A high-speed anti-crosstalk integrated chip and its manufacturing method

Abstract

The present invention relates to the field of semiconductor development technology, and specifically to a high-speed anti-crosstalk integrated chip and a method for manufacturing the same. An underlying structure, a waveguide layer, and a grating structure are grown on a substrate. A laser quantum well structure and a modulator quantum well structure are grown in parallel on the surface of the grating structure. The edges of the modulator and laser regions are etched away to form a waveguide step. A current blocking layer is then grown on both sides of the waveguide step. A P-type ohmic contact layer is grown on top of the waveguide step. The edges of the modulator and laser are etched again until the underlying structure surface is exposed, forming a chip waveguide. Laser and modulator electrodes are separately fabricated. Bars are formed by thinning and dissociation, and the chip is fabricated by end-face coating. The laser grating is fabricated below the quantum well layer, and a groove is provided to disconnect the laser and modulator. This reduces the laser threshold current, increases the laser output power, and prevents electrical signal crosstalk between the laser and modulator.

Description

Technical Field

[0001] The present invention relates to the technical field of laser development, and in particular to a high-speed anti-crosstalk integrated chip and a manufacturing method thereof. Background Art

[0002] With the rapid development of optical communications, artificial intelligence (AI), data centers, and autonomous driving, the requirements for signal transmission rate and distance are becoming increasingly higher. The requirements for increasing the 3dB bandwidth of the light-emitting device itself and reducing external interference to the modulated signal are also increasing.

[0003] For long-distance applications, external modulators are used to overcome the effects of chirp. Among various optical modulators, electroabsorption modulators (EBMs), based on the quantum-confined Stark effect in semiconductor multi-quantum well structures, offer significant advantages and broad application prospects. This is due to their numerous advantages, including small size, compact structure, ease of monolithic integration with semiconductor DFB lasers, low operating voltage, low power consumption, simple and efficient optical coupling between the laser and modulator, and more stable and efficient coupling between the EML device and the optical fiber.

[0004] Electroabsorption modulated distributed feedback semiconductor lasers (EMLs) are a key optical signal generating element in optical communication systems, especially long-distance trunk networks. Research has found that conventional electroabsorption modulated laser chips consist of two parts: a laser chip and an electroabsorption modulator chip. These two components are epitaxially grown on the same substrate and share a common N-electrode. However, in the field of quantum communication, lasers generally emit light using a negative voltage, making the modulator's modulation voltage easily affected by the laser voltage. Therefore, conventional electroabsorption modulated laser chip designs cannot meet the requirements for modulating optical signals in quantum communication applications without affecting laser emission.

[0005] Based on the problems in the prior art, the present invention provides a high-speed anti-crosstalk integrated chip and a manufacturing method thereof. Summary of the Invention

[0006] The purpose of the present invention is to provide a high-speed anti-crosstalk integrated chip to solve the technical problem of signal crosstalk caused by manufacturing a semiconductor laser and a modulator together in the prior art.

[0007] The technical solution of the present invention is: a method for manufacturing a high-speed anti-crosstalk integrated chip, comprising: obtaining an underlying structure by epitaxial growth on a substrate, growing a waveguide layer on the underlying structure; manufacturing a grating structure on the surface of the waveguide layer, epitaxially growing a first quantum well structure on the surface of the grating structure; etching away part of the first quantum well structure, and epitaxially growing a second quantum well structure in the etched empty area, the second quantum well structure and the retained first quantum well structure are arranged in parallel along the length direction, etching from top to bottom until the surface of the underlying structure is exposed, etching away the first quantum well structure and the second quantum well structure. The quantum well structure, grating layer and waveguide layer retain the middle area of ​​parallel contact on both side edges along the length direction to form a waveguide step; the current blocking layer is filled in the etched side edge parts, and a P-type ohmic contact layer is epitaxially grown on the current blocking layer; the side edge parts of the current blocking layer and the P-type ohmic contact layer are etched away from top to bottom, retaining the middle area of ​​parallel contact to construct a chip waveguide; the chip waveguide is etched to construct independent laser waveguide and modulator waveguide; the electrodes of the laser and modulator are made respectively, and the chip preparation is completed through post-processing operations.

