JP2012191013A - Multi-wavelength light-emitting element and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-wavelength light-emitting element that can be manufactured efficiently.SOLUTION: A multi-wavelength light-emitting element 100 includes: a substrate 110 including on a surface, first and second crystal growth planes 121 and 122 whose plane orientations are different from each other; a first semiconductor layer 131 formed by crystal growth of a semiconductor from the first crystal growth plane 121 on the substrate 110; a first semiconductor light-emitting layer 151 formed by crystal growth of a semiconductor on the first semiconductor layer 131; a second semiconductor layer 132 which is formed by crystal growth of a semiconductor from the second crystal growth plane 122 on the substrate 110 and whose main surface is the crystal plane different from a main surface of the first semiconductor layer 131; and a second semiconductor light-emitting layer 152 formed by crystal growth of a semiconductor whose component element is the same as the semiconductor forming the first semiconductor light-emitting layer 151 and whose element composition ratio is different from that of the semiconductor included in the first semiconductor light-emitting layer 151.

Description

  The present invention relates to a multi-wavelength light emitting device and a method for manufacturing the same.

  Various multi-wavelength light emitting devices have been proposed in which a plurality of semiconductor light emitting layers having different emission wavelengths are formed on the same substrate.

  For example, in Patent Document 1, at least one light emitting diode portion made of a GaP-based, AlGaAs-based, or AlGaInP-based compound semiconductor is stacked on the same substrate, and light emission made of a GaN-based compound semiconductor is formed on the light-emitting diode portion. A multi-wavelength light emitting element in which one or more diode portions are stacked is disclosed.

  In Patent Document 2, at least two types of semiconductor light emitting elements are formed on one substrate material, and a plurality of types of phosphors that react to the emission wavelength of each element are applied on each semiconductor light emitting element, A multi-wavelength light-emitting device that emits visible light having a wide range of emission wavelengths by simultaneously emitting the semiconductor light-emitting elements is disclosed.

JP-A-9-55538 JP 2008-71805 A

  In the technique described in Patent Document 1, in order to stack a plurality of semiconductor layers having different emission wavelengths, it is necessary to form the plurality of semiconductor layers in separate steps. In the technique described in Patent Document 2, after forming the first semiconductor light emitting element on the substrate, the second semiconductor light emitting element is formed in a separate process.

  An object of the present invention is to provide a multi-wavelength light emitting device capable of efficient manufacture and a method for manufacturing the same.

The multi-wavelength light emitting device of the present invention is
A substrate having first and second crystal growth planes having different plane orientations on the surface, and first and second light emitting regions corresponding to the first and second crystal growth planes;
A first semiconductor layer provided to be stacked on the first light emitting region on the substrate and formed by crystal growth of a semiconductor from the first crystal growth surface;
A first semiconductor light emitting layer configured to be laminated on the first semiconductor layer and emitting light of a predetermined wavelength formed by crystal growth of a semiconductor;
A crystal plane different from the main surface of the first semiconductor layer, which is provided so as to be stacked on the second light emitting region on the substrate and is formed by crystal growth of a semiconductor starting from the second crystal growth plane. A second semiconductor layer as a main surface;
A semiconductor having the same constituent element as that of the semiconductor forming the first semiconductor light emitting layer and having a different element composition ratio is formed by crystal growth and / or formed on the second semiconductor layer; and / or The wavelength of light emitted from the first semiconductor light-emitting layer, which is formed by crystal growth of a semiconductor having the same constituent element as the semiconductor forming the first semiconductor light-emitting layer and has a layer thickness different from that of the first semiconductor light-emitting layer A second semiconductor light emitting layer that emits light of a different wavelength from
Is provided.

The method for producing the multi-wavelength light emitting device of the present invention includes:
Preparing a substrate having first and second crystal growth surfaces having different plane orientations on the surface;
A first semiconductor layer that forms a first light emitting region on the substrate to form a first semiconductor layer by crystal growth of the semiconductor starting from the first crystal growth surface of the substrate prepared in the preparation step Forming process;
Different from the main surface of the first semiconductor layer so that the second light emitting region is formed and stacked on the substrate by crystal growth of the semiconductor starting from the second crystal growth surface of the substrate prepared in the preparation step. A second semiconductor layer forming step of forming a second semiconductor layer having a crystal plane as a main surface;
At the same time as forming the first semiconductor light emitting layer for emitting light of a predetermined wavelength by crystal growth of the semiconductor so as to be laminated on the first semiconductor layer formed in the first semiconductor layer forming step, the second semiconductor layer formation is performed. A semiconductor having the same constituent element as that of the semiconductor forming the first semiconductor light emitting layer and having a different element composition ratio is crystal-grown so as to be stacked on the second semiconductor layer formed in the process and / or the first semiconductor layer is formed. A semiconductor having the same constituent elements as the semiconductor forming the semiconductor light emitting layer is crystal-grown so as to have a layer thickness different from that of the first semiconductor light emitting layer, so that the wavelength of light emitted by the first semiconductor light emitting layer is different. First and second semiconductor light emitting layer forming steps for forming a second semiconductor light emitting layer that emits light of a wavelength;
Is provided.

