TWI710187B - Structure of vcsel and method for manufacturing the same - Google Patents

Abstract

The invention refers to a Vertical-Cavity Surface-Emitting Laser (VCSEL) having a novel three-trenches structure. By forming a first trench within a mesa around the periphery of an output window of the VCSEL, the overall capacitance is decreased and the time used in the oxidation process for an oxidation layer is shortened. By forming a second trench and a third trench on the periphery of the mesa in a step-like concave manner, the mesa becomes a step-like structure having double mesa-layers. Such that, a larger heat-radiating area can be obtained for decreasing thermal effects, while the metal-gap defects of the metal layer can also be avoided. An implant layer is formed around the periphery of the output window for controlling the modal and constraining the currents, in addition, an output layer is formed on the output window for controlling the output light.

Description

Vertical resonance cavity surface shot laser structure and manufacturing method

The present invention relates to a vertical cavity surface-fired laser structure and manufacturing method, in particular to a vertical cavity surface-fired laser structure and manufacturing method that uses a three-channel structure to reduce overall capacitance and shorten the oxidation process time.

Vertical Cavity Surface Emitting Laser (VCSEL) is a type of light emitting laser diode. Because of its low power and price, it is mainly used in local area networks and has "high speed". And the "low price" advantage. The raw materials for VCSEL light emission and inspection are generally gallium arsenide (GaAs) and indium phosphide (InP), and metal organic vapor deposition (MOCVD) is usually used to make epitaxial wafers. Compared with general side-fired lasers, the mirror surface required for the VCSEL's resonant cavity and photon to resonate back and forth in the cavity is not a natural lattice fracture surface formed by the process, but is formed when the device structure is epitaxially grown.

A general VCSEL structure roughly includes a light-emitting active layer, a resonant cavity, and a Bragg reflector (Distributed Bragg Reflector; DBR) with high reflectivity up and down. When the photon is generated in the light-emitting active layer, it is easy to oscillate back and forth in the cavity. If the population inversion is reached, the laser light will be formed on the surface of the VCSEL element. However, because VCSEL adopts the surface-emitting type, the laser light has a cone shape, which is easier to couple with the optical fiber and does not require additional optical lenses. For the basic structure, manufacturing method, and operating mode of the conventional VCSEL, you can refer to the contents of US Pat. No. 4,949,350 and US Pat. No. 5,468,656.

The present invention improves the structure and manufacturing method of the above-mentioned conventional VCSEL. The unique three-channel structure reduces the overall capacitance and shortens the oxidation process time. The ion implantation area around the optical window is used to control the mode and limit the current. In addition, a light-emitting layer is formed on the light window to control the light-emitting, and the stepped double-layered boss structure helps heat conduction to reduce the thermal effect.

In view of this, the main purpose of the present invention is to provide a vertical resonant cavity surface-fired laser structure and manufacturing method, which can reduce the overall capacitance, shorten the oxidation process time, and form a stepped double-layer boss through the unique three-channel structure Structure to reduce thermal effects.

Another object of the present invention is to provide a vertical resonant cavity surface-fired laser structure and manufacturing method, which can control the mode and current limiting by the ion implantation area around the optical window, and form a light-emitting layer on the optical window to control The light-emitting layer can be a dielectric material, and the material composition can be silicon dioxide (SiO2), silicon nitride (SiN) or a mixture of these two materials, and the reflection coefficient is between 1.5 and 2.0.

To achieve the above objective, the present invention provides a vertical resonant cavity surface-fired laser structure including: a substrate, a first mirror layer on the substrate, an active layer on the first mirror layer, and a second mirror layer. The mirror layer is located on the active layer, an oxide layer is sandwiched in the second mirror layer, a boss area, a first trench, a second trench, a third trench, a dielectric material, and a first contact layer And a second contact layer; wherein the boss area is located on the substrate and is composed of at least a part of the first mirror layer, the activation layer, the second mirror layer and the oxide layer In the middle of a top surface of the boss area, there is a light window; the first trench is located in the boss area and surrounds at least a part of the outer periphery of the light window; A trench extends from the top surface of the boss region through at least the second mirror layer, the oxide layer and the activation layer from top to bottom; the second trench surrounds at least a part of the outer periphery of the boss region The second ditch penetrates at least the second mirror layer and the oxide layer from top to bottom, so that a bottom of the second ditch is located at the active layer or at the first ditch. One of the two at a mirror layer; the third trench surrounds at least a part of the outer periphery of the boss area and is recessed from the bottom of the second trench, and the third trench is formed by Up and down at least penetrate the first mirror layer, so that a bottom of the third trench is located at the substrate; the dielectric material is at least filled in the first trench; the first contact layer is located in the boss area The top surface is in contact with the second mirror layer; the second contact layer is at least located at the bottom of the third trench and at least in contact with the substrate.

