Semiconductor device and photonic circuit

Abstract

The embodiment of the utility model relates to a semiconductor device and a photon circuit. The semiconductor device includes: a substrate; a first waveguide disposed on the substrate; a second waveguide disposed on the substrate and spaced apart from the first waveguide by a first distance; and a heater disposed on the second waveguide and having a first terminal and a second terminal. In addition, the first terminal of the heater is configured to receive a first electrical signal; the second terminal of the heater is configured to receive a second electrical signal; and the heater is configured to carry a time-varying current in response to the first electrical signal and the second electrical signal.

Description

Technical Field

[0001] The present invention relates to a semiconductor device, a photonic circuit, and a method for adjusting the resonant wavelength of an optical modulator. In particular, the present invention relates to a photonic circuit including a heater driven by a time-varying current and related semiconductor devices and methods. Background Art

[0002] In recent years, optical signaling and processing have become increasingly popular, especially using fiber-related applications for signal transmission. Therefore, devices integrating optical and electrical components are used in optoelectronic signal conversion and processing. In the field of optical signaling, optical modulators (such as ring modulators or micro-ring modulators) are elements used to mitigate process mismatch and calibration of optical signals. Optical modulators may include heaters that thermally adjust the resonant wavelength. However, the heaters may generate high current-induced heat, which may induce electromigration (EM) problems and reduce the reliability of the heaters.

[0003] When current flows through a conductive segment, electromigration (EM) occurs, in which the momentum transfer between the conductive electrons and the metal atoms pushes the metal atoms in the direction of the electron flow to displace from their original positions and increase the inhomogeneity of the conductive segment. Over time, EM can create hillocks (accumulation of excess metal) and / or voids (depletion of the original metal) in the conductive segment, which in turn can lead to short circuits (when hillocks are present) or open circuits (when voids are present).

[0004] Therefore, there is a need for an improved light modulator free from EM issues, whereby enhanced reliability of the heater can be achieved. Utility Model Content

[0005] An embodiment of the utility model relates to a semiconductor device, which includes: a substrate; a first waveguide placed on the substrate; a second waveguide placed on the substrate and separated from the first waveguide by a first distance; and a heater placed on the second waveguide and having a first terminal and a second terminal, wherein the first terminal of the heater is configured to receive a first electrical signal; the second terminal of the heater is configured to receive a second electrical signal; and the heater is configured to carry a time-varying current in response to the first electrical signal and the second electrical signal.

[0006] An embodiment of the utility model relates to a photonic circuit, comprising: a first waveguide; and a second waveguide separated from the first waveguide; and a heater, which is placed on the second waveguide and includes one or more pairs of terminals, wherein each of the one or more pairs of terminals includes a first terminal and a second terminal, wherein the first terminal of the heater is configured to receive a first electrical signal and the second terminal of the heater is configured to receive a second electrical signal, so that alternating current passes through the heater from the first terminal to the second terminal within a first duration and from the second terminal to the first terminal within a second duration, and wherein the first electrical signal has a frequency equal to the frequency of the second electrical signal.

[0007] An embodiment of the utility model relates to a method for adjusting the resonant wavelength of an optical modulator, comprising: providing the optical modulator on a substrate and adjacent to a waveguide optically coupled to the optical modulator, wherein the waveguide includes an optical input terminal and an optical output terminal; receiving an optical signal at the optical input terminal of the waveguide; adjusting the resonant wavelength of the optical modulator to a predetermined wavelength by a heater driven by an alternating current; absorbing a portion of the optical signal by the optical modulator; and outputting the adjusted optical signal at the optical output terminal of the waveguide. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Aspects of the present disclosure are best understood from the following detailed description read in conjunction with the accompanying drawings. It should be emphasized that, in accordance with standard practice in the industry, various components are not drawn to scale. In fact, the dimensions of the various components may be arbitrarily increased or reduced for clarity of discussion.

