 to a predetermined flow rate and supplies it to the pipe 215.

  The valve 218 releases the nitrogen gas and water vapor supplied to the pipe 214 to the outside, or stops releasing the nitrogen gas and water vapor to the outside. The valve 219 supplies nitrogen gas and water vapor supplied from the pipe 214 in the direction of the introduction pipe 207 or stops supply of nitrogen gas and water vapor in the direction of the introduction pipe 207. The valve 220 supplies nitrogen gas to the pipe 215 or stops supplying nitrogen gas to the pipe 215.

  The exhaust pipe 221 supplies the nitrogen gas and water vapor in the reaction vessel 201 to the water collector 222. The water collector 222 collects water vapor from the nitrogen gas and water vapor supplied from the exhaust pipe 221.

  The pipe 223 guides the nitrogen gas in the water collector 222 to the exhaust pump 224. The exhaust pump 224 exhausts the nitrogen gas in the water collector 222. The pipe 225 releases nitrogen gas to the outside.

  The control unit 226 controls the lamp 204 so as to heat the heating table 203 to a suitable temperature at which the distribution of the oxidation rate in the in-plane direction of the semiconductor sample 240 is equal to or less than the reference value by a method described later.

  Further, the control unit 226 controls the mass flow controllers 212 and 217 to set the flow rate of nitrogen gas to a predetermined flow rate, and controls the liquid mass flow controller 210 to set the flow rate of water to a predetermined flow rate. Furthermore, the control unit 226 controls opening and closing of the valves 218 to 220.

  The pipes 214 and 215 and the introduction pipe 207 are heated to a temperature at which the water vapor is not liquefied.

  FIG. 14 is a plan view of the lamp 204 shown in FIG. Referring to FIG. 14, lamp 204 includes lamps 2041 to 2047. The lamps 2042 to 2047 are arranged around the lamp 2041. The diameter of the lamp 2041 is longer than the diameter of the lamps 2042 to 2047. The lamp 2041 heats the central portion of the semiconductor sample 240, and the lamps 2042 to 2047 heat the outer peripheral portion of the semiconductor sample 240.

  As described above, as a result of the lamp 240 being composed of the seven lamps 2041 to 2047, the temperature detector 205 is provided corresponding to the seven lamps 2041 to 2047. FIG. 13 shows temperature detectors 205a, 205b, and 205c corresponding to the lamps 2041, 2042, and 2045, respectively.

  By providing the temperature detector 205 corresponding to each of the lamps 2041 to 2047, heating of the heating table 103 by each of the lamps 2041 to 2047 can be controlled independently.

  FIG. 15 is a schematic cross-sectional view of a surface emitting laser element to be oxidized by the semiconductor oxidation apparatus 200 shown in FIG. Referring to FIG. 15, surface emitting laser element 10C includes substrate 1, reflecting layer 2, resonator spacer layer 3, active layer 4, resonator spacer layer 5 and reflecting layer 6 of surface emitting laser element 10 shown in FIG. And the selective oxidation layer 7 are replaced with the substrate 1A, the reflection layer 2A, the resonator spacer layer 3A, the active layer 4A, the resonator spacer layer 5A, the reflection layer 6A, and the selective oxidation layer 77, respectively. The same as the laser element 10.

The substrate 1A is made of n-GaAs having a (100) plane orientation inclined by 2 degrees in the <110> direction. The reflection layer 2A is composed of [low refractive index layer 21A / high refractive index layer 22A] having a period of 35.5 when a pair of the low refractive index layer 21A and the high refractive index layer 22A is taken as one period, and is formed on the substrate 1A. It is formed. The low refractive index layer 21A is made of n-Al _0.9 Ga _0.1 As, and the high refractive index layer 22A is made of n-Al _0.3 Ga _0.7 As. Further, when the oscillation wavelength of the surface emitting laser element 10B was lambda _2, the thickness of each of the low refractive index layer 21A and the high-refractive index layer 22A is, λ _{2 /} 4n (n is the refractive index of each semiconductor layer) Have.

The resonator spacer layer 3A is made of Al _0.5 Ga _0.5 As and is formed on the reflective layer 2A. The active layer 4A has a triple quantum well structure made of GaAs / Al _0.5 Ga _0.5 As and is formed on the resonator spacer layer 3A.

The resonator spacer layer 5A is made of Al _0.5 Ga _0.5 As and is formed on the active layer 4A. The reflection layer 6A is composed of [low refractive index layer 61A / high refractive index layer 62A] of 28 periods when the pair of the low refractive index layer 61A and the high refractive index layer 62A is taken as one period, on the resonator spacer layer 5A. Formed. The low refractive index layer 61A is made of p-Al _0.9 Ga _0.1 As, and the high refractive index layer 62A is made of p-Al _0.3 Ga _0.7 As. Each of the low refractive index layer 61A and the high refractive index layer 62A has a film thickness of λ ₂ / 4n (n is the refractive index of each semiconductor layer).

The selective oxidation layer 77 is made of 30 nm of p-Al _0.99 Ga _0.01 As, and is provided in the reflective layer 6A. More specifically, the selective oxidation layer 77 is provided in p-Al _0.9 Ga _0.1 As in the second period from the resonator spacer layer 5A side in the reflective layer 6A. The selective oxidation layer 77 includes a non-oxidized region 77a and an oxidized region 77b.

  Each of the reflective layers 2A and 6A constitutes a semiconductor distributed Bragg reflector that reflects the oscillation light oscillated in the active layer 4A by Bragg multiple reflection and confines it in the active layer 4A.

  The oxidized region 77b of the selective oxidation layer 77 restricts the injection path of the current injected through the p-side electrode 11 and the reflective layer 6A to the active layer 4A to the non-oxidized region 77a. Accordingly, the current injected into the active layer 4A does not spread in the in-plane direction of the surface emitting laser element 10C, and the surface emitting laser element 10C can oscillate with a low threshold current.

The surface emitting laser element 10C is manufactured according to steps (a) to (e) shown in FIGS. In this case, in the step (a) shown in FIG. 7, n-Al _0.9 Ga _0.1 As / n-Al _0.3 Ga _0.7 As of the reflective layer 2A is changed to trimethylaluminum (TMA), trimethylgallium (TMA). TMG), arsine (AsH ₃ ) and hydrogen selenide (H ₂ Se) are used as raw materials.

Further, Al _0.5 Ga _0.5 As of the resonator spacer layer 3A is formed using trimethylaluminum (TMA), trimethylgallium (TMG), and arsine (AsH ₃ ) as raw materials, and GaAs / Al _{0. 5} Ga _0.5 As is formed using trimethylaluminum (TMA), trimethylgallium (TMG), and arsine (AsH ₃ ) as raw materials.

Further, Al _0.5 Ga _0.5 As for the resonator spacer layer 5A is formed using trimethylaluminum (TMA), trimethylgallium (TMG), and arsine (AsH ₃ ) as raw materials.

_{Further, p-Al 0.9 Ga 0.1 As} / p-Al 0.3 Ga 0.7 As trimethylaluminum reflective layer 6A (TMA), trimethyl gallium (TMG), arsine (AsH ₃₎ and tetrabromide Carbonized carbon (CBr ₄ ) is used as a raw material.

