Optical device and manufacturing method thereof
By using high-refractive-index anti-reflective coatings, high-reflective coatings and cover layers in the packaging shell of the semiconductor laser, the problem of optical performance degradation caused by water vapor penetration is solved, and stable operation in high-humidity environments is achieved. And reduce the cost and assembly difficulty.
Patent Information
- Application Number
- CN202410929100.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-17
- Filing Date
- 2024-07-11
- Publication Date
- 2025-01-17
AI Technical Summary
When used in high-temperature and high-humidity environments, the packaged shells of existing semiconductor lasers are easily affected by moisture infiltration, resulting in a decrease in optical performance. At the same time, the cost of packaging the shells is high and the assembly is difficult.
An anti-reflective film layer and a high-reflective film layer with a high refractive index are used, combined with a cover layer, to cover the front, rear and top surfaces of the semiconductor stack structure to prevent moisture from entering. The anti-reflective film layer and the high-reflective film layer respectively increase the laser transmittance and reduce the laser loss through multiple staggered dielectric film layers.
Without adding a metal or ceramic packaging shell, it can effectively prevent moisture from entering the semiconductor stack structure, reduce costs, reduce assembly steps, and improve the moisture resistance and interference resistance of optical devices.
Smart Images
Figure CN119324371A_ABST
Abstract
Description
[0001] The present invention claims priority to and the benefits of Taiwan Invention Patent Application No. 112126616 filed on July 17, 2023, the entire contents of which are incorporated herein by reference. Technical Field
[0002] The present disclosure relates to an optical device and a manufacturing method thereof, and more particularly to a semiconductor laser element having a sealing coating to prevent water vapor from invading and a manufacturing method thereof. Background Art
[0003] Semiconductor lasers (or laser diodes) have the advantages of small size, low power consumption, fast response, impact resistance, long life, high efficiency and low price, so they are widely used in optical communication systems. In urban areas, optical communication systems are mostly installed in underground conduits. In order to reduce the impact of high temperature and high humidity on the optical performance of laser diodes, they are usually installed in underground conduits. Figure 1 and Figure 2 The package housing 10 shown hermetically packages the laser diode chip to prevent moisture in the environment from penetrating into the laser diode.
[0004] Please refer to Figure 1 and Figure 2 , Figure 1 is a cross-sectional view of a semiconductor laser package 10 of the prior art. Figure 2 It is a bottom view of a semiconductor laser package shell 10 of the prior art. The package shell 10 includes a base 110, a plurality of pins 120, a cylindrical cover 130 and a lens 140; the base 110 can be made of metal or ceramic material, the pins 120 penetrate the upper and lower surfaces of the base 110, and an insulating layer 150 can be arranged between the base 110 and each pin 120 to isolate the conductivity of the base 10 and each pin 120. The laser diode chip (not shown) is mounted on the base 110 and is electrically connected to the pins 120. The cylindrical cover 130 is an airtight sealing cover, which is combined with the base 110 to airtightly seal the laser diode chip to improve the moisture resistance and interference resistance of the laser diode chip. The lens 140 is arranged on the top of the cylindrical cover 130, and is used to focus or collimate the laser emitted from the laser diode chip and then inject it into the optical fiber in the optical communication system.
[0005] However, the use of the packaging shell 10 not only increases the cost of the optical communication system, but also increases the difficulty of assembling the cylindrical cover 130 and the base 110 due to the very high requirements for the installation and alignment of the lens 140 and the laser diode chip.
[0006] The above “prior art” only provides background information and is not used to admit that the subject matter disclosed in the above “prior art” constitutes the prior art of the present disclosure, and any part of the above “prior art” is not used to admit that any part of the present invention (including the above “prior art”) constitutes the prior art of the present disclosure. Summary of the invention
[0007] One embodiment of the present disclosure provides an optical device, which includes a semiconductor stacking structure, an anti-reflection film layer and a high-reflection film layer. The semiconductor stacking structure is used to generate laser light when receiving current, and the laser light is emitted from the front end face of the semiconductor stacking structure, wherein the front end face is the side face of the semiconductor stacking structure; the anti-reflection film layer is arranged on the front end face, and is used to improve the penetration rate of the laser light; the high-reflection film layer is arranged on the rear end face of the semiconductor stacking structure, wherein the rear end face is the other side face of the semiconductor stacking structure, and the high-reflection film layer is used to reduce the loss of the laser light on the rear end face. The refractive index of the anti-reflection film layer and the high-reflection film layer is greater than 2, and the thickness of the high-reflection film layer is greater than the thickness of the anti-reflection film layer.
[0008] In some embodiments, the anti-reflection film layer and the high-reflection film layer include tantalum pentoxide.
[0009] In some embodiments, the optical device further includes a cap layer disposed on a top surface of the semiconductor stack structure, wherein a refractive index of the cap layer is greater than 1.4.
[0010] In some embodiments, the capping layer includes silicon dioxide or silicon nitride.
[0011] In some embodiments, the semiconductor stacking structure includes a substrate, an active layer, a first coating layer, and a second coating layer, the active layer is disposed on the substrate, the first coating layer is disposed between the substrate and the active layer, and the second coating layer is disposed on the active layer; the optical device also includes a first electrode layer and a second electrode layer, the first electrode layer is disposed below the substrate, the second electrode layer is disposed above the second coating layer and is at least partially exposed outside the cover layer.