[0009] Figure 1A is a block diagram of an optical communication system according to some embodiments.

[0010] Figure 1B is a schematic diagram of a semiconductor structure of a photonic device according to some embodiments.

[0011] Figure 2A is a top view of a photonic device according to some embodiments.

[0012] Figure 2B is a top view of a photonic device according to some embodiments.

[0013] Figure 2C According to some embodiments, Figure 2A and Figure 2B A cross section of the photonic device along section line AA.

[0014] Figure 3A is a top view of a photonic device according to some embodiments.

[0015] Figure 3Bis a top view of a photonic device according to some embodiments.

[0016] Figure 4A is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention.

[0017] Figure 4B is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention.

[0018] Figure 4C is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention.

[0019] Figure 4D is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention.

[0020] Figure 5 is a flow chart illustrating a method for adjusting the resonant wavelength of a light modulator according to some embodiments. DETAILED DESCRIPTION

[0021] The following disclosure provides many different embodiments or examples for implementing the different features of the provided target. The following describes the specific examples of components and arrangements to simplify the present disclosure. Of course, these are only examples and are not intended to be limiting. For example, in the following description, the first member is formed above or on the second member and can include an embodiment in which the first and second members in direct contact are formed, and can also include an embodiment in which an additional member can be formed between the first and second members so that the first and second members may not be in direct contact. In addition, the present disclosure can repeat element symbols and / or letters in various examples. This repetition is for simplicity and clarity and does not itself indicate the relationship between the various embodiments and / or configurations discussed.

[0022] Additionally, for convenience of description, spatially relative terms (e.g., "below," "beneath," "below," "above," "upper," and the like) may be used herein to describe the relationship of one element or component to another element or components, as illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

[0023] The embodiments or examples illustrated in the figures are disclosed as follows using specific language. However, it should be understood that the embodiments and examples are not intended to be limiting. A person skilled in the art would generally appreciate that any changes or modifications to the disclosed embodiments and any further applications of the principles disclosed in the present disclosure may be considered.

[0024] Furthermore, it should be understood that only a few processing steps and / or features of a device may be briefly described. Moreover, additional processing steps and / or features may be added, and some of the following processing steps and / or features may be removed or changed while still implementing the claims. Therefore, it should be understood that the following descriptions represent examples only and are not intended to imply that one or more steps or features are required.

[0025] In addition, the present disclosure may repeat reference numerals and / or letters in various examples. This repetition is for simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or configurations discussed.

[0026] Figure 1A is a block diagram of an optical communication system 10 according to some embodiments. Figure 1A As shown in , the optical communication system 10 includes a light source 11, a modulator 12, a receiver 13, a driver 14, a processor 15, and a waveguide 16. Figure 1A Also shown are optical signals 17 and 17 ′ transmitted within the optical communication system 10 .

[0027] Figure 1A Illustrating how the light source 11 can transmit an optical signal to the modulator 12, the optical signal 17 can be modulated by the modulator 12 to become a modulated optical signal 17', and the modulated optical signal 17' can be received by the receiver 13. The light source 11, the modulator 12, and the receiver 13 can be connected by a waveguide 16, such as an optical fiber or a light pipe. In some embodiments, the light source 11 can emit the optical signal 17. For example, the optical signal 17 can include a laser beam and a light beam. In some embodiments, the waveguide 16 can include an optical fiber, an optical waveguide, or a light pipe.

[0028] The optical communication system 10 may be part of an internal component of a computer system. For example, the optical communication system 10 may be part of, for example, a personal or laptop computer, where the modulator 12 is included in a processor of the computer system and the receiver 13 is included therein. The receiver 13 may be an internal card of the computer system, such as a video controller card, a network interface card, a memory, or the like. In one embodiment, the optical communication system 10 may be included in a single chip or chipset, where the light source 11 and the receiver 13 are internal components of the chip or chipset. In another embodiment, the optical communication system 10 may be included in a communication network, where the light source 11 and the receiver 13 are included in separate components of the communication network.