Further, p-Al _0.99 Ga _0.01 As for the selective oxidation layer 77 is formed using trimethylaluminum (TMA), trimethylgallium (TMG), arsine (AsH ₃ ), and carbon tetrabromide (CBr ₄ ) as raw materials. Then, p-GaAs of the contact layer 8 is formed using trimethyl gallium (TMG), arsine (AsH ₃ ), and carbon tetrabromide (CBr ₄ ) as raw materials.

  Further, in the step (d) shown in FIG. 8, the n selective oxidation layers 77 in the n mesa structures 41 to 4 n formed on the substrate 1 </ b> A (= wafer 141) use the semiconductor oxidation apparatus 200. It is oxidized.

  The oxidation of the selective oxidation layer 77 using the semiconductor oxidation apparatus 200 will be described in detail. When step (c) shown in FIG. 7 is completed, n stacked bodies 41 to 4n shown in step (c) in FIG. 7 are formed on wafer 141 (= substrate 1). Then, the wafer 141 on which the n stacked bodies 41 to 4n are formed is placed on the sample tray 206 as the semiconductor sample 240, and the sample tray 206 is set on the heating table 203 in the reaction vessel 201.

  Thereafter, the control unit 226 controls the mass flow controller 212 to flow a predetermined flow rate of nitrogen gas into the reaction vessel 201 via the pipes 211, 214, 215, the valve 219 and the introduction pipe 207. Thereby, the inside of the reaction vessel 201 is replaced with nitrogen gas.

  Further, the control unit 226 controls the mass flow controller 212 to flow 5 SLM nitrogen gas to the vaporizer 213 via the pipe 211.

  Further, the control unit 226 controls the liquid mass flow controller 210 to pump 50 g / hr of water from the water reservoir 208 and supply it to the vaporizer 213.

  The vaporizer 213 vaporizes the water supplied from the liquid mass flow controller 210 to generate water vapor, transports the generated water vapor using the nitrogen gas supplied from the mass flow controller 212 as a carrier gas, and supplies the water vapor to the pipe 214. And discharged outside the system through the valve 218.

  When these nitrogen gas and water vapor supply systems are in an equilibrium state, the control unit 226 closes the valve 220, opens the valve 219, and closes the valve 218. Thus, 50 g / hr of water vapor is transported by 5 SLM nitrogen gas and supplied to the reaction vessel 201.

  Next, the control unit 226 controls the lamps 2041 to 2047 so that the temperature of the heating table 203 near the lamp 2041 becomes 430 ° C., and the temperature of the heating table 203 near the lamps 2042 to 2047 becomes 427 to 429 ° C. The heating table 203 is heated.

  The outer peripheral portion of the heating table 203 is heated to 427 to 429 ° C., the central portion of the heating table 203 is heated to 430 ° C., and a state where 5 SLM nitrogen gas and 50 g / hr of water vapor are caused to flow into the reaction vessel 201 is predetermined. Hold for hours.

Thereby, the selective oxidation layer 77 made of p-Al _0.99 Ga _0.01 As is oxidized from the outer peripheral portion, and a non-oxidized region 77a and an oxidized region 77b are formed in the reflective layer 6A.

  When a predetermined time elapses, the control unit 226 controls to open the valve 218, close the valve 219, open the valve 220, and further control the lamps 2041 to 2047 to stop heating.

  Then, the semiconductor sample 240 is rapidly cooled by the nitrogen gas supplied from the mass flow controller 217. Thereby, the oxidation of the selective oxidation layer 77 using the semiconductor oxidation apparatus 200 is completed.

  The selective oxidation layer 77 was oxidized using the semiconductor oxidation device 200, and the diameter distribution of the non-oxidized regions 77a in the plurality of surface emitting laser elements 10C manufactured on the wafer 141 was examined. As a result, the diameter of the non-oxidized region 77a was 4.0 μm on average, and the variation in diameter was ± 5% or less on average.

  Thus, by oxidizing the selective oxidation layer 77 using the semiconductor oxidation apparatus 200, the variation in the diameter of the non-oxidized region 77a can be suppressed to a reference value (= ± 5%) or less. The average variation in the diameter of the non-oxidized region 77a is ± 5% or less because the outer peripheral portion of the semiconductor sample 240 is heated to 427 to 429 ° C., and the inner peripheral portion of the semiconductor sample 240 is heated to 430 ° C. This is because the selective oxidation layer 77 is oxidized.

  And the set temperature (= 427-429 degreeC) of this outer peripheral part and the set temperature (= 430 degreeC) of a center part are the temperature determined based on the experimental result. For comparison, in the semiconductor oxidation apparatus 200, when all the set temperatures of the lamps 2041 to 2047 are set to 430 ° C. and the selective oxidation layer 77 is oxidized, the non-oxidized region 77a has an average diameter of 3.7 μm. The diameter variation was ± 10% on average. In the vicinity of the center of the wafer 141, the diameter of the non-oxidized region 77a is relatively long, and in the outer peripheral portion of the wafer 141, the diameter of the non-oxidized region 77a is relatively short.

The diameter of the non-oxidized region 77a is relatively long near the center of the wafer 141 because the selective oxide film 77 (= p-Al _0.99 Ga _0.01 As) having _undergone crystal growth is near the center of the wafer 141. This is because the film thickness is relatively thin and the oxidation rate of the selective oxide film 77 (= p-Al _0.99 Ga _0.01 As) is relatively slow, and the diameter of the non-oxidized region 77 a at the outer peripheral portion of the wafer 141. Is relatively short at the outer peripheral portion of the wafer 141, the film thickness of the selective oxide layer 77 (= p-Al _0.99 Ga _0.01 As) on which the crystal is grown is relatively thick. This is because (= p-Al _0.99 Ga _0.01 As) has a relatively high oxidation rate (see FIGS. 4 and 10).

Therefore, in order to slow down the oxidation rate of the selective oxide film 77 (= p-Al _0.99 Ga _0.01 As) in the outer peripheral portion of the wafer 141, the set temperature of the outer peripheral portion 141A of the wafer 141 is set to the inner peripheral portion of the wafer 141. It set to 427-429 degreeC lower than the preset temperature (= 430 degreeC) of the part 141B. As a result, as described above, the diameter of the non-oxidized region 77a was 4.0 μm on average, and the variation in diameter was ± 5% or less on average.

  Therefore, the set temperature of the outer peripheral portion (= 427 to 429 ° C.) and the set temperature of the inner peripheral portion (= 430 ° C.) are temperatures determined based on experimental results.

  In the semiconductor oxidation apparatus 200 shown in FIG. 13, the selective oxidation layers 7, 71, 56 of the surface emitting laser elements 10, 10A, 10B may be subjected to oxidation.

  Others are the same as in the first embodiment.

[Embodiment 3]
FIG. 16 is a schematic diagram of a semiconductor oxidation apparatus according to the third embodiment. Referring to FIG. 16, a semiconductor oxidation apparatus 300 according to Embodiment 3 includes a reaction vessel 301, a base 302, a heating table 303, a rotating shaft 304, a heater 305, a temperature detector 306, and a sample tray. 307, an introduction pipe 308, a bubbler 309, pipes 310 to 313, 321, a mass flow controller 314, 315, valves 316 to 318, an exhaust pipe 319, a water collector 320, and a control unit 322. Prepare.