[0012] One embodiment of the present disclosure provides another optical device, which includes a semiconductor stack structure, an anti-reflection film layer and a high-reflection film layer; the semiconductor stack structure is used to generate laser light when receiving current, and the laser light is emitted from the front end face of the semiconductor stack, wherein the front end face is the side face of the semiconductor stack structure; the anti-reflection film layer is disposed on the front end face of the semiconductor stack structure to improve the penetration rate of the laser light; the high-reflection film layer is disposed on the rear end face of the semiconductor stack structure to reduce the loss of the laser light at the rear end face, wherein the rear end face is the other side face of the semiconductor stack structure. The anti-reflection film layer and the high-reflection film layer respectively include a plurality of first dielectric film layers and at least one second dielectric film layer arranged in an alternating manner, the first dielectric film layer and the second dielectric film layer have different refractive indices, and the refractive indices of the first dielectric film layer and the second dielectric film layer are greater than 1.4.
[0013] In some embodiments, a first dielectric film layer in the anti-reflection film layer contacts the front end surface of the semiconductor stack structure, and a first dielectric film layer in the high-reflection film layer contacts the rear end surface of the semiconductor stack structure.
[0014] In some embodiments, the refractive index of the first dielectric film layer is greater than the refractive index of the second dielectric film layer, a first dielectric film layer in the anti-reflective film layer is arranged farthest from the front end surface of the semiconductor stack structure, and a first dielectric film layer in the high-reflective film layer is arranged farthest from the rear end surface of the semiconductor stack structure.
[0015] In some embodiments, the first dielectric film layer includes tantalum pentoxide, and the second dielectric film layer includes silicon dioxide.
[0016] In some embodiments, the reflectivity of the anti-reflection film layer is lower than 0.2%, and the reflectivity of the high-reflection film layer is higher than 80%.
[0017] In some embodiments, the first thickness of the anti-reflection film layer is less than the second thickness of the high-reflection film layer, the first thickness is at least 450 nm, and the second thickness is about 1200 nm.
[0018] In some embodiments, the optical device also includes a cover layer, which is disposed on the semiconductor stack structure and includes a plurality of third dielectric film layers and a plurality of fourth dielectric film layers alternately arranged, the refractive index of the plurality of third dielectric film layers is different from the refractive index of the plurality of fourth dielectric film layers, and the refractive index of the third dielectric film layers and the fourth dielectric film layers are both greater than 1.4.
[0019] In some embodiments, the number of the third dielectric film layers is equal to the number of the fourth dielectric film layers.
[0020] In some embodiments, the third dielectric film layer includes silicon dioxide, and the fourth dielectric film layer includes silicon nitride.
[0021] In some embodiments, the third dielectric film layer includes silicon nitride, and the fourth dielectric film layer includes silicon dioxide.
[0022] In some embodiments, the semiconductor stacking structure includes a substrate, an active layer, a first coating layer, and a second coating layer, the active layer is disposed on the substrate, the first coating layer is disposed between the substrate and the active layer, and the second coating layer is disposed on the active layer; the optical device also includes a first electrode layer and a second electrode layer, the first electrode layer is disposed below the substrate, the second electrode layer is disposed above the second coating layer and is at least partially exposed outside the cover layer.
[0023] Another embodiment of the present disclosure provides a method for manufacturing an optical device, including: providing a semiconductor stacking structure, which can generate laser when receiving current, and the laser is emitted from the front end surface of the semiconductor stacking structure, wherein the front end surface is the side surface of the semiconductor stacking structure; and coating a first dielectric film layer on the front end surface and the rear end surface of the semiconductor stacking structure, the refractive index of the first dielectric film layer is greater than 2, wherein the rear end surface is a side surface of the semiconductor stacking structure that is roughly parallel to the front end surface.
[0024] In some embodiments, the method for manufacturing an optical device further includes: coating a second dielectric film layer on a surface of the first dielectric film layer, wherein the refractive index of the second dielectric film layer is approximately 1.4; and coating another first dielectric film layer on a surface of the second dielectric film layer.
[0025] In some embodiments, the method for manufacturing an optical device further includes: coating a third dielectric film layer on the top surface of the semiconductor stack structure, wherein the refractive index of the third dielectric film layer is greater than 1.4.
[0026] In some embodiments, the method for manufacturing an optical device further includes: coating a fourth dielectric film layer on the third dielectric film layer, wherein the refractive index of the fourth dielectric film layer is different from the refractive index of the third dielectric film layer, and the refractive index of the fourth dielectric film layer is greater than 1.4.
[0027] The optical device provided by the present disclosure uses a film layer with a refractive index of not less than 1.4 as an anti-reflection film layer, a high-reflection film layer and a cover layer to cover the front end face, the rear end face and the top surface of the semiconductor stack structure, which can prevent moisture from entering the semiconductor stack structure; therefore, the optical device of the present disclosure can be used in optical communication systems that are usually assembled in high humidity environments without adding additional metal or ceramic packaging shells, which has the advantages of reducing costs and reducing assembly steps. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The content of the present disclosure can be more fully understood by referring to the embodiments and claims, and the present disclosure should also be understood to be associated with the reference numerals of the accompanying drawings, which refer to similar elements throughout the description of the embodiments.
[0029] Figure 1 It is a cross-sectional view of a semiconductor laser package shell in the prior art.
[0030] Figure 2 It is a bottom view of a semiconductor laser packaging shell in the prior art.
[0031] Figure 3 is a stereogram of an optical device drawn according to some embodiments of the present disclosure.
[0032] Figure 4 is a side view of an optical device according to some embodiments of the present disclosure.
[0033] Figure 5 is a cross-sectional view of a semiconductor stacked structure drawn according to some embodiments of the present disclosure.
[0034] Figure 6 is a stereogram of an optical device drawn according to some embodiments of the present disclosure.
[0035] Figure 7 is a side view of an optical device according to some embodiments of the present disclosure.
[0036] Figure 8 is a cross-sectional view of a semiconductor stacked structure drawn according to some embodiments of the present disclosure.
[0037] Fig. 9 is a cross-sectional view of an anti-reflection film layer drawn according to some embodiments of the present disclosure.