[0008] Preferably, the grooves are etched from top to bottom to divide the chip waveguide into parallel and independent laser regions and modulator regions, and the length of the laser region is greater than the length of the modulator region;

[0009] The groove passes through the waveguide layer from top to bottom until the surface of the underlying structure is exposed, and the length of the groove is not less than the width of the chip waveguide.

[0010] Preferably, the laser waveguide structure of the laser region is close to the end face of the modulator region and the modulator waveguide structure of the modulator region is close to the end face of the laser region, wherein at least one end face is constructed as a multi-bevel tip structure to prevent the signal from being transmitted back and forth between the laser and the modulator;

[0011] The modulator waveguide structure of the modulator region is constructed as a multi-bevel tip structure near the end face of the external optical fiber to prevent the optical signal from being transmitted back and forth between the modulator and the optical fiber.

[0012] Preferably, corresponding P electrodes are fabricated on the top surfaces of the laser and modulator, and corresponding N electrodes are fabricated on the bottom structure surfaces of the laser and modulator regions.

[0013] Preferably, the structural layers of the second quantum well structure and the first quantum well structure are arranged in parallel and correspond one to one;

[0014] The first quantum well structure comprises, from bottom to top, a first spacer layer, a first quantum well layer, and a second spacer layer; the second quantum well structure comprises, from bottom to top, a third spacer layer, a second quantum well layer, and a fourth spacer layer.

[0015] Preferably, the energy band width of the second quantum well layer is not less than the energy band width of the first quantum well layer.

[0016] Preferably, the bottom layer structure includes a buffer layer and a chemical corrosion barrier layer in order from bottom to top;

[0017] The current blocking layer includes a Fe-InP layer and a Si-InP layer; the P-type ohmic contact layer includes a P-type waveguide confinement layer and an ohmic contact layer; and the Si-InP layer is used to isolate the diffusion of P-type doping between the Fe-InP layer and the P-type waveguide confinement layer.

[0018] Preferably, the grating structure fabrication includes: performing etching by an ICP etching process to fabricate a grating pattern, with the etching depth being between 100-200 nm; and growing an InGaAsP layer for filling the grating on the grating pattern.

[0019] A high-speed anti-crosstalk integrated chip is manufactured using the manufacturing method of the high-speed anti-crosstalk integrated chip, the chip comprising an underlying structure and a laser waveguide structure and a modulator waveguide structure independently and parallelly arranged on the underlying structure;

[0020] The bottom layer structure includes a buffer layer and a top chemical corrosion barrier layer;

[0021] The laser waveguide structure includes a first waveguide step provided on the surface of the underlying structure, a P-type waveguide confinement layer and an ohmic contact layer provided on the top of the first waveguide step, and a Si-InP layer and a Fe-InP layer filled on both sides of the first waveguide step and between the underlying structure and the P-type waveguide confinement layer;

[0022] The first waveguide step includes, from bottom to top, a waveguide layer, a grating layer, a first spacer layer, a first quantum well layer, and a second spacer layer;

[0023] The modulator waveguide structure includes a second waveguide step provided on the surface of the underlying structure, a P-type waveguide confinement layer and an ohmic contact layer provided on the top of the second waveguide step, and a Si-InP layer and a Fe-InP layer filled on both sides of the second waveguide step and between the underlying structure and the P-type waveguide confinement layer;

[0024] The second waveguide step includes, from bottom to top, a waveguide layer, a grating layer, a third spacer layer, a second quantum well layer, and a fourth spacer layer;

[0025] Corresponding laser P electrodes and modulator P electrodes are set on the surfaces of the chemical corrosion blocking layer corresponding to the laser area and the modulator area; laser N electrodes and modulator N electrodes are set on the surfaces of the ohmic contact layers of the laser waveguide structure and the modulator waveguide structure.