[0029] As will be discussed in more detail, the modulator 12 may include a waveguide placed between a p-type semiconductor material and an n-type semiconductor material. In a particular embodiment, such a pattern may form a discrete shape from the light input end to the light output end of the waveguide. In one embodiment, the modulator 12 may be an optical modulator. For example, the modulator 12 may be a ring modulator (RM) or a micro-ring modulator.

[0030] In some embodiments, the driver 14 is electrically connected to the processor 15. The driver 14 may be configured to drive the modulator 12. In some embodiments, the light source 11 may include a light source (e.g., a VCSEL diode). In some embodiments, the receiver 13 may include an amplifier and a light detector ( Figure 1A 1 and 13). During optical communication between the light source 11 and the receiver 13, the processor 15 may generate and transmit an electrical signal to the driver 14. At the same time, the driver 14 may control the modulator 12 based on the electrical signal generated by the processor 15, so that the optical signal 17 emitted from the light source 11 through the waveguide 16 may be coupled to the modulator 12. In addition, the optical signal 17 radiated onto the modulator 12 may be modulated to generate an optical signal 17'. The optical signal 17' generated by the modulator 12 is transmitted to the receiver 13 through the waveguide 16 and received by the receiver 13. Subsequently, the receiver 13 may convert the optical signal 17' into a photocurrent (another electrical signal) and the photocurrent may be amplified by the amplifier. The amplified electrical signal may then be transmitted to other elements in the computer system.

[0031] Figure 1B 1 is a schematic diagram of a semiconductor structure 100 of a photonic device according to some embodiments. The semiconductor structure 100 may include a substrate 129, a dielectric layer 127, a semiconductor layer 128, a waveguide 126, a driver 14, and a modulator 12. In some embodiments, the modulator 12 may include a waveguide (or optical coupling portion) 123 and electrical coupling portions 121 and 122. Figure 1B A modulator 12 is shown coupled to a driver 14 .

[0032] refer to Figure 1B , the semiconductor structure 100 includes a substrate 129. In some embodiments, the substrate 129 may be a silicon substrate, a silicon germanium substrate, or a substrate formed of other semiconductor materials. In some embodiments, the substrate 129 may be doped with a p-type dopant (e.g., boron or BF 2 ), n-type dopants (such as phosphorus or arsenic), or a combination thereof. Alternatively, substrate 129 may be an intrinsic semiconductor substrate. In an alternative embodiment, substrate 129 is a dielectric substrate formed of, for example, silicon oxide.

[0033] The dielectric layer 127 may be disposed on the substrate 129. In some embodiments, the material of the dielectric layer 127 includes silicon oxide, silicon nitride, titanium oxide, or the like. In some embodiments, the dielectric layer 127 may be considered as a plurality of dielectric layers.

[0034] The semiconductor layer 128 may be disposed on the dielectric layer 127. That is, the semiconductor layer 128 may be disposed on the substrate 129. In some embodiments, the dielectric layer 127 may be disposed between the semiconductor layer 128 and the substrate 129. In some embodiments, the material of the semiconductor layer 128 may be the same as or different from the material of the substrate 129. For example, the semiconductor layer 128 may be made of a suitable elemental semiconductor (e.g., crystalline silicon, diamond, or germanium), a suitable compound semiconductor (e.g., gallium arsenide, silicon carbide, indium arsenide, or indium phosphide), or a suitable alloy semiconductor (e.g., silicon germanium carbide, gallium arsenic phosphide, or gallium indium phosphide). In some embodiments, the semiconductor layer 128 may include the modulator 12 and the waveguide 126. Figure 1B , the semiconductor layer 128 can be doped to form various regions, such as electrical coupling portions 121 and 122. In some embodiments, the optical coupling portion 123 can also be doped.

