WO2019062118A1 - Waveguide phase shifter and preparation method therefor - Google Patents

Abstract

A waveguide phase shifter, a semiconductor substrate thereof at least comprising a substrate layer, an oxide layer and a top silicon layer (10), wherein the oxide layer is located between the substrate layer and the top silicon layer. The top silicon layer (10) is at least one ridge-shaped waveguide (11) arranged horizontally. At least one highly doped region (12) corresponding to the ridge-shaped waveguide (11) is formed close to a horizontal position of the ridge-shaped waveguide (11) by means of ion injection, and a first metal electrode (13) for connecting an anode of a power source and a second metal electrode (14) for connecting a cathode of the power source are respectively formed on an upper surface at two ends of each highly doped region (12). Also provided is a method for preparing a waveguide phase shifter. According to the waveguide phase shifter, by providing a heated highly doped region at an edge of a ridge-shaped waveguide, the phase modulation of optical waves passing through the ridge-shaped waveguide is realized, the heating efficiency of the ridge-shaped waveguide is increased, and the adjustment range of a phase is improved.

Description

Waveguide phase shifter and preparation method thereof

cross reference

The present application is hereby incorporated by reference in its entirety in its entirety in its entirety in its entirety in the the the the the the the the the the

Technical field

Embodiments of the present invention relate to the field of optical semiconductor technologies, and in particular, to a waveguide phase shifter and a method for fabricating the same.

Background technique

A laser radar is a radar system that emits a laser beam to detect the position and velocity of a target. Its working principle is similar to microwave radar. Obtaining an equal-phase-interval multiplexed laser through the phase shifter array, thereby controlling the outgoing light direction and transmitting the detection signal to the target, and then comparing the received signal reflected from the target, that is, the target echo and the transmitted signal, through the software. The target can accurately obtain the target distance, azimuth, altitude, speed, shape and other parameters to detect, track and identify the target. The development of artificial intelligence, automatic driving, and the rise of assisted driving will greatly promote the application of laser radar in the civilian field.

The optical phase shifter array is capable of controlling the angle of the outgoing beam and is a core component of the laser radar. At present, the optical phase shifter array is mainly obtained by the main optical path passing through the MMI structure or the star beam splitter, dividing the light into multiple paths, and then introducing the phase shifter array through the waveguide. Principle of silicon waveguide optical phase shifter: By using the thermo-optic effect of silicon material, the refractive index of the silicon waveguide is changed by setting different temperatures, and finally the phase adjustment of the beam is realized. The phase modulation mode of the silicon waveguide thermo-optical phase shifter array mainly adopts the method of heating the metal by the top. The utility model is characterized in that an optical isolation layer is added between the silicon waveguide and the metal, and after heating the metal, the heat is conducted to the waveguide to achieve the phase modulation effect.

The top heating of the metal reduces the heating efficiency, while the metal cannot withstand too high a temperature, the phase adjustment is limited, and the scanning angle is small, <3 degrees, which is difficult to apply in practice.

Summary of the invention

The embodiment of the invention provides a waveguide phase shifter and a preparation method thereof, which are used to solve the problem that the phase shifter using the thermo-optic effect in the prior art has limited phase adjustment and is difficult to be applied in practice.

In one aspect, the invention provides a waveguide phase shifter comprising:

a semiconductor substrate, the semiconductor substrate including at least a substrate layer, an oxide layer, and a top silicon layer, wherein the oxide layer is located between the substrate layer and the top silicon layer, and a waveguide is etched at the top silicon layer An array, the waveguide array being at least one horizontally arranged ridge waveguide, and at least one high doping corresponding to the ridge waveguide is formed by ion implantation at a horizontal position of the top silicon layer adjacent to the ridge waveguide In the region, a first metal electrode for connecting the power source anode and a second metal electrode for connecting the power source cathode are respectively formed on the upper surfaces of each of the highly doped regions.

In another aspect, an embodiment of the present invention provides a method for preparing the waveguide phase shifter described above, including:

Acquiring a first semiconductor substrate, the first semiconductor substrate comprising at least a substrate layer, an oxide layer and a top silicon layer, wherein the oxide layer is located intermediate the substrate layer and the top silicon layer;

Etching a waveguide array on the top silicon layer, the waveguide array being at least one horizontally arranged ridge waveguide, thereby obtaining a second semiconductor substrate;

Determining a length of a highly doped region corresponding to the ridge waveguide according to a preset phase difference and a position of each ridge waveguide in the waveguide array, and then approaching the ridge waveguide in the top silicon layer Forming at least one highly doped region corresponding to the ridge waveguide by ion implantation to obtain a third semiconductor substrate;

Forming a first metal electrode for connecting the power source anode and a second metal electrode for connecting the power source cathode to the upper surface of each of the highly doped regions of the third semiconductor substrate, thereby obtaining a fourth semiconductor substrate .

