CN-122000790-A - Structure of passive waveguide butt-joint laser and manufacturing method thereof

CN122000790ACN 122000790 ACN122000790 ACN 122000790ACN-122000790-A

Abstract

The invention relates to the technical field of semiconductor light-emitting devices, and provides a structure of a passive waveguide butt-joint laser and a manufacturing method thereof. The structure comprises a substrate, an epitaxial structure and a butt joint structure, wherein the butt joint structure comprises a first butt joint part and a second butt joint part, the first butt joint part is obtained by growing a plurality of functional layers in a butt joint channel after the epitaxial structure is etched to obtain the butt joint channel and a butt joint step, the second butt joint part is obtained by growing a plurality of functional layers on the surface of the butt joint step and the surface of the first butt joint part, one or more functional layers in the first butt joint part are designed to be a current blocking structure, and the current blocking structure is a reverse PN junction or a semi-insulating doped growth structure containing Fe-InP. According to the invention, the current blocking structure is arranged in the butt joint structure, so that the loss caused by current leakage of the passive waveguide area can be reduced, and the performance of the laser is improved, the current threshold is reduced, the reliability is improved, and the frequency response performance is improved.

Inventors

YU XUEPING
CAO MINGDE
LV JUN
CHENG WENTAO
XIAO FAN
WANG DINGLI
ZHAO JIANYI
HUANG XIAODONG

Assignees

武汉光迅科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (10)