  The base 302 is disposed in the reaction vessel 301. The heating table 303 is installed on the base 302 and is fixed to one end of the rotating shaft 304. A part of the rotating shaft 304 is disposed in the reaction vessel 301 and is fixed to the bottom surface of the reaction vessel 301 so as to be rotatable in the direction of an arrow 323.

  The heater 305 is built in the base 302. The temperature detector 306 is disposed in the base 302 so that the tip is embedded in the heating table 303. The sample tray 307 is made of carbon and is disposed on one main surface of the heating table 303.

  The introduction pipe 308 is fixed to the upper surface of the reaction container 301 so that a part thereof is disposed in the reaction container 301 and one end thereof is disposed above the heating table 303. The one end of the introduction pipe 308 is wide.

  The pipe 310 is immersed in water 330 held at one end by a bubbler 309. One end of the pipe 311 is connected to the bubbler 309. The pipe 312 has one end connected to the introduction pipe 308 and the other end connected to the pipe 311. One end of the pipe 313 is connected to the pipe 312.

  The mass flow controller 314 is disposed in the pipe 310, and the mass flow controller 315 is disposed in the pipe 313. The valve 316 is disposed in the pipe 311 in the vicinity of the other end of the pipe 311. The valve 317 is disposed in the pipe 313 between a connection part between the pipe 311 and the pipe 312 and a connection part between the pipe 312 and the pipe 313. The valve 318 is disposed in the pipe 313 in the vicinity of the connection portion between the pipe 312 and the pipe 313.

  One end of the exhaust pipe 319 is connected to the side surface of the reaction vessel 301, and the other end is disposed in the water collector 320. One end of the pipe 321 is connected to the water collector 320.

  The reaction vessel 301 accommodates a base 302, a heating table 303, a part of a rotating shaft 304, a heater 305, a temperature detector 306, a sample tray 307, and a part of an introduction tube 308. The heating table 303 supports the sample tray 307.

  The rotating shaft 304 rotates the heating table 303 in the direction of the arrow 323 according to the control from the control unit 322. The heater 305 heats the semiconductor sample 340 via the heating table 303 and the sample tray 307 according to control from the control unit 322.

  The temperature detector 306 detects the temperature Ts of the heating table 303 and outputs the detected temperature Ts to the control unit 322. The sample tray 307 supports the semiconductor sample 340. The introduction pipe 308 introduces nitrogen gas and water vapor supplied via the valve 317 into the reaction vessel 301 and introduces nitrogen gas supplied via the valve 318 into the reaction vessel 301.

  The bubbler 309 holds the water 330 heated to about 85 ° C. by a heater (not shown), and when a predetermined flow rate of nitrogen gas is supplied via the pipe 310, the nitrogen gas is used as a carrier gas and the temperature is about 85 ° C. Steam is supplied to the pipe 311.

  The pipe 310 releases the nitrogen gas supplied from the mass flow controller 314 into the water 330 held in the bubbler 309. The pipe 311 discharges the nitrogen gas and water vapor supplied from the bubbler 309 to the outside via the valve 316 or supplies them to the pipe 312.

  The pipe 312 supplies the nitrogen gas and water vapor supplied from the pipe 311 to the introduction pipe 308 and supplies the nitrogen gas supplied from the pipe 313 to the introduction pipe 308. The pipe 313 supplies the nitrogen gas supplied via the mass flow controller 315 to the pipe 312 via the valve 318.

  The mass flow controller 314 sets the flow rate of the nitrogen gas supplied to the other end to a predetermined flow rate and supplies it to the pipe 310 according to the control from the control unit 322. The mass flow controller 315 sets the flow rate of the nitrogen gas supplied to the other end to a predetermined flow rate and supplies it to the pipe 313 in accordance with the control from the control unit 322.

  The valve 316 releases the nitrogen gas and water vapor supplied to the pipe 311 to the outside, or stops releasing the nitrogen gas and water vapor to the outside. The valve 317 supplies nitrogen gas and water vapor supplied from the pipe 311 in the direction of the introduction pipe 308 or stops supply of nitrogen gas and water vapor in the direction of the introduction pipe 308. The valve 318 supplies nitrogen gas to the pipe 312 or stops supplying nitrogen gas to the pipe 312.

  The exhaust pipe 319 supplies nitrogen gas and water vapor in the reaction vessel 301 to the water collector 320. The water collector 320 collects water vapor from the nitrogen gas and water vapor supplied from the exhaust pipe 319 and discharges the nitrogen gas to the outside through the pipe 321. The pipe 321 releases the nitrogen gas supplied to the water collector 320 to the outside.

  The control unit 322 has a function of a thyristor temperature control circuit, and heats the heating table 303 to a suitable temperature at which the distribution of the oxidation rate in the in-plane direction of the semiconductor sample 340 is equal to or less than a reference value by a method described later. The heater 305 is controlled.

  In addition, the control unit 322 controls the mass flow controllers 314 and 315 so that the flow rate of nitrogen gas is set to a predetermined flow rate. Further, the control unit 322 controls opening and closing of the valves 316 to 318.

  The pipes 311 and 312, the introduction pipe 308, and the reaction vessel 301 are heated to a temperature at which water vapor is not liquefied.

  FIG. 17 is a plan view of the heating table 303 and the heater 305 shown in FIG. Referring to FIG. 17, heater 305 includes heaters 305A and 305B. Each of the heaters 305A and 305B is constituted by a resistance heater made of nichrome wire. The heating table 303 has a substantially circular planar shape. The heater 305A is arranged inside the heating table 303 along the circumference of the heating table 303, and the heater 305B is arranged inside the heater 305A.

  As described above, the heater 305 includes the heater 305A disposed on the outside and the heater 305B disposed on the inside. The heaters 305 </ b> A and 305 </ b> B heat the heating table 303 independently of each other according to control from the control unit 322. Therefore, the control unit 322 independently sets the set temperature of the heating table 303 heated by the heater 305A and the set temperature of the heating table 303 heated by the heater 305B based on the temperature Ts received from the temperature detector 306. The heaters 305A and 305B are independently controlled so that the set temperature is set.

When the surface emitting laser element 10C is manufactured, the semiconductor oxidation apparatus 300 shown in FIG. 16 selects the selective oxidation layer 77 made of p-Al _0.99 Ga _0.01 As in the step (d) shown in FIG. Oxidation forms a non-oxidized region 77a and an oxidized region 77b.

  The oxidation of the selective oxidation layer 77 using the semiconductor oxidation apparatus 300 will be described in detail. When step (c) shown in FIG. 7 is completed, n mesa structures 41 to 4n shown in step (c) in FIG. 7 are formed on wafer 141 (= substrate 1). Then, the wafer 141 on which the n mesa structures 41 to 4n are formed is placed on the sample tray 307 as the semiconductor sample 340, and the sample tray 307 is set on the heating table 303 in the reaction vessel 301.