[0038] Fig.10 is a cross-sectional view of an anti-reflection film layer drawn according to some embodiments of the present disclosure.
[0039] Fig.11 is a cross-sectional view of a cover layer drawn according to some embodiments of the present disclosure.
[0040] Fig.12 is a flow chart of a method for manufacturing an optical device drawn according to some embodiments of the present disclosure.
[0041] Fig.13 A picture to Fig.13 The D graphs are based on Fig.12 Schematic diagram of the operating steps drawn for the method of making an optical device.
[0042] The reference numerals are as follows:
[0043] 10: Encapsulation shell
[0044] 20: Optical Devices
[0045] 40: Optical Devices
[0046] 110: Base
[0047] 120: Pin
[0048] 130: Cylindrical cover
[0049] 140: Lens
[0050] 150: Insulation layer
[0051] 210:Semiconductor stack structure
[0052] 212: Front end
[0053] 214: rear end
[0054] 216: Top
[0055] 220:Substrate
[0056] 230: Active layer
[0057] 240: First coating layer
[0058] 250: Second coating layer
[0059] 260: first electrode layer
[0060] 270: Second electrode layer
[0061] 310: Anti-reflective film
[0062] 320: High reflective film
[0063] 330: Covering layer
[0064] 410:Semiconductor stack structure
[0065] 412: Front end
[0066] 414: rear end
[0067] 420:Substrate
[0068] 430: Active layer
[0069] 440: First coating layer
[0070] 450: Second coating layer
[0071] 452: Ridge Platform
[0072] 460: first electrode layer
[0073] 470: second electrode layer
[0074] 510: Anti-reflective film
[0075] 512: first dielectric film layer
[0076] 512A: first dielectric film layer
[0077] 512B: first dielectric film layer
[0078] 512C: First dielectric film layer
[0079] 512D: First dielectric film layer
[0080] 514: second dielectric film layer
[0081] 514A: second dielectric film layer
[0082] 514B: second dielectric film layer
[0083] 514C: Second dielectric film layer
[0084] 520: High reflective film
[0085] 530: Covering layer
[0086] 532: third dielectric film layer
[0087] 534: fourth dielectric film layer
[0088] 600: Method
[0089] 602,604,606,608: Steps
[0090] 710:Semiconductor stack structure
[0091] 712: front end
[0092] 714: rear end
[0093] 716: Top
[0094] 810: Anti-reflective film
[0095] 812: first dielectric film layer
[0096] 814: second dielectric film layer
[0097] 820: High reflective film
[0098] 822: third dielectric film layer
[0099] 824: fourth dielectric film layer
[0100] 830: Covering layer
[0101] 832: Fifth dielectric film layer
[0102] 834: Sixth dielectric film layer
[0103] T1: First thickness
[0104] T2: Second thickness
[0105] T3: The third thickness
[0106] T4: First thickness
[0107] T5: Second thickness
[0108] T6: The third thickness DETAILED DESCRIPTION
[0109] The following uses more specific text to describe various embodiments or examples of the present disclosure shown in the accompanying drawings. It should be understood that these descriptions are only illustrative and are not intended to limit the present disclosure. For those skilled in the art of the present disclosure, any changes or modifications to the described embodiments, as well as further applications of the principles described in this document, are generally customary changes. Component symbols may be reused between embodiments, but it does not mean that one or more features of one embodiment must appear in another embodiment, even if the same component symbols are used.
[0110] Spatially relative terms may be used herein, such as "below", "under", "below", "above", "above", etc., to facilitate description of the relationship between one (or some) element or component and another (or some) element or component in the drawings. In addition to the orientation depicted in the drawings, spatially relative terms are used to include different orientations of the device in use or operation. When the device is turned to a different orientation (rotated 90 degrees or other orientations), the spatially relative terms used herein will also be interpreted according to the orientation after the rotation.
[0111] Please refer to Figure 3 and Figure 4 , Figure 3 is a stereogram of an optical device 20 drawn according to some embodiments of the present disclosure, Figure 4 2 is a side view of an optical device 20 drawn according to some embodiments of the present disclosure. The optical device 20 includes a semiconductor stack structure 210, an anti-reflection film layer 310 disposed on the front end face 212 of the semiconductor stack structure 210, a high-reflection film layer 320 disposed on the rear end face 214 of the semiconductor stack structure 210, and a cap layer 330 disposed on the top surface 216 of the semiconductor stack structure 210; wherein the front end face 212 and the rear end face 214 are two opposite and substantially parallel side surfaces of the semiconductor stack structure 210, and the top surface 216 is adjacent to the front end face 212 and the rear end face 214.
[0112] The semiconductor stack structure 210 includes a plurality of semiconductor layers (eg Figure 5 As shown in FIG. 2 , these semiconductor layers are configured to form an edge emitting laser diode, which means that when the semiconductor stack structure 210 is biased, the laser light generated will be output from its front end surface 212. Figure 5The semiconductor stacked structure 210 includes a substrate 220, an active layer 230, a first coating layer 240, and a second coating layer 250; the first coating layer 240, the active layer 230, and the second coating layer 250 are sequentially disposed on the substrate 220 from bottom to top. The optical device 20 may further include a first electrode layer 260 and a second electrode layer 270 to facilitate application of a bias voltage to the semiconductor stacked structure 210; the first electrode layer 260 is disposed on or below the substrate 220, and the second electrode layer 270 is disposed on or above the upper surface of the second coating layer 250.
[0113] The substrate 220 is a growth and / or support base, and the substrate 220 may include indium phosphide (InP). The active layer 230 may include a multiple-quantum well structure to improve the light-emitting efficiency of the light-emitting device 20; in some embodiments, a double heterostructure or a single quantum well structure may also be used as the active layer 230. When a proper voltage is applied to both ends of the semiconductor stack structure 210 (i.e., the first electrode layer 260 and the second electrode layer 270), carriers (including electrons and holes) are injected into the active layer 230 and recombine in the active layer 230 to emit light.