A waveguide phase shifter according to an embodiment of the present invention and a method for fabricating the same, by providing a highly doped region on a side of the ridge waveguide, and then heating the highly doped region to achieve the ridge waveguide The purpose of heating is to achieve phase modulation of the light waves passing through the ridge waveguide. The integrated edge-heated waveguide phase shifter solution improves the heating efficiency of the ridge waveguide, and adopts a simple structure to completely separate the photon transmission and the carrier transport path space, thereby effectively reducing the current carrying current. Sub-absorption losses, waveguide bending losses, and other potential optical losses, and the structure requires low process accuracy and high yield. The laser radar using the waveguide phase shifter enables a high-angle, high-precision scanning function.

DRAWINGS

1 is a schematic structural view of a waveguide phase shifter according to an embodiment of the present invention;

2 is a schematic flow chart of a method for preparing a waveguide phase shifter according to an embodiment of the present invention;

3 is a schematic structural view of a first semiconductor substrate according to an embodiment of the present invention;

4 is a schematic structural view of a second semiconductor substrate according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a third semiconductor substrate according to an embodiment of the present invention; FIG.

FIG. 6 is a schematic structural view of a fourth semiconductor substrate according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

FIG. 1 is a schematic structural diagram of a waveguide phase shifter according to an embodiment of the present invention, as shown in FIG.

a semiconductor substrate, the semiconductor substrate including at least a substrate layer, an oxide layer, and a top silicon layer 10, wherein the oxide layer is located between the substrate layer and the top silicon layer 10, and the top silicon layer 10 is engraved Etching the waveguide array, the waveguide array being at least one horizontally arranged ridge waveguide 11 and corresponding to the ridge waveguide 11 by ion implantation at a horizontal position of the top silicon layer close to the ridge waveguide 11 At least one highly doped region 12, at each of the upper surfaces of each of the highly doped regions 12, respectively forms a first metal electrode 13 for connecting the power source anode and a second metal electrode 14 for connecting the power source cathode.

A waveguide phase shifter is an optical device used to change the phase of a passing light wave. For example, when a waveguide phase shifter is applied to a laser radar, a waveguide phase shifter is integrated behind the beam splitter, so that the light wave passes through the beam splitter. After being divided into a plurality of optical waves of the same phase, phase modulation is performed by different waveguides of the waveguide phase shifter, and then light waves of different phases are transmitted through an optical antenna connected behind the waveguide phase shifter to realize part of the function of the radar.

The waveguide phase shifter of the embodiment of the present invention phase-modulates the passing light wave by a thermo-optic effect, and heats the ridge-shaped waveguide 11 through which the light wave passes, thereby changing the refractive index of the ridge-shaped waveguide 11, and further, the light wave. The phase is modulated. The waveguide phase shifter is integrated on a semiconductor substrate, wherein the semiconductor substrate can adopt the most commonly used SOI substrate, and the SOI substrate is divided into three layers from bottom to top, respectively being a substrate layer and an oxide layer. And the top silicon layer 10, wherein the main components of the phase shifter are located in the top silicon layer 10, and the thickness of the top silicon layer 10 can be made according to actual needs, for example, 220 to 500 nm.

Further, the top silicon layer of the semiconductor substrate is intrinsic silicon.

The material of the top silicon layer is intrinsic silicon, thereby obtaining good light guiding properties and high electrical resistance properties, wherein the intrinsic silicon has a resistivity of 100000 Ω - 1 Ω / cm.

Forming a waveguide array by etching or the like on the top silicon layer, wherein the waveguide array is a row of horizontally arranged ridge waveguides 11, that is, the etching depth thereof does not etch away the entire top layer of the silicon layer 10 For example, 70 to 200 nm. The number of the ridge waveguides 11 can be adjusted according to specific needs, for example, the number of the ridge waveguides 11 in the laser radar is the same as the number of in-phase optical waves output by the beam splitter before the waveguide phase shifter. correspond.