[0026] Preferably, the end face of the laser waveguide structure of the laser zone close to the modulator zone and the end face of the modulator waveguide structure of the modulator zone close to the external optical fiber are respectively constructed as multi-bevel tip structures, and the multi-bevel tip structures are used to avoid the optical signal from reflecting back and forth between the laser and the modulator, and between the modulator and the optical fiber, thereby preventing optical crosstalk.

[0027] Compared with the prior art, the advantages of the present invention are:

[0028] Compared with making the grating above the quantum well, making the laser grating below the quantum well layer reduces the hole accumulation effect in the grating layer, increases the hole injection efficiency, reduces the threshold current of the laser, and increases the output power of the laser.

[0029] By etching a groove through the active area, the laser and modulator of the chip waveguide are completely separated, and corresponding electrodes are made on the independent laser and modulator respectively to avoid electrical signal crosstalk between the laser and modulator.

[0030] By setting the end face of the laser close to the modulator and the end face of the modulator close to the optical fiber as multi-bevel tip structures, the optical path is changed, and the light originally reflected back to the laser or modulator is reflected out, preventing it from reaching the inside of the laser or modulator. This ensures that the light between the laser-modulator and the optical fiber propagates in one direction without back reflection, avoids optical crosstalk between the laser, modulator and optical fiber, reduces the chirp noise generated by the modulator during optical fiber propagation, and thus reduces the dispersion of the signal during optical fiber propagation, allowing the optical signal to be transmitted over a longer distance.

[0031] Moreover, due to the provision of a multi-bevel tip structure, it is possible to eliminate the need for an isolator between the modulator and the optical fiber, thereby achieving unidirectional propagation of light, simplifying the packaging process, and reducing packaging costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0033] Figure 1 A side view schematic diagram of the bottom layer structure of the present invention;

[0034] Figure 2 A side view schematic diagram of making a grating pattern on the surface of the underlying structure according to the present invention;

[0035] Figure 3 A side view schematic diagram of growing a first quantum well structure layer on the surface of the grating structure according to the present invention;

[0036] Figure 4 This is a side view schematic diagram of etching and removing a portion of the first quantum well structure layer according to the present invention;

[0037] Figure 5A schematic side view of the first quantum well structure and the second quantum well structure layer of the present invention;

[0038] Figure 6 is a schematic cross-sectional view of a waveguide step formed after etching according to the present invention;

[0039] Figure 7 This is a schematic cross-sectional view of the epitaxial growth of the current blocking layer according to the present invention;

[0040] Figure 8 This is a schematic cross-sectional view of the fifth epitaxial growth of the P-InP waveguide confinement layer and the ohmic contact layer according to the present invention;

[0041] Figure 9 This is a schematic cross-sectional view of the device waveguide after etching according to the present invention;

[0042] Figure 10 This is a three-dimensional schematic diagram of the device waveguide after etching according to the present invention;

[0043] Figure 11 A schematic top view of the laser and modulator in the device of the present invention is shown disconnected;

[0044] Figure 12 This is a three-dimensional schematic diagram of the chip after the laser and modulator P-type and N-type electrodes are completed respectively;

[0045] Wherein: 1. substrate; 2. buffer layer; 3. chemical corrosion barrier layer; 4. waveguide layer; 5. grating layer; 6. first spacer layer; 7. first quantum well layer; 8. second spacer layer; 9. third spacer layer; 10. second quantum well layer; 11. fourth spacer layer; 12. Fe-InP layer; 13. Si-InP layer; 14. P-type waveguide confinement layer; 15. ohmic contact layer; 16. trench;

[0046] 20. First dielectric film; 30. Second dielectric film. DETAILED DESCRIPTION

[0047] The present invention will be described in further detail below with reference to specific embodiments:

[0048] The manufacturing method of the high-speed anti-crosstalk integrated chip is as follows:

[0049] (1) Preparing the underlying structure on the substrate;

[0050] A buffer layer 2 , a chemical corrosion barrier layer 3 , and a waveguide layer 4 are epitaxially grown on the substrate 1 by epitaxial growth technology.