1. The structure of the passive waveguide butt joint laser is characterized by comprising a substrate (1), an epitaxial structure (2) and a butt joint structure (3); The epitaxial structure (2) is obtained by growing a plurality of functional layers on a substrate (1); The butt joint structure (3) comprises a first butt joint part (31) and a second butt joint part (32), wherein the first butt joint part (31) is obtained by growing a plurality of functional layers in a butt joint channel (21) after etching the epitaxial structure (2) to obtain the butt joint channel (21) and a butt joint step (22); the second butt joint part (32) is obtained by growing a plurality of functional layers on the surface of the butt joint step (22) and the surface of the first butt joint part (31); One or more functional layers in the first butt joint part (31) are designed as a current blocking structure, wherein the current blocking structure is a reverse PN junction or a semi-insulating doped growth structure containing Fe-InP.
2. The structure of the passive waveguide junction laser according to claim 1, characterized in that when the position of the first junction portion (31) close to the second junction portion (32) is designed as a current blocking structure of a reverse PN junction, the epitaxial structure (2) sequentially includes a first InP buffer layer (201), a grating layer (202), a grating protection layer (203), a first InP spacer layer (204), a lower confinement layer (205), a lower waveguide layer (206), a multiple quantum well layer (207), an upper waveguide layer (208), an upper confinement layer (209), a second InP spacer layer (210), a first anti-corrosion layer (211), and a first InP cladding layer (212) according to a growth direction; The first butt joint part (31) sequentially comprises a second InP buffer layer (311), an InGaAsP layer (312), a third InP spacer layer (313), a second corrosion resistant layer (314), a second InP cover layer (315), a first P-InP layer (316) and a first N-InP layer (317) according to the growth direction, wherein the first P-InP layer (316) and the first N-InP layer (317) form the current blocking structure.
3. The structure of the passive waveguide junction laser according to claim 1, characterized in that when the position of the first junction portion (31) near the bottom of the junction channel (21) is designed as a current blocking structure of a reverse PN junction, the epitaxial structure (2) sequentially includes, in terms of growth direction, a first InP buffer layer (201), a grating layer (202), a grating protection layer (203), a first InP spacer layer (204), a third anti-corrosion layer (213), a fourth InP spacer layer (214), a lower confinement layer (205), a lower waveguide layer (206), a multiple quantum well layer (207), an upper waveguide layer (208), an upper confinement layer (209), a second InP spacer layer (210), a first anti-corrosion layer (211), and a first InP cladding layer (212); The first butt joint part (31) sequentially comprises a second InP buffer layer (311), a first P-InP layer (316), a first N-InP layer (317), an InGaAsP layer (312), a third InP spacing layer (313), a second corrosion resistant layer (314) and a second InP covering layer (315) according to the growth direction, wherein the first P-InP layer (316) and the first N-InP layer (317) form the current blocking structure.
4. The structure of a passive waveguide junction laser according to claim 1, characterized in that when the position of the first junction portion (31) near the bottom of the junction channel (21) is designed as a current blocking structure comprising a semi-insulating doped growth structure of Fe-InP, the epitaxial structure (2) comprises, in order according to the growth direction, a first InP buffer layer (201), a grating layer (202), a grating protection layer (203), a first InP spacer layer (204), a third anti-corrosion layer (213), a fourth InP spacer layer (214), a lower confinement layer (205), a lower waveguide layer (206), a multiple quantum well layer (207), an upper waveguide layer (208), an upper confinement layer (209), a second InP spacer layer (210), a first anti-corrosion layer (211), and a first InP cladding layer (212); The first butt joint part (31) sequentially comprises a second InP buffer layer (311), a first N-InP layer (317), an Fe-InP layer (318), a second N-InP layer (319), an InGaAsP layer (312), a third InP spacing layer (313), a second corrosion resistant layer (314) and a second InP covering layer (315) according to the growth direction, wherein the first N-InP layer (317), the Fe-InP layer (318) and the second N-InP layer (319) form the current blocking structure.
5. The structure of a passive waveguide junction laser according to any of claims 1 to 4, wherein the second junction (32) comprises, in order of growth direction, a second P-InP layer (321), an InGaAs contact layer (322), and a metal thin film electrode layer (323).
6. A passive waveguide docking laser structure according to any of claims 1-4 wherein the lasers suitable for use include one or more of DFB lasers, FP lasers and VCSEL lasers.
7. A method of fabricating a passive waveguide docking laser structure as claimed in any one of claims 1 to 6, comprising: manufacturing an epitaxial structure (2) on a substrate (1); Depositing a dielectric film on the epitaxial structure (2), photoetching a preset butt joint pattern on the surface of the dielectric film, etching the position of the preset butt joint pattern according to the preset butt joint pattern to obtain a butt joint channel (21), and forming a butt joint step (22) at the part outside the preset butt joint pattern; Growing a plurality of functional layers in the butt joint channel (21), and designing one or more of the functional layers into a current blocking structure to obtain a first butt joint part (31) of a butt joint structure (3), wherein the current blocking structure is a reverse PN junction or a semi-insulating doped growth structure containing Fe-InP; And removing the dielectric film on the surface of the butt joint step (22), and growing a functional layer on the surfaces of the first butt joint part (31) and the butt joint step (22) to obtain a second butt joint part (32) of the butt joint structure (3).