In order to phase-modulate the light waves in the ridge waveguide 11, it is necessary to heat-treat the ridge waveguide 11. In the horizontal position of the top silicon layer close to each ridge waveguide 11, ions are implanted, and the ions may be boron, phosphorus or the like to realize doping of silicon N-type or P-type, thereby forming two sides of each ridge waveguide 11 The horizontal position forms at least one highly doped region 12. The highly doped region 12 may be located on either side of the ridge waveguide, or an equal-length highly doped region 12 may be disposed on both sides of the ridge waveguide. For convenience of description, in the following embodiments, The case where only one highly doped region 12 is formed on one side of each ridge waveguide 11 is taken as an example. The resistivity of the highly doped region 12 is greatly reduced compared to the intrinsic silicon, and its resistivity is 0.00001 Ω - 1 Ω / cm.

Then, a first metal electrode 13 for connecting the power source anode and a second metal electrode 14 for connecting the power source cathode are respectively formed on the upper surfaces of both ends of each of the highly doped regions 12. When the first metal electrode 13 and the second metal electrode 14 are respectively connected to the respective power source anodes and cathodes, a current is formed on the highly doped regions. Further, since the resistivity of the intrinsic silicon is much higher than that of the highly doped region 12, no current flows into the ridge waveguide 11, and light waves are mainly confined in the ridge waveguide 11, thereby realizing light waves. The spatial separation of transmission and electronic transmission routes reduces the loss of optical transmission.

Further, the operating temperature of the highly doped region 12 is controlled by the power supply anode input power connected to the first metal electrode 13 of the highly doped region 12.

The highly doped region 12 generates heat during the flow of current and eventually reaches a stable operating temperature that is controlled by the input power of the anode connected through the first metal electrode 13. The specific input power needs to be calculated according to actual conditions, for example, according to parameters such as the length of the highly doped region 12 and the ridge waveguide 11, the amount of phase to be adjusted by the light wave, and the doping concentration of the highly doped region 12. And actually adjusted. The highly heated doped region 12 transfers heat to the ridge waveguide 11 through the top silicon layer 10, thereby heating the ridge waveguide 11, and further adjusting the phase of the light passing through the ridge waveguide 11.

The waveguide phase shifter of the embodiment of the present invention achieves the purpose of heating the ridge waveguide 11 by providing a highly doped region 12 on the side of the ridge waveguide 11 and then heating the highly doped region 12 to be electrically heated. Thereby, the phase modulation of the light wave passing through the ridge waveguide 11 is realized, the heating efficiency of the ridge waveguide 11 is improved, and the adjustment range of the phase is improved, and the laser radar using the waveguide phase shifter is realized at the same time. Angle, high-precision scanning function.

Based on the above embodiment, further, as shown in FIG. 1, the lengths of the highly doped regions 12 corresponding to all the ridge waveguides 11 in the waveguide array are horizontally arranged in the waveguide array according to the ridge waveguide 11. The order is incremented or decremented.

There are many kinds of phase modulation methods for the waveguide phase shifter using the thermo-optic effect, and the most important ones are two, one is an equal length heating waveguide, and the other is a unequal length heating waveguide. Wherein the equal length heating waveguides, that is, the lengths of all the highly doped regions 12 are equal, the operating temperature of each highly doped region 12 is controlled by adjusting the input power to each of the highly doped regions 12, respectively, using the ridge waveguide 11 heating temperature difference for different phase modulation. Although the method is relatively simple in manufacturing process, due to the temperature difference between the highly doped regions, it is necessary to overcome the heating temperature of the adjacent ridge waveguide by the highly doped region 12 corresponding to each ridge waveguide 11 . influences. At this time, it is necessary to achieve thermal isolation by adding a heat insulating layer between each of the ridge waveguides 11 or by increasing the pitch, so that the spacing between the adjacent two pairs of the ridge waveguide 11 and the highly doped region 12 may be more than 100 μm or more. And the number of components in the phase shifter also rises exponentially, making the size of the waveguide phase shifter larger is not conducive to integration.