In a preferred embodiment, the vertical cavity surface-fired laser structure further includes an insulating layer covering at least a part of an outer surface of the boss region, and the first contact layer is in contact with the second contact layer At least a part of the layer is exposed outside the insulating layer; the first mirror layer is an n-type distributed Bragg reflector (DBR), and the second mirror layer is a p-type distributed Bragg reflector layer; the material of the first mirror layer and the second mirror layer include aluminum gallium arsenide (AlGaAs) with different aluminum mole percentages, and the oxide layer has the relatively highest moire in the second mirror layer Ear percentage aluminum; the oxide layer extends horizontally from the inner periphery of the first trench toward the center of the boss area; the dielectric material is a polymer material with low dielectric properties; and, the first contact layer and the The second contact layers are all metal layers.

In a preferred embodiment, the vertical resonant cavity surface-fired laser structure further includes an ion implantation layer located in the second mirror layer. The ion implantation layer partially overlaps the oxide layer, and the relative aperture size of the oxide layer and ion implantation is used to control the optical mode. The ion implantation belongs to gain-guided, and oxidation belongs to index guided. , The optical mode can be controlled by the mixed application of the two; and the ion implantation layer located in the boss area is located between the light window and the first trench, and surrounds the light window At least a part of the outer periphery; wherein the first contact layer is in contact with an upper surface of the second mirror layer.

In a preferred embodiment, the vertical resonant cavity surface-fired laser structure further includes: a light-emitting layer located on the light window on the top surface of the boss area.

In a preferred embodiment, the second contact layer extends from the bottom of the third trench up to a portion of the second mirror layer along the third trench and the second trench each having an inclined surface. On the upper surface, a top surface of the second contact layer is approximately at the same height as the first contact layer; a plane is formed at the bottom of the second trench, so that the second contact layer is in the second trench The bottom constitutes a horizontally extending state.

To achieve the above objective, the present invention provides a method for manufacturing a vertical cavity surface-fired laser structure, which includes the following steps: providing a laser chip substrate, on which a semiconductor process is performed from bottom to top Sequentially constituted: a substrate, a first mirror layer on the substrate, an active layer on the first mirror layer, and a second mirror layer on the active layer; using a first mask and implementing a first The masking process is to form a first mask layer having a first predetermined pattern on the upper surface of the second mirror layer, the first predetermined pattern is corresponding to the pattern of the first mask; an ion implantation is performed The procedure is to perform ion implantation on the area of the second mirror layer not covered by the first mask layer to form an ion implantation layer, and a bottom of the ion implantation layer is still a predetermined height away from the activation layer; When the first mask layer has not been removed, a second mask is used and a second mask is implemented to form the upper surface of the second mirror layer and above the first photoresist layer A second mask layer with a second predetermined pattern, the second predetermined pattern corresponding to the pattern of the second photomask; a first etching process is performed to the second mirror layer, the activation layer and the first The area of a mirror layer not covered by the second photoresist layer is etched to form a first trench, and the first trench penetrates the second mirror layer and the second mirror layer downward from the upper surface of the second mirror layer The activation layer is such that a bottom of the first trench is located on the first mirror layer; an oxidation process is performed to form a horizontally extending oxide layer in the second mirror layer through the first trench, and the oxide layer It is close to the ion implantation layer in height, and even partially overlaps. A second etching process is performed to form a second trench on the second mirror layer, and the second trench is from the first The upper surface of the two mirror layers penetrates at least the second mirror layer and the oxide layer downward, so that a bottom of the second trench is located at either the active layer or the first mirror layer; implement a The third etching process is to form a downwardly recessed third trench at the bottom of the second trench, and the third trench penetrates at least the first mirror layer from top to bottom, so that one of the third trenches The bottom is located at the substrate; a dielectric material is filled in the first trench. The dielectric material is a polymer, which can be Polymide, and the reflection coefficient is 1.5 to 1.6. In the present invention, by digging the first trench and filling the polymer, the area of the semiconductor material with high dielectric coefficient can be reduced, so the capacitance can be reduced. And an insulating layer, a first contact layer, and a second contact layer are respectively formed on appropriate areas on the laser wafer substrate; wherein the first contact layer is located on the top surface of the boss area and contacts On the upper surface of the second mirror layer; the second contact layer is located at least at the bottom of the third trench and at least in contact with the substrate, and the second contact layer is along the bottom of the third trench The third trench and the second trench each have an inclined surface extending upward to the upper surface of the second mirror layer, so that a top surface of the second contact layer is substantially at the same height as the first contact layer ; At least a portion of the first contact layer and the second contact layer are exposed outside the insulating layer; wherein, the second trench and the third trench can define a protrusion on the laser chip substrate The mesa region, the second trench and the third trench are both at least a part of the outer periphery of the boss region; the boss region is located on the substrate and is formed by at least a part of the second A mirror layer, the activation layer, the second mirror layer, and the oxide layer are assembled, and a light window is provided at a center of a top surface of the boss region; the first trench is located on the boss Within the area and surrounding at least a part of the outer periphery of the light window, and separated from the second trench; the first trench penetrates at least the first trench from the top surface of the boss area from top to bottom Two mirror layers, the oxide layer and the activation layer.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings of the present invention. However, the accompanying detailed description and accompanying drawings are only provided for reference and illustration and are not intended to limit the present invention. .