[0114] The first cladding layer 240 has a lower refractive index than the active layer 230 to increase the possibility of total internal reflection of the light released from the active layer 230 at the interface between the active layer 230 and the first cladding layer 240; similarly, the second cladding layer 250 also has a lower refractive index than the active layer 230 to increase the possibility of total internal reflection of the light at the interface between the active layer 230 and the second cladding layer 250. In other words, the first cladding layer 240 and the second cladding layer 250 act to confine most of the light released from the active layer 230 in the active layer 230, and transmit between the anti-reflection film layer 310 and the high-reflection film layer 320 in a total internal reflection manner, and finally emit from the anti-reflection film layer 310.
[0115] In some embodiments, the first coating layer 240 and the second coating layer 250 may include indium phosphide and may be doped to have different conductivity types so as not to affect the carrier injection efficiency of the semiconductor stack structure 210 when it is subjected to a bias voltage; for example, when the first coating layer 240 is an n-type semiconductor layer, the second coating layer 250 is a p-type semiconductor layer.
[0116] Re-reference Figure 3 and Figure 4The reflectivity of the anti-reflection film layer 310 can be lower than 0.2%, thereby increasing the light emission efficiency; specifically, the anti-reflection film layer 310 can reduce the reflection of light at the front end surface 212 of the semiconductor stack structure 210, allowing the light to be emitted from the front end surface 212; the reflectivity of the high-reflection module 320 can be higher than 80%, which is used to prevent light from being emitted from the rear end surface 214 of the semiconductor stack structure 210 and reduce the light loss at the rear end surface 214 of the semiconductor stack structure 210.
[0117] exist Figure 3 and Figure 4 , the anti-reflection film layer 310 includes a single-layer structure, and the high-reflection film layer 320 includes a single-layer structure. Further, the anti-reflection film layer 310 and the high-reflection film layer 320 may be film layers with a high refractive index; herein, the high-refractive index film layer refers to a film layer with a refractive index of at least 1.4. Generally speaking, a film layer with a high refractive index has a denser structure, thereby having a better water vapor blocking ability and can act as a water vapor barrier layer; therefore, the use of a high-refractive index anti-reflection film layer 310 can prevent water vapor from penetrating into the semiconductor stack structure 210 from the front end face 212 of the semiconductor stack structure 210, and the use of a high-refractive index high-reflection film layer 320 can prevent water vapor from penetrating into the semiconductor stack structure 210 from the rear end face 214 of the semiconductor stack structure 210.
[0118] In some embodiments, the anti-reflective film layer 310 can be formed on the front end surface 212 of the semiconductor stack structure 210 by vapor deposition using a dielectric material with a refractive index greater than 2, and the high reflective layer 320 can also be formed on the rear end surface 214 of the semiconductor stack structure 210 by vapor deposition using a dielectric material with a refractive index greater than 2.
[0119] The anti-reflection film layer 310 and the high-reflection film layer 320 can be made of the same material, but have different thicknesses and different reflectivities. The anti-reflection film layer 310 and the high-reflection film layer 320 can be made of tantalum pentoxide (Ta2O5), the anti-reflection film layer 310 has a first thickness T1, the high-reflection film layer 320 has a second thickness T2, and the first thickness T1 is less than the second thickness T2 to provide a lower reflectivity so that light can be emitted from the front end 212 of the semiconductor stacked structure 210. In some embodiments, the first thickness T1 of the anti-reflection film layer 310 is not less than 450 nanometers, for example, it can be about 700 nanometers; the second thickness T2 of the high-reflection film layer 320 can be about 1200 nanometers.
[0120] The cap layer 330 is a dielectric film layer with a high refractive index to provide better waterproof performance; specifically, the cap layer 330 is made of a material with a refractive index of at least 1.4 and different from the anti-reflective film layer 310 and the high-reflective film layer 320. In some embodiments, the material of the cap layer 330 may be silicon dioxide (SiO2) or silicon nitride (Si3N4), and the cap layer 330 may have a third thickness T3 that is less than the first thickness T1 and the second thickness T2. The cap layer 330 may be, for example, formed on the top surface 216 of the semiconductor stack structure 210 and the second electrode layer 270 by vapor deposition; wherein the second electrode layer 270 is at least partially exposed outside the cap layer 330 to facilitate the application of voltage to the semiconductor stack structure 210. It should be particularly noted that the second electrode layer 270 can be brought into contact with the second coating layer 250 by, for example, a Damascus inlay process after the deposition of the cap layer 330 is completed, or the first electrode layer 260 and the second electrode layer 270 can be formed on the semiconductor stack structure 210 before the anti-reflection film layer 310, the high-reflection film layer 320 and the cap layer 330 are deposited, and when the cap layer 330 is deposited, at least a portion of the second electrode layer 270 is blocked by a barrier to allow at least a portion of the second electrode layer 270 to be exposed outside the cap layer 330; wherein the latter may have a better water vapor blocking ability than the former.
[0121] In summary, the optical device 20 provided by the present disclosure deposits film layers with high refractive index and good waterproof performance on the front face 212, the rear face 214 and the top face 216 of the semiconductor stack structure 210, respectively, to provide protection to prevent moisture from entering the semiconductor stack structure 210. Therefore, the optical device 20 of the present disclosure can be applied to optical communication systems that are usually assembled in high humidity environments without adding additional metal or ceramic packaging shells, which has the advantages of reducing costs and reducing assembly steps.
