阅读说明：本技术 电吸收调制激光器的制作方法 (Method for manufacturing electric absorption modulation laser ) 是由 周代兵 梁松 赵玲娟 王圩 于 2020-12-23 设计创作，主要内容包括：本发明提供了一种电吸收调制激光器的制作方法,包括：在同一衬底上依次生长缓冲层和有源层,有源层包括第一有源层、作为激光器区有源层的第二有源层和作为波长稳定区有源层的第三有源层；刻蚀掉第一有源层,并对接生长调制器区有源层；在作为激光器区有源层的第二有源层内制作光栅；在调制器区有源层上、作为激光器区有源层的第二有源层上和作为波长稳定区有源层的第三有源层上依次生长包层和接触层；刻蚀部分包层和接触层制作脊型波导；刻蚀掉调制器区与激光器区之间、激光器区与波长稳定区之间的接触层,并注入氦离子形成电隔离沟；制作调制器区、激光器区和波长稳定器区的P型电极；对衬底进行背面减薄,并在衬底背面制作大面积N型电极。(The invention provides a manufacturing method of an electroabsorption modulated laser, which comprises the following steps: sequentially growing a buffer layer and an active layer on the same substrate, wherein the active layer comprises a first active layer, a second active layer serving as a laser region active layer and a third active layer serving as a wavelength stable region active layer; etching the first active layer, and butt-growing the modulator region active layer; manufacturing a grating in a second active layer serving as an active layer of the laser area; sequentially growing a cladding layer and a contact layer on the modulator region active layer, the second active layer serving as the laser region active layer and the third active layer serving as the wavelength stabilization region active layer; etching part of the cladding and the contact layer to manufacture a ridge waveguide; etching off contact layers between the modulator area and the laser area and between the laser area and the wavelength stabilizing area, and injecting helium ions to form an electric isolation groove; manufacturing P-type electrodes of a modulator area, a laser area and a wavelength stabilizer area; and thinning the back surface of the substrate, and manufacturing a large-area N-type electrode on the back surface of the substrate.)

1. A method of making an electroabsorption modulated laser, comprising:

sequentially growing a buffer layer and an active layer on the same substrate, wherein the active layer comprises a first active layer, a second active layer used as a laser region active layer and a third active layer used as a wavelength stable region active layer;

etching the first active layer, and butt-growing the modulator region active layer;

manufacturing a grating in the second active layer serving as the active layer of the laser area;

growing a cladding layer and a contact layer on the modulator region active layer, the second active layer serving as the laser region active layer and the third active layer serving as the wavelength stabilization region active layer in sequence;

etching part of the cladding and the contact layer to manufacture a ridge waveguide;

etching off contact layers between the modulator area and the laser area and between the laser area and the wavelength stabilizing area, and injecting helium ions to form an electric isolation groove;

manufacturing P-type electrodes of the modulator area, the laser area and the wavelength stabilizer area;

and thinning the back of the same substrate, and manufacturing a large-area N-type electrode on the back of the substrate.

2. The method of claim 1, wherein the first active layer, the second active layer as a laser region active layer, and the third active layer as a wavelength stabilization region active layer are sequentially disposed adjacent to each other.

3. The method of claim 1 wherein the modulator region active layer has a bandgap wavelength less than the bandgap wavelength of the second active layer as a laser region active layer and the third active layer as a wavelength stabilization region active layer.

4. The method of claim 1 wherein the active layer comprises multiple quantum wells and a grating layer grown sequentially on the buffer layer.

5. The method of claim 4 wherein the grating layer is used to form a grating.

6. The method of fabricating an electro-absorption modulated laser as claimed in claim 4, wherein the grating layer material is InGaAsP; the multiple quantum wells are made of the same material and are InGaAsP or InGaAlAs.

7. The method of fabricating an electroabsorption modulated laser of claim 6 wherein the multiple quantum well comprises a first and a second confinement layer and a multiple quantum well layer between the first and second confinement layers.

8. The method of fabricating an electroabsorption modulated laser as claimed in claim 1,

the modulator region active layer comprises a plurality of quantum wells which are arranged in a stacked mode, wherein the quantum wells are made of the same material and are InGaAsP or InGaAlAs.