  According to the present invention, on the first and second semiconductor layers formed by crystal growth of the semiconductor from the first and second crystal growth planes having different plane orientations, the main plane crystal planes are different from each other. Even if a semiconductor having the same constituent element and different element composition ratio is crystal-grown and / or a semiconductor having the same constituent element is crystal-grown with a different layer thickness, the first and second emission wavelengths are different. Since the two semiconductor light-emitting layers can be formed, the first and second semiconductor light-emitting layers can be formed in the same process, and thus the multi-wavelength light-emitting element can be efficiently manufactured.

It is a top view of the multiwavelength light emitting element concerning an embodiment. It is II-II sectional drawing in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. (A)-(d) is sectional drawing of the specific example of a board | substrate and the 1st-3rd u <-> semiconductor layer. (A)-(f) is explanatory drawing of the manufacturing method of the multiwavelength light emitting element which concerns on embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(Multi-wavelength light emitting device)
1 to 3 show a multiwavelength light emitting device 100 according to the present embodiment.

<Board>
The multi-wavelength light emitting device 100 according to this embodiment includes a substrate 110 serving as a base.

Examples of the substrate 110 include a sapphire substrate and a SiC substrate. Of these, a sapphire substrate which is a single crystal substrate having an Al ₂ O ₃ corundum structure is preferable from the viewpoint of versatility. The main surface of the substrate 110 (the surface perpendicular to the thickness direction of the substrate) is the a-plane <{11-20} plane> in which the normal direction is the a-axis, and the normal direction is the c-axis. Any c-plane <{0001} plane> and m-plane <{1-100} plane> whose normal direction is the m-axis may be used, and r-plane <{1-102} plane>, Other crystal planes such as n-plane <{11-23} plane> may be used. Further, the main surface of the substrate 110 may be a miscut surface in which the a-axis or the like is inclined at a predetermined angle (eg, 45 °, 60 °, or a slight angle within several degrees) with respect to the normal direction of the main surface. Good. That is, the substrate 110 may be a miscut substrate. The plane directions of the a-plane, c-plane, and m-plane are orthogonal to each other.

  The substrate 110 has first to third crystal growth surfaces 121 to 123 having different surface orientations on the surface, and the first to third corresponding to the first to third crystal growth surfaces 121 to 123. Light emitting areas A1 to A3 are configured. The substrate 110 has only first and second crystal growth surfaces 121 and 122 having different surface orientations on the surface, and the first and second crystal growth surfaces 121 and 122 corresponding to the first and second crystal growth surfaces 121 and 122 are provided. Two light emitting areas A1 and A2 may be configured. The substrate 110 has a crystal growth surface having a surface orientation different from that of the first to third crystal growth surfaces 121 to 123 on the surface, and one or more light emitting regions corresponding to the crystal growth surface are formed. Also good. That is, more than three light emitting regions may be configured.

  The first to third crystal growth surfaces 121 to 123 are angled (typically, the main surface of the substrate 110, one side surface of the first groove 111 formed in the substrate 110, and the direction in which the first groove 111 extends). 90 °) and extending from one side surface of the second concave groove 112. The first and second concave grooves 111 and 112 may be U-shaped grooves, V-shaped grooves, or trapezoidal grooves as long as they have side surfaces. The first and second concave grooves 111 and 112 have, for example, a groove opening width of 0.5 to 10 μm, a groove depth of 0.75 to 100 μm, and an angle formed with respect to the main surface of the groove side surface of 70 to 120 °. It is. Only one of the first and second concave grooves 111 and 112 may be formed, or a plurality of the first and second concave grooves 111 and 112 may be formed to extend in parallel with an interval between each other. In the latter case, the groove interval is, for example, 1 to 100 μm. The first to third crystal growth surfaces 121 to 123 may be configured by other concave side surfaces or convex or convex side surfaces.