[0051] Refer to the attached Figure 1As shown, an N-type InP buffer layer, a chemical etching barrier layer 3, and an N-type InP layer are sequentially grown on a semi-insulating InP substrate 1 using MOCVD or MBE epitaxial growth technology. The N-type InP buffer layer is used to remove substrate defects, the chemical etching barrier layer 3 is used for chemical selective etching, and the N-type InP layer serves as the N-type waveguide layer of the device.

[0052] (2) Preparation of grating structure layer, including grating pattern production and grating filling;

[0053] In the attached Figure 1 Based on the structure of the N-type InP layer, a grating pattern is made on the surface of the N-type InP layer by Ebeam writing or holography technology, and then etched by ICP etching process (inductively coupled plasma etching). The etching depth is between 100-200nm. The result after the grating structure is etched is shown in the attached figure. Figure 2 As shown, the grating pattern only covers part of the surface of the N-type InP layer (laser region).

[0054] The laser wavelength is determined by the grating period. This structure is mainly used to enable the laser to operate in single-mode mode, meeting the basic requirements of long-distance transmission of light in optical fibers.

[0055] In the attached Figure 2 On the basis of the structure of the grating pattern and the surface of the N-type InP layer, an InGaAsP layer for filling the grating is epitaxially grown by MOCVD or EBM epitaxial growth technology. The InGaAsP layer covers the laser area and the modulator area to prepare the grating layer 5. Figure 3 shown.

[0056] (3) Fabricating a waveguide step structure;

[0057] a. On the surface of the grating structure, the first spacer layer 6, the first quantum well layer 7, and the second spacer layer 8 are sequentially epitaxially grown by MOCVD or EBM epitaxial growth technology. The quantum well structure layer is used to make the gain material of the laser. The structure after production is shown in the attached figure. Figure 3 The schematic diagram shown.

[0058] b. In the attached Figure 3 On the basis of the above, part of the first spacer layer 6, the first quantum well layer 7, and the second spacer layer 8 are removed by PECVD, photolithography, RIE and ICP etching processes. The remaining space is set as the laser region (domain) for growing the second quantum well structure for making the modulator that is connected to the first quantum well structure. See the attached Figure 4 As shown. Figure 12 or attached Figure 11 As shown, the second quantum well structure and the retained first quantum well structure are arranged in parallel front and back along the length direction.

[0059] c. A first dielectric film 20 is deposited on the surface of the second spacer layer 8 of the first quantum well structure using PECVD. The dielectric film is generally made of silicon oxide, silicon nitride, etc., which plays a protective role. Then, the epitaxial growth of the quantum well structure of the modulator is performed to prevent the first quantum well structure from being disturbed.

[0060] d. In the attached Figure 4 On this basis, the third spacer layer 9, the second quantum well layer 10 and the fourth spacer layer 11 of the second quantum well structure are epitaxially grown in the reserved modulator area in sequence by MOCVD or EBM epitaxial growth technology. The production results are shown in the attached figure. Figure 5 shown.

[0061] The second quantum well layer 10 is used to make a modulator, and the energy band width of the second quantum well layer 10 is not less than the energy band width of the first quantum well layer 7. The specific difference is determined by the modulation voltage. The wavelength range of the first quantum well layer 7 is 1310nm-1550nm.

[0062] The lengths of the laser zone and modulator zone are determined according to the requirements for the laser output power and modulator speed. The longer the laser zone waveguide, the greater its output power. Generally, the shorter the modulation zone, the faster the modulator operating speed.

[0063] e. In Figure 5 On the basis of the above, the first dielectric film 20 is removed by RIE etching technology (reactive ion etching);

[0064] Then, a second dielectric film 30 is deposited by PECVD technology. The second dielectric film 30 covers the second spacer layer 8 in the laser region and the fourth spacer layer 11 in the modulator region.