10: Base

21: The first mirror layer

22: activated layer

23: second mirror layer

231: Oxide layer

24: Ion implantation layer

240: upper surface

25: insulating layer

26: Dielectric materials

27: Metal layer

270: first contact layer

271:273: second contact layer

2710: top surface

274: light emitting layer

30: boss area

300: light window

31: The first ditch

32: The second ditch

321, 331: bottom

33: Third Ditch

51, 52: pattern

510, 520: central circle area

511: ring area

521: Peripheral Area

5100, 5110, 5200, 5210: mask

Figure 1 is a schematic cross-sectional view of a preferred embodiment of the vertical cavity surface-fired laser structure of the present invention; Figure 2A is a schematic diagram of the first stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention; Figure 2B It is a schematic diagram of an embodiment of the pattern of the first mask of the present invention; FIG. 3A is a schematic diagram of the second stage in the manufacturing method of the vertical cavity surface shot laser structure of the present invention; FIG. 3B is the second stage of the present invention The schematic diagram of the embodiment of the mask pattern; Figure 4 is a schematic diagram of the third stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention; Figure 5 is the manufacturing method of the vertical cavity surface-fired laser structure of the present invention Schematic diagram of the fourth stage; Figure 6 is a schematic diagram of the fifth stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention; and Figure 7 is the sixth stage of the manufacturing method of the vertical cavity surface-fired laser structure of the present invention Schematic.

The vertical cavity surface-fired laser structure and manufacturing method of the present invention mainly uses a unique three-channel structure to reduce the overall capacitance, shorten the oxidation process time, and form a stepped double-layered boss structure to reduce the thermal effect. In addition, the ion implantation area around the light window is used to control the modal and current limiting, and an outgoing light layer is formed on the light window to control the light.

Please refer to FIG. 1, which is a schematic cross-sectional view of a preferred embodiment of the vertical cavity surface-fired laser structure of the present invention.

In this embodiment, the vertical cavity surface-fired laser structure of the present invention is constructed on a laser chip substrate mainly made of gallium arsenide (GaAs) or indium phosphide (InP). And the substrate sequentially includes from bottom to top: a substrate 10, a first mirror layer 21 on the substrate 10, an active layer 22 (Active Region) on the first mirror layer 21, and a second The mirror layer 23 is located on the activation layer 22. An oxide layer 231 (Oxide Layer) is sandwiched in the second mirror layer 23. In this embodiment, the first mirror layer 21 is an n-type distributed Bragg reflector (distributed Bragg reflector; DBR for short), which can also be called a lower mirror layer, and the second mirror layer 23 is a p-type The distributed Bragg mirror layer may also be referred to as the upper mirror layer. The material of the first mirror layer 21 and the second mirror layer 23 includes a multilayer structure of aluminum gallium arsenide (AlGaAs) with different percentages of aluminum mol, and the oxide layer 231 has an opposite The highest molar percentage of aluminum. Therefore, during the oxidation process, the oxide layer 231 can form insulating aluminum oxide (Al2O3) during the oxidation process.

The vertical cavity surface-fired laser structure of the present invention further includes on the substrate: a boss region 30 (Mesa), a first trench 31 (Isolation Trench), a second trench 32, and a third trench 33 , A dielectric material 26 (Dielectric Material), a first contact layer 270 (Contact Layer), a second contact layer 271~273, an ion implantation layer 24 (Implant Region), an insulating layer 25 (Insolating Layer) , And a power output layer 274 (Power Output Layer).