  Specifically, for example, when the substrate 110 is a sapphire substrate, the first crystal growth surface 121 is a main surface of the substrate 110 and the second crystal growth surface 122 is as shown in FIG. One side surface of the first groove 111 that is a trapezoidal groove extending in the m-axis direction and the second groove 112 that is a trapezoidal groove in which the third crystal growth surface 123 extends in the c-axis direction perpendicular to the first groove 111. As shown in FIG. 4B, the first crystal growth surface 121 is a c-plane which is the main surface of the substrate 110, and the second crystal growth surface 122 is a trapezoid extending in the m-axis direction. One side surface of the first concave groove 111 that is a groove and one side surface of the second concave groove 112 that is a trapezoidal groove in which the third crystal growth surface 123 extends in the a-axis direction perpendicular to the first concave groove 111. As shown in the second configuration, FIG. 4C, the first crystal growth surface 121 is the main surface of the substrate 110. The n-plane, the c-plane which is one side surface of the first groove 111 which is a trapezoidal groove in which the second crystal growth surface 122 extends in the m-axis direction, and the third crystal growth surface 123 are orthogonal to the first groove 111. A third configuration which is one side surface of the second concave groove 112 which is a trapezoidal groove extending in the direction, and an r-plane in which the first crystal growth surface 121 is the main surface of the substrate 110 as shown in FIG. The second crystal growth surface 122 is a trapezoidal groove extending in the direction orthogonal to the first concave groove 111, and one side surface of the first concave groove 111, which is a trapezoidal groove extending in the a-axis direction. The 4th structure which is one side surface of the 2nd ditch | groove 112 is mentioned.

<First to third u-semiconductor layers>
The multi-wavelength light emitting device 100 according to this embodiment includes first to third u− semiconductor layers 131 to 133 provided to be stacked in the first to third light emitting regions A1 to A3 on the substrate 110. . These first to third u− semiconductor layers 131 to 133 are formed by crystal growth of undoped semiconductors starting from the first to third crystal growth surfaces 121 to 123, respectively.

  Examples of the semiconductor forming the first to third u− semiconductor layers 131 to 133 include GaN, InGaN, and AlGaN. The first to third u− semiconductor layers 131 to 133 may be formed of the same semiconductor or may include different semiconductors. The thickness of the first to third u− semiconductor layers 131 to 133 is, for example, 2 to 100 μm.

  The first u− semiconductor layer 131 may have a crystal plane that is the same as the crystal plane of the main surface of the substrate 110 as a main surface, or may have a crystal plane that is different from the crystal plane of the main surface of the substrate 110 as a main surface. The second u − semiconductor layer 132 has a crystal plane different from the main surface of the first semiconductor layer as the main surface. The third u− semiconductor layer 133 has a crystal plane different from the main surfaces of the first and second semiconductor layers as a main surface.

  Specifically, when the semiconductor forming the first to third u− semiconductor layers 131 to 133 is GaN, in the first configuration, as shown in FIG. 4A, the substrate that is the first crystal growth surface 121. The undoped GaN crystal grows starting from the a-plane of the main surface of 110, and the first u-semiconductor layer 131 has the c-plane as the main surface, and the extending direction of the first groove 111 is the a-axis direction, and The first u-GaN layer 131 in which the extending direction of the second groove 112 is the m-axis direction is formed, and undoped GaN is formed from one side surface of the first groove 111 that is the second crystal growth surface 122. The crystal grows, and the second u− semiconductor layer 132 has an m-plane as a main surface, the extending direction of the first groove 111 is the a-axis direction, and the extending direction of the second groove 112 is the c-axis direction. A second u-GaN layer 132 is formed and further The undoped GaN crystal grows starting from one side surface of the second concave groove 112 which is the crystal growth surface 123, and the third u-semiconductor layer 133 has the a-plane as the main surface and extends the first concave groove 111. A third u-GaN layer 133 is formed in which the direction is the m-axis direction and the direction in which the second groove 112 extends is the c-axis direction.

  In the case of the second configuration, as shown in FIG. 4B, undoped GaN grows from the c-plane of the main surface of the substrate 110, which is the first crystal growth surface 121, to form the first u-semiconductor layer 131. The c-plane (or m-plane) is the main surface, the extending direction of the first groove 111 is the a-axis direction, and the extending direction of the second groove 112 is the m-axis (or c-axis) direction. The 1u-GaN layer 131 is formed, and undoped GaN grows from one side surface of the first concave groove 111 which is the second crystal growth surface 122, and the m-plane is formed as the second u-semiconductor layer 132. A second u-GaN layer 132 is formed which has a main surface, the first groove 111 extends in the a-axis direction, and the second groove 112 extends in the c-axis direction. Starting from one side surface of the second concave groove 112 that is the growth surface 123 As the third u-GaN layer 133, the undoped GaN crystal grows, the c-plane is the main surface, the extending direction of the first groove 111 is the m-axis direction, and the extending direction of the second groove 112 is A third u-GaN layer 133 that is in the a-axis direction is formed.

  In the case of the third configuration, as shown in FIG. 4C, undoped GaN grows from the n-plane of the main surface of the substrate 110, which is the first crystal growth surface 121, to form the first u-semiconductor layer 131. A first u-GaN layer 131 having a c-plane as a main surface, the first groove 111 extending in the a-axis direction, and the second groove 112 extending in the m-axis direction is formed. The undoped GaN crystal grows starting from one side surface of the first groove 111 which is the second crystal growth surface 122, and the semipolar {0-101} plane is the main surface as the second u− semiconductor layer 132. In addition, a second u-GaN layer 132 is formed in which the extending direction of the first concave groove 111 is the a-axis direction and the extending direction of the second concave groove 112 is an intermediate direction between the c-axis and the m-axis, One of the second concave grooves 112 which is the third crystal growth surface 123 The undoped GaN crystal grows starting from the side surface, and the third u-semiconductor layer 133 has a crystal plane intermediate between the a plane and the c plane as the main plane, and the extending direction of the first concave groove 111 is the m-axis direction. In addition, the third u-GaN layer 133 is formed in which the extending direction of the second groove 112 is an intermediate direction between the a-axis and the c-axis.