[0065] f. Waveguide steps are formed by photolithography, RIE and ICP etching, see Appendix Figure 6 As shown, etching is performed from top to bottom until the surface of the chemical corrosion barrier layer 13 is exposed. The outer edges of the first quantum well structure, the second quantum well structure, the grating layer, and the waveguide layer along the length direction are removed. The remaining first quantum well structure and the second quantum well structure are arranged side by side, with the structural layers arranged side by side and corresponding to each other. This forms a waveguide step structure that protrudes from the surface of the underlying structure.

[0066] In the waveguide step structure, the grating is set below the quantum well in the light-emitting area, which can avoid the hole accumulation effect caused by the grating being set above the quantum well, increase the carrier injection efficiency, and improve the output power of the chip.

[0067] (4) Making a current blocking layer;

[0068] exist Figure 6On the basis of the above, Fe-InP layer and Si-InP layer are grown on both sides of the waveguide step by MOCVD or EBM epitaxial growth technology (no growth is done on both sides of the second dielectric film 30). The Fe-InP layer is a non-conductive material, and the Si-InP layer is set on top of the Fe-InP layer. The fabrication results are shown in the attached figure. Figure 7 shown.

[0069] By providing a current blocking layer to block the current applied to the chip, the laser's threshold current can be lowered and the modulator spot can be improved. The light emerging from the modulator end face approaches a circular spot, facilitating coupling between the modulator and the optical fiber and reducing optical coupling losses. Furthermore, the modulator's parasitic capacitance can be reduced, increasing the chip's 3dB modulation bandwidth.

[0070] (5) Fabricating a P-type ohmic contact layer, including a P-type layer and an ohmic contact layer;

[0071] In the attached Figure 7 On this basis, the second dielectric film 30 is removed by etching.

[0072] Refer to the attached Figure 8 As shown in the figure, a P-InP waveguide confinement layer and an ohmic contact layer are sequentially grown on the surface of the Si-InP layer using MOCVD or EBM epitaxial growth technology. The Si-InP layer isolates the Fe-InP layer and the P-InP waveguide confinement layer. The P-InP waveguide confinement layer is used to restrict the outward propagation of light, and the Si-InP layer is used to isolate the diffusion of P-type dopants between the Fe-InP layer and the P-type waveguide confinement layer.

[0073] (6) Fabrication of chip waveguides;

[0074] In the attached Figure 8 On this basis, the chip waveguide is made through photolithography, ICP and chemical etching processes. The specific operations are as follows:

[0075] The edge portions on both sides of the current blocking layer and the P-type ohmic contact layer are etched away from top to bottom until the surface of the chemical corrosion blocking layer 3 is exposed. The edge portions on both sides of the current blocking layer and the P-type ohmic contact layer along the length direction are etched away, leaving the middle area of ​​the parallel contact, and forming a protruding chip waveguide structure on the top of the bottom structure. Figure 9 shown.

[0076] A groove 16 is etched from top to bottom. The groove 16 passes through the waveguide layer 4 until the surface of the chemical etching barrier layer 3 is exposed. The length of the groove 16 is not less than the width of the chip waveguide. Figure 10As shown by the double-dashed line in the provided schematic diagram of the chip waveguide, a trench is etched along the double-dashed line, with a length equal to the chip waveguide width. This trench completely disconnects the P-type material of the laser and modulator, and partially disconnects the N-type material. This further reduces the laser's threshold current and prevents electrical signal interaction between the laser and modulator, allowing the chip's signals to travel longer distances in optical fiber. This waveguide structure further reduces the modulator's parasitic capacitance, increases the modulator's 3dB modulation bandwidth, and improves the device's operating speed.

[0077] See attached Figure 12 As shown, the laser waveguide and the modulator waveguide are disconnected and independent from each other. The length of the laser is greater than that of the modulator. Generally, the laser is 300-500 microns and the modulator is 100 microns long.

