JP2009054813A - Semiconductor element, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor element and a manufacturing method thereof, in which the semiconductor element can be easily divided into bar-shaped or chip-shaped parts. <P>SOLUTION: This bluish purple semiconductor laser element 100 (semiconductor element) includes a semiconductor substrate 10 having a cut-out face 10a on which a first region 11a constituted by a GaN layer 11 and a second region 12a constituted by an Al<SB>x</SB>Ga<SB>(1-x)</SB>N layer 12 made of a material different from that of the GaN layer 11 and joined with the GaN layer 11 are disposed in stripes and a semiconductor laser device layer 20 having a device center part formed on the region 11a on the cut-out face 10a and a device end face part 100a formed on the second region 12a on the cut-out face 10a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a manufacturing method thereof.

  Conventionally, a semiconductor light emitting device made of a nitride material such as gallium nitride (GaN) is a blue-violet semiconductor laser (LD) used in a disk device or a light emitting diode (LED) used in a light source for illumination. Has been put to practical use. In addition, since the emission wavelength of nitride-based semiconductor light-emitting elements is in a wide range from the ultraviolet wavelength to the near-infrared wavelength, it can also be used as a light source for video display equipment such as projector devices. Has been. In particular, when practical use in lighting equipment and video display equipment is put to practical use, nitride semiconductor light emitting devices are expected to have large-scale demand, and demands for mass production and cost reduction of nitride semiconductor light emitting devices are expected. Is big.

  Therefore, it has been studied to mass-produce and reduce the cost of semiconductor light-emitting devices by forming a semiconductor layer on a growth substrate having a large area. For this reason, conventionally, a method for manufacturing a growth substrate having a large area has been proposed (for example, see Patent Document 1).

  In Patent Document 1, a GaN layer is grown on a GaAs substrate (original substrate), and the GaN layer (ingot) is sliced on a plane parallel to the growth direction of the layer, thereby obtaining a large area and nonpolarity. A method of forming a single crystal GaN substrate having a plane (non-c plane) has been proposed.

JP 2002-29897 A

  However, in the method for manufacturing a single crystal GaN substrate proposed in Patent Document 1, since the single crystal GaN substrate is harder than a GaAs substrate, the semiconductor light emitting device formed in a wafer shape is divided into bars or chips. In the dividing step, it is difficult to break. That is, where the semiconductor light emitting element should be divided in parallel along the direction in which the resonator extends, the semiconductor light emitting element may be broken in an oblique crystal direction, thereby destroying the light emitting element. Therefore, the semiconductor light emitting device using the single crystal GaN substrate according to the manufacturing method of Patent Document 1 has a problem that it is difficult to easily divide the semiconductor light emitting device.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a semiconductor device that can be easily divided into a bar shape or a chip shape, and a method for manufacturing the same. It is to be.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, a semiconductor element according to a first aspect of the present invention includes a first region composed of a first semiconductor layer and a second semiconductor made of a material different from that of the first semiconductor layer and joined to the first semiconductor layer. A semiconductor substrate having a main surface in which a second region composed of layers is arranged in a striped pattern, an element central portion formed on the first region of the main surface, and an element formed on the second region of the main surface And a semiconductor element layer having an end surface portion.

  In the semiconductor element according to the first aspect of the present invention, as described above, the semiconductor element having the element end face portion formed on the second region of the second semiconductor layer made of a material different from the first region of the first semiconductor layer. By providing the layer, for example, when the semiconductor substrate is formed so that the hardness of the second region is smaller than the hardness of the first region, the semiconductor substrate is more easily cracked in the second region than in the first region. That is, in the second region having a low hardness, the wafer on which the semiconductor element layer is formed can be easily divided into bar shapes (or chip shapes), and the semiconductor elements can be reliably aligned with the extending direction of the resonator. Can be divided in parallel. As a result, the semiconductor element can be prevented from being broken to the vicinity of the central part of the element by dividing in the direction intersecting with the extending direction of the resonator, thereby improving the yield in manufacturing the semiconductor element. Can be made.

  In the semiconductor device according to the first aspect, preferably, the hardness of the second region of the second semiconductor layer is smaller than the hardness of the first region of the first semiconductor layer on the main surface. If comprised in this way, a semiconductor element layer can be divided | segmented easily in the 2nd area | region where hardness of the main surface is small.

In the semiconductor element according to the first aspect, preferably, the first semiconductor layer includes GaN, and the second semiconductor layer includes Al _X Ga _(1-X) N (0 <X ≦ 1). According to this structure, the hardness is small in the main surface than the hardness _{Al X Ga (1-X)} N in the main surface of GaN, the _{Al X Ga (1-X)} N layer region of the semiconductor substrate The semiconductor element can be easily divided.

The semiconductor element according to the first aspect preferably further includes an electrode portion having substantially the same width as the first region of the first semiconductor layer and formed on the upper surface of the semiconductor element layer. According to this structure, the first region comprising GaN is formed on the current path area substantially the same width of the electrode subordinates portion, than the refractive index of the first semiconductor layer Al _{X Ga} (1-X _{) Since} the refractive index of the second semiconductor layer containing N is small, it is possible to effectively suppress light from leaking from the first region (element central portion) to the adjacent second region (element end face portion). .