  Thereafter, the control unit 322 controls the mass flow controller 315 to flow 5 SLM nitrogen gas, and the mass flow controller 315 performs piping 313, 312 with 5 SLM nitrogen gas as a carrier gas in accordance with control from the control unit 322. It flows to the reaction vessel 301 through the valve 318 and the introduction pipe 308. Thereby, the inside of the reaction vessel 301 is replaced with nitrogen gas.

  In addition, the control unit 322 controls the mass flow controller 314 to flow nitrogen gas, and the mass flow controller 314 flows nitrogen gas to the bubbler 309 via the pipe 310 in accordance with control from the control unit 322. As a result, 85 ° C. water 330 held in the bubbler 309 is bubbled by nitrogen gas, and the bubbler 309 supplies water vapor to the reaction vessel 301 via the pipes 311, 312, the valve 317 and the introduction pipe 308. That is, the bubbler 309 supplies the oxidation material to the reaction vessel 301.

  Furthermore, the control unit 322 sets the set temperature of the temperature detector 306 to 430 ° C., sets the output power of the thyristor temperature control circuit that controls the heater 305B to 60%, and controls the heater 305A. Is set to 58% to control the heaters 305A and 305B.

  The heaters 305A and 305B heat the heating table 303 according to the control from the control unit 322 and hold it for a predetermined time in a state where water vapor and 5SLM nitrogen gas are allowed to flow into the reaction vessel 301.

Thereby, the selective oxidation layer 77 made of p-Al _0.99 Ga _0.01 As is oxidized from the outer peripheral portion, and a non-oxidized region 77a and an oxidized region 77b are formed in the reflective layer 6A.

  And when predetermined time passes, the control part 322 controls heater 305A, 305B so that a heating may be stopped. At the same time, the control unit 322 opens and closes the valve 316 and the valve 317 so as to stop the flow of water vapor and 5 SLM nitrogen gas to the reaction vessel 301, opens the valve 318, and supplies nitrogen gas via the mass flow controller 315. Introduce into the reaction vessel 301.

  Then, the semiconductor sample 340 is rapidly cooled, and the oxidation of the selective oxidation layer 77 using the semiconductor oxidation apparatus 300 is completed.

  The selective oxidation layer 77 was oxidized using the semiconductor oxidation device 300, and the diameter distribution of the non-oxidized regions 77a in the plurality of surface emitting laser elements 10C manufactured on the wafer 141 was examined. As a result, the diameter of the non-oxidized region 77a was 3.0 μm on average, and the variation in diameter was ± 2% or less on average.

  Thus, by oxidizing the selective oxidation layer 77 using the semiconductor oxidation device 300, the variation in the diameter of the non-oxidized region 77a can be suppressed to a reference value (= ± 5%) or less. The variation in the diameter of the non-oxidized region 77a is ± 5% or less because the outer periphery of the semiconductor sample 340 is heated by the heater 305A with the output power set to 58%, and the central portion of the semiconductor sample 340 is output with the output power. This is because the selective oxidation layer 77 is oxidized by heating with the heater 305B set to 60%.

  The output power setting is an output determined based on the experimental result. In the semiconductor oxidation apparatus 300, the set temperature of the temperature detector 306 is set to 430 ° C., the output power of the thyristor control circuit that controls the heater 305B is set to 60%, and the heating table 303 is set to 430 ° C. throughout the entire area. As a result of adjusting the output power of the thyristor control circuit that controls the heater 305A to oxidize the selective oxidation layer 77, the non-oxidized region 7a has an average diameter of 2.8 μm and an average diameter variation of ± 10. %Met. In the vicinity of the center of the wafer 141, the diameter of the non-oxidized region 77a is relatively long, and in the outer peripheral portion of the wafer 141, the diameter of the non-oxidized region 77a is relatively short.

The diameter of the non-oxidized region 77a is relatively long near the center of the wafer 141 because the selective oxide film 77 (= p-Al _0.99 Ga _0.01 As) having _undergone crystal growth is near the center of the wafer 141. This is because the film thickness is relatively thin and the oxidation rate of the selective oxide film 77 (= p-Al _0.99 Ga _0.01 As) is relatively slow, and the diameter of the non-oxidized region 77 a at the outer peripheral portion of the wafer 141. Is relatively short at the outer peripheral portion of the wafer 141, the film thickness of the selective oxide layer 77 (= p-Al _0.99 Ga _0.01 As) on which the crystal is grown is relatively thick. This is because (= p-Al _0.99 Ga _0.01 As) has a relatively high oxidation rate (see FIGS. 4 and 10).

Therefore, in order to slow down the oxidation rate of the selective oxide film 77 (= p-Al _0.99 Ga _0.01 As) at the outer peripheral portion of the wafer 141, the output power of the heater 305A for heating the outer peripheral portion 141A of the wafer 141 is changed. It was set to 58%, which is lower than the output power (60%) of the heater 305B that heats the central portion 141B of the wafer 141. As a result, as described above, the diameter of the non-oxidized region 77a was 4.0 μm on average, and the variation in diameter was ± 5% or less on average.

  Therefore, the output power of the heater 305A that heats the outer peripheral portion 141A of the wafer 141 and the output power of the heater 305B that heats the central portion 141B of the wafer 141 are temperatures determined based on experimental results.

  In the semiconductor oxidation apparatus 300 shown in FIG. 16, the selective oxidation layers 7, 71, 56 of the surface emitting laser elements 10, 10A, 10B may be subjected to oxidation.

  Others are the same as in the first embodiment.

[Embodiment 4]
FIG. 18 is a schematic diagram of a semiconductor oxidation apparatus according to the fourth embodiment. Referring to FIG. 18, the semiconductor oxidation apparatus 400 according to the fourth embodiment includes a reaction vessel 401, a heating table 402, a rotating shaft 403, a lamp house 404, a lamp 405, a bubbler 406, and pipes 407 to 410. , 418, mass flow controllers 411 and 412, valves 413 to 415, an exhaust pipe 416, a water collector 417, and a control unit 419.

  The heating table 402 is fixed to one end of the rotating shaft 403. A part of the rotating shaft 403 is disposed in the reaction vessel 401 and is fixed to the bottom surface of the reaction vessel 401 so as to be rotatable in the direction of an arrow 420.

  The lamp house 404 is installed on the upper surface of the reaction vessel 401. The lamp 405 is installed in the lamp house 404. The pipe 407 is immersed in water 430 held at one end by the bubbler 406. One end of the pipe 408 is connected to the bubbler 406. The pipe 409 has one end connected to the introduction pipe 408 and the other end installed in the reaction vessel 401. One end of the pipe 410 is connected to the pipe 409.

  The mass flow controller 411 is disposed in the pipe 407, and the mass flow controller 412 is disposed in the pipe 410. The valve 413 is disposed in the pipe 408 in the vicinity of the other end of the pipe 408. The valve 414 is disposed in the pipe 409 between a connection part between the pipe 408 and the pipe 409 and a connection part between the pipe 409 and the pipe 410. The valve 415 is disposed in the pipe 410 in the vicinity of the connection portion between the pipe 409 and the pipe 410.