[0122] Please refer to Figure 6 and Figure 7 , Figure 6 is a stereogram of an optical device 40 drawn according to some embodiments of the present disclosure, Figure 7 4 is a side view of an optical device 40 drawn according to some embodiments of the present disclosure. The optical device 40 includes a semiconductor stack structure 410, an anti-reflection film layer 510 disposed on a front end face 412 of the semiconductor stack structure 410, and a high-reflection film layer 520 disposed on a rear end face 414 of the semiconductor stack structure 410; wherein the front end face 412 and the rear end face 414 are two opposite and substantially parallel side faces of the semiconductor stack structure 410.
[0123] The semiconductor stack structure 410 includes a plurality of semiconductor layers (eg Figure 8These semiconductor layers are configured to form an edge-emitting laser diode, which means that when the semiconductor stack structure 410 is biased, the laser light generated will be output from its front face 412. Figure 8 The semiconductor stacked structure 410 includes a substrate 420, an active layer 430, a first cladding layer 440, and a second cladding layer 450. The active layer 430 is disposed between the first cladding layer 440 and the second cladding layer 450, and the first cladding layer 440 contacts the substrate 420; the upper portion of the second cladding layer 450 is partially removed to form a ridge platform (ridge masa) 452. The optical device 40 also includes a first electrode layer 460 and a second electrode layer 470; the first electrode layer 460 is disposed on the lower surface of the substrate 420, and the second electrode layer 470 can be disposed on the ridge platform 452 and contact the second cladding layer 450.
[0124] The ridge platform 452 can limit the size and position of the current passing through the active layer 430 when a forward bias is applied to the semiconductor stack structure 410, so that the carriers injected into the active layer 430 can be recombined only in the local area below the ridge platform 452; therefore, compared to Figure 5 The semiconductor stack structure 210 shown, Figure 8 The semiconductor stacked structure 410 shown has a smaller light emitting area to maintain a stable light mode.
[0125] In addition to having a lower refractive index than the active layer 430 so that most of the light released by the active layer 430 can be transmitted between the anti-reflection film layer 310 and the high-reflection film layer 320 by total internal reflection, the first cladding layer 440 and the second cladding layer 450 can also be composed of semiconductor materials with a higher energy gap to create a carrier barrier to prevent electrons or holes from escaping from the active layer 430 and reducing the quantum efficiency.
[0126] Re-reference Figure 6 and Figure 7 , the reflectivity of the anti-reflection film layer 510 is different from the reflectivity of the high-reflection film layer 520; more specifically, the reflectivity of the anti-reflection film layer 510 is less than the reflectivity of the high-reflection film layer 520, so when an appropriate voltage is applied to the first electrode layer 460 and the second electrode layer 470 of the semiconductor stacked structure 410 to excite the active layer 430, the laser can oscillate back and forth between the anti-reflection film layer 510 and the high-reflection film layer 520, and finally emit from the anti-reflection film layer 510. In some embodiments, the reflectivity of the anti-reflection film layer 510 can be lower than 0.2%, and the reflectivity of the high-reflection film layer 520 can be higher than 80%.
[0127] The anti-reflection film layer 510 may include a multi-layer structure, and the high-reflection film layer 520 may include a multi-layer structure. Specifically, the anti-reflection film layer 510 and the high-reflection film layer 520 are layers including materials with higher refractive index and materials with lower refractive index alternately configured; wherein "higher" and "lower" are used to indicate relative refractive index, that is, the refractive index of one material in the anti-reflection film layer 510 / high-reflection film layer 520 is higher than the refractive index of another material in the anti-reflection film layer 510 / high-reflection film layer 520. For example, the anti-reflection film layer 510 may include first dielectric film layers 512 and second dielectric film layers 514 alternately configured, such as Fig. 9 and Fig.10 As shown. The first dielectric film layer 512 has a first refractive index, and the second dielectric film layer 514 has a second refractive index smaller than the first refractive index; wherein the first refractive index of the first dielectric film layer 512 and the second refractive index of the second dielectric film layer 514 are at least 1.4. In some embodiments, the first refractive index may be greater than 2, and the second refractive index may be approximately 1.5; for example, the first dielectric film layer 512 may be formed of tantalum pentoxide, and the second dielectric film layer 514 may be formed of silicon dioxide. Since the film layer formed by the material with a higher refractive index has a denser structure than the film layer formed by the material with a lower refractive index, it can be used as a water vapor barrier layer to prevent water vapor from penetrating into the semiconductor stack structure; therefore, the outermost layer of the anti-reflection film layer 510 (i.e., the film layer farthest from the front end surface 410 of the semiconductor stack structure 410) is usually the first dielectric film layer 512 containing the material with a higher refractive index.
[0128] The second dielectric film layer 514 may include any number of layers. The number of the first dielectric film layer 512 is one layer greater than the number of the second dielectric film layer 514. Usually, the film layer contacting the front face 412 of the semiconductor stack structure 410 is the first dielectric film layer 512 with a higher refractive index.
[0129] Please refer to Fig. 9 , Fig. 9 The anti-reflection film layer 510 is an example of a three-layer dielectric film layer, which includes two first dielectric film layers 512 and one second dielectric film layer 514; the second dielectric film layer 514 is disposed between the first dielectric film layers 512. Each first dielectric film layer 512 and the second dielectric film layer 514 in the anti-reflection film layer 510 may have different thicknesses to enhance the water vapor barrier capability; the first dielectric film layer 512 contacting the semiconductor stack structure 410 has a first thickness T4, the second dielectric film layer 514 has a second thickness T5, and the first dielectric film layer 512 farthest from the semiconductor stack structure 410 has a third thickness T6, the first thickness T4 is less than the second thickness T5, and the third thickness T6 is greater than the second thickness T5. In some embodiments, the first thickness T4 is about 20 nanometers, the second thickness T5 is about 80 nanometers, and the third thickness T6 is about 389 nanometers.