  According to a second aspect of the present invention, there is provided a method for manufacturing a semiconductor device, wherein a first region made of a first semiconductor layer and a second region made of a second semiconductor layer made of a material different from the first semiconductor layer are arranged in a stripe pattern. Forming a semiconductor substrate having a main surface, forming a semiconductor element layer on the first region and the second region of the semiconductor substrate, and forming the semiconductor substrate in the second region of the second semiconductor layer of the semiconductor substrate; Dividing the semiconductor element layer.

  In the method for manufacturing a semiconductor element according to the second aspect of the present invention, as described above, by including the step of dividing the semiconductor substrate and the semiconductor element layer at the second region portion of the second semiconductor layer of the semiconductor substrate, for example, When the semiconductor substrate is formed so that the hardness of the second region is smaller than the hardness of the first region, the semiconductor substrate is more likely to crack in the second region than in the first region. That is, in the second region having a low hardness, it is possible to easily obtain a semiconductor element divided into a bar shape (or a chip shape) from the wafer on which the semiconductor element layer is formed, and to reliably extend the semiconductor element to the resonator. It can be divided substantially parallel to the direction. As a result, the semiconductor element can be prevented from being broken to the vicinity of the central part of the element by dividing in the direction intersecting with the extending direction of the resonator, thereby improving the yield in manufacturing the semiconductor element. Can be made.

  In the method of manufacturing a semiconductor element according to the second aspect, preferably, the step of forming a semiconductor substrate includes a semiconductor growth layer in which first semiconductor layers and second semiconductor layers are alternately stacked on a growth substrate. And a step of dividing the growth surface of the semiconductor growth layer along a direction intersecting the growth surface. If comprised in this way, the semiconductor substrate by which the main surface for growing a semiconductor element layer was striped by the 1st area | region of the 1st semiconductor layer and the 2nd area | region of the 2nd semiconductor layer was obtained. it can.

In the method for manufacturing a semiconductor element according to the second aspect, preferably, when the hardnesses at the main surfaces of the first semiconductor layer and the second semiconductor layer are β ₁ and β ₂ , respectively, the first semiconductor layer and the second semiconductor layer The semiconductor layer has a relationship of β ₁ > β ₂ . If comprised in this way, the semiconductor element by which a semiconductor element layer is easily divided | segmented in the 2nd area | region of the 2nd semiconductor layer with small hardness of a main surface can be obtained.

In the method of manufacturing a semiconductor element according to the second aspect, preferably, the first semiconductor layer includes GaN, and the second semiconductor layer includes Al _X Ga _(1-X) N (0 <X ≦ 1). . According to this structure, the hardness is small in the main surface than the hardness _{Al X Ga (1-X)} N in the main surface of _{GaN, Al X Ga (1-} X) of the semiconductor substrate N layer region ( A semiconductor element divided in the second region) can be obtained.

Preferably, the method for manufacturing a semiconductor device according to the second aspect further includes a step of forming an electrode portion on the upper surface of the semiconductor element layer having substantially the same width as the first region of the first semiconductor layer. . According to this structure, the first region comprising GaN is formed on the current path area substantially the same width of the electrode subordinates portion, than the refractive index of the first region Al _{X Ga (1-X)} Since the refractive index of the second region containing N is small, it is possible to obtain a semiconductor element in which light is prevented from leaking from the first region (element central portion) to the adjacent second region (element end face portion). .

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

(First embodiment)
FIG. 1 is a perspective view for explaining the structure of the blue-violet semiconductor laser device according to the first embodiment of the present invention. The configuration of the blue-violet semiconductor laser device 100 according to the first embodiment will be described with reference to FIG. In the first embodiment, a case where the present invention is applied to a blue-violet semiconductor laser element which is an example of a semiconductor element will be described.

  As shown in FIG. 1, a blue-violet semiconductor laser device 100 (oscillation wavelength: about 400 nm) according to the first embodiment of the present invention includes a semiconductor substrate 10, a semiconductor laser device layer 20, and electrodes (p-side electrode 30 and n-side). Electrode 31). The semiconductor laser element layer 20 is an example of the “semiconductor element layer” in the present invention.

Here, in the first embodiment, as shown in FIG. 1, the semiconductor substrate 10 is a stripe in which Al _X Ga _(1-X) N (0 <X ≦ 1) layers 12 are bonded to both ends of the GaN layer 11. It is comprised so that a shaped substrate may be formed. In the following description, the Al _X Ga _(1-X) N (0 <X ≦ 1) layer 12 is described as the Al _X Ga _(1-X) N layer 12. In addition, the semiconductor laser element layer 20 is configured so that the vicinity of the central portion in the direction of arrow B (the vicinity of the light emitting layer) is formed in a region corresponding to the upper surface of the GaN layer 11 (first region 11a). The GaN layer 11 and the Al _X Ga _(1-X) N layer 12 are examples of the “first semiconductor layer” and the “second semiconductor layer” in the present invention, respectively.

In the first _embodiment, the hardness beta ₂ in the second region 12a of the _{Al X Ga (1-X)} N layer 12 (see FIG. 1), the hardness of the first region 11a of GaN layer 11 (see FIG. 1) smaller than β ₁ (about 1200 kgmm ⁻² to about 1700 kgmm ⁻² by the Knoop hardness measurement method) (β ₁ > β ₂ ).