[0035] In some embodiments, the waveguide 126 may be placed on the substrate 129. The waveguide 126 may be formed in the semiconductor layer 128. The waveguide 126 may have an input terminal and an output terminal. The input terminal of the waveguide 126 may be coupled to Figure 1A In some embodiments, the output terminal of the waveguide 126 can be coupled to Figure 1A The receiver 13 shown in FIG. 1 is a receiver 13 shown in FIG. 1 . The optical signal (eg Figure 1A The optical signal 17) shown in FIG. 1 can be received at an input terminal of the waveguide 126, transmitted through the waveguide 126, and then output at an output terminal of the waveguide 126.

[0036] The modulator 12 may include a waveguide. In some embodiments, the modulator 12 may include a curved waveguide. The modulator 12 may include a ring profile. The modulator 12 may include an optical coupling portion 123 and electrical coupling portions 121 and 122. In some embodiments, the modulator 12 may be placed on a substrate 129 and adjacent to a waveguide 126. In some embodiments, the modulator 12 may be separated from the waveguide 126 by a distance. The distance is small enough so that an optical signal in the waveguide 126 can be optically coupled to the modulator 12. In some embodiments, a portion of the optical signal within a specific frequency / wavelength range in the waveguide 126 may be absorbed or refracted by the modulator 12 so that the optical signal may be modulated and output at an output terminal of the waveguide 126.

[0037] The light coupling portion 123 of the modulator 12 may be annular or elliptical. In some embodiments, the light coupling portion 123 may be separated from the waveguide 126. In some embodiments, the light coupling portion 123 may include a waveguide. In some embodiments, the light coupling portion 123 may be doped with a p-type dopant and / or an n-type dopant. In another embodiment, the light coupling portion 123 may be undoped or an intrinsic semiconductor.

[0038] In some embodiments, the electrical coupling portions 121 and 122 may be formed in the semiconductor layer 128. The semiconductor layer 128 may be doped to form the electrical coupling portions 121 and 122. In some embodiments, the electrical coupling portions 121 and 122 are placed on the substrate 129. The electrical coupling portions 121 and 122 may be placed adjacent to the optical coupling portion 123. In some embodiments, the optical coupling portion 123 is placed between the electrical coupling portions 121 and 122.

[0039] In some embodiments, the semiconductor material in the electrically coupled portion 121 may be doped with a dopant of a first conductivity type. At the same time, the semiconductor material in the electrically coupled portion 122 may be doped with a dopant of a second conductivity type. In some embodiments, the first conductivity type is opposite to the second conductivity type. For example, the dopant of the first conductivity type may be a p-type dopant and the dopant of the second conductivity type may be an n-type dopant. That is, the semiconductor material in the electrically coupled portion 121 may be doped with a p-type dopant, while the semiconductor material in the electrically coupled portion 122 may be doped with an n-type dopant. However, the electrically coupled portion 121 may also be doped with an n-type dopant, and the electrically coupled portion 122 may be doped with a p-type dopant. In some embodiments, the p-type dopant includes, for example, boron, BF 2 On the other hand, the n-type dopant may include, for example, phosphorus, arsenic, or the like.

[0040] refer to Figure 1B , the driver 14 may be electrically coupled to the modulator 12. The driver 14 may apply a voltage to the electrically coupled portion 121. In some embodiments, the driver 14 may apply a voltage to the electrically coupled portion 122. That is, the modulator 12 may be configured to receive a voltage through the electrically coupled portions 121 and 122. By the applied voltage, the resonant wavelength or frequency of the modulator 12 may be adjusted to approach a predetermined value. A portion of the optical signal in the waveguide 126 may be optically coupled to the modulator when the wavelength of the portion of the optical signal resonates with the modulator 12. Therefore, the desired output optical signal at the output terminal of the waveguide 126 may be modulated by the modulator 12 absorbing a portion of the optical signal.