Another type of unequal length heating waveguide is to design a highly doped region 12 of unequal length such that the length of the heating region of the ridge waveguide 11 varies with the length of the highly doped region 12, using the ridge waveguide 11 The lengths of the heating are different to perform different phase modulations, and the heating temperatures of the ridge waveguides 11 can be considered to be the same or approximately the same. Since the heating temperature of the ridge waveguide 11 is the same, the pitch of the ridge waveguide 11 can be shortened, for example, the distance between the adjacent two pairs of the ridge waveguide 11 and the highly doped region 12 is 5 μm. Long heating. Compared to the equal length heating waveguide, the size of the waveguide phase shifter using unequal length heating is greatly reduced, thereby facilitating integration. The same heating temperature also means that the phase can be specifically adjusted by adjusting the heating temperature, and since there is no temperature difference, it can be known that the range that can be adjusted is larger than that of the equal length heating waveguide to realize the high-angle scanning of the laser radar. Features. In order to express convenience and improve integration performance, in the following embodiments, the unequal length heating waveguide is used as the phase modulation mode of the waveguide phase shifter.

Since the phase adjustment of the ridge waveguide 11 is different, the length of the highly doped region 12 corresponding to the ridge waveguide 11 is also different. For ease of fabrication, the length of the highly doped regions 12 can be ordered as desired such that the length of the highly doped regions 12 in the waveguide array is sequentially incremented or decremented.

Further, a difference in length of the highly doped region 12 corresponding to two adjacent ridge waveguides 11 in the waveguide array is set according to a preset phase difference.

Each waveguide phase shifter pre-sets a phase difference according to the specific technical requirements and the optical wave band of the waveguide phase shifter before the fabrication, and then calculates the required optical path difference according to the phase difference, and then calculates the adjacent two optical paths. The length of the heating zone required between the ridge waveguides 11 is different, and finally the difference in length of the highly doped regions 12 corresponding to the adjacent two ridge waveguides 11 is calculated. After the length difference of the adjacent highly doped regions 12 is obtained, the length of each highly doped region 12 can be designed according to the actual waveguide phase shifter condition and technical requirements.

In the embodiment of the present invention, the waveguide phase shifter realizes a phase modulation mode of unequal-length heating by designing a highly doped region 12 of unequal length, thereby reducing the size of the waveguide phase shifter and improving the range of phase adjustment. And facilitate the integration of the waveguide phase shifter.

Based on the above embodiment, further, the ends of the second metal electrodes of all the highly doped regions on the waveguide phase shifter are located on the same side of the waveguide array, and all the second metal electrodes are connected to be connected to The same power cathode.

After the length difference between two adjacent highly doped regions is acquired according to the preset phase difference, and the lengths of two adjacent highly doped regions are designed, there are many methods for designing the position of each highly doped region. For a highly doped region, the actual working area is a conductive region between the first metal electrode and the second metal electrode, so even if the same length design is adopted when forming a highly doped region, The distance between the first metal electrode and the second metal electrode corresponding to the adjacent two highly doped regions satisfies the calculated difference in length between the adjacent two highly doped regions to achieve a preset phase difference. Of course, in these designs, a relatively convenient design also places the first metal electrode and the second metal electrode at each end of each highly doped region. And, one end of all highly doped regions on the waveguide phase shifter is located on the same side of the waveguide array, for example, the end of the second metal electrode is located on the same side of the waveguide array, at this time due to the second The metal electrodes are all used to connect the cathode of the power supply, so it is also possible to connect all of the second metal electrodes and simultaneously connect them to the cathode of the power supply.

In the embodiment of the invention, the waveguide phase shifter is made simpler and more convenient by placing one end of the highly doped region on the same side of the waveguide array and connecting all the second metal electrodes.

2 is a schematic flow chart of a method for preparing a waveguide phase shifter according to an embodiment of the present invention, FIG. 3 is a schematic structural view of a first semiconductor substrate according to an embodiment of the present invention, and FIG. 4 is a schematic structural view of a second semiconductor substrate according to an embodiment of the present invention; 5 is a schematic structural view of a third semiconductor substrate according to an embodiment of the present invention. FIG. 6 is a schematic structural diagram of a fourth semiconductor substrate according to an embodiment of the present invention. As shown in FIG. 2, the method includes:

Step S01, acquiring a first semiconductor substrate, the first semiconductor substrate comprising at least a substrate layer, an oxide layer and a top silicon layer, wherein the oxide layer is located between the substrate layer and the top silicon layer;

A waveguide phase shifter is an optical device for changing the phase of a light wave passing through, and is integrated on a semiconductor substrate, wherein the semiconductor substrate can employ the most commonly used SOI substrate from bottom to top. Divided into three layers, respectively, a substrate layer 30, an oxide layer 20 and a top silicon layer 10, wherein the main components of the phase shifter are located in the top silicon layer 10, and the thickness of the top silicon layer 10 can be performed according to actual needs. The production is, for example, 220 to 500 nm.