  Here, the hardness of the semiconductor layer is generally used as a scale representing the degree of hardness of a substance. The hardness measurement method includes, for example, a Vickers hardness measurement method and a Knoop hardness measurement method. These methods are based on the value obtained by dividing the load by the area calculated from the dent shape remaining after removing the load after pushing the pyramid-shaped indenter made of diamond into the surface of the object to be measured with a predetermined load. It is known as a method for measuring the hardness of a measurement object.

  Further, as shown in FIG. 1, the semiconductor laser element layer 20 is composed of semiconductor laser element layers such as an n-type AlGaN cladding layer 21, an active layer 22, and a p-type AlGaN cladding layer 23. The n-type AlGaN cladding layer 21 has a larger band gap than the active layer 22, and the p-type AlGaN cladding layer 23 has a larger band gap than the active layer 22. As the material of the n-type AlGaN cladding layer 21 and the p-type AlGaN cladding layer 23, a nitride compound or the like is used as described above. Further, the semiconductor laser element layer 20 having the above-described configuration may be formed of a nitride-based semiconductor layer having a wurtz structure made of GaN, AlN, InN, BN, TlN, and mixed crystals thereof.

  Further, an optical guide layer or the like having an intermediate band gap between the n-type AlGaN cladding layer 21 and the active layer 22 may be formed between the n-type AlGaN cladding layer 21 and the active layer 22. An optical guide layer having an intermediate band gap between the active layer 22 and the p-type AlGaN cladding layer 23 may be formed between the p-type AlGaN cladding layer 23 and the p-type AlGaN cladding layer 23.

  The active layer 22 may be undoped or doped with impurities such as Si. In particular, InGaN or the like is used as the material of the active layer 22. The active layer 22 is formed by a multiple quantum well (MQW) structure in which, for example, four barrier layers made of GaN and three well layers made of InGaN are alternately stacked. The active layer 22 may be formed of a single layer or a single quantum well (SQW) structure.

  Further, as shown in FIG. 1, a ridge portion 23a is formed on the upper surface side of the p-type AlGaN cladding layer 23. The ridge portion 23a is a convex portion extending in a ridge shape in the direction in which the resonator extends (in the direction of arrow A). ing. The ridge portion 23a forms a waveguide structure. The method for forming the waveguide structure is not limited to the method for forming the ridge portion 23a, and the waveguide structure may be formed by a buried heterostructure or the like.

  Further, as shown in FIG. 1, on the upper surface of the ridge portion 23a of the p-type AlGaN cladding layer 23, a p-side electrode 30 is provided along the direction in which the ridge portion 23a extends (arrow A direction) (see FIG. 1). Is formed. Note that a contact layer (not shown) having a smaller band gap than that of the p-type AlGaN cladding layer 23 may be formed between the p-type AlGaN cladding layer 23 and the p-side electrode 30. Further, as shown in FIG. 1, an n-side electrode 31 is formed on the lower surface of the semiconductor substrate 10 adjusted to a predetermined thickness by polishing or etching.

  2 to 7 are views for explaining a manufacturing process of the blue-violet semiconductor laser device according to the first embodiment of the present invention. A manufacturing process for the blue-violet semiconductor laser device 100 according to the first embodiment is now described with reference to FIGS.

  In the manufacturing process of the blue-violet semiconductor laser device 100 according to the first embodiment of the present invention, first, a formation process of a semiconductor substrate which is a base substrate for crystal growth, a formation process of a semiconductor laser element layer and an electrode on the semiconductor substrate, I do. Then, a blue-violet semiconductor laser device 100 as shown in FIG. 1 is formed by performing a dividing step on the semiconductor laser device formed in a wafer shape. Hereinafter, it demonstrates concretely in order of each process.

  First, in the process of forming a semiconductor substrate, as shown in FIG. 2, after preparing a sapphire substrate 60 as a growth substrate for forming a semiconductor growth layer 50, an organometallic chemistry is formed on the upper surface of the sapphire substrate 60. The GaN layer 11 is epitaxially grown to a predetermined thickness (about several hundred μm) by a chemical vapor deposition method (MOCVD method). At that time, in order to grow the growth surface of the GaN layer 11 as a polar surface (c-plane), a sapphire substrate 60 having a substantially (0001) plane as a main surface is used.

The growth substrate on which the GaN layer 11 is grown is not limited to the sapphire substrate 60, but a nitride semiconductor substrate or a heterogeneous substrate that is not a nitride semiconductor (for example, an α-SiC substrate, a ZnO substrate, a spinel substrate, and LiAlO). ₃ substrates) may be used. Further, a GaAs substrate having a substantially (111) plane as a main surface may be used.

  Further, since the GaN layer 11 is formed by a thin film growth method utilizing a reaction from a gas phase to a solid layer, in addition to the MOCVD method, a hydride vapor phase growth method (HVPE method) or an organometallic chloride is used. A vapor phase growth method (MOC method) or the like may be applied.

As shown in FIG. 2, when the GaN layer 11 is formed on the sapphire substrate 60, the sapphire substrate 60 and the GaN layer are usually stacked in order to stack a buffer layer (not shown) immediately before the GaN layer 11. Warpage due to the difference in lattice constant from the layer 11 is unlikely to occur. Further, in the film formation on the GaAs substrate, when the lateral growth method is used, the warpage due to the difference in lattice constant between the GaAs substrate and the GaN layer hardly occurs. However, the coefficient of thermal expansion α _sub of the sapphire substrate 60 (having about 7.5 × 10 ⁻⁶ / K for the a-axis and about 8.5 × 10 ⁻⁶ / K for the c-axis) On the sapphire substrate 60 because it has a coefficient of thermal expansion α ₁ of about 5.59 × 10 ⁻⁶ / K for the a-axis and about 3.17 × 10 ⁻⁶ / K for the c-axis. When a single layer of only the GaN layer 11 is laminated thickly, due to thermal stress (stress in the direction of arrow P in FIG. 2) in the cooling process after growth, the GaN layer 11 side (in the direction of arrow C in FIG. 2) Some convex warpage deformation occurs.