The boss area 30 is located on the substrate 10 and is composed of at least a part of the first mirror layer 21, the active layer 22, the second mirror layer 23, and the oxide layer 231. A light window 300 is provided at a center of a top surface of the boss area 30. In this embodiment, the oxide layer 231 is close to the bottom of the ion implantation layer 24 in height, and even partially overlaps.

The first trench 31 is located in the boss area 30 and surrounds at least a part of the outer periphery of the light window 300. The first trench 31 penetrates at least the second mirror layer 23, the oxide layer 231 and the activation layer 22 from the top surface of the boss region 30 from top to bottom, so that the bottom of the first trench 31 is located at the first Mirror layer 21.

The second trench 32 surrounds at least a part of the outer periphery of the upper half of the boss area 30 and is spaced apart from the first trench 31. The second trench 32 penetrates at least the second mirror layer 23 and the oxide layer 231 from top to bottom, so that a bottom 321 of the second trench 32 is located at the active layer 22 or the first mirror layer 21. One of them. The oxide layer 231 extends horizontally from the inner periphery of the trench 31 toward the center of the boss region 30.

The third trench 33 surrounds at least a part of the outer periphery of the lower half of the boss area 30 and is recessed downward from the bottom 321 of the second trench 32. Moreover, the third trench 33 penetrates at least the first mirror layer 21 (or through the active layer 22 and the first mirror layer 21) from top to bottom, so that a bottom 331 of the third trench 33 is located on the At the upper surface of the substrate 10.

In this embodiment, it is preferable that the dielectric material 26 is a polymer material with low dielectric properties, and the dielectric material 26 is filled at least in the first trench 31, which can reduce the vertical cavity surface laser The effectiveness of the overall capacitance of the radiation structure. In this embodiment, the dielectric material 26 is a polymer, which can be Polymide, and has a reflection coefficient of 1.5 to 1.6. In the present invention, by digging the first trench 31 and filling the polymer (dielectric material 26), the area of the semiconductor material with high dielectric coefficient can be reduced, so the capacitance can be reduced. The first contact layer 270 and the second contact layers 271 to 273 are all part of the metal layer 27. The first contact layer 270 is located on the top surface of the boss area 30 and contacts an upper surface 240 of the second mirror layer 23. The second contact layers 271, 272, and 273 are at least located at the bottom 331 of the third trench 33 and at least in contact with the substrate 10. In this embodiment, the second contact layers 271, 272, and 273 extend upward from the bottom 331 of the third trench 33 along the third trench 33 and the second trench 32 each having an inclined surface. The upper surface 240 of the second mirror layer 23 makes a top surface 2710 of the second contact layer 271, 272, and 273 approximately the same height as the top surface of the first contact layer 270. Therefore, the first contact layer 270 and the second contact layers 271, 272, and 273 of the present invention are not only located on the same surface of the substrate 10, but also located at approximately the same height, which facilitates the subsequent wire bonding process. In addition, a plane is formed on the bottom 321 of the second trench 32, so that the second contact layers 271, 272, and 273 form a horizontally extending state on the bottom 321 of the second trench 32. In this way, not only can a stepped double-layer boss structure be formed, the larger lower boss can increase the heat dissipation area and reduce the thermal effect, and at the same time, the two-stage recessed inclined surfaces of the second and third trench structures 32, 33 The slope becomes slower and the bottom 321 of the second trench 32 forms a plane, so that the second contact layer 271, 272, 273 is less likely to cause gold breakage during electroplating, sputtering, or vapor deposition of the metal layer.

The ion implantation layer 24 is located in the second mirror layer 23 and above the active layer 22. In this embodiment, the bottom of the ion implantation layer 24 partially overlaps the oxide layer 231, and the relative aperture size of the oxide layer 231 and the ion implantation 24 is used to control the optical mode. Among them, ion implantation belongs to gain-guided, and oxidation belongs to index guided. The mixed application of the two can control the optical mode. Moreover, the ion implantation layer 24 located in the boss area 30 is located between the light window 300 and the first trench 31 and surrounds at least a part of the outer periphery of the light window 300. Wherein, the first contact layer 270 is in contact with an upper surface of the ion implantation layer 24. In the present invention, the ion implantation area 24 is additionally provided around the light window 300, which can be used to control the optical mode and limit the current. In this embodiment, the ion implantation process can implant protons (Proton) or oxygen ions. Between 2~4um.