[0041] Figure 2A 2 is a top view of a photonic device according to some embodiments, the photonic device including a modulator 12A and a waveguide 216. In some embodiments, Figure 2A The modulator 12A in may correspond to Figure 1B The modulator 12 in FIG. 1 and the waveguide 216 may correspond to Figure 1B The waveguide 126 in FIG. Figure 2A , the modulator 12A may be separated from the waveguide 216 by a distance D1. The distance D1 may be small enough to optically couple the optical signal in the waveguide 216 to the modulator 12A. The modulator 12A may include a waveguide (or optical coupling portion) 210 and a heater 230. Figure 2AContains section line AA, where the details of the section along the section line are Figure 2C Presented in.

[0042] refer to Figure 2A The waveguide 216 may have an input terminal for receiving an optical signal and an output terminal for transmitting an optical signal. In some embodiments, the waveguide 216 may have a width (or diameter) in the range of 0.01 μm to 10 μm.

[0043] The modulator 12A includes a waveguide (optical coupling portion) 210. In some embodiments, the waveguide 210 may be a curved waveguide. In some embodiments, the waveguide 210 may be annular. In some embodiments, the waveguide 210 may be elliptical. The waveguide 210 may have a radius. When the radius of the waveguide 210 increases, the free spectral range (FSR) of the modulator 12A may decrease. Therefore, the power used to modulate the resonance of the modulator 12A may decrease. In other words, the power consumption of the modulator 12A may be reduced when the size of the modulator 12A increases.

[0044] In some embodiments, waveguide 210 may have a width (diameter) in the range of 0.01 μm to 10 μm. In one embodiment, the width of waveguide 210 may exceed 1 μm. In some embodiments, the width of waveguide 210 may be in the range of 1 μm to 10 μm. The process sensitivity of modulator 12A may decrease as its width increases. In other words, the stability of modulator 12A may increase as the width increases.

[0045] refer to Figure 2A , the modulator 12A may include a heater 230 placed thereon. In some embodiments, the heater 230 may cover a portion of the waveguide 210. In some embodiments, the heater 230 may expose another portion of the waveguide 210. In some embodiments, the heater 230 may expose 5% to 55% of the waveguide 210. In some embodiments, the heater 230 may be fan-shaped to cover the waveguide 210. In some embodiments, the modulator 12A may include a dielectric layer ( Figure 2C ).

[0046] In some embodiments, the heater 230 may include two terminals 231 and 232. The terminal 231 of the heater 230 may be configured to receive a first electrical signal VA. The terminal 232 of the heater 230 may be configured to receive a second electrical signal VB. In some embodiments, the heater 230 may be configured to carry a time-varying current Iac in response to the first electrical signal VA and the second electrical signal VB. The term "carry" used in the present disclosure may be understood as the heater 230 being able to enable electrons or holes to be transmitted thereon. In some embodiments, the time-varying current Iac may flow through the heater 230 from the terminal 231 to the terminal 232 within a first duration, wherein the voltage level of the first electrical signal VA exceeds the voltage level of the second electrical signal VB. In some embodiments, the time-varying current Iac may be an alternating current (AC).

[0047] In some embodiments, the first electrical signal VA and the second electrical signal VB are opposite to each other. That is, the first electrical signal VA and the second electrical signal VB are AC signals. The details of the first electrical signal VA, the second electrical signal and the time-varying current Iac will be described in detail in FIG. 4A to FIG. 4D discussed in.

[0048] In some embodiments, heater 230 may be configured to thermally modulate the resonant wavelength of modulator 12A. Heater 230 may provide heat to modulator 12A so that its temperature may be increased. In some embodiments, modulator 12A may have a temperature coefficient of about 0.07 nm / °C. For example, if the resonant wavelength of the modulator is 1312 nm at 27°C, then the thermally modulated resonant wavelength may be 1312.7 nm at 37°C. As temperature increases, the resonant wavelength may be modulated at the nanometer level. In some embodiments, the resonant wavelength (frequency) of modulator 12A may thermally increase as temperature increases.