Therefore, after the GaN layer 11 is grown, as shown in FIG. 2, an Al _X Ga _(1-X) N layer 12 having a lattice constant different from that of the GaN layer 11 has a predetermined thickness (about several tens of μm). Epitaxial growth. The growth of the _{Al X Ga (1-X)} N layer _12, the lattice of the _{Al X Ga (1-X)} ( in the a-axis direction with about 3.112) lattice constant _b 2 of the N layer 12 is GaN layer 11 The Al _x Ga _(1-X) N layer 12 has a figure smaller than the constant b ₁ (having about 3.112 ≦ b ₂ <3.189 in the a-axis direction) (b ₁ > b ₂ ). As shown in FIG. 2, a stress is generated in the direction toward the inside of the semiconductor layer (the direction of the arrow Q). _{Therefore, Al X Ga (1-X} ) internal stress generated in the N layer 12 is pulled back from being deformed in a convex shape on the GaN layer 11 side in the direction of arrow D (see FIG. 2) (cancel) acts as a role.

Further, as shown in FIG. _2, after growing the _{Al X Ga (1-X)} N layer 12, again, it is epitaxially grown on the GaN layer 11 a predetermined thickness (about several 100 [mu] m). Further, after the growth of the GaN layer 11, the Al _X Ga _(1-X) N layer 12 is again epitaxially grown to a predetermined thickness (about several tens of μm). Again, the lattice constant _{b 1} of the GaN layer _11, in order to have Al _{X Ga (1-X)} magnitude related to the lattice constant _{b 2} of the N layer 12 _(b 1> _{b 2),} mutual semiconductor layer The action of canceling out the stress generated inside occurs. That is, as shown in FIG. 2, by repeatedly laminating the GaN layer 11 and the Al _X Ga _(1-X) N layer 12, the semiconductor growth layer 50 is not warped on the sapphire substrate 60, Or it forms so that it may have big thickness in the state where curvature was relieved. In addition, the semiconductor growth layer 50 may be slightly warped. Even when the semiconductor growth layer 50 is slightly warped, the degree of warping is the growth substrate or support substrate for the semiconductor substrate 10 to form the semiconductor laser element layer 20 after the formation of the semiconductor substrate 10 described later. When it is used as, it does not cause any trouble.

In this manner, the semiconductor growth layer 50 (see FIG. 2) is formed by repeatedly stacking the GaN layer 11 and the Al _X Ga _(1-X) N layer 12 on the sapphire substrate 60 a predetermined number of times. Is done.

  Then, as shown in FIG. 3, the sapphire substrate 60 is separated and removed from the semiconductor growth layer 50. At that time, the sapphire substrate 60 may be physically removed by a slicer (not shown) or the like. If the growth substrate is a GaAs substrate or the like, it may be removed by chemical etching.

Thereafter, as shown in FIG. 3, with respect to the growth surface (surface perpendicular to the direction of arrow C) of the semiconductor growth layer 50 in which the GaN layer 11 and the Al _X Ga _(1-X) N layer 12 are repeatedly stacked. Slicing along a dividing line 600 (broken line) using a slicer (not shown) or the like in a substantially vertical direction (stacking direction of the semiconductor growth layer 50 (arrow C direction in FIG. 3)) Thus, the semiconductor substrate 10 is cut out from the semiconductor growth layer 50 into a thin plate shape. As a result, as shown in FIG. 4, the first regions 11 a of the GaN layer 11 and the second regions 12 a of the Al _X Ga _(1-X) N layer 12 are alternately arranged in the lateral direction (arrow B direction). A semiconductor substrate 10 having a large area can be obtained.

  In the first embodiment, as shown in FIG. 4, the cut-out surface 10a of the semiconductor substrate 10 (the surface in which the first region 11a and the second region 12a are arranged in a stripe pattern) is the m-plane ((1- 100) plane) or a plane ((11-20) plane) to obtain the semiconductor substrate 10 having a main surface composed of a nonpolar plane (non-c plane). Here, the nonpolar plane (non-c plane) is a plane (m plane or a plane) in the normal direction to a polar plane called c plane ((0001) plane) in crystal growth of the GaN layer 11. Show. Thus, the striped semiconductor substrate 10 is formed (manufactured). The cut surface 10a is an example of the “main surface” in the present invention.

  Next, in the process of forming the semiconductor laser element layer and the electrode on the semiconductor substrate, as shown in FIG. 5, the n-type AlGaN cladding layer 21 is formed on the upper surface (cut surface 10a) of the semiconductor substrate 10 by MOCVD. Semiconductor layers such as the active layer 22 and the p-type AlGaN cladding layer 23 are sequentially stacked. Then, as shown in FIG. 6, patterning by lithography and dry etching are performed on the upper surface side of the p-type AlGaN cladding layer 23 to extend in a ridge shape in the direction perpendicular to the drawing (the direction of arrow A in FIG. 7). A ridge portion 23a is formed.