[0130] Please refer to Fig.10 , Fig.10 The anti-reflection film layer 510 is shown as a seven-layer dielectric film layer. The seven dielectric film layers include four first dielectric film layers 512A, 512B, 512C, and 512D arranged in sequence from left to right, and three second dielectric film layers 514A, 514B, and 514C arranged in sequence from left to right. The first dielectric film layer 512A contacts the front face 412 of the semiconductor stack structure 410, and the second dielectric film layers 514A, 514B, and 514C are disposed between two adjacent first dielectric film layers 512A, 512B, 512C, and 512D. The first refractive index of the first dielectric film layers 512A, 512B, 512C, and 512D and the second refractive index of the second dielectric film layers 514A, 514B, and 514C are at least 1.4. In some embodiments, the first dielectric film layers 512A, 512B, 512C, and 512D may be formed of tantalum pentoxide having a first refractive index greater than 2, and the second dielectric film layers 514A, 514B, and 514C may be formed of silicon dioxide having a second refractive index of about 1.5.
[0131] The number of anti-reflection film layers 510 and the thickness of each layer in the anti-reflection film layer 510 can be adjusted according to the wavelength band of the laser emitted by the semiconductor stack structure 410 to improve the penetration rate of the laser. Fig.10 The thickness data of the first dielectric film layers 512A, 512B, 512C and 512D and the second dielectric film layers 514A, 514B and 514C in the anti-reflection film layer 510 are shown, where the unit of thickness is nanometer.
[0132]
[0133] Re-reference Figure 6 and Figure 7 , the high reflective layer 520 may be a single layer or a multi-layer structure. When the high reflective layer 520 is a single layer structure, tantalum pentoxide with a refractive index greater than 2 may be selected and formed on the rear end face 414 of the semiconductor stack structure 410 by vapor deposition. When the high reflective layer 520 is a multi-layer structure, it may be composed of a staggered arrangement of tantalum pentoxide film layers with a refractive index greater than 2 and silicon dioxide film layers with a refractive index of about 1.5, and usually the outermost layer of the high reflective film layer 520 (i.e., the film layer farthest from the rear end face 414 of the semiconductor stack structure 410) includes a higher refractive index material. The silicon dioxide film layer may include any number of layers, and the number of tantalum pentoxide film layers is one more than the number of silicon dioxide film layers; usually, the film layer contacting the rear end face 414 of the semiconductor stack structure 410 is a tantalum pentoxide film layer.
[0134] The optical device 40 may further include a cap layer 530 disposed above the semiconductor stack structure 410, the anti-reflection film layer 510, and the high-reflection film layer 520; wherein, before the cap layer 530 is disposed, a protective layer (not shown) may be disposed on both sides of the ridge platform 452, and the protective layer has an upper surface that is substantially coplanar with the top surface of the ridge platform 452 and / or the top surface of the second electrode layer 470, so that the cap layer 530 subsequently deposited on the protective layer and the second electrode layer 470 has a flat profile. Of course, in some embodiments, the cap layer 530 may have a profile, and the profile follows the profile of the ridge platform 452 and / or the second electrode layer 470.
[0135] The cap layer 530 is a layer including a higher refractive index material and / or a lower refractive index material; wherein, "higher" and "lower" are used to indicate relative refractive index, that is, the refractive index of one material in the cap layer 530 is higher than the refractive index of another material in the cap layer 530. For example, the cap layer 530 may include a third dielectric film layer 532 and a fourth dielectric film layer 534 that are alternately configured, such as Fig.11 Compared to Figure 4 The single-layer structure capping layer 330 is made of silicon dioxide or silicon nitride. Fig.11 The multi-layer structure cap layer 530 in which the third dielectric film layer 532 and the fourth dielectric film layer 534 are alternately arranged has better water vapor barrier capability.
[0136] The third dielectric film layer 532 may include any number of layers. The number of the fourth dielectric film layers 534 is the same as the number of the third dielectric film layers 532 , and the thickness of the third dielectric film layer 532 is substantially the same as the thickness of the fourth dielectric film layer 534 . Fig.11 The middle cover layer 530 is exemplified by four dielectric film layers, which include two third dielectric film layers 532 and two fourth dielectric film layers 534 ; and one of the third dielectric film layers 532 contacts the semiconductor stacking structure 410 , the anti-reflection layer 510 and the high-reflection layer 520 .
[0137] In some embodiments, the third dielectric film layer 532 has a third refractive index, and the fourth dielectric film layer 534 has a fourth refractive index greater than the third refractive index; wherein the third refractive index and the fourth refractive index are at least 1.4. For example, the third dielectric film layer 532 may be formed of silicon dioxide having a refractive index of about 1.5, and the fourth dielectric film layer 534 may be formed of silicon nitride having a refractive index greater than 2. In other embodiments, the third refractive index of the third dielectric film layer 532 may be greater than the fourth refractive index of the fourth dielectric film layer 534; for example, the third dielectric film layer 532 may be formed of silicon nitride having a refractive index greater than 2, and the fourth dielectric film layer 534 may be formed of silicon dioxide having a refractive index of about 1.5.
[0138] In summary, the optical device 40 provided by the present disclosure not only deposits the anti-reflection film layer 510 and the high-reflection film layer 520 with high refractive index and good waterproof performance on the front end face 412 and the rear end face 414 of the semiconductor stack structure 410, but also deposits the cap layer 530 on the semiconductor stack structure 410, the reflective film layer 510 and the high-reflection film layer 520 to provide protection to prevent moisture from entering the semiconductor stack structure 410. Therefore, the optical device 40 of the present disclosure can be applied to optical communication systems that are usually assembled in high humidity environments without adding additional metal or ceramic packaging shells, which has the advantages of reducing costs and reducing assembly steps.