  One end of the exhaust pipe 416 is connected to the side surface of the reaction vessel 401, and the other end is disposed in the water collector 417. One end of the pipe 418 is connected to the water collector 417.

  The reaction container 401 accommodates the heating table 402, a part of the rotating shaft 403, and a part of the piping 409. The heating table 402 supports the semiconductor sample 440.

  The rotating shaft 403 rotates the heating table 402 in the direction of the arrow 420 in accordance with control from the control unit 419. The lamp house 404 stores the lamp 405. The lamp 405 heats the semiconductor sample 440 from above according to control from the control unit 419.

  The bubbler 406 holds the water 430 heated to about 85 ° C. by a heater (not shown), and when a predetermined amount of nitrogen gas is supplied through the pipe 407, the bubbler 406 uses the nitrogen gas as a carrier gas at about 85 ° C. Steam is supplied to the pipe 408.

  The pipe 407 discharges the nitrogen gas supplied from the mass flow controller 411 into the water 430 held by the bubbler 406. The pipe 408 discharges the nitrogen gas and water vapor supplied from the bubbler 406 to the outside via the valve 413 or supplies them to the pipe 409.

  The pipe 409 supplies the nitrogen gas and water vapor supplied from the pipe 408 to the reaction container 401 and supplies the nitrogen gas supplied from the pipe 410 to the reaction container 401. The pipe 410 supplies the nitrogen gas supplied via the mass flow controller 412 to the pipe 409 via the valve 415.

  The mass flow controller 412 sets the flow rate of the nitrogen gas supplied to the other end to a predetermined flow rate and supplies it to the pipe 407 in accordance with the control from the control unit 419. The mass flow controller 412 sets the flow rate of the nitrogen gas supplied to the other end to a predetermined flow rate and supplies it to the pipe 410 according to the control from the control unit 419.

  The valve 413 releases the nitrogen gas and water vapor supplied to the pipe 408 to the outside, or stops releasing the nitrogen gas and water vapor to the outside. The valve 414 supplies nitrogen gas and water vapor supplied from the pipe 408 in the direction of the reaction vessel 401 or stops supplying nitrogen gas and water vapor in the direction of the reaction vessel 401. The valve 415 supplies nitrogen gas to the pipe 409 or stops supplying nitrogen gas to the pipe 409.

  The exhaust pipe 416 supplies the nitrogen gas and water vapor in the reaction vessel 401 to the water collector 417. The water collector 417 collects water vapor out of the nitrogen gas and water vapor supplied from the exhaust pipe 416 and releases the nitrogen gas to the outside through the pipe 418. The pipe 418 discharges the nitrogen gas supplied to the water collector 417 to the outside.

  The control unit 419 controls the lamp 405 so as to heat the heating table 402 to a suitable temperature at which the distribution of the oxidation rate in the in-plane direction of the semiconductor sample 440 is equal to or less than the reference value by a method described later.

  Further, the control unit 419 controls the mass flow controllers 411 and 412 so as to set the flow rate of nitrogen gas to a predetermined flow rate. Further, the control unit 419 controls opening and closing of the valves 413 to 415.

  The pipes 408 and 409 are heated to a temperature at which the water vapor is not liquefied.

  A lamp 405 illustrated in FIG. 18 includes seven lamps arranged in the same manner as the lamps 2041 to 2047 illustrated in FIG. 14. Therefore, like the lamp 204, the lamp 405 is composed of lamps provided corresponding to the central portion and the outer peripheral portion of the semiconductor sample 440, respectively.

  When any of the surface emitting laser elements 10, 10A, 10B, and 10C described above is manufactured, the semiconductor oxidation apparatus 400 shown in FIG. 18 is selectively oxidized layers 7, 56, and 71 in the step (d) shown in FIG. , 77 are selectively oxidized to form non-oxidized regions 7a, 56a, 71a, 77a and oxidized regions 7b, 56b, 71b, 77b.

  The oxidation of the selective oxidation layer 7 using the semiconductor oxidation apparatus 400 will be described in detail. When step (c) shown in FIG. 7 is completed, n stacked bodies 41 to 4n shown in step (c) in FIG. 7 are formed on wafer 141 (= substrate 1). Then, the wafer 141 on which the n stacked bodies 41 to 4n are formed is placed on the heating table 402 in the reaction vessel 401 as the semiconductor sample 440.

  Thereafter, the control unit 419 controls the mass flow controller 412 to flow 5 SLM nitrogen gas, and the mass flow controller 412 controls the pipes 410, 409 and 5SLM nitrogen gas as carrier gas in accordance with the control from the control unit 419. It flows to the reaction vessel 401 through the valve 415. Thereby, the inside of the reaction vessel 401 is replaced with nitrogen gas.

  Further, the control unit 319 controls the mass flow controller 411 so as to flow nitrogen gas, and the mass flow controller 411 flows nitrogen gas to the bubbler 406 via the pipe 407 in accordance with control from the control unit 419. As a result, 85 ° C. water 430 held in the bubbler 406 is bubbled by nitrogen gas, and the bubbler 406 supplies water vapor to the reaction vessel 401 via the pipes 408 and 409 and the valve 414. That is, the bubbler 406 supplies the oxidation material to the reaction vessel 401.

  Further, the control unit 419 controls the lamps 2042 to 2047 so as to heat the outer peripheral portion of the heating table 403 to 365 ° C., and controls the lamp 2041 so as to heat the central portion of the heating table 403 to 370 ° C.

  The lamps 2042 to 2047 heat the outer peripheral portion of the heating table 403 to 365 ° C. according to the control from the control unit 419, and the lamp 2041 is connected to the center of the heating table 403 according to the control from the control unit 419. The part is heated to 370 ° C.

  Thereafter, the lamps 2041 to 2047 heat the heating table 403 and hold it for a predetermined time in a state where water vapor and 5 SLM nitrogen gas are flowed into the reaction vessel 401.

  Thereby, the selective oxidation layer 7 made of p-AlAs is oxidized from the outer peripheral portion, and the non-oxidized region 7 a and the oxidized region 7 b are formed in the reflective layer 6.

  And when predetermined time passes, the control part 419 will control the lamps 2041-2047 so that heating may be stopped. At the same time, the control unit 419 opens and closes the valve 413 and the valve 414 so as to stop the flow of water vapor and 5 SLM nitrogen gas to the reaction vessel 401, opens the valve 415, and supplies nitrogen gas via the mass flow controller 412. Introduce into the reaction vessel 401.

  Then, the semiconductor sample 440 is rapidly cooled, and the oxidation of the selective oxidation layer 7 using the semiconductor oxidation apparatus 400 is completed.

  The selective oxidation layer 7 was oxidized using the semiconductor oxidation apparatus 400, and the diameter distribution of the non-oxidized regions 7a in the plurality of surface emitting laser elements 10 manufactured on the wafer 141 was examined. As a result, the diameter of the non-oxidized region 7a was 4.0 μm on average, and the variation in diameter was ± 5% or less on average.