  Further, as shown in FIG. 6, a p-side electrode 30 is formed on the upper surface of the ridge portion 23a of the p-type AlGaN cladding layer 23 by vacuum deposition. Also, as shown in FIG. 6, an n-side electrode 31 is formed by vacuum deposition on the lower surface of the semiconductor substrate 10 adjusted to a predetermined thickness by polishing or etching. In this manner, the semiconductor laser element layer 20 and the electrode layers (p-side electrode 30 and n-side electrode 31) on the semiconductor substrate 10 are formed.

Here, in the first embodiment, the dividing step is performed on the semiconductor laser element formed in a wafer shape by the following method. Specifically, after the cleavage plane forming step (bar-shaped cleavage), as shown in FIG. 7, the region 20a (corresponding to the second region 12a of the Al _X Ga _(1-X) N layer 12 of the semiconductor substrate 10 ₎ In the broken line area), a plurality of marking lines (not shown) are formed in the direction in which the resonator extends by the diamond cutter or the like from the lower surface side of the n-side electrode 31 toward the semiconductor laser element layer 20 (in the direction of arrow A in FIG. 1). Then, division is performed sequentially along each marking line. According to this structure, the hardness of the first region 11a of GaN layer 11 and the second region 12a of the _{Al X Ga (1-X)} N layer 12 than the hardness beta ₁ in (see FIG. 7) (see FIG. 7) beta _{Since 2} is small (β ₁ > β ₂ ), a region where the element end face portion 100a (see FIG. 1) is formed (as shown in FIG. 6, Al _X Ga _{(1-X ) Since} the split surface (cleavage surface) is reliably formed in the substantially central portion of the region 20a corresponding to the second region 12a of the N layer 12, the resonator extends in the element end surface portion 100a (second region 12a). A chip-like blue-violet semiconductor laser device 100 (see FIG. 1) divided in a direction substantially parallel to the direction (the direction of arrow A in FIG. 1) can be easily obtained. Further, as shown in FIG. 7, the bar-like blue-violet semiconductor laser device 100 can be reliably divided into a direction substantially parallel to the direction in which the resonator extends (the direction of the arrow A), so that an unintended direction ( For example, it is possible to prevent the semiconductor laser element layer 20 from being broken to the vicinity of the central portion (light emitting layer vicinity region) by the division progressing in a direction intersecting the arrow A direction. Thereby, the yield at the time of manufacturing the blue-violet semiconductor laser device 100 can be improved.

  From the above, as shown in FIG. 1, a blue-violet semiconductor laser device 100 formed into a chip is formed. Thus, the blue-violet semiconductor laser device 100 according to the first embodiment is formed.

In the first embodiment, as described above, the element end face portion formed on the Al _X Ga _(1-X) N layer 12 (second region 12a) made of a material different from that of the GaN layer 11 (first region 11a). By providing the semiconductor laser element layer 20 having 100a (see FIG. 1), for example, when the semiconductor substrate 10 is formed so that the hardness of the second region 12a is smaller than the hardness of the first region 11a, the semiconductor substrate 10 is easier to crack in the second region 12a than in the first region 11a. That is, the wafer (blue-violet semiconductor laser device 100 (see FIG. 7)) on which the semiconductor laser device layer 20 is formed in the Al _X Ga _(1-X) N layer 12 having a small hardness can be easily formed into a bar shape (or a chip shape). ) And the semiconductor laser element layer 20 can be reliably divided substantially in parallel with the direction in which the resonator extends (the direction of arrow A in FIG. 1). As a result, the semiconductor laser element layer 20 is broken up to the vicinity of the central portion of the semiconductor laser element layer 20 as the division proceeds in a direction intersecting with the direction in which the resonator extends (the direction of arrow A in FIG. 1). Therefore, the yield when manufacturing the blue-violet semiconductor laser device 100 can be improved.

In the first embodiment, the hardness β ₂ in the second region 12 a of the Al _X Ga _(1-X) N layer 12 is smaller than the hardness β ₁ in the first region 11 a of the GaN layer 11 in the cut surface 10 a. By doing (β ₁ > β ₂ ), the semiconductor laser element layer 20 can be easily divided into bars in the second region 12a having a small hardness in the cut surface 10a.

In the first embodiment, the GaN layer 11 is configured to contain GaN, and the Al _X Ga _(1-X) N layer 12 bonded to the GaN layer 11 is replaced with Al _X Ga _(1-X) N. (0 <X ≦ 1) is included so that the second of the Al _X Ga _(1-X) N layer 12 is more than the hardness β ₁ in the first region 11 a of the GaN layer 11 in the cut surface 10 a. since hardness beta ₂ is smaller in the region 12a, the _{Al X Ga (1-X)} portion of the N layer 12 of the semiconductor substrate 10, it is possible to easily divide the wafer-shaped blue-violet semiconductor laser device 100.

(Second Embodiment)
FIG. 8 is a perspective view for explaining the structure of the green semiconductor laser device according to the second embodiment of the present invention. With reference to FIG. 8, in the second embodiment, unlike the first embodiment, a case where the configuration of the semiconductor element in the present invention is applied to a green semiconductor laser element 200 will be described. The green semiconductor laser element 200 is an example of the “semiconductor element” in the present invention.