Further, the top silicon layer 10 of the semiconductor substrate is intrinsic silicon.

The material of the top silicon layer is intrinsic silicon, thereby obtaining good light guiding properties and high electrical resistance properties, wherein the intrinsic silicon has a resistivity of 100000 Ω - 1 Ω / cm.

Step S02, etching a waveguide array in the top silicon layer, the waveguide array is at least one horizontally arranged ridge waveguide, thereby obtaining a second semiconductor substrate;

Forming a waveguide array on a top silicon layer 10 of the first semiconductor substrate by a conventional semiconductor process such as photolithography and etching, wherein the waveguide array is a row of horizontally arranged ridge waveguides 11, that is, the etching depth thereof is not The entire top layer of the silicon layer 10 is etched away, for example, 70 to 200 nm. The number of the ridge waveguides 11 can be adjusted according to specific needs, for example, the number of the ridge waveguides 11 in the laser radar corresponds to the number of light waves output by the beam splitter before the waveguide phase shifter. Thereby a second semiconductor substrate is obtained.

Step S03, determining a length of the highly doped region corresponding to the ridge waveguide according to a preset phase difference and a position of each ridge waveguide in the waveguide array, and then approaching the ridge in the top silicon layer a horizontal position of the waveguide is formed by ion implantation to form at least one highly doped region corresponding to the ridge waveguide, thereby obtaining a third semiconductor substrate;

In order to phase-modulate the light waves in the ridge waveguide 11, it is necessary to heat-treat the ridge waveguide 11. At a horizontal position of the top silicon layer of the second semiconductor substrate near each of the ridge waveguides 11, at least one height is formed at a horizontal position on each side of each ridge waveguide 11 by a conventional semiconductor process such as photolithography, ion implantation, and annealing. Doped region 12, wherein the ions may be boron, phosphorus, etc., to achieve doping of silicon N-type or P-type. Thereby a third semiconductor substrate is obtained. The highly doped region 12 may be located on either side of the ridge waveguide, or an equal-length highly doped region 12 may be disposed on both sides of the ridge waveguide. For convenience of description, in the following embodiments, The case where only one highly doped region 12 is formed on one side of each ridge waveguide 11 is taken as an example. The resistivity of the highly doped region 12 is greatly reduced compared to the intrinsic silicon, and its resistivity is 0.00001 Ω - 1 Ω / cm.

Step S04, forming a first metal electrode for connecting the power source anode and a second metal electrode for connecting the power source cathode on the upper surfaces of each of the highly doped regions of the third semiconductor substrate, thereby obtaining a fourth Semiconductor substrate.

Forming a first metal electrode 13 for connecting the power source anode and a second electrode for connecting the power source cathode by using a process such as photolithography, deposition metal, and lift-off on the upper surfaces of each of the highly doped regions 12 of the third semiconductor substrate Metal electrode 14. Thereby a fourth semiconductor substrate is obtained. When the first metal electrode 13 and the second metal electrode 14 are respectively connected to the respective power source anodes and cathodes, a current is formed on the highly doped regions. Further, since the resistivity of the intrinsic silicon is much higher than that of the highly doped region 12, no current flows into the ridge waveguide 11, and light waves are mainly confined in the ridge waveguide 11, thereby realizing light waves. The spatial separation of transmission and electronic transmission routes reduces the loss of optical transmission.

Further, the operating temperature of the highly doped region 12 is controlled by the power supply anode input power connected to the first metal electrode 13 of the highly doped region 12.

The highly doped region 12 generates heat during the flow of current and eventually reaches a stable operating temperature that is controlled by the input power of the anode connected through the first metal electrode 13. The specific input power needs to be calculated according to actual conditions, for example, according to parameters such as the length of the highly doped region 12 and the ridge waveguide 11, the amount of phase to be adjusted by the light wave, and the doping concentration of the highly doped region 12. And actually adjusted. The highly heated doped region 12 transfers heat to the ridge waveguide 11 through the top silicon layer 10, thereby heating the ridge waveguide 11, and further adjusting the phase of the light passing through the ridge waveguide 11.