8. The method for fabricating a passive waveguide junction laser structure according to claim 7, wherein, when designing the position of the first junction portion (31) close to the second junction portion (32) as a current blocking structure of a reverse PN junction, the fabricating an epitaxial structure (2) on the substrate (1) specifically includes: Sequentially growing a first InP buffer layer (201), a grating layer (202) and a grating protective layer (203) on the surface of a substrate (1), manufacturing a grating on the grating layer (202), sequentially growing a first InP spacing layer (204), a lower limiting layer (205), a lower waveguide layer (206), a multiple quantum well layer (207), an upper waveguide layer (208), an upper limiting layer (209), a second InP spacing layer (210), a first corrosion-resistant layer (211) and a first InP covering layer (212) on the surface of the grating protective layer (203); Etching the preset butt joint pattern position, wherein the etching is performed according to the preset butt joint pattern until the etching reaches the first InP spacer layer (204); -said growing a plurality of functional layers in said docking channel (21), -designing one or more of said plurality of functional layers as a current blocking structure, -obtaining a first docking portion (31) of the docking structure (3), comprising in particular: After etching to obtain a butt joint channel (21) and a butt joint step (22), carrying out acid treatment on the epitaxial wafer, and cleaning and blow-drying; A second InP buffer layer (311), an InGaAsP layer (312), a third InP spacer layer (313), a second anti-corrosion layer (314), a second InP cladding layer (315), a first P-InP layer (316) and a first N-InP layer (317) are sequentially grown in the butt joint channel (21).
9. The method for fabricating a passive waveguide junction laser structure according to claim 7, wherein, when designing the position of the first junction portion (31) near the bottom of the junction channel (21) as a current blocking structure of a reverse PN junction, the fabricating an epitaxial structure (2) on the substrate (1) specifically includes: Sequentially growing a first InP buffer layer (201), a grating layer (202) and a grating protective layer (203) on the surface of a substrate (1), manufacturing a grating on the grating layer (202), sequentially growing a first InP spacing layer (204), a third corrosion resistant layer (213), a fourth InP spacing layer (214), a lower limiting layer (205), a lower waveguide layer (206), a multiple quantum well layer (207), an upper waveguide layer (208), an upper limiting layer (209), a second InP spacing layer (210), a first corrosion resistant layer (211) and a first InP covering layer (212) on the surface of the grating protective layer (203); Etching the preset butt joint pattern position, wherein the etching is performed according to the preset butt joint pattern until the etching reaches a third corrosion resistant layer (213); -said growing a plurality of functional layers in said docking channel (21), -designing one or more of said plurality of functional layers as a current blocking structure, -obtaining a first docking portion (31) of the docking structure (3), comprising in particular: After etching to obtain a butt joint channel (21) and a butt joint step (22), carrying out acid treatment on the epitaxial wafer, and cleaning and blow-drying; a second InP buffer layer (311), a first P-InP layer (316), a first N-InP layer (317), an InGaAsP layer (312), a third InP spacer layer (313), a second anti-corrosion layer (314) and a second InP cladding layer (315) are grown in the butt-joint channel (21) in sequence.
10. The method for fabricating a structure of a passive waveguide junction laser according to claim 7, wherein, when designing the first junction (31) near the bottom of the junction channel (21) as a current blocking structure comprising a semi-insulating doped growth structure of Fe-InP, the fabricating of the epitaxial structure (2) on the substrate (1) specifically comprises: Sequentially growing a first InP buffer layer (201), a grating layer (202) and a grating protective layer (203) on the surface of a substrate (1), manufacturing a grating on the grating layer (202), sequentially growing a first InP spacing layer (204), a third corrosion resistant layer (213), a fourth InP spacing layer (214), a lower limiting layer (205), a lower waveguide layer (206), a multiple quantum well layer (207), an upper waveguide layer (208), an upper limiting layer (209), a second InP spacing layer (210), a first corrosion resistant layer (211) and a first InP covering layer (212) on the surface of the grating protective layer (203); Etching the preset butt joint pattern position, wherein the etching is performed according to the preset butt joint pattern until the etching reaches a third corrosion resistant layer (213); -said growing a plurality of functional layers in said docking channel (21), -designing one or more of said plurality of functional layers as a current blocking structure, -obtaining a first docking portion (31) of the docking structure (3), comprising in particular: After etching to obtain a butt joint channel (21) and a butt joint step (22), carrying out acid treatment on the epitaxial wafer, and cleaning and blow-drying; A second InP buffer layer (311), a first N-InP layer (317), an Fe-InP layer (318), a second N-InP layer (319), an InGaAsP layer (312), a third InP spacer layer (313), a second corrosion resistant layer (314) and a second InP cladding layer (315) are grown in sequence in the butt-joint channel (21).