[0078] Furthermore, the isolation groove end face of the laser waveguide and the isolation groove end face of the modulator are manufactured into different shapes to prevent optical signal interference caused by reflected light between the laser and the modulator, and between the modulator and the optical fiber.

[0079] The laser waveguide structure of the laser region is close to the end face of the modulator region, and the modulator waveguide structure of the modulator region is close to the end face of the laser region, wherein at least one end face is configured as a multi-bevel tip structure. The end face of the modulator waveguide structure of the modulator region close to the external optical fiber is configured as a multi-bevel tip structure.

[0080] For example, see Appendix Figure 11 As shown, the broken end face of the laser is the second end face, the broken end face of the modulator is the third end face, the outer edge end of the laser is the first end face, and the outer edge end of the modulator is the fourth end face, wherein the second end face of the laser (close to the modulator side) and the fourth end face of the modulator are formed into a multi-bevel tip structure by cutting.

[0081] Since the laser and modulator are completely etched apart, and the etched end faces are each provided with a multi-slanted tip structure, the light cannot maintain its original parallel path propagation and cannot return to the chip, thus avoiding the problem of light "oscillation" crosstalk between the modulator and the laser.

[0082] Moreover, due to the multi-bevel tip structure, the reflection and propagation of light are blocked, which can reduce the interference of the reflected light from the optical fiber on the modulator, further reduce the interference of external signals on the modulator, ensure the unidirectional propagation of light between the laser, modulator and optical fiber, and make both the optical signal and the electrical signal cleaner.

[0083] At the same time, due to the multi-bevel tip structure, it is possible to avoid using an isolator between the modulator and the optical fiber (in conventional technology, an isolator is set between the modulator and the optical fiber to prevent mutual reflection of light between the interfaces), thereby achieving unidirectional propagation of light, simplifying the packaging process, and reducing packaging costs.

[0084] Therefore, through the tip design and AR coating of the second and fourth end faces, the crosstalk caused by reflection of light between the laser, modulator, and optical fiber is reduced, the dispersion loss caused by the signal transmission process in the optical fiber can be reduced, and the signal transmission distance can be increased.

[0085] (7) Making electrodes;

[0086] Using photolithography, Ebeam evaporation, sputtering, or RTA, N-type electrodes for the laser and modulator are fabricated in the laser and modulator regions corresponding to the chemical etching barrier layer 3. P-type electrodes for the laser and modulator are fabricated on the surface of the corresponding ohmic contact layer. Because the electrodes are fabricated on the chemical etching barrier layer 3, parasitic capacitance is reduced and the device's operating speed is improved.

[0087] (8) Post-processing;

[0088] Bar strips are made through thinning, cleavage and other processes, HR reflective film is applied to the first end face, and AR anti-reflective film is applied to the second, third and fourth end faces respectively. The chip process is now completed.

[0089] The above-mentioned method for manufacturing a high-speed anti-crosstalk integrated chip has significant advantages in reducing parasitic capacitance, lowering the threshold current of the laser, increasing the output power of the laser, avoiding electrical signal crosstalk and optical signal crosstalk between the laser and the isolator, reducing signal dispersion during optical fiber propagation, and increasing the transmission distance of optical signals by fabricating the laser grating below the quantum well layer and setting an isolation groove.

[0090] By adopting the above-mentioned manufacturing method, the present invention also discloses a high-speed anti-crosstalk integrated chip, such as Figure 12 As shown, the chip includes an underlying structure and a laser waveguide structure and a modulator waveguide structure independently and parallelly arranged on the underlying structure.

[0091] The bottom layer structure includes: a substrate 1, a buffer layer 2 and a chemical corrosion barrier layer 3.