[0049] Figure 2B is a top view of a photonic device according to some embodiments. Figure 2B Similar to Figure 2A , which is different from Figure 2B In FIG. 2 , the time-varying current Iac flows through the heater 230 in different directions.

[0050] In some embodiments, the heater 230 may be configured to carry a time-varying current Iac in response to the first electrical signal VA and the second electrical signal VB. In some embodiments, the time-varying current Iac may flow through the heater 230 from the terminal 232 to the terminal 231 for a second duration, wherein the voltage level of the second electrical signal VB exceeds the voltage level of the first electrical signal VA. The details of the first electrical signal VA, the second electrical signal, and the time-varying current Iac will be described in detail in FIG. 4A to FIG. 4D discussed in.

[0051] refer to Figure 2A and Figure 2B, using an AC signal to drive the heater 230, the current Iac passing through the heater 230 may flow alternately to the left and right. Therefore, electromigration occurring in the heater 230 may be eliminated. In addition, the current density passing through the heater 230 may be reduced by using an AC signal. Therefore, electromigration of the heater 230 may be prevented and the reliability of the heater 230 may be improved. The current Iac passing through the heater 230 may be the same as in the previous practice, and therefore the thermal efficiency of the heater 230 is not affected.

[0052] Figure 2C is along Figure 2A and Figure 2B A cross section of the photonic device along section line AA. Figure 2C The device includes a substrate 219 , a dielectric layer 217 , a waveguide 210 , electrical coupling portions 211 and 212 , a dielectric layer 235 and a heater 230 .

[0053] like Figure 2C As shown in FIG. 2 , dielectric layer 217 is placed on substrate 219. Substrate 219 is similar to Figure 1B The substrate 129 in the embodiment of the present invention and the dielectric layer 217 are similar to Figure 1B The dielectric layer 127 in FIG. 1 is shown in FIG. 1 , and therefore a detailed description thereof is omitted for the sake of brevity.

[0054] The waveguide 210 may be placed on a substrate 219. In some embodiments, a dielectric layer 217 may be placed between the waveguide 210 and the substrate 219. The waveguide 210 may include two regions 210a and 210b. The region 210a may be placed adjacent to the region 210b. In some embodiments, the regions 210a and 210b may be placed side by side.

[0055] In one embodiment, the size of region 210a may be different from the size of region 210b. For example, the width of region 210a may exceed the width of region 210b. In another embodiment, the size of region 210a may be equal to the size of region 210b. For example, the width of region 210a may be substantially equal to the width of region 210b. In some embodiments, the height of regions 210a and 210b may be the same. In some embodiments, regions 210a and 210b may have a total width corresponding to Figure 2A The width of the waveguide 210 in FIG.

[0056] In some embodiments, the regions 210a and 210b may be doped with the same dopant. In other embodiments, the semiconductor material in the region 210a may be doped with a dopant of a conductivity type. The semiconductor material in the region 210b of the waveguide 210 may be doped with a dopant of a conductivity type different from the dopant in the region 210a. For example, the semiconductor material in the region 210a of the waveguide 210 may be doped with a p-type dopant, while the semiconductor material in the region 210b of the waveguide 210 may be doped with an n-type dopant.

[0057] In some embodiments, the electrically coupled portion 211 may be placed adjacent to the region 210a. That is, the region 210a may be placed between the electrically coupled portion 211 and the region 210b. In some embodiments, the electrically coupled portion 212 may be placed adjacent to the region 210b. That is, the region 210b may be placed between the electrically coupled portion 212 and the region 210a. The electrically coupled portions 211 and 212 may correspond to Figure 1B That is, the electrically coupled portions 211 and 212 may be doped with dopants of different conductive types.