[0139] Fig.12 is a flow chart of a method for manufacturing an optical device according to some embodiments of the present disclosure. Fig.12 The optical device manufacturing method 600 includes steps S602, S604, S606 and S608. Fig.13 A picture to Fig.13 The D graphs are based on Fig.12 Schematic diagram of the operating steps drawn for the method of making an optical device.
[0140] refer to Fig.13 Figure A, in Fig.12 In step S602 , a semiconductor stack structure 710 is provided; the semiconductor stack structure 710 can generate laser light when receiving current, and the laser light generated by the semiconductor stack structure 710 is emitted from its front end surface 712 ; wherein the front end surface 712 is a side surface of the semiconductor stack structure 710 .
[0141] refer to Fig.13 Figure B, in Fig.12 In step S604, an anti-reflection film layer 810 is formed on the front end surface 712 of the semiconductor stack structure 710; wherein the anti-reflection film layer 810 can be formed on the front end surface 712 of the semiconductor stack structure 710 by one or more chemical vapor deposition (CVD) methods or physical vapor deposition (PVD) methods. The anti-reflection film layer 810 can be a single-layer dielectric film layer and include a material with a refractive index greater than 2, such as tantalum pentoxide. The anti-reflection film layer 810 can be a multi-layer structure; for example, the anti-reflection film layer 810 includes a plurality of first dielectric film layers 812 and at least one second dielectric film layer 814, which are alternately stacked on each other.
[0142] The first dielectric film layer 812 and the second dielectric film layer 814 have different refractive indices; the refractive indices of the first dielectric film layer 812 and the second dielectric film layer 814 are at least 1.4, and the refractive index of the first dielectric film layer 812 contacting the front end 712 of the semiconductor stack structure 710 must be greater than the refractive index of the second dielectric film layer 814. The second dielectric film layer 814 can include any number of layers, and the number of the first dielectric film layer 812 is one more than the number of the second dielectric film layer 814; in other words, the anti-reflective film layer 810 is an odd-numbered layer structure. In some embodiments, the first dielectric film layer 812 includes tantalum pentoxide with a refractive index greater than 2, and the second dielectric film layer 814 includes silicon dioxide with a refractive index of about 1.5.
[0143] refer to Fig.13 Figure C, in Fig.12 In step S606, a high-reflection film layer 820 is formed on the rear end face 714 of the semiconductor stack structure 710; wherein the rear end face 714 is a side of the semiconductor stack structure 710 and is substantially parallel to the front end face 712. The high-reflection film layer 820 can be formed on the rear end face 714 of the semiconductor stack structure 710 using one or more chemical vapor deposition methods or physical vapor deposition methods. The high-reflection film layer 820 can be a single-layer structure or a multi-layer structure formed by alternating stacking of a third dielectric film layer 822 and a fourth dielectric film layer 824 with different refractive indices. The high-reflection film layer 820 with a single-layer structure may include a material with a refractive index greater than 2, such as tantalum pentoxide; the third dielectric film layer 822 and the fourth dielectric film layer 824 in the high-reflection film layer 820 with a multi-layer structure may be tantalum pentoxide with a refractive index greater than 2 and silicon dioxide with a refractive index of approximately 1.5, respectively. In other words, the high-reflection film layer 820 may have the same material and dielectric film layer arrangement sequence as the anti-reflection film layer 810 . The difference between the two is that the high-reflection film layer 820 is thicker than the anti-reflection film layer 810 to prevent the laser from penetrating the high-reflection film layer 820 and emitting.
[0144] refer to Fig.13 In the D figure, Fig.12 In step S608, a cap layer 830 is formed on the top surface 716 of the semiconductor stack structure 710; wherein the top surface 716 is adjacent to the front face 712 and the rear face 714. The cap layer 820 can be formed on the top surface 714 of the semiconductor stack structure 710 using one or more chemical vapor deposition methods or physical vapor deposition methods. In some embodiments, if the cap layer 830 is formed after the anti-reflection film layer 810 and the high-reflection film layer 820, the cap layer 830 can simultaneously cover the top surface 714 of the semiconductor stack structure 710, the anti-reflection film layer 810 and the high-reflection film layer 820 to increase the water vapor barrier capability.
[0145] In some embodiments, the cap layer 830 may be a single dielectric film layer and include a material having a refractive index greater than 1.4, such as silicon dioxide or silicon nitride. In some embodiments, the cap layer 830 includes a fifth dielectric film layer 832 and a sixth dielectric film layer 834, which are alternately stacked on each other, and the cap layer 830 is an even-numbered layer structure. The fifth dielectric film layer 832 and the sixth dielectric film layer 834 have different refractive indices, and the refractive indices of both are at least 1.4. In some embodiments, the cap layer 830 is a multilayer structure in which silicon dioxide and silicon oxide are alternately configured.
[0146] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions or modifications may be made herein without departing from the technology of the present disclosure as defined by the appended claims. For example, many of the procedures discussed above may be implemented with different methodologies, and may be replaced by other procedures, or a combination thereof.
[0147] Furthermore, the scope of the present invention is not intended to be limited to the particular embodiments of the procedures, machines, articles, compositions, devices, methods, and steps described in this specification. As will be readily appreciated by those skilled in the art from the disclosure of the present invention, procedures, machines, articles, compositions, devices, methods, or steps currently existing or later developed that perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein may be used in accordance with the present invention. Therefore, the appended claims are intended to include within their scope such processes, machines, manufactures, compositions of matter, means, methods, and steps.