The insulating layer 25 covers at least a part of an outer surface of the boss region 30, and at least a part of the first contact layer 270 and the second contact layers 271, 272, 273 are exposed to the insulating layer 25 outside. The light-emitting layer 274 is located on the light window 300 on the top surface of the boss region 30 and can be used to control the light. The principle is to adjust the refractive index, thickness and optical wavelength of the material of the light-emitting layer 274. In this embodiment, the material of the light emitting layer 274 can be Si3N4, SiO2, Si3O4, SiN, or SiNO, etc. In this embodiment, the light-emitting layer 274 can be a dielectric material, and the material composition can be silicon dioxide (SiO2), silicon nitride (SiN) or a mixture of these two materials, and the reflection coefficient is between 1.5 and 2.0.

Please refer to FIGS. 2A to 7, which are schematic diagrams of several stages of a preferred embodiment of the manufacturing method of the vertical cavity surface-fired laser structure of the present invention.

As shown in FIG. 2A, it is a schematic diagram of the first stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention. The manufacturing method of the vertical cavity surface-fired laser structure of the present invention firstly provides a laser wafer substrate, on which the laser wafer substrate is formed sequentially from bottom to top: a substrate 10, a first mirror layer 21 On the substrate 10, an active layer 22 is on the first mirror layer 21, and the second mirror layer 23 is on the active layer 22. Next, using a first mask and implementing a first mask process procedure, a first mask layer having a first predetermined pattern is formed on an upper surface 240 of the second mirror layer 23, the first predetermined pattern It is the pattern 51 corresponding to the first mask. As shown in FIG. 2B, it is a schematic diagram of an embodiment of the pattern 51 of the first mask of the present invention. The pattern 51 of the first mask includes a central circular area 510 and an annular area 511 surrounding the periphery of the central circular area; wherein the radius of the central circular area 510 is r1, and the circular area 511 The radius of the inner circumference is r2, and the radius of the outer periphery of the annular region 511 is r3. The center circle area 510 of the first mask pattern 51 defines the position of the light window 300 that will be covered by the mask 5100 on the upper surface 240 of the second mirror layer 23, and the ring of the first mask pattern 51 The shaped area 511 defines an area where the upper surface 240 of the second mirror layer 23 will be covered by the mask 5110 and will not be implanted by ions. The first mask layer includes the masks 5100 and 5110. Next, as shown in FIG. 2A, an ion implantation procedure is implemented to perform ion implantation on the area of the second mirror layer 23 not covered by the first mask layer (masks 5100, 5110) to form an ion implant The implanted layer 24, and a bottom of the ion implanted layer 24 and the activation layer 22 are still separated by a predetermined height. In this embodiment, a part of the bottom of the ion implantation effective area may overlap with the position of the oxide layer. In the present invention, the ion implantation area 24 is additionally provided around the light window 300, which can be used to control the mode and limit the current.

As shown in FIG. 3A, it is a schematic diagram of the second stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention. In the case where the first mask layers 5100 and 5110 have not been removed, a second mask is used and a second mask process procedure is performed. On the upper surface 240 of the second mirror layer 23 and the first mask A second mask layer having a second predetermined pattern is formed above the layers 5100 and 5110, and the second predetermined pattern corresponds to the pattern 52 of the second mask. As shown in FIG. 3B, it is a schematic diagram of an embodiment of the pattern 52 of the second mask of the present invention. The pattern 52 of the second mask includes a central circular area 520 and a peripheral area 521 surrounding the periphery of the central circular area; wherein the radius of the central circular area 520 is R1, which is within the peripheral area 521 The radius of the circumference is R2. The central circular area 520 and the peripheral area 521 of the second mask pattern 52 define the positions on the upper surface 240 of the second mirror layer 23 that will be covered by the masks 5200, 5210, and are not covered by the masks 5200, The area covered by 5210 is the location where the first trench 31 will be etched later. The second mask layer includes the masks 5200 and 5210.

In this embodiment, the value of the radius R1 of the central circular area 520 of the second mask pattern 52 is between the inner radius r2 and the outer radius r3 of the annular area 511 of the first mask pattern 51 In other words, r2<R1<r3; and, the value of the radius R2 of the inner circumference of the peripheral area 521 of the second mask pattern 52 is greater than the value of the ring-shaped area 511 of the first mask pattern 51 The outer radius r3, that is, r3<R2. Therefore, when performing the aforementioned two mask process procedures of the first mask and the second mask, it will have a self-alignment effect, so that the aperture of the oxide layer 231 obtained by the subsequent process is aligned with the aperture of the ion implantation layer 24 Increased accuracy.

Next, as shown in FIG. 4, it is a schematic diagram of the third stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention. A first etching process is performed to etch the second mirror layer 23, the activation layer 22, and the area of the first mirror layer 21 not covered by the second mask layer (mask 5200, 5210) to form a The first trench 31, and the first trench 31 penetrates the second mirror layer 23 and the activation layer 22 downward from the upper surface 240 of the second mirror layer 23, so that a bottom of the first trench 31 is located The first mirror layer 21.