[0092] The laser waveguide structure includes a first waveguide step arranged on the surface of the underlying structure, a P-type waveguide confinement layer 14 and an ohmic contact layer 15 arranged on the top of the first waveguide step, and a Si-InP layer 13 and a Fe-InP layer 12 filling both sides of the first waveguide step and between the underlying structure and the P-type waveguide confinement layer;

[0093] The first waveguide step includes, from bottom to top, a waveguide layer 4, a grating layer 5, a first spacer layer 6, a first quantum well layer 7, and a second spacer layer 8.

[0094] The modulator waveguide structure includes a second waveguide step provided on the surface of the underlying structure, a P-type waveguide confinement layer 14 and an ohmic contact layer 15 provided on the top of the second waveguide step, and a Si-InP layer 13 and a Fe-InP layer 14 filling both sides of the second waveguide step and between the underlying structure and the P-type waveguide confinement layer;

[0095] The second waveguide step includes, from bottom to top, a waveguide layer 4, a grating layer 5, a third spacer layer 9, a second quantum well layer 10, and a fourth spacer layer 11.

[0096] Corresponding laser P electrodes and modulator P electrodes are set on the surfaces of the chemical corrosion blocking layers corresponding to the laser area and the modulator area; laser N electrodes and modulator N electrodes are set on the surfaces of the ohmic contact layers of the laser waveguide structure and the modulator waveguide structure.

[0097] Among them, the end face of the laser waveguide structure in the laser zone close to the modulator zone and the end face of the modulator waveguide structure in the modulator zone close to the external optical fiber are respectively constructed as multi-bevel tip structures, which intercept reflected light to prevent optical crosstalk.

[0098] In the chip provided by the present invention, the grating layer is arranged below the quantum well, and the laser waveguide is disconnected from the modulator waveguide, which can reduce the parasitic capacitance of the modulator, increase the 3dB modulation bandwidth of the modulator, and improve the operating speed of the device. Except for the underlying structure, the doped region above the laser waveguide and the modulator waveguide are completely disconnected, and the electrodes are independently manufactured for each, avoiding current signal crosstalk between the laser and the modulator.

[0099] The second and fourth light-emitting surfaces of the independent laser and modulator are designed with a pointed structure, which changes the reflected light path and prevents optical signal crosstalk between the laser and modulator, and between the modulator and the optical fiber. This makes the chip signal cleaner.

[0100] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they are not intended to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A method for manufacturing a high-speed anti-crosstalk integrated chip, characterized in that: include: A bottom layer structure is obtained on a substrate by epitaxial growth, and a waveguide layer is grown on the bottom layer structure; Fabricating a grating structure on the surface of the waveguide layer, and epitaxially growing a first quantum well structure on the surface of the grating structure; Etch away part of the first quantum well structure, and epitaxially grow the second quantum well structure in the etched empty area. The second quantum well structure and the retained first quantum well structure are arranged in parallel along the length direction, and etching is performed from top to bottom until the surface of the underlying structure is exposed. The edge portions of the first quantum well structure, the second quantum well structure, the grating layer, and the waveguide layer along the length direction are etched away, and the middle area where they are in parallel contact is retained to form a waveguide step. Filling the etched edge portions on both sides with a current blocking layer, and epitaxially growing a P-type ohmic contact layer on the current blocking layer; Etching from top to bottom removes the edge portions of the current blocking layer and the P-type ohmic contact layer on both sides, retaining the middle area of ​​the parallel contact to construct the chip waveguide; etching grooves from top to bottom to divide the chip waveguide into parallel and independent laser areas and modulator areas, with the length of the laser area being longer than the length of the modulator area; The groove passes through the waveguide layer from top to bottom until the surface of the underlying structure is exposed, and the length of the groove is not less than the width of the chip waveguide; The laser waveguide structure of the laser region is close to the end face of the modulator region, and the modulator waveguide structure of the modulator region is close to the end face of the laser region, wherein at least one end face is configured as a multi-bevel tip structure to prevent signals from being transmitted back and forth between the laser and the modulator; Etching chip waveguides to construct independent laser waveguides and modulator waveguides; The modulator waveguide structure of the modulator region is constructed with a multi-bevel tip structure close to the end face of the external optical fiber to prevent the optical signal from being transmitted back and forth between the modulator and the optical fiber; The electrodes of the laser and modulator are made separately, and the chip preparation is completed through post-processing operations.