9. The method of fabricating an electroabsorption modulated laser as claimed in claim 8,

the quantum well comprises a third confinement layer, a fourth confinement layer, and a multi-quantum well layer between the third confinement layer and the fourth confinement layer.

10. The method of claim 1, wherein the cladding layer is a P-doped InP layer with a thickness of 1.5-1.8 μm; the contact layer is a P-type doped InGaAs layer, and the thickness of the contact layer is 180-220 nm.

Technical Field

The invention relates to the field of optoelectronic devices, in particular to a manufacturing method of an electric absorption modulation laser with stable wavelength.

Background

Electro-absorption modulated lasers (EMLs) have been widely used in fiber optic communication systems. In order to reduce power consumption and application cost, a large number of refrigeration-free EML laser chips are used, and in the use process of the refrigeration-free EML laser chips, the temperature of the chips rises along with the continuous work of the laser, so that the lasing wavelength of the laser chips drifts, and the transmission performance of the laser in the optical fiber is affected. The common solution is to change the laser current intensity to control the wavelength shift, but there are many disadvantages in controlling the wavelength shift by changing the laser current intensity, such as limited drift range of the current intensity adjusting wavelength; the change in current intensity will change the output light intensity, which in turn affects the transmission and reception of light.

Disclosure of Invention

In view of the above, in order to solve a series of adverse effects caused by controlling wavelength drift by changing the current intensity of the laser, the present invention provides a method for manufacturing an electro-absorption modulated laser, which realizes the stabilization of the lasing wavelength by adding a wavelength stabilizer to the electro-absorption modulated laser.

In order to achieve the above object, the present invention provides a method for manufacturing an electroabsorption modulated laser, comprising: sequentially growing a buffer layer and an active layer on the same substrate, wherein the active layer comprises a first active layer, a second active layer serving as a laser region active layer and a third active layer serving as a wavelength stable region active layer; etching the first active layer, and butt-growing the modulator region active layer; manufacturing a grating in a second active layer serving as an active layer of the laser area; sequentially growing a cladding layer and a contact layer on the modulator region active layer, the second active layer serving as the laser region active layer and the third active layer serving as the wavelength stabilization region active layer; etching part of the cladding and the contact layer to manufacture a ridge waveguide; etching off contact layers between the modulator area and the laser area and between the laser area and the wavelength stabilizing area, and injecting helium ions to form an electric isolation groove; manufacturing P-type electrodes of a modulator area, a laser area and a wavelength stabilizer area; and thinning the back of the same substrate, and manufacturing a large-area N-type electrode on the back of the substrate.

According to an embodiment of the present invention, wherein the first active layer, the second active layer as the laser region active layer, and the third active layer as the wavelength stabilization region active layer are adjacently disposed in this order.

According to an embodiment of the present invention, wherein the modulator region active layer has a bandgap wavelength smaller than that of the second active layer as the laser region active layer and the third active layer as the wavelength stabilization region active layer.

According to an embodiment of the present invention, wherein the active layer includes a multiple quantum well and a grating layer sequentially grown on the buffer layer.

According to an embodiment of the present invention, the grating layer is used to fabricate a grating.

According to the embodiment of the invention, the grating layer material is InGaAsP; the multiple quantum wells are of the same material and are InGaAsP or InGaAlAs.

According to an embodiment of the present invention, wherein the multiple quantum well includes a first separate confinement layer, a second separate confinement layer, and a multiple quantum well layer between the first separate confinement layer and the second separate confinement layer.

According to an embodiment of the invention, the modulator region active layer comprises a plurality of quantum wells arranged in a stack, the quantum wells being of the same material and being InGaAsP or InGaAlAs.

According to an embodiment of the present invention, wherein the quantum well comprises a third confinement layer, a fourth confinement layer and a multi-quantum well layer between the third confinement layer and the fourth confinement layer.

According to the embodiment of the invention, the cladding layer is a P-type doped InP layer with the thickness of 1.5-1.8 μm; the contact layer is a P-type doped InGaAs layer with a thickness of 180-220 nm.