[0058] Figure 2C The electrically coupled portion 211 in the embodiment may include two regions 211a and 211b. In some embodiments, region 211a may be placed adjacent to region 210a. Region 211b may be placed adjacent to region 211a of the electrically coupled portion 211. In some embodiments, region 211a may be placed between region 211b and region 210a. In one embodiment, region 211b may have a height different from the height of region 211a. For example, the height of region 211b may exceed the height of region 211a. The heights of regions 211a and 211b of the electrically coupled portion 211 are not limited. For example, the height of region 211b may be substantially equal to the height of region 211a. In some embodiments, region 211b may be connected to a driver 14 (e.g., Figure 1B ).

[0059] In some embodiments, the semiconductor material of regions 211a and 211b may be of the same conductivity type. For example, both regions 211a and 211b may be doped with p-type dopants. In one embodiment, region 211a may have a doping concentration equal to the doping concentration of region 211b. In another embodiment, the doping concentration of region 211a may be different from the doping concentration of region 211b. For example, the doping concentration of region 211b may exceed the doping concentration of region 211a. In some embodiments, the electrically coupled portion 211 may include one or more regions. In other words, the electrically coupled portion 211 may include several regions with different doping concentrations. In some embodiments, the doping concentration may decrease from the side of the electrically coupled portion 211 toward the waveguide 210. In some embodiments, the doping concentration may gradually decrease from the electrically coupled portion 211 toward the waveguide 210.

[0060] In some embodiments, region 210a may be doped with the same dopant as regions 211a and 211b. In one embodiment, region 210a may have a doping concentration substantially equal to the doping concentration of regions 211a and 211b. In another embodiment, the doping concentration of region 210a may be different from the doping concentration of regions 211a and 211b. For example, the doping concentration of region 210a may be less than the doping concentration of regions 211a and 211b. The p-type doping concentration may decrease from region 211b toward region 210a.

[0061] Figure 2C The electrically coupled portion 212 in the embodiment may include two regions 212a and 212b. In some embodiments, the region 212a may be placed adjacent to the region 210b. In some embodiments, the region 212a may be placed between the region 212b and the region 210b. In one embodiment, the region 212b may have a height different from the height of the region 212a. For example, the height of the region 212b may exceed the height of the region 212a. The height of the region of the electrically coupled portion 212 is not limited. For example, the height of the region 212b may be substantially equal to the height of the region 212a. In some embodiments, the region 212b may be connected to the driver 14 (e.g., Figure 1B ). By connecting to the driver 14 through the regions 211b and 212b, electrical signals can be transmitted through the regions 211b, 211a, 210a, 210b, 212a, and 212b. That is, there may be a conductive path through the regions 211b, 211a, 210a, 210b, 212a, and 212b, so that the resonant wavelength of the modulator 12A can be adjusted.

[0062] In some embodiments, the semiconductor material of regions 212a and 212b may be of the same conductivity type. For example, both regions 212a and 212b may be doped with n-type dopants. In one embodiment, region 212a may have a doping concentration equal to the doping concentration of region 212b. In another embodiment, the doping concentration of region 212a may be different from the doping concentration of region 212b. For example, the doping concentration of region 212b may exceed the doping concentration of region 212a. In some embodiments, the electrically coupled portion 212 may include one or more regions. In other words, the electrically coupled portion 212 may include several regions with different doping concentrations. In some embodiments, the doping concentration may decrease from the side of the electrically coupled portion 212 toward the waveguide 210. In some embodiments, the doping concentration may gradually decrease from the electrically coupled portion 212 toward the waveguide 210.

[0063] In some embodiments, region 210b may be doped with the same dopant as regions 212a and 212b. In other words, region 210b may be doped with an n-type dopant. In one embodiment, region 210b may have a doping concentration substantially equal to the doping concentration of region 212a. In another embodiment, the doping concentration of region 210b may be different from the doping concentration of region 212a. For example, the doping concentration of region 210b may be less than the doping concentration of region 212a. The n-type doping concentration may decrease from region 212b toward region 210b.