Description

Structure of passive waveguide butt-joint laser and manufacturing method thereof Technical Field The invention relates to the technical field of semiconductor light-emitting devices, in particular to a structure of a passive waveguide butt-joint laser and a manufacturing method thereof. Background With the development of communication technology, a higher demand is also put on communication rate, and a high-speed device is a key for improving the communication rate, wherein a semiconductor laser with high reliability, high speed and low cost is a precondition for the development of a high-speed device and a high-speed integrated device. The Distributed-feedback laser (DFB laser) has the characteristics of single longitudinal mode and long transmission distance, and is suitable for the requirements of high-speed devices in 5G technology and data center application. In order to improve the performance of the high-speed DFB laser, methods such as quantum well hybridization, selective area growth (SELECTIVE AREA growth, abbreviated as SAG), butt-joint growth technology (abbreviated as button-joint), a spot-size converter (Spot Size Converters, abbreviated as SSC) and the like are developed, and compared with the solution of the problem of light limitation, the method of plating an SiO 2 insulating layer on a passive waveguide to limit the expansion of current in a waveguide area in the preparation process of the passive waveguide Butt-joint laser is found, but a P-cladding cladding doped below the insulating layer can provide a leakage channel for the current, and the background concentration can be gradually increased along with the change of an epitaxial growth period, so that the current is diffused in the passive waveguide area to generate loss, so that the conventional preparation process does not achieve an ideal effect. In view of this, overcoming the drawbacks of the prior art is a problem to be solved in the art. Disclosure of Invention The invention aims to solve the technical problem that the current is easy to diffuse in a passive waveguide area due to the structure of the conventional passive waveguide butt joint laser, so that larger loss is generated. The invention adopts the following technical scheme: In a first aspect, the present invention provides a structure of a passive waveguide docking laser, comprising a substrate 1, an epitaxial structure 2 and a docking structure 3; the epitaxial structure 2 is obtained by growing a plurality of functional layers on a substrate 1; the docking structure 3 comprises a first docking portion 31 and a second docking portion 32, wherein the first docking portion 31 is obtained by growing a plurality of functional layers in the docking channel 21 after etching the epitaxial structure 2 to obtain the docking channel 21 and the docking step 22; the second abutting portion 32 is obtained by growing a plurality of functional layers on the surface of the abutting step 22 and the surface of the first abutting portion 31; one or more of the functional layers in the first docking portion 31 are designed as current blocking structures, wherein the current blocking structures are reverse PN junctions or semi-insulating doped growth structures comprising Fe-InP. Preferably, when the position of the first abutting portion 31 near the second abutting portion 32 is designed as a current blocking structure of a reverse PN junction, the epitaxial structure 2 includes, in order according to a growth direction, a first InP buffer layer 201, a grating layer 202, a grating protection layer 203, a first InP spacer layer 204, a lower confinement layer 205, a lower waveguide layer 206, a multiple quantum well layer 207, an upper waveguide layer 208, an upper confinement layer 209, a second InP spacer layer 210, a first anti-corrosion layer 211, and a first InP cladding layer 212; The butt-joint channel 21 is etched to the first InP spacer 204, and the first butt-joint portion 31 sequentially includes a second InP buffer layer 311, an InGaAsP layer 312, a third InP spacer layer 313, a second anti-corrosion layer 314, a second InP cladding layer 315, a first P-InP layer 316, and a first N-InP layer 317 according to a growth direction, where the first P-InP layer 316 and the first N-InP layer 317 form the current blocking structure. Preferably, when the position of the first abutting portion 31 near the bottom of the abutting channel 21 is designed as a current blocking structure of a reverse PN junction, the epitaxial structure 2 includes, in order according to the growth direction, a first InP buffer layer 201, a grating layer 202, a grating protection layer 203, a first InP spacer layer 204, a third anti-corrosion layer 213, a fourth InP spacer layer 214, a lower confinement layer 205, a lower waveguide layer 206, a multiple quantum well layer 207, an upper waveguide layer 208, an upper confinement layer 209, a second InP spacer layer 210, a first anti-corrosion layer 211, and a f