According to the technical scheme, the manufacturing method of the electric absorption modulation laser has the following beneficial effects:

by adding the wavelength stabilizer into the electro-absorption modulation laser integrated by the modulator and the laser, under the condition of not changing the current of a laser area, the injected current of the wavelength stabilizer is changed, so that the refractive index of the waveguide of the phase and wavelength stabilizer is changed, the wavelength is effectively adjusted, and is stabilized in a target area, and the change and the stabilization of the wavelength of the laser are realized; the adverse effect caused by current regulation is avoided, and various performances of light transmission in the optical fiber are improved.

Drawings

FIG. 1 schematically illustrates a flow diagram of a method of fabricating an electroabsorption modulated laser in accordance with an embodiment of the present invention;

fig. 2 schematically shows a three-dimensional structure of an electroabsorption modulated laser according to an embodiment of the invention.

Detailed Description

To control the electroabsorption modulated laser chip during use. The invention provides a manufacturing method of an electric absorption modulation laser, which can realize the stability of the lasing wavelength and improve various performances of the laser transmission in the optical fiber.

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.

Fig. 1 and 2 schematically show a flow diagram and a three-dimensional structure diagram of a method for manufacturing an electroabsorption modulated laser according to an embodiment of the present invention, respectively. The manufacturing method is specifically described with reference to fig. 1 and 2.

As shown in fig. 1 and 2, the manufacturing method includes operations S101 to S108.

In operation S101, a buffer layer and an active layer are sequentially grown on the same substrate, the active layer including a first active layer, a second active layer as a laser region active layer, and a third active layer as a wavelength stable region active layer.

According to an embodiment of the invention, an electroabsorption modulated laser is a device integrated by a modulator section (EAM), a laser section (LD) and a wavelength stabilizer Section (SW). Mask growth patterns of a modulator, a laser and a wavelength stabilizer are respectively manufactured on the same substrate 10, and then a buffer layer 20 and an active layer 30 are epitaxially grown in sequence on the mask growth patterns. Wherein the substrate 10 may comprise an InP-based material system and the buffer layer 20 may be an InP layer.

According to an embodiment of the present invention, the active layers include a first active layer, a second active layer 30 as a laser region active layer, and a third active layer as a wavelength stabilization region active layer, which are sequentially disposed adjacent to each other, wherein the first active layer is an active layer outside the laser region and the wavelength stabilization region, including a modulator region portion and a portion between the modulator and the laser.

According to an embodiment of the present invention, the first active layer, the second active layer 30 as the laser region active layer, and the third active layer as the wavelength stabilization region active layer are the same active layer, including multiple quantum wells and a grating layer sequentially grown on the buffer layer. The grating layer can be an InGaAsP layer and is used for manufacturing a grating; the multiple quantum wells are of the same material and may be InGaAsP or InGaAlAs. The multiple quantum well active layer comprises at least one quantum well active layer and a barrier layer.

According to the embodiment of the invention, the grating layer is a multi-quantum well below and comprises a first separate confinement layer, a second separate confinement layer and a multi-quantum well layer between the first separate confinement layer and the second separate confinement layer. The first respective confinement layer is an upper respective confinement layer in the quantum well, and the second respective confinement layer is a lower respective confinement layer in the quantum well.

According to the embodiment of the invention, the region where the wavelength stabilizer is arranged is added into the electro-absorption modulation laser, so that the stability of the wavelength is effectively adjusted by adjusting the current of the wavelength stabilizer, and the wavelength drift of the device caused by overhigh temperature during operation is controlled.

In operation S102, the first active layer is etched away and the modulator region active layer is grown in an abutting manner.

According to an embodiment of the present invention, after the active layer, i.e., the first active layer, outside the laser region and the wavelength stabilization region is removed by selective etching through a silicon dioxide mask, the modulator region is epitaxially grown using a butting technique, and the modulator region active layer 40 is grown butting against the laser region.

According to an embodiment of the present invention, the modulator region active layer 40 has a band gap wavelength smaller than that of the second active layer 30 as a laser region active layer and the third active layer as a wavelength stabilization region active layer.

According to the embodiment of the present invention, the modulation region active layer 40 is a multiple quantum well active layer, the multiple quantum well active layer includes at least one quantum well active layer and a barrier layer, and the multiple quantum well active layers are made of the same material and are InGaAsP or InGaAlAs.