Next, as shown in FIG. 5, it is a schematic diagram of the fourth stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention. An oxidation process is performed to form a horizontally extending oxide layer 231 in the second mirror layer 23 through the first trench 31, and the oxide layer 231 is close to the ion implantation layer 24 in height, even There may be a partial overlap, and the oxide layer 231 is located on the active layer 22. Compared with the conventional technology, which does not have the structure of the first trench 31, the oxidation process of the oxide layer must be performed through the second trench 32, in the present invention, since the oxidation process of the oxide layer 231 is relatively speaking The first trench 31 is closer to the light window 300, so the required oxidation distance is relatively short, and the time required for the oxidation process is therefore shortened, and the problem of stress accumulation due to the long oxidation distance of the oxide layer 231 is reduced. .

Next, as shown in FIG. 6, it is a schematic diagram of the fifth stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention. A second etching process is performed to form a second trench 32 on the second mirror layer 23, and the second trench 32 penetrates at least through the second mirror from the upper surface 240 of the second mirror layer 23 downward The layer 23 and the oxide layer 231 make a bottom 321 of the second trench 32 located at either the active layer 22 or the first mirror layer 21. In addition, a contact pad is formed on a predetermined area of the upper surface 240 of the second mirror layer 23 by a metal plating process, which will become a part of the first contact layer 270 later.

Next, as shown in FIG. 7, it is a schematic diagram of the sixth stage in the manufacturing method of the vertical cavity surface-fired laser structure of the present invention. A third etching process is performed to form a downwardly recessed third trench 33 at the bottom 321 of the second trench 32, and the third trench 33 penetrates at least the first mirror layer 21 from top to bottom ( Or penetrate the active layer 22 and the first mirror layer 21) so that a bottom 331 of the third trench 33 is located at the substrate 10.

Afterwards, a dielectric material 26 is filled in the first trench 31 to provide the effect of reducing the overall capacitance of the vertical resonant cavity surface-fired laser structure; and to form an appropriate area on the laser chip substrate. The light emitting layer 274, an insulating layer 25, and a metal layer 27 (including the first contact layer 270 and the second contact layers 271, 272, and 273). In this way, the vertical cavity surface-fired laser structure of the present invention as shown in FIG. 1 can be manufactured.

In this embodiment, as shown in FIG. 1, the second trench 32 and the third trench 33 define a boss area 30 on the laser chip substrate, and the second trench 32 and the third trench Both the trenches 33 surround at least a part of the outer periphery of the boss area 30. The boss area 30 is located on the substrate 10 and is composed of at least a part of the first mirror layer 21, the active layer 22, the second mirror layer 23 and the oxide layer 231. A light window 300 is provided at a center of a top surface of the boss area 30. The first trench 31 is located in the boss area 30 and surrounds at least a part of the outer periphery of the light window 300 and is separated from the second trench 32 by a distance. The first trench 31 penetrates at least the second mirror layer 23, the oxide layer 231 and the activation layer 22 from the top surface of the boss region 30 from top to bottom.

In this embodiment, the light-emitting layer 274 is located on the light window 300 on the top surface of the boss area 30 and can be used to control light-emitting. The ion implantation layer 24 is located in the second mirror layer 23 and above the oxide layer 231, but the bottom of the ion implantation layer 24 can partially overlap with the oxide layer 231, and is located in the boss region 30 The ion implantation layer 24 is located between the light window 300 and the first trench 31 and surrounds at least a part of the outer periphery of the light window 300, and can be used to control mode and limit current.

In this embodiment, the first contact layer 270 is located on the top surface of the boss area 30 and contacts the upper surface of the second mirror layer 23. The second contact layers 271, 272, 273 are located at least at the bottom 331 of the third trench 33 and at least contact the substrate 10, and the second contact layers 271, 272, 273 are formed by the third trench 33 The bottom 331 has an inclined surface along the third trench 33 and the second trench 32, respectively, and extends upward to the upper surface of the second mirror layer 23, so that a top surface of the second contact layer 271, 272, 273 The surface is approximately at the same height as the first contact layer 270. Therefore, the first contact layer 270 and the second contact layers 271, 272, 273 is not only located on the same surface of the substrate 10, but also located at approximately the same height position, which can facilitate the subsequent wire bonding process. At least a part of the first contact layer 270 and the second contact layers 271, 272, and 273 are exposed outside the insulating layer 25. Wherein, a plane is formed on the bottom 321 of the second trench 32, so that the second contact layers 271, 272, 273 form a horizontally extending state on the bottom 321 of the second trench 32. In this way, not only can a stepped double-layer boss structure be formed, the larger lower boss can increase the heat dissipation area and reduce the thermal effect, and at the same time, the two-stage recessed inclined surfaces of the second and third trench structures 32, 33 The slope becomes slower and the bottom 321 of the second trench 32 forms a plane, so that the second contact layer 271, 272, 273 is less likely to cause gold breakage during electroplating, sputtering, or vapor deposition of the metal layer.