As shown in FIG. 8, the green semiconductor laser device 200 (oscillation wavelength: about 530 nm) according to the second embodiment of the present invention has Al _X Ga _{(1− X)} A striped semiconductor substrate 10 to which an N layer 12 is bonded, a semiconductor laser element layer 220, and electrode layers (p-side electrode 30 and n-side electrode 31). The semiconductor laser element layer 220 is an example of the “semiconductor element layer” in the present invention.

  The semiconductor laser element layer 220 is composed of semiconductor laser element layers such as an n-type AlGaN cladding layer 221, an active layer 222, and a p-type AlGaN cladding layer 223. The active layer 222 is formed by a multiple quantum well (MQW) structure in which, for example, four barrier layers made of InGaN and three well layers made of InGaN are alternately stacked. Note that the active layer 222 may be formed of a single layer or a single quantum well (SQW) structure.

  The blue-violet semiconductor according to the first embodiment is adjusted by adjusting the composition ratio of Al and In constituting the cladding layer and the active layer (including the well layer, the barrier layer, the light guide layer, and the carrier block layer). A green semiconductor laser element 200 (see FIG. 8) having an oscillation wavelength different from that of the laser element 100 (see FIG. 1) is formed.

  The remaining structure and manufacturing process of the green semiconductor laser device 200 according to the second embodiment are the same as those of the first embodiment.

  In the second embodiment, as described above, a semiconductor that emits green laser light onto a striped semiconductor substrate 10 having a nonpolar surface (non-c surface) as a main surface (cut-out surface 10a (see FIG. 4)). By forming the laser element layer 220, since the influence of the piezoelectric field does not occur, the light emission efficiency of the semiconductor laser element layer 220 can be further improved. The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
FIG. 9 is a perspective view for explaining the structure of a blue-violet light emitting diode (LED) according to the third embodiment of the present invention. With reference to FIG. 9, in the third embodiment, a case where the configuration of the semiconductor element in the first embodiment is applied to a blue-violet light emitting diode 300 will be described. The blue-violet light emitting diode 300 is an example of the “semiconductor element” in the present invention.

In the blue-violet light emitting diode 300 (oscillation wavelength: about 400 nm) according to the third embodiment of the present invention, as shown in FIG. 9, both ends of the GaN layer 11 (width: about several hundred μm), as in the first embodiment. A striped semiconductor substrate 10 (see FIG. 8) having an Al _X Ga _(1-X) N layer 12 (width: about several tens of μm) bonded thereto, a light emitting diode layer 320 (LED portion), and an electrode (p-side electrode) 330 and the n-side electrode 331).

  Here, in the third embodiment, as shown in FIG. 9, the vicinity of the central portion of the light emitting diode layer 320 (the vicinity of the light emitting layer) is formed in a region corresponding to the upper part of the GaN layer 11 (first region 11a). It is configured as follows.

  Further, as shown in FIG. 9, the light emitting diode layer 320 includes semiconductor light emitting element layers such as an n-type AlGaN cladding layer 321, an active layer 322, and a p-type AlGaN cladding layer 323. The active layer 322 is formed by a multiple quantum well (MQW) structure in which, for example, four barrier layers made of GaN and three well layers made of InGaN are alternately stacked. Note that the active layer 322 may be formed of a single layer or a single quantum well (SQW) structure. Further, as shown in FIG. 9, the light emitting diode layer 320 has convex portions formed by etching a part of the n-type AlGaN cladding layer 321 and the outer peripheral portions of the active layer 322 and the p-type AlGaN cladding layer 323 by etching or the like. A mesa portion 320a having a shape is formed.

  As shown in FIG. 9, a p-side electrode 330 (reflection electrode) made of an Al layer, an Ag layer, or the like is formed on the upper surface of the mesa portion 320a of the light emitting diode layer 320 by vacuum deposition. Note that a contact layer (not shown) including a material having a smaller band gap and a better ohmic property than the p-type AlGaN cladding layer 323 between the p-type AlGaN cladding layer 323 and the p-side electrode 330. ) May be formed. Further, as shown in FIG. 9, an n-side electrode 331 is formed by vacuum deposition on the lower surface of the semiconductor substrate 10 adjusted to a predetermined thickness by polishing or etching.

  The remaining structure of the blue-violet light emitting diode 300 according to the third embodiment is the same as that of the first embodiment.

  FIG. 10 is a view for explaining a manufacturing process of a blue-violet light emitting diode (LED) according to the third embodiment of the present invention. A manufacturing process of the blue-violet light emitting diode 300 according to the third embodiment will be described with reference to FIGS.

  In the third embodiment of the present invention, as shown in FIG. 10, first, a manufacturing process of the semiconductor substrate that is the original substrate for crystal growth is performed by the same manufacturing process as in the first and second embodiments. And forming a light emitting diode layer and an electrode. A blue-violet light emitting diode 300 as shown in FIG. 9 is formed by performing a dividing process on the light emitting diode formed in a wafer shape.

Here, in the third embodiment, the dividing process is performed on the wafer-like light emitting diode by the following method. Specifically, as shown in FIG. 10, first, a region 320 b of the light emitting diode layer 320 corresponding to the second region 12 a on the Al _X Ga _(1-X) N layer 12 of the semiconductor substrate 10 (the region of the broken line portion). ), A plurality of marking lines (not shown) are formed in a direction (arrow E direction) substantially parallel to the region 320b from the lower surface side of the n-side electrode 331 by a diamond cutter or the like, and then along each marking line. To sequentially divide. Thereafter, even in a region 320c (broken line region) in a direction substantially perpendicular to the region 320b of the light emitting diode layer 320, a plurality of inscriptions are made by diamond cutters or the like from the lower surface side of the n-side electrode 331 toward the light emitting diode layer 320. A line (not shown) is formed, and further division is performed along each marking line.