  In the case of the fourth configuration, as shown in FIG. 4D, undoped GaN crystal grows from the r-plane of the main surface of the substrate 110 which is the first crystal growth surface 121, and the first u− semiconductor layer 131 is formed. , A first u-GaN layer 131 is formed in which the a-plane is the main surface, the extending direction of the first groove 111 is the m-axis direction, and the extending direction of the second groove 112 is the c-axis direction. The undoped GaN crystal grows starting from one side surface of the first concave groove 111 which is the second crystal growth surface 122, and the {11-22} plane is the main surface as the second u− semiconductor layer 132, A second u-GaN layer 132 is formed in which the direction in which the first groove 111 extends is the m-axis direction and the direction in which the second groove 112 extends is an intermediate direction between the a-axis and the c-axis. One side surface of the second groove 112 which is the crystal growth surface 123 is Undoped GaN crystal grows as a starting point, and the third u-semiconductor layer 133 has an m-plane as a main surface, the extending direction of the first groove 111 is the c-axis direction, and the extending direction of the second groove 112 A third u-GaN layer 133 is formed in the direction of the a-axis.

  A low temperature buffer layer having a thickness of about 20 to 30 nm may be provided between the substrate 110 and the first to third u− semiconductor layers 131 to 133. In addition, it is expected that the heights of the first to third u− semiconductor layers 131 to 133 configured as described above are not aligned with difficulty in crystal growth, and in that case, the heights may be aligned by performing polishing or the like. .

<First to third n-type semiconductor layers>
The multi-wavelength light emitting device 100 according to the present embodiment includes first to third n-type semiconductor layers 141 to 143 provided to be stacked on the first to third u− semiconductor layers 131 to 133. The first to third n-type semiconductor layers 141 to 143 are formed by epitaxially growing a semiconductor doped with an n-type dopant, starting from the main surface of the first to third u− semiconductor layers 131 to 133. It is a thing. Therefore, the first to third n-type semiconductor layers 141 to 143 have the same crystal plane as the main surface of the first to third u− semiconductor layers 131 to 133 as the main surface.

  Examples of the semiconductor constituting the first to third n-type semiconductor layers 141 to 143 include GaN, InGaN, and AlGaN. The first to third n-type semiconductor layers 141 to 143 may be composed of the same semiconductor, or may be composed of different semiconductors.

Examples of the n-type dopant contained in the first to third n-type semiconductor layers 141 to 143 include Si, Ge, and the like. The concentration of the n-type dopant is, for example, 1.0 × 10 ^{17 to} 20 × 10 ¹⁷ / cm ³ .

  The first to third n-type semiconductor layers 141 to 143 may be composed of a single layer, or may be composed of a plurality of layers having different types and concentrations of n-type dopants. The thickness of the first to third n-type semiconductor layers 141 to 143 is, for example, 2 to 10 μm.

<First to third light emitting layers>
The multi-wavelength light emitting device 100 according to the present embodiment includes first to third light emitting layers 151 to 153 provided to be stacked on the first to third n-type semiconductor layers 141 to 143. These first to third light emitting layers 151 to 153 are formed by epitaxially growing a semiconductor from the main surface of the first to third n-type semiconductor layers 141 to 143, respectively. Accordingly, the first to third light emitting layers 151 to 153 have the same crystal plane as the main surface of the first to third n-type semiconductor layers 141 to 143 and the first to third u− semiconductor layers 131 to 133. .

  The first to third light emitting layers 151 to 153 have an alternately stacked structure of first to third well layers (first to third semiconductor light emitting layers) 151a to 153a and first to third barrier layers 151b to 153b. It is composed of multiple quantum well layers. The number of layers of the first to third well layers 151a to 153a and the first to third barrier layers 151b to 153b is, for example, 5 to 15.

  Examples of the semiconductor forming the first to third well layers 151a to 153a include InGaN, InGaAlN, and the like. The thickness of the first to third well layers 151a to 153a is, for example, 1 to 20 nm.

  Examples of the semiconductor forming the first to third barrier layers 151b to 153b include GaN, InGaN (however, larger than the band gap of the first to third well layers 151a to 153a). The thickness of the first to third barrier layers 151b to 153b is, for example, 5 to 20 nm.