The preparation method provided by the embodiment of the present invention is used to prepare the above-mentioned waveguide phase shifter, and its function and structure are specifically referred to the above embodiments, and details are not described herein again.

The waveguide phase shifter of the embodiment of the present invention achieves the purpose of heating the ridge waveguide 11 by providing a highly doped region 12 on the side of the ridge waveguide 11 and then heating the highly doped region 12 to be electrically heated. Thereby, the phase modulation of the light wave passing through the ridge waveguide 11 is realized, the heating efficiency of the ridge waveguide 11 is improved, and the adjustment range of the phase is improved, and the laser radar using the waveguide phase shifter is realized at the same time. Angle, high-precision scanning function.

Based on the above embodiments, further, the lengths of the highly doped regions corresponding to all the ridge waveguides in the waveguide array are increased or decreased in the order in which the ridge waveguides are horizontally arranged in the waveguide array.

There are many kinds of phase modulation methods for the waveguide phase shifter using the thermo-optic effect, and the most important ones are two, one is an equal length heating waveguide, and the other is a unequal length heating waveguide. Wherein the equal length heating waveguides, that is, the lengths of all the highly doped regions are equal, different phase modulation is performed by adjusting the operating temperature of each highly doped region by using the temperature difference of the ridge waveguide heating. Due to the temperature difference between the highly doped regions, it is necessary to overcome the influence of the highly doped region corresponding to each ridge waveguide on the heating temperature of the adjacent ridge waveguide. At this time, it is necessary to achieve thermal isolation by adding a heat insulating layer or increasing the pitch between each ridge waveguide, thereby causing the spacing between adjacent two pairs of ridge waveguides and highly doped regions to be more than 100 μm or more, and phase shifting. The number of components in the device also rises exponentially, making the size of the waveguide phase shifter larger is not conducive to integration.

Another type of unequal-length heating waveguide is to design a highly doped region of unequal length such that the length of the heating region of the ridge waveguide varies with the length of the highly doped region, and the length of heating by the ridge waveguide is different. Different phase modulations are performed, and the heating temperatures of the ridge waveguides may be considered to be the same or approximately the same. Since the heating temperature of the ridge waveguide is the same, the pitch of the ridge waveguide can be shortened relatively, for example, the distance between adjacent two pairs of ridge waveguides and the highly doped region is 5 μm, thereby achieving unequal length heating. Compared to the equal length heating waveguide, the size of the waveguide phase shifter using unequal length heating is greatly reduced, thereby facilitating integration. The same heating temperature also means that the phase can be specifically adjusted by adjusting the heating temperature, and since there is no temperature difference, it can be known that the range that can be adjusted is larger than that of the equal length heating waveguide to realize the high-angle scanning of the laser radar. Features. In order to express convenience and improve integration performance, in the following embodiments, the unequal length heating waveguide is used as the phase modulation mode of the waveguide phase shifter.

Since the phase adjustment of the ridge waveguide is different, the length of the highly doped region corresponding to the ridge waveguide is also different. For ease of fabrication, the length of the highly doped regions can be ordered as desired such that the length of the highly doped regions in the waveguide array is sequentially incremented or decremented.

Further, a length difference of the highly doped regions corresponding to adjacent two ridge waveguides in the waveguide array is set according to a preset phase difference.

Each waveguide phase shifter pre-sets a phase difference according to the specific technical requirements and the optical wave band of the waveguide phase shifter before the fabrication, and then calculates the required optical path difference according to the phase difference, and then calculates the adjacent two optical paths. The length of the heating zone required between the ridge waveguides is poor, and finally the length difference of the highly doped regions corresponding to the adjacent two ridge waveguides is calculated. After obtaining the difference in length between adjacent highly doped regions, the length of each highly doped region can be designed according to the actual waveguide phase shifter condition and technical requirements.

In the embodiment of the present invention, the waveguide phase shifter realizes a phase modulation method of unequal-length heating by designing a highly doped region of unequal length, thereby reducing the size of the waveguide phase shifter and improving the range of phase adjustment. And facilitate the integration of the waveguide phase shifter.

Based on the above embodiment, further, the end of the second metal electrode of the highly doped region is located on the same side of the waveguide array, and correspondingly,

On the basis of the fourth semiconductor substrate, the second metal electrodes of all the highly doped regions are connected by metal to connect the same power source cathode, thereby obtaining a fifth semiconductor substrate.