  In this way, as shown in FIG. 9, blue-violet light emitting diodes 300 separated from the wafer shape into chips are formed. The other manufacturing processes of the blue-violet light emitting diode 300 in the third embodiment are the same as those in the first and second embodiments.

In the third embodiment, as described above, the _second of the Al _X Ga _(1-X) N layer 12 having a hardness β ₂ smaller than the hardness β ₁ in the first region 11 a of the GaN layer 11 in the dividing step. Since the region 320b (see FIG. 10) of the light emitting diode layer 320 corresponding to the region 12a is divided along a marking line (not shown) formed on the n-side electrode 331 side, the first and second embodiments described above are performed. Similar to the embodiment, the wafer-like blue-violet light emitting diode 300 can be easily divided. In addition, since the wafer-like blue-violet light emitting diode 300 can be reliably divided along the marking line, the division proceeds in an unintended oblique direction (for example, a direction that crosses the marking line obliquely). Therefore, it is possible to prevent the light emitting diode layer 320 from being broken to the vicinity of the central portion. Thereby, the yield at the time of manufacturing the blue-violet light emitting diode 300 (refer FIG. 9) can be improved. The remaining effects of the third embodiment are similar to those of the aforementioned first and second embodiments.

(Fourth embodiment)
FIG. 11 is a perspective view for explaining the structure of a blue-violet semiconductor laser device according to the fourth embodiment of the present invention. Referring to FIG. 11, in the fourth embodiment, unlike the first embodiment (see FIG. 1), the width of the Al _X Ga _(1-X) N layer region is wider than the width of the GaN layer region. A blue-violet semiconductor laser device 400 in which a striped semiconductor substrate is formed will be described.

  Here, in the fourth embodiment, as shown in FIG. 11, the ridge portion 420a of the semiconductor laser element layer 420 composed of a p-type cladding layer, an active layer, an n-type cladding layer, and the like, and the p-side electrode 430 are provided. The ridges 420a and the p-side electrode 430 formed of protrusions are formed in regions corresponding to substantially directly above the GaN layer 11 (first region 11a) of the striped semiconductor substrate 410, respectively. The GaN layer 11 is formed to have substantially the same width. The semiconductor laser element layer 420 and the p-side electrode 430 are examples of the “semiconductor element layer” and the “electrode part” in the present invention, respectively. The remaining structure and manufacturing process of the blue-violet semiconductor laser device 400 according to the fourth embodiment are the same as those of the first and second embodiments.

In the fourth embodiment, as described above, the p-side electrode 430 having substantially the same width as the first region 11a of the GaN layer 11 and formed on the upper surface of the semiconductor laser element layer 420 is provided. The first region 11 a containing gallium nitride (GaN) is formed to have substantially the same width as the current path region under the p-side electrode 430, and Al _X Ga _{(1-X) is} larger than the refractive index of the GaN layer 11. Since the refractive index of the Al _X Ga _(1-X) N layer 12 containing N is small, the adjacent Al _X Ga _(1-X) from the central portion (light emitting layer) of the semiconductor laser element layer 420 through the GaN layer 11 Light can be effectively prevented from leaking laterally (in the direction of arrow B in FIG. 11) to the N layer 12 (element end surface portion 400a). The remaining effects of the fourth embodiment are similar to those of the aforementioned first and second embodiments.

(Modification of the fourth embodiment)
FIG. 12 is a perspective view for explaining the structure of a blue-violet semiconductor laser device according to a modification of the fourth embodiment of the present invention. With reference to FIG. 12, in the modification of the fourth embodiment, a case where a ridge portion is not formed in the semiconductor laser element layer 520 will be described, unlike the fourth embodiment (see FIG. 11).

  Here, in the modification of the fourth embodiment, as shown in FIG. 12, the semiconductor laser element layer 520 composed of a p-type cladding layer, an active layer, an n-type cladding layer, and the like is provided in the fourth embodiment. Such a ridge 420a (see FIG. 11) is not formed. On the other hand, only the p-side electrode 430 is formed in a region substantially corresponding to the GaN layer 11 (first region 11a) of the semiconductor substrate 410, and the width of the p-side electrode 430 is set so that the GaN layer 11 has a width. It is formed so as to have substantially the same width.

  The remaining structure and manufacturing process of the blue-violet semiconductor laser device 500 according to the modification of the fourth embodiment are the same as those of the fourth embodiment.

Even when configured as in the modification of the fourth embodiment, light is emitted from the light emitting layer to the adjacent Al _X Ga _(1-X) N layer 12 via the GaN layer 11 (in the direction of arrow B in FIG. 12). Can be prevented from leaking out, and therefore the manufacturing process for forming the ridge portion in the semiconductor laser element layer 520 can be omitted. Therefore, the productivity of the blue-violet semiconductor laser device 500 can be improved. The semiconductor laser element layer 520 is an example of the “semiconductor element layer” in the present invention. The remaining effects of the modification of the fourth embodiment are similar to those of the aforementioned fourth embodiment.