  In the first to third light emitting layers 151 to 153, the first to third well layers 151a to 153a are made of the same constituent element (for example, the constituent elements are the same for In, Ga, and N). In addition to being formed, the first to third barrier layers 151b to 153b are also formed by crystal growth of a semiconductor made of the same constituent element (for example, the constituent elements are the same in Ga and N). Yes. The first to third well layers 151a to 153a are first to third n-type semiconductor layers 141 to 143 having crystal planes different from each other as main surfaces, and accordingly, main surfaces of the first to third u− semiconductor layers 131 to 133 Since the same crystal plane as the main surface is used, for example, when it is formed of InGaN, the efficiency of incorporation of InN into the layer (InN mixed crystal ratio) is different, so that the elemental composition ratios are different from each other. Therefore, and / or the layer thicknesses are different from each other, and as a result, they are configured to emit light having different wavelengths.

  The first to third light emitting layers 151 to 153 may be configured to emit R (red), G (green), and (blue) light, for example. Thus, a one-chip white light emitting element (white LED) can be configured.

<First to third p-type semiconductor layers>
The multi-wavelength light emitting device 100 according to the present embodiment includes first to third p-type semiconductor layers 161 to 163 provided to be stacked on the first to third light emitting layers 151 to 153.

  Examples of the semiconductor constituting the first to third p-type semiconductor layers 161 to 163 include GaN, InGaN, and AlGaN. The first to third p-type semiconductor layers 161 to 163 may be composed of the same semiconductor, or may be composed of different semiconductors.

Examples of the p-type dopant contained in the first to third p-type semiconductor layers 161 to 163 include Mg and Cd. The free hole concentration measured by the Hall effect measurement is, for example, 2.0 × 10 ¹⁷ to 10 × 10 ¹⁷ / cm ³ .

  The first to third p-type semiconductor layers 161 to 163 may be composed of a single layer, or may be composed of a plurality of layers having different types and concentrations of the p-type dopant. The thickness of the first to third p-type semiconductor layers 161 to 163 is, for example, 50 to 200 nm.

<N-type electrode and p-type electrode>
The multi-wavelength light emitting device 100 according to the present embodiment includes first to third n-type electrodes 171 to 173 and first to first electrodes provided to be electrically connected to the first to third n-type semiconductor layers 141 to 143. First to third p-type electrodes 181 to 183 are provided so as to be electrically connected to the 3p-type semiconductor layers 161 to 163.

  Examples of the constituent electrode material of the first to third n-type electrodes 171 to 173 include a laminated structure such as Ti / Al, Ti / Al / Mo / Au, and Hf / Au, or an alloy. The thicknesses of the first to third n-type electrodes 171 to 173 are, for example, Ti / Al (10 nm / 500 nm).

  Examples of the first to third p-type electrodes 181 to 183 include a laminated structure such as Pd / Pt / Au, Ni / Au, and Pd / Mo / Au, an alloy, or an oxide such as ITO (indium tin oxide). System transparent conductive material. Note that pad electrodes for wire bonding are necessary on the first to third p-type electrodes 181 to 183, and in many cases, the same material system as that of the first to third n-type electrodes 171 to 173 is used. The thickness of the first to third p-type electrodes 181 to 183 is, for example, 10 to 200 nm in the case of ITO.

(Manufacturing method of multi-wavelength light emitting device)
Next, a method for manufacturing the multi-wavelength light emitting device 100 according to the present embodiment will be described with reference to FIGS. In the manufacturing method of the multi-wavelength light emitting device 100 according to the following embodiment, u-GaN layers as first to third u-semiconductor layers 131 to 133 on the wafer 110 '(substrate 110), first to third n-type. N-type GaN layer doped with Si as the semiconductor layers 141 to 143, multiple quantum well layers as the first to third light emitting layers 151 to 153 (first to third well layers 151a to 153a: InGaN layers, first to first Third barrier layers 151b to 153b: GaN layers) and Mg-doped p-type GaN layers as first to third p-type semiconductor layers 161 to 163 are sequentially formed, and then first to third n-type semiconductor layers are formed. For example, the first to third n-type electrodes 171 to 173 and the first to third p-type electrodes 181 to 183 are formed on the GaN layers 141 to 143 and the first to third p-type GaN layers 161 to 163, respectively. .

<Wafer (substrate) preparation process>
In the formation region of each multi-wavelength light emitting element 100 on the wafer 110 ′, as shown in FIG. 5A, the photoresist patterning is formed so that only the groove formation planned portion becomes an opening. As shown in FIG. 2B, the photoresist 200 is etched using the photoresist 200 as an etching resist to form the first and second concave grooves 111 and 112 on the surface of the wafer 110 ′, and then the photoresist 200 is removed.

  At this time, in the formation region of each multi-wavelength light emitting device 100 of the wafer 110 ′, the main surface of the substrate 110 and the second crystal growth surface 122 are the first crystal growth surfaces 121 having different plane orientations on the surface. One side surface of the first concave groove 111 and one side surface of the second concave groove 112 that is the third crystal growth surface 123 are exposed.