  Thus, by oxidizing the selective oxidation layer 7 using the semiconductor oxidation device 400, the variation in the diameter of the non-oxidized region 7a can be suppressed to a reference value (= ± 5%) or less. The variation in the diameter of the non-oxidized region 7a on average is ± 5% or less because the outer peripheral portion of the semiconductor sample 440 is heated to 365 ° C., and the central portion of the semiconductor sample 440 is heated to 370 ° C. This is because 7 was oxidized.

  The set temperature (= 365 ° C.) of the outer peripheral portion and the set temperature (= 370 ° C.) of the central portion are temperatures determined based on experimental results. For comparison, in the semiconductor oxidation apparatus 400, the selective oxidation layer 7 was oxidized by setting the set temperature of the lamp 405 to 370 ° C., and the diameter distribution of the non-oxidized region 7a was examined. The average diameter variation was ± 10%. In the vicinity of the center of the wafer 141, the diameter of the non-oxidized region 7a is relatively long, and in the outer peripheral portion of the wafer 141, the diameter of the non-oxidized region 7a is relatively short.

  The diameter of the non-oxidized region 7a is relatively long near the center of the wafer 141. The film thickness of the selective oxide film 7 (= p-AlAs) on which the crystal is grown is relatively thin near the center of the wafer 141. This is because the oxidation rate of the selective oxide film 7 (= p-AlAs) is relatively slow, and the diameter of the non-oxidized region 7a is relatively short in the outer peripheral portion of the wafer 141. This is because the grown selective oxide layer 7 (= p-AlAs) is relatively thick and the selective oxide film 7 (= p-AlAs) has a relatively high oxidation rate (see FIGS. 4 and 10). ).

  Therefore, in order to slow down the oxidation rate of the selective oxide film 7 (= p-AlAs) at the outer peripheral portion of the wafer 141, the set temperature of the outer peripheral portion 141A of the wafer 141 is set to the set temperature (= 370 ° C.) of the central portion 141B of the wafer 141. ) Lower than 365). As a result, as described above, the diameter of the non-oxidized region 7a was 4.0 μm on average, and the variation in diameter was ± 5% or less on average.

  Therefore, the set temperature (= 365 ° C.) of the outer peripheral portion and the set temperature (= 370 ° C.) of the central portion are temperatures determined based on experimental results.

  In the semiconductor oxidation apparatus 400 shown in FIG. 18, the selective oxidation layers 56, 71, and 77 of the surface emitting laser elements 10A, 10B, and 10C may be oxidized.

  Others are the same as in the first embodiment.

[Application example]
FIG. 19 is a plan view of a surface emitting laser array according to the present invention. Referring to FIG. 19, surface emitting laser array 500 includes a substrate 501 and a plurality of surface emitting laser elements 502. The plurality of surface emitting laser elements 502 are formed on the substrate 501 and arranged in an i × j two-dimensional manner. More specifically, the plurality of surface emitting laser elements 502 are arranged in 5 rows in the vertical direction and 8 rows in the horizontal direction. The surface emitting laser element 502 is composed of any of the surface emitting laser elements 10, 10A, 10C described above.

  Therefore, the surface emitting laser array 500 is manufactured by the manufacturing method described above using any of the semiconductor oxidation apparatuses 100, 200, 300, and 400 described above. As a result, a surface-emitting laser array 500 including 40 surface-emitting laser elements 10, 10A, and 10C with good uniformity in which the diameter distribution of the non-oxidized regions 7a, 71a, and 77a is ± 5% or less can be manufactured.

  Since the surface emitting laser elements 10, 10A, and 10C can be manufactured in a lump on a single substrate and no creaking is required, parallelization and a two-dimensional high density integrated array can be easily manufactured at low cost. .

  FIG. 20 is a schematic diagram of an optical transmission system according to the present invention. Referring to FIG. 20, an optical transmission system 600 according to the present invention includes boards 601, 602, surface emitting laser arrays 603, 606, optical fiber groups 604, 607, and light receiving elements 605, 608.

  The surface emitting laser array 603 and the light receiving element 608 are formed on one main surface 601A of the board 601. The light receiving element 605 and the surface emitting laser array 606 are formed on one main surface 602A of the board 602. Each of the surface emitting laser arrays 603 and 606 includes a surface emitting laser array 500 shown in FIG.

  The light receiving element 605 includes a plurality of light receiving elements provided corresponding to the plurality of surface emitting laser elements included in the surface emitting laser array 603.

  The optical fiber group 604 includes a plurality of optical fibers 6041. The plurality of optical fibers 6041 are arranged in parallel between the surface emitting laser array 603 and the light receiving element 605. In this case, the plurality of optical fibers 6041 are provided corresponding to the plurality of surface emitting laser elements included in the surface emitting laser array 603 and the plurality of light receiving elements included in the light receiving element 605. Each optical fiber 6041 transmits the light emitted from the corresponding surface emitting laser element (any one of the surface emitting laser elements 10, 10A, and 10C) to the corresponding light receiving element.

  The light receiving element 608 includes a plurality of light receiving elements provided corresponding to the plurality of surface emitting laser elements included in the surface emitting laser array 606.

  The optical fiber group 607 includes a plurality of optical fibers 6071. The plurality of optical fibers 6071 are arranged in parallel between the surface emitting laser array 606 and the light receiving element 608. In this case, the plurality of optical fibers 6071 are provided corresponding to the plurality of surface emitting laser elements included in the surface emitting laser array 606 and the plurality of light receiving elements included in the light receiving element 608. Each optical fiber 6071 transmits the light emitted from the corresponding surface emitting laser element (any one of the surface emitting laser elements 10, 10A, and 10C) to the corresponding light receiving element.

  The surface emitting laser array 603 emits a plurality of lights, and the emitted light enters the optical fiber group 604. The optical fiber group 604 transmits a plurality of lights from the surface emitting laser array 603 to the light receiving element 605. The light receiving element 605 receives a plurality of lights transmitted by the optical fiber 604, converts the received plurality of lights into electrical signals, and outputs them.

  The surface emitting laser array 606 emits a plurality of lights, and the emitted light enters the optical fiber group 607. The optical fiber group 607 transmits a plurality of lights from the surface emitting laser array 606 to the light receiving element 608. The light receiving element 608 receives a plurality of lights transmitted by the optical fiber 607, converts the received plurality of lights into electrical signals, and outputs them.

  Thus, the optical transmission system 600 is a parallel optical transmission system that transmits and receives light between the boards 601 and 602 in parallel.

  FIG. 21 is another schematic diagram of the optical transmission system according to the present invention. Referring to FIG. 21, the optical transmission system 700 includes silicon (Si) substrates 701 and 702, surface emitting laser arrays 703 and 705, and light receiving elements 704 and 706.

  Each of the surface emitting laser arrays 703 and 705 includes a plurality of surface emitting laser elements 10 each having an active layer 4 having a GaInNAs / GaAs quantum well structure. The surface emitting laser array 703 emits light from the substrate 1 side, and the surface emitting laser array 705 emits light from the side opposite to the substrate 1.

  The surface emitting laser array 703 and the light receiving element 706 are installed on one main surface 701A of the Si substrate 701. The light receiving element 704 and the surface emitting laser array 705 are installed on one main surface 702A of the Si substrate 702.