  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 embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

In the first to fourth embodiments, the GaN layer 11 (first semiconductor layer region) and the Al _X Ga _(1-X) N layer 12 (second semiconductor layer region) are repeatedly stacked on the sapphire substrate 60. However, the present invention is not limited to this, and the present invention is not limited thereto, and Al _X Ga _(1-X) N (0 <X ≦ 1) and In _Y are applied to the sapphire substrate 60. A step of forming a semiconductor growth layer may be performed by repeatedly stacking different kinds of semiconductor layers made of Ga _(1-Y) N (0 <Y ≦ 1) or the like.

  Moreover, in the said 1st-4th embodiment, although the example which used the sapphire substrate 60 as a board | substrate for the growth of the striped semiconductor substrate 10 was shown, this invention is not restricted to this, For example, GaAs other than a sapphire substrate, A substrate made of a material such as SiC and Si may be used.

Further, in the first to fourth embodiments, the blue-violet semiconductor laser element 100, the green semiconductor laser element 200, and the blue-violet light emission are performed using the striped semiconductor substrate 10 whose main surface is a nonpolar plane (non-c plane). Although an example in which the diode 300 and the blue-violet semiconductor laser elements 400 and 500 are formed has been described, the present invention is not limited to this, and a semiconductor in which the GaN layer 11 and the Al _X Ga _(1-X) N layer 12 are repeatedly stacked. By subjecting the growth surface of the growth layer 50 to slice processing in an oblique direction (a direction intersecting the stacking direction of the semiconductor growth layer 50 (arrow B direction) at a predetermined angle), the semiconductor growth layer 50 to the semiconductor substrate The semiconductor element may be formed using a semiconductor substrate having a semipolar surface as a main surface by cutting out the substrate into a thin plate shape.

It is a perspective view for demonstrating the structure of the blue-violet semiconductor laser device by 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the blue-violet semiconductor laser device by 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the blue-violet semiconductor laser device by 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the blue-violet semiconductor laser device by 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the blue-violet semiconductor laser device by 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the blue-violet semiconductor laser device by 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the blue-violet semiconductor laser device by 1st Embodiment of this invention. It is a perspective view for demonstrating the structure of the green semiconductor laser element by 2nd Embodiment of this invention. It is a perspective view for demonstrating the structure of the blue-violet light emitting diode by 3rd Embodiment of this invention. It is a figure for demonstrating the manufacturing process of the blue-violet light emitting diode by 3rd Embodiment of this invention. It is a perspective view for demonstrating the structure of the blue-violet semiconductor laser device by 4th Embodiment of this invention. It is a perspective view for demonstrating the structure of the blue-violet semiconductor laser element by the modification of 4th Embodiment of this invention.

Explanation of symbols

10 Semiconductor substrate 10a Cut-out surface (main surface)
11 GaN layer (first semiconductor layer)
11a first region _{12 Al X Ga (1-X} ) N layer (second semiconductor layer)
12a Second region 20, 220, 420, 520 Semiconductor laser element layer (semiconductor element layer)
100a, 400a Element end face 320 Light emitting diode layer (semiconductor element layer)
430 p-side electrode (electrode part)

Claims (9)

A first surface made of a first semiconductor layer and a second surface made of a material different from that of the first semiconductor layer and made of a second semiconductor layer joined to the first semiconductor layer have a main surface arranged in a stripe pattern. A semiconductor substrate;
A semiconductor element comprising: a semiconductor element layer having an element central portion formed on the first region of the main surface and an element end surface portion formed on the second region of the main surface.   2. The semiconductor element according to claim 1, wherein a hardness of the second region of the second semiconductor layer is smaller than a hardness of the first region of the first semiconductor layer on the main surface. 3. The semiconductor device according to claim 1, wherein the first semiconductor layer includes GaN, and the second semiconductor layer includes Al _X Ga _(1-X) N (0 <X ≦ 1).   4. The device according to claim 1, further comprising an electrode portion having substantially the same width as the first region of the first semiconductor layer and formed on an upper surface of the semiconductor element layer. 5. Semiconductor element. Forming a semiconductor substrate having a main surface in which a first region made of a first semiconductor layer and a second region made of a second semiconductor layer made of a material different from the first semiconductor layer are arranged in a stripe pattern;
Forming a semiconductor element layer on the first region and the second region of the semiconductor substrate;
A step of dividing the semiconductor substrate and the semiconductor element layer in the second region of the second semiconductor layer of the semiconductor substrate.   The step of forming the semiconductor substrate includes a step of forming a semiconductor growth layer in which the first semiconductor layer and the second semiconductor layer are alternately stacked on a growth substrate, and a growth surface of the semiconductor growth layer. The method of manufacturing a semiconductor device according to claim 5, comprising a step of dividing along a direction intersecting the growth surface. When the hardness at the main surface of the first semiconductor layer and the second semiconductor layer is β ₁ and β ₂ , respectively,
The method for manufacturing a semiconductor element according to claim 5, wherein the first semiconductor layer and the second semiconductor layer have a relationship of β ₁ > β ₂ . 8. The device according to claim 5, wherein the first semiconductor layer includes GaN, and the second semiconductor layer includes Al _X Ga _(1-X) N (0 <X ≦ 1). A method for manufacturing a semiconductor device.   9. The method according to claim 5, further comprising a step of forming an electrode portion on the upper surface of the semiconductor element layer having substantially the same width as the first region of the first semiconductor layer. A method for manufacturing a semiconductor device.

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