<Semiconductor layer formation process>
The following methods for forming each semiconductor layer include metal organic vapor phase epitaxy (MOVPE), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (Hyride Vapor Phase Epitaxy). HVPE) and the like, and among these, metalorganic vapor phase epitaxy is the most common. Below, the formation method of each semiconductor layer using a metal organic chemical vapor deposition method is demonstrated.

  The MOVPE apparatus used for forming each semiconductor layer includes a wafer transfer system, a wafer heating system, a gas supply system, and a gas exhaust system, which are electronically controlled. The wafer heating system is composed of a thermocouple, a resistance heater, and a carbon or SiC susceptor provided thereon. The MOVPE apparatus is configured so that a semiconductor layer is crystal-grown by a reactive gas on a wafer 110 'set on a susceptor of a quartz tray to be conveyed in a wafer heating system.

-U-GaN layer formation process-
Using the MOVPE apparatus, the wafer 110 ′ having the first and second concave grooves 111 and 112 formed on the surface is set on a quartz tray so that the surface faces upward. And the pressure in the reaction vessel is set to 10 to 100 kPa, and H ₂ is circulated as a carrier gas in a flow channel installed in the reaction vessel, and this state is maintained for several minutes to thermally Clean it.

Next, the temperature of the wafer 110 ′ is set to 1050 to 1150 ° C., the pressure in the reaction vessel is set to 10 to 100 kPa, and the carrier gas H ₂ is circulated in the reaction vessel at a flow rate of about 10 L / min. As a reaction gas, a group V element supply source (NH ₃ ) and a group III element supply source (TMG) are flowed so that the respective supply flow rates are 0.1 to 5 L / min and 50 to 150 μmol / min.

  At this time, as shown in FIG. 5C, the crystal growth condition is selected so that the undoped GaN is stacked on the substrate 110 starting from the main surface of the substrate 110 which is the first crystal growth surface 121. The first u-GaN layer 131 is grown to form the first light emitting region A1. The second u-GaN layer 132 is formed by crystal growth so that undoped GaN is stacked on the substrate 110 starting from one side surface of the first concave groove 111 that is the second crystal growth surface 122. Thus, the second light emitting area A2 is configured. Further, the third u-GaN layer 133 is formed by crystal growth so that undoped GaN is stacked on the substrate 110 starting from one side surface of the second concave groove 112 which is the third crystal growth surface 123. Constitutes the third light emitting region A3.

  The first to third u-GaN layers 131 to 133 are formed by crystal growth starting from the first to third crystal growth surfaces 121 to 123, respectively, and thus have principal surfaces with different plane orientations. .

  The first to third u-GaN layers 131 to 133 may be formed by individually growing a crystal by selecting a crystal growth condition or by masking a portion where the crystal is not grown. Depending on selection, two or all of the first to third u-GaN layers 131 to 133 may be formed by crystal growth at the same time.

  In the case where the low temperature buffer layer is formed before the first to third u-GaN layers 131 to 133 are formed, the temperature of the wafer 110 ′ may be set to 400 to 500 ° C. and GaN may be grown. Further, a mask may be provided in a portion other than the first to third light emitting areas A1 to A3 in the wafer 110 '.

-N-type GaN layer formation process-
The pressure in the reaction vessel is 10 to 100 kPa, and the carrier gas H ₂ is in the reaction vessel at a flow rate of ₅ to 15 L / min (hereinafter, the gas flow rate is a value in a standard state (0 ° C., 1 atm)). As a reaction gas, a group V element supply source (NH ₃ ), a group III element supply source 1 (TMG), and an n-type doping element supply source (SiH ₄ ) are supplied as 0, respectively. . 1-5 L / min, 50-150 μmol / min, and 1-5 × 10 ⁻³ μmol / min.

  At this time, as shown in FIG. 5D, GaN doped with Si, which is an n-type dopant, starts from the main surface of the first to third u-GaN layers 131 to 133 by selecting crystal growth conditions. The first to third n-type GaN layers 141 to 143 are formed by epitaxial crystal growth so as to be stacked on the first to third u-GaN layers 131 to 133. Accordingly, the first to third n-type GaN layers 141 to 143 also have principal surfaces with different plane orientations, like the first to third u-GaN layers 131 to 133.

  The first to third n-type GaN layers 141 to 143 may be formed by crystal growth individually by selecting crystal growth conditions or by masking a portion where crystal growth is not performed. Depending on selection, two or all of the first to third n-type GaN layers 141 to 143 may be formed by crystal growth at the same time.

-Light emitting layer formation process-
The temperature of the wafer 110 ′ is set to about 800 ° C., the pressure in the reaction vessel is set to 10 k to 100 kPa, and the carrier gas N ₂ is circulated at a flow rate of ₅ to 15 L / min in the reaction vessel while the reaction gas is supplied there. As a group V element supply source (NH ₃ ), a group III element supply source 1 (TMG), and a group III element supply source 2 (TMI), the respective supply flow rates are 0.1 to 5 L / min, 5 to 15 μmol. / Min, and 2 to 30 μmol / min.