2. The method for manufacturing a high-speed anti-crosstalk integrated chip according to claim 1, characterized in that: Corresponding P electrodes are made on the top surfaces of the laser and modulator, and corresponding N electrodes are made on the bottom structure surfaces of the laser and modulator regions.

3. The method for manufacturing a high-speed anti-crosstalk integrated chip according to claim 1, characterized in that: The structural layers of the second quantum well structure and the first quantum well structure are arranged in parallel and in one-to-one correspondence; The first quantum well structure comprises, from bottom to top, a first spacer layer, a first quantum well layer, and a second spacer layer; the second quantum well structure comprises, from bottom to top, a third spacer layer, a second quantum well layer, and a fourth spacer layer.

4. The method for manufacturing a high-speed anti-crosstalk integrated chip according to claim 3, characterized in that: The energy band width of the second quantum well layer is not less than the energy band width of the first quantum well layer.

5. The method for manufacturing a high-speed anti-crosstalk integrated chip according to claim 1, characterized in that: The bottom layer structure includes a buffer layer and a chemical corrosion barrier layer in order from bottom to top; The current blocking layer includes a Fe-InP layer and a Si-InP layer; the P-type ohmic contact layer includes a P-type waveguide confinement layer and an ohmic contact layer; and the Si-InP layer is used to isolate the diffusion of P-type doping between the Fe-InP layer and the P-type waveguide confinement layer.

6. The method for manufacturing a high-speed anti-crosstalk integrated chip according to claim 1, characterized in that: The grating structure production includes: etching through an ICP etching process to produce a grating pattern, with the etching depth being between 100-200 nm; and growing an InGaAsP layer for filling the grating on the grating pattern.

7. A high-speed anti-crosstalk integrated chip, characterized in that: The high-speed anti-crosstalk integrated chip is manufactured by the manufacturing method of any one of claims 1 to 6, wherein the chip comprises an underlying structure and a laser waveguide structure and a modulator waveguide structure independently and parallelly arranged on the underlying structure; The bottom layer structure includes a buffer layer and a top chemical corrosion barrier layer; The laser waveguide structure includes a first waveguide step provided on the surface of the underlying structure, a P-type waveguide confinement layer and an ohmic contact layer provided on the top of the first waveguide step, and a Si-InP layer and a Fe-InP layer filled on both sides of the first waveguide step and between the underlying structure and the P-type waveguide confinement layer; The first waveguide step includes, from bottom to top, a waveguide layer, a grating layer, a first spacer layer, a first quantum well layer, and a second spacer layer; The modulator waveguide structure includes a second waveguide step provided on the surface of the underlying structure, a P-type waveguide confinement layer and an ohmic contact layer provided on the top of the second waveguide step, and a Si-InP layer and a Fe-InP layer filled on both sides of the second waveguide step and between the underlying structure and the P-type waveguide confinement layer; The second waveguide step includes, from bottom to top, a waveguide layer, a grating layer, a third spacer layer, a second quantum well layer, and a fourth spacer layer; Corresponding laser P electrodes and modulator P electrodes are set on the surfaces of the chemical corrosion blocking layer corresponding to the laser area and the modulator area; laser N electrodes and modulator N electrodes are set on the surfaces of the ohmic contact layers of the laser waveguide structure and the modulator waveguide structure.

8. The high-speed anti-crosstalk integrated chip according to claim 7, characterized in that: The end face of the laser waveguide structure of the laser zone close to the modulator zone and the end face of the modulator waveguide structure of the modulator zone close to the external optical fiber are respectively constructed as multi-bevel tip structures. The multi-bevel tip structures are used to avoid the optical signal from being reflected back and forth between the laser and the modulator, and between the modulator and the optical fiber, thereby preventing optical crosstalk.

Images