According to an embodiment of the present invention, the modulation region active layer 40 is a multiple quantum well active layer composed of a plurality of quantum wells arranged in a stack, including a third confinement layer, a fourth confinement layer, and a multiple quantum well layer between the third confinement layer and the fourth confinement layer. The third respective confinement layer is an upper respective confinement layer in the quantum well, and the fourth respective confinement layer is a lower respective confinement layer in the quantum well.

In operation S103, a grating is fabricated in the second active layer as the laser region active layer.

According to an embodiment of the present invention, the grating 50 is fabricated in the second active layer 30 as the active layer of the laser region using electron beam lithography, focused ion beam lithography, or the like.

In operation S104, a cladding layer and a contact layer are sequentially grown on the modulator region active layer, the second active layer as the laser region active layer, and the third active layer as the wavelength stabilization region active layer.

According to an embodiment of the present invention, the cladding layer 60 is epitaxially grown on the modulator region active layer, the second active layer as the laser region active layer, and the third active layer as the wavelength stabilization region active layer simultaneously, and the contact layer 70 is epitaxially grown on the same cladding layer 60.

According to the embodiment of the invention, the cladding layer 60 is a P-type doped InP layer with the thickness of 1.5-1.8 μm; the contact layer 70 is a P-type doped InGaAs layer with a thickness of 180-220 nm.

In operation S105, a ridge waveguide is fabricated by etching a portion of the cladding layer and the contact layer.

According to the embodiment of the invention, the cladding layer 60 and the contact layer 70 are simultaneously epitaxially grown on the modulator region active layer, the second active layer as the laser region active layer and the third active layer as the wavelength stabilization region active layer by using the traditional photoetching process, part of the cladding layer and the contact layer are removed, and the cladding layer and the contact layer with the width of 3-5 μm are remained, so that the straight mesa type ridge waveguide with the width of 3-5 μm is formed.

In operation 106, the contact layers between the modulator region and the laser region, and between the laser region and the wavelength stabilization region are etched away, and helium ions are implanted to form electrically isolated trenches.

According to the embodiment of the present invention, the electrical isolation trenches 80 are formed between the modulator region and the laser region, and between the laser region and the wavelength stabilization region, respectively, by etching the contact layers between the modulator region and the laser region, and between the laser region and the wavelength stabilization region using the inductively coupled plasma etcher, and implanting helium ions using an ion implantation technique.

According to the embodiment of the present invention, helium ion implantation is performed at the position where the contact layers between the modulator region and the laser region and between the laser region and the wavelength stabilization region are etched away, so that helium ion beams pass through the active layer of each region and the respective growth layers below through the cladding layer 60 until the speed is slowly reduced due to the resistance of the respective growth layers and finally stay in a certain growth layer, and the electrical isolation trench 80 is formed.

In operation 107, P-type electrodes for the modulator region, the laser region, and the wavelength stabilizer region are fabricated.

In operation 108, the same substrate is back-thinned and a large area N-type electrode is formed on the back of the substrate.

According to the embodiment of the invention, the P-type electrodes of the modulator area, the laser area and the wavelength stabilizer area are manufactured by adopting a photoetching and electroplating method; and then sealing the front side of the laser of the device, mechanically grinding the back side of the substrate to thin the substrate, and manufacturing a large-area N-type electrode on the back side of the substrate by utilizing a photoetching and electroplating method, thereby completing the preparation of the electroabsorption modulated laser with stable wavelength.

According to the embodiment of the invention, the wavelength stabilizer is added into the electro-absorption modulation laser integrated by the modulator and the laser, under the condition of not changing the current of the laser area, the wavelength can be effectively adjusted by adjusting the current of the wavelength stable area, and the wavelength is stabilized in the target area, so that the stability of the lasing wavelength can be effectively, accurately and quickly realized, the adverse effect caused by current regulation and control is avoided, and various performances of light transmission in the optical fiber are improved.

Those skilled in the art will appreciate that various combinations and/or combinations of features recited in the various embodiments and/or claims of the present disclosure can be made, even if such combinations or combinations are not expressly recited in the present disclosure. In particular, various combinations and/or combinations of the features recited in the various embodiments and/or claims of the present disclosure may be made without departing from the spirit or teaching of the present disclosure. All such combinations and/or associations fall within the scope of the present invention.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.