  The surface emitting laser array 703 oscillates a plurality of lights having an oscillation wavelength in the range of 1.1 to 1.6 μm, and emits the oscillated plurality of lights toward the light receiving element 704 through the Si substrate 701. The light receiving element 704 receives a plurality of lights emitted from the surface emitting laser array 703, converts the received plurality of lights into electrical signals, and outputs them to the outside.

The surface emitting laser array 705 also oscillates a plurality of lights having an oscillation wavelength in the range of 1.1 to 1.6 μm, and emits the oscillated lights toward the light receiving element 706. The light receiving element 706 receives the plurality of lights emitted from the surface emitting laser array 705 via the Si substrate 701, converts the received plurality of lights into electric signals, and outputs them to the outside.
Thus, the optical transmission system 700 is a parallel optical transmission system that transmits and receives light in parallel between chips.

  The surface-emitting laser elements constituting the surface-emitting laser arrays 703 and 705 of the optical transmission system 700 include III or N such as GaNAs, GaInNAs, GaInAsSb, GaInNP, GaNP, GaNAsSb, GaInNAsSb, InNAs, and InNPAs in addition to GaInNAs. What is necessary is just to provide the active layer which consists of a quantum well structure which used the -V group mixed crystal semiconductor for the well layer.

  A surface emitting laser element having an active layer having a quantum well structure using a III-V mixed crystal semiconductor containing N or As as a well layer oscillates oscillation light in the range of 1.1 to 1.6 μm. The oscillation light propagates through the silica-based fiber with low loss and passes through the Si substrate with low absorption.

  A surface emitting laser device having an active layer having a quantum well structure using a III-V mixed crystal semiconductor containing N or As as a well layer is fabricated on a GaAs substrate, has a good temperature characteristic, and is refracted. In order to obtain a large difference in rate, the semiconductor distributed Bragg reflector made of AlGaAs / GaAs or AlAs / GaAs that can increase the reflectivity is used.

  Furthermore, since a surface emitting laser element including an active layer having a quantum well structure using a III-V group mixed crystal semiconductor containing N or As as a well layer has a long oscillation wavelength, the surface-emitting laser element having a particularly high thermal conductivity is used. The semiconductor distributed Bragg reflector made of a combination of AlAs / GaAs is used.

  FIG. 22 is a schematic view of an image forming apparatus according to the present invention. Referring to FIG. 22, image forming apparatus 800 includes surface emitting laser array 801, lenses 802 and 804, polygon mirror 803, and photoconductor 805.

  The surface emitting laser array 801 emits a plurality of beams. The lens 802 guides a plurality of beams emitted from the surface emitting laser array 801 to the polygon mirror 803.

  The polygon mirror 803 rotates clockwise at a predetermined speed, scans a plurality of beams received from the lens 802 in the main scanning direction and the sub-scanning direction, and guides them to the lens 804. The lens 804 guides a plurality of beams scanned by the polygon mirror 803 to the photoconductor 805.

  As described above, the image forming apparatus 800 uses the same optical system including the lenses 802 and 804 and the polygon mirror 803 for the plurality of beams from the surface emitting laser array 801, rotates the polygon mirror 803 at a high speed, and sets the dot position. Light is condensed on a photoconductor 805 as a surface to be scanned as a plurality of light spots separated in the sub-scanning direction by adjusting the lighting timing.

  FIG. 23 is a plan view of the surface emitting laser array 801 shown in FIG. Referring to FIG. 23, surface emitting laser array 801 has a structure in which m × n surface emitting laser elements 8011 are arranged in a substantially parallelogram. More specifically, the surface emitting laser array 801 is composed of 40 surface emitting laser elements 8011 arranged in four columns in the vertical direction and ten columns in the horizontal direction. The surface emitting laser element 8011 is composed of any one of the surface emitting laser elements 10, 10A, and 10C.

  If the distance between two adjacent surface-emitting laser elements 8011 in the vertical direction is d, the recording density is determined by d / n. Accordingly, the surface emitting laser array 801 determines the interval d and the number n of arrangements in the main scanning direction in consideration of the recording density.

  In FIG. 23, 40 surface emitting laser elements 8011 are arranged at an interval d of 40 μm in the sub-scanning direction, at an interval of 40 μm in the main scanning direction, and shifted by 10 μm in the sub-scanning direction as going to the main scanning direction. Is done.

  Then, by adjusting the lighting timing of the 40 surface emitting laser elements 8011, 40 dots can be written on the photoconductor 805 at regular intervals in the sub-scanning direction.

  When the magnification of the optical system is the same, writing can be performed with higher density as the distance d in the sub-scanning direction of the surface emitting laser array 801 is narrower. Since the surface-emitting laser element 8011 is composed of any one of the surface-emitting laser elements 10, 10A, and 10C, the surface-emitting laser array 801 has a plurality of non-oxidized regions 7a, 71a, and 77a having a size distribution of ± 5% or less. A plurality of lights produced by a surface emitting laser element and having a uniform output can be emitted. As a result, the image forming apparatus 300 can perform uniform writing.

  In addition, 40 dots can be written simultaneously, and high-speed printing is possible. Further, higher speed printing is possible by increasing the number of arrays.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims for patent.

The present invention is applied to a semiconductor oxidation apparatus capable of making the size of a non-oxidized region in a wafer uniform. The present invention is also applied to a method for manufacturing a surface emitting laser element capable of making the dimensions of non-oxidized regions in a wafer uniform. Furthermore, the present invention is applied to a surface-emitting laser array including a surface-emitting laser element manufactured by a method for manufacturing a surface-emitting laser element capable of making the dimensions of non-oxidized regions in a wafer uniform. Furthermore, the present invention is applied to an optical transmission system including a surface-emitting laser element or a surface-emitting laser array manufactured by a method for manufacturing a surface-emitting laser element that can make the dimensions of non-oxidized regions in a wafer uniform. Furthermore, the present invention is applied to an image forming apparatus including a surface-emitting laser element or a surface-emitting laser array manufactured by a method for manufacturing a surface-emitting laser element that can make the dimensions of a non-oxidized region in a wafer uniform.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic of the semiconductor oxidation apparatus by Embodiment 1 of this invention. It is a top view of the heating table and heater shown in FIG. It is sectional drawing of the semiconductor sample shown in FIG. It is a figure which shows the relationship between an oxidation rate and a film thickness. It is sectional drawing which shows the arrangement | positioning relationship between a semiconductor sample and a heater. It is a schematic sectional drawing of the surface emitting laser element which the semiconductor oxidation apparatus shown in FIG. FIG. 7 is a first process chart showing a method for manufacturing the surface emitting laser element shown in FIG. 6. FIG. 7 is a second process diagram showing a method for manufacturing the surface emitting laser element shown in FIG. 6. 3 is a plan view showing an oxidation process of a selective oxidation layer 7. FIG. It is the top view and sectional drawing of a semiconductor sample. FIG. 6 is another schematic cross-sectional view of the surface emitting laser element to be oxidized by the semiconductor oxidation apparatus shown in FIG. 1. FIG. 2 is a schematic cross-sectional view of an edge-emitting laser element to be oxidized by the semiconductor oxidation apparatus shown in FIG. 1. FIG. 3 is a schematic diagram of a semiconductor oxidation apparatus according to a second embodiment. It is a top view of the lamp | ramp shown in FIG. It is a schematic sectional drawing of the surface emitting laser element which the semiconductor oxidation apparatus shown in FIG. FIG. 5 is a schematic diagram of a semiconductor oxidation apparatus according to a third embodiment. It is a top view of the heating table and heater shown in FIG. FIG. 6 is a schematic diagram of a semiconductor oxidation apparatus according to a fourth embodiment. It is a top view of the surface emitting laser array by this invention. 1 is a schematic diagram of an optical transmission system according to the present invention. It is another schematic diagram of the optical transmission system according to the present invention. 1 is a schematic view of an image forming apparatus according to the present invention. It is a top view of the surface emitting laser array shown in FIG. It is a figure which shows the conventional semiconductor oxidation apparatus which performs an oxidation process.