  At this time, by selecting the crystal growth conditions, epitaxial crystal growth is performed so that InGaN is stacked on the first to third n-type GaN layers 141 to 143 starting from the main surfaces of the first to third n-type GaN layers 141 to 143. Thus, the first to third well layers 151a to 153a are formed simultaneously.

Next, the group V element supply source (NH ₃ ) and the group III element supply source (TMG) are flowed so that the respective supply flow rates are 0.1 to 5 L / min and 5 to 15 μmol / min.

  At this time, by selecting the crystal growth conditions, epitaxial crystals are grown so that GaN is stacked on the first to third well layers 151a to 153a starting from the main surfaces of the first to third well layers 151a to 153a. The first to third barrier layers 151b to 153b are formed at the same time.

  Then, by repeating the same operation as described above, the first to third well layers 151a to 153a and the first to third barrier layers 151b to 153b are alternately stacked as shown in FIG. First to third light emitting layers 151 to 153 of the formed multiple quantum well layer are formed.

  Here, the first to third n-type semiconductor layers 141 to 143 whose main surfaces are different crystal planes of the first to third light emitting layers 151 to 153, and accordingly, the first to third u− semiconductor layers 131 to 133. Since the same crystal plane as the main surface is used as the main surface, the efficiency of incorporation of InN into the first to third well layers 151a to 153a in the first to third light emitting layers 151 to 153 is different. The elemental composition ratios are different from each other and / or the layer thicknesses are different from each other. As a result, the first to third light emitting layers 151 to 153 are configured to emit light having different wavelengths. The emission wavelengths of the first to third light emitting layers 151 to 153 depend on the well width (thickness) and the InN mixed crystal ratio of the first to third well layers 151a to 153a, but the higher the InN mixed crystal ratio, the higher the InN mixed crystal ratio. The emission wavelength is a long wavelength. The InN mixed crystal ratio is determined by the TMI molar flow rate / (TMG molar flow rate + TMI molar flow rate) and the growth temperature.

  As described above, according to the method for manufacturing the multi-wavelength light emitting device 100 according to the present embodiment, the semiconductor is formed by crystal growth from the first to third crystal growth surfaces 121 to 123 having different plane orientations. Even if semiconductors having the same constituent elements and different element composition ratios grow on the first to third u-GaN layers 131 to 133 whose main surface crystal planes are different from each other, and / or have the same configuration Since the first to third well layers 151a to 153a having different emission wavelengths can be formed even if the elemental semiconductor has different crystal thickness and crystal growth, the first to third semiconductor light emitting layers 151 to 153 are formed in the same process. Therefore, the multi-wavelength light emitting device 100 can be efficiently manufactured.

-Formation of p-type GaN layer-
The temperature of the wafer 110 ′ is 1000 to 1100 ° C., the pressure in the reaction vessel is 10 k to 100 kPa, and the carrier gas H ₂ is circulated at a flow rate of ₅ to 15 L / min in the reaction vessel. As a reaction gas, a group V element supply source (NH ₃ ), a group III element supply source 1 (TMG), a group III element supply source 3 (TMA), and a p-type doping element supply source (Cp ₂ Mg) are respectively used. Supply flow rate is 0.1 to 5 L / min, 50 to 150 μmol / min, 2 to 80 μmol / min, and 0.03 to 30 μmol / min.

  At this time, as shown in FIG. 5 (f), by selecting the crystal growth conditions, GaN doped with Mg, which is a p-type dopant, starts from the main surfaces of the first to third light emitting layers 151 to 153. The first to third p-type GaN layers 161 to 163 are formed by crystal growth so as to be stacked on the first to third light emitting layers 151 to 153.

<N-type electrode and p-type electrode formation step>
After the first to third n-type GaN layers 141 to 143 are exposed by partially reactive ion etching of the semiconductor layer formed on the wafer 110 ′, vacuum deposition, sputtering, CVD (Chemical Vapor Deposition), etc. The first to third n-type electrodes 171 to 173 on the first to third n-type GaN layers 141 to 143 and the first to third p-type electrodes 181 to 183 on the first to third p-type GaN layers 161 to 163 by the above method. Respectively.

  Then, the wafer 110 ′ is cleaved individually to produce the multi-wavelength light emitting device 100 according to this embodiment.

  The present invention is useful for a multi-wavelength light emitting device and a method for manufacturing the same.