After the length difference between two adjacent highly doped regions is obtained according to the preset phase difference, and the lengths of two adjacent highly doped regions are designed, there are many methods for designing the position of each highly doped region. For a highly doped region, the actual working area is a conductive region between the first metal electrode and the second metal electrode, so even if the same length design is adopted when forming a highly doped region, The distance between the first metal electrode and the second metal electrode corresponding to the adjacent two highly doped regions satisfies the calculated difference in length between the adjacent two highly doped regions to achieve a preset phase difference. Of course, in these designs, a relatively convenient design also places the first metal electrode and the second metal electrode at each end of each highly doped region. And, one end of all the highly doped regions on the fourth semiconductor substrate are located on the same side of the waveguide array, for example, the end of the second metal electrode is located on the same side of the waveguide array, Both metal electrodes are used to connect the cathode of the power supply, so it is also possible to connect all of the second metal electrodes and simultaneously connect them to the cathode of the power supply. Thereby a fifth semiconductor substrate is formed.

The preparation method provided by the embodiment of the present invention is used to prepare the above-mentioned waveguide phase shifter, and its function and structure are specifically referred to the above embodiments, and details are not described herein again.

In the embodiment of the invention, the waveguide phase shifter is made simpler and more convenient by placing one end of the highly doped region on the same side of the waveguide array and connecting all the second metal electrodes.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not limited thereto; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that The technical solutions described in the foregoing embodiments are modified, or the equivalents of the technical features are replaced. The modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (9)

A waveguide phase shifter, comprising: a semiconductor substrate, the semiconductor substrate including at least a substrate layer, an oxide layer, and a top silicon layer, wherein the oxide layer is located between the substrate layer and the top silicon layer, and a waveguide is etched at the top silicon layer An array, the waveguide array being at least one horizontally arranged ridge waveguide, and at least one high doping corresponding to the ridge waveguide is formed by ion implantation at a horizontal position of the top silicon layer adjacent to the ridge waveguide In the region, a first metal electrode for connecting the power source anode and a second metal electrode for connecting the power source cathode are respectively formed on the upper surfaces of each of the highly doped regions. The waveguide phase shifter according to claim 1, wherein a length of a highly doped region corresponding to all ridge waveguides in said waveguide array is arranged horizontally in said waveguide array according to said ridge waveguide Increment or decrement. The waveguide phase shifter according to claim 2, wherein a length difference of said highly doped regions corresponding to adjacent two ridge waveguides in said waveguide array is set according to a preset phase difference. The waveguide phase shifter of claim 1 wherein the top silicon layer of the semiconductor substrate is intrinsic silicon. The waveguide phase shifter of claim 1 wherein the operating temperature of said highly doped region is controlled by said power supply anode input power coupled to said first metal electrode of said highly doped region. The waveguide phase shifter according to any one of claims 1 to 5, wherein the end of the second metal electrode of all highly doped regions on the waveguide phase shifter is located on the same side as the waveguide array. All of the second metal electrodes are connected for connection to the same power cathode. A method of fabricating a waveguide phase shifter according to any of claims 1-6, comprising: Acquiring a first semiconductor substrate, the first semiconductor substrate comprising at least a substrate layer, an oxide layer and a top silicon layer, wherein the oxide layer is located intermediate the substrate layer and the top silicon layer; Etching a waveguide array on the top silicon layer, the waveguide array being at least one horizontally arranged ridge waveguide, thereby obtaining a second semiconductor substrate; Determining a length of a highly doped region corresponding to the ridge waveguide according to a preset phase difference and a position of each ridge waveguide in the waveguide array, and then approaching the ridge waveguide in the top silicon layer Forming at least one highly doped region corresponding to the ridge waveguide by ion implantation to obtain a third semiconductor substrate; Forming a first metal electrode for connecting the power source anode and a second metal electrode for connecting the power source cathode to the upper surface of each of the highly doped regions of the third semiconductor substrate, thereby obtaining a fourth semiconductor substrate . The method according to claim 7, wherein the ends of the second metal electrodes of the highly doped regions are located on the same side of the waveguide array, and correspondingly, On the basis of the fourth semiconductor substrate, the second metal electrodes of all the highly doped regions are connected by metal to connect the same power source cathode, thereby obtaining a fifth semiconductor substrate. The method of claim 7 wherein the top silicon layer of the semiconductor substrate is intrinsic silicon.

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