The above descriptions are only the preferred and feasible embodiments of the present invention, and do not limit the patent scope of the present invention. Therefore, all equivalent technical changes made by using the description and illustrations of the present invention are included in the scope of the present invention.

10‧‧‧Base

21‧‧‧First mirror layer

22‧‧‧Activated layer

23‧‧‧Second mirror layer

231‧‧‧Oxide layer

24‧‧‧Ion implantation layer

240‧‧‧Upper surface

25‧‧‧Insulation layer

26‧‧‧Dielectric materials

27‧‧‧Metal layer

270‧‧‧First contact layer

271~273‧‧‧Second contact layer

2710‧‧‧Top surface

274‧‧‧light emitting layer

30‧‧‧Protrusion area

300‧‧‧Light window

31‧‧‧First Ditch

32‧‧‧Second Ditch

321, 331‧‧‧Bottom

33‧‧‧Third Ditch

Claims (10)

A vertical cavity surface-fired laser structure, comprising: a substrate; a first mirror layer on the substrate; an active layer on the first mirror layer; a second mirror layer on the active layer; An oxide layer is sandwiched in the second mirror layer; a boss area is located on the substrate and consists of at least a part of the first mirror layer, the activation layer, the second mirror layer, and the oxide layer Assembled, there is a light window at a center of a top surface of the boss area; a first trench is located in the boss area and surrounds at least a part of the outer periphery of the light window The first trench is from the top surface of the boss region through at least the second mirror layer, the oxide layer and the activation layer from top to bottom; a second trench surrounds the outer periphery of the boss region At least a part of and spaced apart from the first trench, the second trench at least penetrates the second mirror layer and the oxide layer from top to bottom, so that a bottom of the second trench is located on the active layer Or the first mirror layer; a third trench, which surrounds at least a part of the outer periphery of the boss area and is recessed downward from the bottom of the second trench, and the first Three trenches penetrate at least the first mirror layer from top to bottom, so that a bottom of the third trench is located at the substrate; a dielectric material is filled at least in the first trench; a first contact layer is located The top surface of the boss area is in contact with the second mirror layer; and a second contact layer is located at least at the bottom of the third trench and at least in contact with the substrate. The vertical cavity surface-fired laser structure described in the first item of the scope of patent application, wherein: the vertical cavity surface-fired laser structure further includes an insulating layer covering at least a part of an outer surface of the boss area And at least a part of the first contact layer and the second contact layer are exposed outside the insulating layer; the first mirror layer is an n-type distributed Bragg reflector (DBR) , And the second mirror layer is a p-type distributed Bragg reflector layer; the materials of the first mirror layer and the second mirror layer include aluminum gallium arsenide (AlGaAs) with different aluminum mole percentages, and the The oxide layer in the second mirror layer is aluminum with the relatively highest molar percentage; the oxide layer extends at least horizontally from the inner periphery of the first trench toward the center of the boss region; the dielectric material has low dielectric properties的 polymer material; and the first contact layer and the second contact layer are both metal layers. The vertical resonant cavity surface-fired laser structure described in item 1 of the scope of patent application further includes: an ion implantation layer located in the second mirror layer and whose height is close to or overlapping with the oxide layer, and , The ion implantation layer located in the boss area is located between the light window and the first trench and surrounds at least a part of the outer periphery of the light window; wherein, the first contact layer is It is in contact with an upper surface of the second mirror layer. As described in item 1 of the scope of patent application, the vertical resonant cavity surface-fired laser structure further includes: a light emitting layer located on the light window on the top surface of the boss area. The vertical resonant cavity surface-fired laser structure described in the first item of the scope of patent application, wherein: the second contact layer is formed from the bottom of the third trench along the third trench and the second trench. An inclined surface extends upward to an upper surface of the second mirror layer, so that a top surface of the second contact layer is substantially at the same height as the first contact layer; a bottom of the second trench is formed The plane makes the second contact layer form a horizontally extending state at the bottom of the second trench. A method for manufacturing a vertical cavity surface-fired laser structure includes the following steps: a laser chip substrate is provided on which a semiconductor manufacturing process is formed from bottom to top: a substrate, a substrate A mirror layer is located on the substrate, an activation layer is located on the first mirror layer, and a second mirror layer is located on the activation layer; a first mask is used and a first mask process procedure is performed, and the second mirror layer is A first mask layer having a first predetermined pattern is formed on an upper surface of the mirror layer, the first predetermined pattern is corresponding to the pattern of the first mask; an ion implantation procedure is performed