100 Multi-wavelength light emitting device 110 Substrate 110 ′ Wafer 111 First concave groove 112 Second concave groove 121-123 First to third crystal growth surfaces 131-133 First to third u-semiconductor layers (first to third u-GaN layer)
141-143 First to third n-type semiconductor layers (first to third n-type GaN layers)
151-153 1st-3rd light emitting layer 151a-153a 1st-3rd well layer (1st-3rd semiconductor light emitting layer)
151b to 153b First to third barrier layers 161 to 163 First to third p-type semiconductor layers (first to third p-type GaN layers)
171 to 173 First to third n-type electrodes 181 to 183 First to third p-type electrodes 200 Photoresist A1 to A3 First to third light emitting regions

Claims (7)

A substrate having first and second crystal growth planes having different plane orientations on the surface, and first and second light emitting regions corresponding to the first and second crystal growth planes;
A first semiconductor layer provided to be stacked on the first light emitting region on the substrate and formed by crystal growth of a semiconductor from the first crystal growth surface;
A first semiconductor light emitting layer configured to be laminated on the first semiconductor layer and emitting light of a predetermined wavelength formed by crystal growth of a semiconductor;
A crystal plane different from the main surface of the first semiconductor layer, which is provided so as to be stacked on the second light emitting region on the substrate and is formed by crystal growth of a semiconductor starting from the second crystal growth plane. A second semiconductor layer as a main surface;
A semiconductor which is provided so as to be stacked on the second semiconductor layer and has the same constituent element as the semiconductor forming the first semiconductor light emitting layer and has a different element composition ratio is formed by crystal growth; and / or The light of the light emitted by the first semiconductor light-emitting layer is formed by crystal growth of a semiconductor having the same constituent element as the semiconductor forming the first semiconductor light-emitting layer and having a layer thickness different from that of the first semiconductor light-emitting layer. A second semiconductor light emitting layer that emits light of a wavelength different from the wavelength;
A multi-wavelength light emitting device comprising: The multi-wavelength light emitting device according to claim 1,
One of the said 1st and 2nd crystal growth surfaces is a multiwavelength light emitting element which is a side surface of the ditch | groove formed in the surface of the said board | substrate. The multi-wavelength light emitting device according to claim 2,
The multi-wavelength light emitting device, wherein the other of the first and second crystal growth surfaces is the main surface of the substrate. The multi-wavelength light emitting device according to any one of claims 1 to 3,
A multi-wavelength light emitting device in which the semiconductor forming the first and second semiconductor layers is GaN, and the semiconductor forming the first and second semiconductor light emitting layers is InGaN. The multi-wavelength light emitting device according to any one of claims 1 to 4,
A multi-wavelength light emitting device in which the substrate is a sapphire substrate. The multi-wavelength light emitting device according to any one of claims 1 to 5,
The substrate has a third crystal growth surface having a surface orientation different from that of the first and second crystal growth surfaces on the surface, and a third light emitting region corresponding to the third crystal growth surface is formed.
Different from the main surfaces of the first and second semiconductor layers provided to be stacked on the third light emitting region on the substrate and formed by crystal growth of the semiconductor starting from the third crystal growth surface. A third semiconductor layer having a crystal plane as a main surface;
A semiconductor that is provided so as to be stacked on the third semiconductor layer and that has the same constituent element as the semiconductor forming the first and second semiconductor light emitting layers and has a different element composition ratio is formed by crystal growth; And / or a semiconductor having the same constituent element as that of the semiconductor forming the first and second semiconductor light emitting layers is formed by crystal growth and has a layer thickness different from that of the first and second semiconductor light emitting layers. A third semiconductor light emitting layer that emits light having a wavelength different from that of light emitted by the first and second semiconductor light emitting layers;
A multi-wavelength light emitting device further comprising: Preparing a substrate having first and second crystal growth surfaces having different plane orientations on the surface;
A first semiconductor layer that forms a first light emitting region on the substrate to form a first semiconductor layer by crystal growth of the semiconductor starting from the first crystal growth surface of the substrate prepared in the preparation step Forming process;
Different from the main surface of the first semiconductor layer so that the second light emitting region is formed and stacked on the substrate by crystal growth of the semiconductor starting from the second crystal growth surface of the substrate prepared in the preparation step. A second semiconductor layer forming step of forming a second semiconductor layer having a crystal plane as a main surface;
At the same time as forming the first semiconductor light emitting layer for emitting light of a predetermined wavelength by crystal growth of the semiconductor so as to be laminated on the first semiconductor layer formed in the first semiconductor layer forming step, the second semiconductor layer formation is performed. A semiconductor having the same constituent element as that of the semiconductor forming the first semiconductor light emitting layer and having a different element composition ratio is crystal-grown so as to be stacked on the second semiconductor layer formed in the process and / or the first semiconductor layer is formed. A semiconductor having the same constituent elements as the semiconductor forming the semiconductor light emitting layer is crystal-grown so as to have a layer thickness different from that of the first semiconductor light emitting layer, so that the wavelength of light emitted by the first semiconductor light emitting layer is different. First and second semiconductor light emitting layer forming steps for forming a second semiconductor light emitting layer that emits light of a wavelength;
The manufacturing method of the multiwavelength light emitting element provided with.

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