Claims
1. An optical device, comprising: A semiconductor stack structure, used for generating a laser when receiving a current, and emitting the laser from a front end surface of the semiconductor stack structure, the front end surface being a side surface of the semiconductor stack structure; An anti-reflection film layer is disposed on the front end surface to improve the penetration rate of the laser; as well as A high-reflection film layer is disposed on a rear end face of the semiconductor stack structure, the rear end face being the other side face of the semiconductor stack structure, and the high-reflection film layer is used to reduce the loss of the laser on the rear end face. The refractive indexes of the anti-reflection film layer and the high-reflection film layer are greater than 2, and a thickness of the high-reflection film layer is greater than a thickness of the anti-reflection film layer. 2 . The optical device as claimed in claim 1 , wherein the anti-reflection film layer and the high-reflection film layer comprise tantalum pentoxide.
3. The optical device according to claim 1, further comprising: A cap layer is disposed on a top surface of the semiconductor stack structure, wherein the refractive index of the cap layer is greater than 1.
4. The optical device as claimed in claim 3 , wherein the cap layer comprises silicon dioxide or silicon nitride.
5. The optical device of claim 3, wherein: The semiconductor stack structure comprises: a substrate; an active layer disposed on the substrate; a first coating layer disposed between the substrate and the active layer; and a second coating layer disposed on the active layer; and The optical device also includes: a first electrode layer disposed above the substrate; and A second electrode layer is disposed on the second coating layer and at least partially exposed outside the cover layer.
6. An optical device comprising: A semiconductor stack structure, used for generating a laser when receiving a current, and emitting the laser from a front end surface of the semiconductor stack, the front end surface being a side surface of the semiconductor stack structure; An anti-reflection film layer is disposed on the front end surface to improve the penetration rate of the laser; as well as a high-reflection film layer, disposed on a rear end face of the semiconductor stack structure, the rear end face being the other side face of the semiconductor stack structure, the high-reflection film layer being used to reduce the loss of the laser on the rear end face, The anti-reflection film layer and the high-reflection film layer respectively include a plurality of first dielectric film layers and at least one second dielectric film layer that are staggered, the plurality of first dielectric film layers and the second dielectric film layers have different refractive indices, and the refractive indices of the plurality of first dielectric film layers and the second dielectric film layers are greater than 1.
4. 7 . The optical device as claimed in claim 6 , wherein one of the plurality of first dielectric film layers in the anti-reflection film layer contacts the front end surface, and one of the plurality of first dielectric film layers in the high-reflection film layer contacts the rear end surface.
8. An optical device as described in claim 6, wherein the refractive index of the plurality of first dielectric film layers is greater than the refractive index of the second dielectric film layer, a first dielectric film layer in the anti-reflection film layer is disposed farthest from the front end surface, and a first dielectric film layer in the high-reflection film layer is disposed farthest from the rear end surface. 9 . The optical device of claim 8 , wherein the first dielectric film layers comprise tantalum pentoxide, and the second dielectric film layers comprise silicon dioxide. 10 . The optical device as claimed in claim 6 , wherein a reflectivity of the anti-reflection film layer is lower than 0.2%, and a reflectivity of the high-reflection film layer is higher than 80%. 11 . The optical device as claimed in claim 6 , wherein a first thickness of the anti-reflection film layer is smaller than a second thickness of the high-reflection film layer, the first thickness is at least 450 nm, and the second thickness is 1200 nm.
12. The optical device of claim 6, further comprising: A cap layer is arranged on the semiconductor stack structure, and the cap layer includes a plurality of third dielectric film layers and a plurality of fourth dielectric film layers that are alternately arranged, the refractive index of the plurality of third dielectric film layers is different from the refractive index of the plurality of fourth dielectric film layers, and the refractive index of the plurality of third dielectric film layers and the plurality of fourth dielectric film layers is greater than 1.
4. 13 . The optical device of claim 12 , wherein the number of the third dielectric film layers is equal to the number of the fourth dielectric film layers.
14. The optical device of claim 12, wherein the plurality of third dielectric film layers comprise silicon dioxide, and the plurality of fourth dielectric film layers comprise silicon nitride. 15 . The optical device of claim 12 , wherein the plurality of third dielectric film layers comprise silicon nitride, and the plurality of fourth dielectric film layers comprise silicon dioxide.
16. The optical device of claim 12, wherein: The semiconductor stack structure comprises: a substrate; an active layer disposed on the substrate; a first coating layer disposed between the substrate and the active layer; and a second coating layer disposed on the active layer; and The optical device also includes: a first electrode layer disposed below the substrate; and A second electrode layer is disposed on the second coating layer and at least partially exposed outside the cover layer.
17. A method for manufacturing an optical device, comprising: A semiconductor stack structure is provided, wherein the semiconductor stack structure is used to generate a laser when receiving a current, and the laser is emitted from a front end surface of the semiconductor stack structure, wherein the front end surface is a side surface of the semiconductor stack structure; and A first dielectric film layer is coated on the front face and a rear face of the semiconductor stack structure, wherein the refractive index of the first dielectric film layer is greater than 2, and the rear face is another side face of the semiconductor stack structure.
18. The method for manufacturing an optical device according to claim 17, further comprising: Coating a second dielectric film layer on the surface of the first dielectric film layer, wherein the refractive index of the second dielectric film layer is greater than 1.4; as well as Another first dielectric film layer is coated on the surface of the second dielectric film layer.
19. The method for manufacturing an optical device according to claim 17 or 18, further comprising: A third dielectric film layer is coated on a top surface of the semiconductor stack structure, wherein the refractive index of the third dielectric film layer is greater than 1.
4.
20. The method for manufacturing an optical device according to claim 19, further comprising: A fourth dielectric film layer is coated on the third dielectric film layer, wherein the refractive index of the fourth dielectric film layer is different from that of the third dielectric film layer, and the refractive index of the fourth dielectric film layer is greater than 1.4.