to the second mirror layer The area not covered by the first photoresist layer is ion implanted to form an ion implantation layer, and a bottom of the ion implantation layer is still a predetermined height away from the activation layer; the first mask has not been removed In the case of layer, a second mask is used and a second mask manufacturing process is performed, and a first mask with a second predetermined pattern is formed on the upper surface of the second mirror layer and above the first mask layer Two mask layers, the second predetermined pattern is a pattern corresponding to the second mask; a first etching process is performed, and the second mirror layer, the activation layer, and the first mirror layer are not covered by the second mirror layer The area covered by the mask layer is etched to form a first trench, and the first trench penetrates the second mirror layer and the activation layer from the upper surface of the second mirror layer downward to make the first trench A bottom is located on the first mirror layer; an oxidation process is performed to form an oxide layer extending horizontally in the second mirror layer through the first trench, and the oxide layer is close to or overlaps the second mirror layer in height The bottom of the ion implantation layer; a second etching process is performed to form a second trench on the second mirror layer, and the second trench is from the upper surface of the second mirror layer downward at least through the The second mirror layer and the oxide layer are such that a bottom of the second trench is located at one of the active layer or the first mirror layer; and a metal plating process is performed on the second mirror layer A predetermined area of the upper surface forms a contact pad; a third etching process is performed to form a third trench recessed downward at the bottom of the second trench, and the third trench is at least from top to bottom Pass through the first mirror layer so that a bottom of the third trench is located at the substrate; and fill a dielectric material in the first trench, and respectively form an appropriate area on the laser chip substrate An insulating layer, a first contact layer, and a second contact layer; wherein the second trench and the third trench define a boss area on the laser chip substrate, the second trench and the first Both of the three trenches surround at least a part of the outer periphery of the boss area; the boss area is located on the substrate and consists of at least a part of the first mirror layer, the activation layer, and the second The two mirror layers and the oxide layer are composed of a light window at a center of a top surface of the boss area; the first trench is located in the boss area and surrounds the light window At least a part of the outer periphery of the rim and the second trench is separated by a distance; the first trench is from the top surface of the boss region through at least the second mirror layer, the oxide layer and the activation Layer; where , The first contact layer is located on the top surface of the boss area and in contact with the second mirror layer; the second contact layer is located at least on the bottom of the third trench and at least in contact with the substrate, and the The second contact layer extends upward to the upper surface of the second mirror layer from the bottom of the third trench along the third trench and the second trench each having an inclined surface, so that the second contact layer A top surface of is substantially located at the same height as the first contact layer; at least a part of the first contact layer and the second contact layer are exposed outside the insulating layer. As described in item 6 of the scope of patent application, the method for manufacturing a vertical cavity surface-fired laser structure, wherein: the first mirror layer is an n-type distributed Bragg reflector (DBR), and the first mirror layer The second mirror layer is a p-type distributed Bragg reflector layer; the materials of the first mirror layer and the second mirror layer include aluminum gallium arsenide (AlGaAs) with different percentages of aluminum mol, and the oxide layer is in the first The second mirror layer is aluminum with the relatively highest molar percentage; the oxide layer extends horizontally at least from the inner periphery of the first trench toward the center of the boss area; the dielectric material is a polymer material with low dielectric properties ; And the first contact layer and the second contact layer are both metal layers. As described in item 6 of the scope of patent application, the method for manufacturing a vertical resonant cavity surface shot laser structure, wherein the ion implantation layer is located in the second mirror layer, and the ion implantation layer located in the boss region The layer is located between the light window and the first trench and surrounds at least a part of the outer periphery of the light window. As described in item 6 of the scope of patent application, the manufacturing method of the vertical resonant cavity surface-fired laser structure further includes the following steps: forming a light emitting layer, which is located on the light window on the top surface of the boss area. The method for manufacturing a vertical resonant cavity surface-fired laser structure as described in item 6 of the scope of patent application, wherein a plane is formed on the bottom of the second trench, so that the second contact layer is formed on the bottom of the second trench A state of horizontal extension.

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