Explanation of symbols

  1, 1A, 51, 501 substrate, 2, 2A, 6, 6A reflective layer, 3, 3A, 5, 5A resonator spacer layer, 4, 4A, 54 active layer, 7, 56, 71, 77 selective oxidation layer, 7a, 56a, 71a, 77a Non-oxidized region, 7b, 56b, 71b, 77b Oxidized region, 8 contact layer, 9 Insulating resin, 10, 10A, 10C, 51-5n, 502, 8011 Surface emitting laser element, 10B End surface Light emitting laser element, 11 p-side electrode, 12 n-side electrode, 21, 21A, 61, 61A low refractive index layer, 22, 22A, 62, 62A high refractive index layer, 31-3n resist pattern, 41-4n, 50 stack Body, 52, 57 cladding layer, 53, 55 guide layer, 58 upper electrode, 59 lower electrode, 100, 200, 300, 400, 900 semiconductor oxidation device, 101, 01, 301, 401, 901 Reaction vessel, 102, 202, 302 Base, 103, 203, 303 Heating table, 104, 304, 403 Rotating shaft, 105, 105A, 105B, 305, 305A, 305B, 904 Heater, 106 , 205, 205a, 205b, 205c, 306 Temperature detector, 107, 206, 307, 402, 903 Sample holder, 108, 207, 308, 905 Introduction pipe, 109, 208 Reservoir, 110, 112, 115-117, 124, 126, 209, 211, 214 to 216, 223, 225, 310 to 313, 321, 407 to 410, 418 piping, 111, 210 liquid mass flow controller, 113, 118, 212, 217, 314, 315, 411 412 Mass Flow Control 114, 213 Vaporizer, 119 to 121, 218 to 220, 316 to 318, 413 to 415 Valve, 122, 221, 319, 416, 906 Exhaust pipe, 123, 222, 320, 417 Water collector, 125 , 224 Exhaust pump, 127, 226, 322, 419 Control unit, 128, 323, 420 Arrow, 130, 230, 430 Water, 140, 240, 440, 910 Semiconductor sample, 141 Wafer, 141A Outer part, 141B Inner part , 142 semiconductor layer, 204, 405, 2041 to 2047 lamp, 309, 406 bubbler, 404 lamp house, 500, 801 surface emitting laser array, 600, 700 optical transmission system, 601 602 board, 601A, 602A, 701A, 702A One main surface, 603, 606 703, 705 Surface emitting laser array, 604, 607 Optical fiber group, 605, 608, 704, 706 Light receiving element, 701, 702 Si substrate, 800 Image forming apparatus, 802, 804 Lens, 803 Polygon mirror, 805 Photoconductor, 902 Heating Stage, 6041, 6071 optical fiber.

Claims (16)

A reaction vessel;
A support base installed in the reaction vessel and supporting the sample;
A plurality of heating devices each heating the sample via the support;
A supply unit for supplying an oxidizing material into the reaction vessel;
A semiconductor oxidation apparatus comprising: a control unit that controls the plurality of heating devices so as to heat the sample to a suitable temperature that suppresses a distribution of an oxidation rate in an in-plane direction of the sample to a reference value or less.   2. The semiconductor oxidation apparatus according to claim 1, wherein the control unit controls the plurality of heating devices to heat the sample to a suitable temperature that cancels the distribution of the oxidation rate based on factors other than the temperature of the sample. .   The semiconductor oxidation device according to claim 1, wherein the plurality of heating devices are divided and arranged in a direction from the center of the support base toward the outer periphery.   The semiconductor oxidation apparatus according to any one of claims 1 to 3, wherein the suitable temperature is a temperature determined based on an experimental result.   5. The semiconductor oxidation apparatus according to claim 1, wherein each of the plurality of heating devices is a resistance heater. 6.   5. The semiconductor oxidation apparatus according to claim 1, wherein each of the plurality of heating devices is a lamp heater. A first reflective layer composed of a semiconductor distributed black reflector, a first resonator spacer layer, an active layer, a second resonator spacer layer, and a second reflective layer composed of the semiconductor distributed black reflector are sequentially formed on the wafer. A first step of stacking;
A second step of forming a plurality of surface emitting laser elements on the wafer by etching the active layer, the second resonator spacer layer, and the active layer into a mesa shape;
A third step of setting the wafer on a support in the reaction vessel;
A fourth step of supplying an oxidizing material into the reaction vessel;
The wafer is heated to a suitable temperature at which the distribution of oxidation rates in the plurality of selectively oxidized layers included in the plurality of second reflective layers of the plurality of surface-emitting laser elements formed on the wafer is below a reference value. And a step of manufacturing the surface-emitting laser element.   8. The method of manufacturing a surface emitting laser element according to claim 7, wherein the fifth step heats the wafer to the suitable temperature that cancels the distribution of the oxidation rate based on factors other than the temperature of the wafer.   9. The method for manufacturing a surface emitting laser element according to claim 8, wherein the suitable temperature is a temperature determined based on an experimental result.   The surface light emission according to any one of claims 7 to 9, wherein in the fifth step, the wafer is heated to the favorable temperature by a plurality of heating devices arranged in a radial direction of the wafer. A method for manufacturing a laser element.   The method of manufacturing a surface emitting laser element according to claim 10, wherein each of the plurality of heating devices is a resistance heater.   The method of manufacturing a surface emitting laser element according to claim 10, wherein each of the plurality of heating devices is a lamp heater.   The method of manufacturing a surface emitting laser element according to claim 7, wherein the active layer includes a GaInNAs-based material. A substrate,
A plurality of surface emitting laser elements formed on the substrate,
Each of these surface emitting laser elements is a surface emitting laser array which is a surface emitting laser element manufactured by the manufacturing method of the surface emitting laser element of any one of Claims 7-13.   An optical transmission system comprising a surface-emitting laser element manufactured by the method for manufacturing a surface-emitting laser element according to any one of claims 7 to 13 or the surface-emitting laser array according to claim 14 as a light source.   An image forming apparatus comprising a surface-emitting laser element manufactured by the method for manufacturing a surface-emitting laser element according to claim 7 or a surface-emitting laser array according to claim 14 as a light source.