[0064] The regions 211a and 211b of the electrical coupling portion 211 and the region 210a of the waveguide 210 may be p-type doped at different concentrations, and the regions 212a and 212b of the electrical coupling portion 212 and the region 210b of the waveguide 210 may be n-type doped at different concentrations. That is, the regions 211a, 211b, and 210a and the regions 212a, 212b, and 210b may form a PN junction.

[0065] refer to Figure 2C , the waveguide 210 and the regions 211b and 211a of the electrical coupling portion 211 may form a groove 215a. The height of the region 211a may be lower than the height of the region 211b and the region 210a of the waveguide 210. In some embodiments, the groove 215a is recessed from the top surface of the region 210a. The waveguide 210 and the regions 212b and 212a of the electrical coupling portion 212 may form a groove 215b. The height of the region 212a may be lower than the height of the region 212b and the region 210b of the waveguide 210. In some embodiments, the groove 215b is recessed from the top surface of the region 210b. In some embodiments, the levels of the regions 211a and 212a may be substantially the same.

[0066] In some embodiments, dielectric layer 235 is placed on waveguide 210 and electrical coupling portions 211 and 212. Dielectric layer 235 may fill in recesses 215a and 215b. In some embodiments, dielectric layer 235 may contact top surfaces of waveguide 210, regions 211a and 211b of electrical coupling portion 211, and regions 212a and 212b of electrical coupling portion 212. In some embodiments, dielectric layer 235 may have a planarizable top surface. In some embodiments, properties and materials of dielectric layer 235 may be similar to dielectric layer 217.

[0067] In some embodiments, the heater 230 may be placed on the dielectric layer 235. The heater 230 may cover the waveguide 210. In some embodiments, the heater 230 may cover the waveguide 210 and the electrical coupling portions 211 and 212. The heater 230 may be a metal heater. For example, the heater 230 may generate heat induced by current. The form and type of the heater 230 are not limited.

[0068] Figure 3A is a top view of a photonic device according to some embodiments, wherein modulator 12B is similar to Figure 2A The modulator 12A in FIG. 1 is different from the modulator 12A in FIG. 1 in that: Figure 3A , the modulator 12B may have a heater 330 having four terminals 331, 332, 333, and 334 for receiving electrical signals. The modulator 12B may include a waveguide (or an optical coupling portion) 210 and a heater 330 covering the waveguide 210. In some embodiments, the heater 330 may completely cover the waveguide 210. In some embodiments, the heater 330 may have a shape that conforms to the waveguide 210. For example, the heater 330 may be annular or elliptical.

[0069] In some embodiments, a terminal 331 (or first terminal 331) of the heater 330 may be opposite to a terminal 333 (or third terminal 333) of the heater 330. Both the terminals 331 and 333 extend horizontally. A terminal 332 (or second terminal 332) of the heater 330 may be opposite to a terminal 334 (or fourth terminal 334) of the heater 330. Both the terminals 332 and 334 extend vertically. In some embodiments, the terminals 331, 332, 333, and 334 may be equally spaced along the circumference of the heater 330. In some embodiments, the terminal 334 may cover a portion of the waveguide 216.

[0070] The first terminal 331 and the third terminal 333 may be configured to receive a first electrical signal VA. The second terminal 332 and the fourth terminal 334 may be configured to receive a second electrical signal VB. In some embodiments, the heater 330 may be configured to carry a time-varying current Iac in response to the first electrical signal VA and the second electrical signal VB. In some embodiments, the time-varying current Iac may flow through the heater 330 from the first terminal 331 to the second terminal 332 and the fourth terminal 334 during a first duration, wherein the voltage level of the first electrical signal VA exceeds the voltage level of the second electrical signal VB. At the same time, the time-varying current Iac may also flow through the heater 330 from the third terminal 333 to the second terminal 332 and the fourth terminal 334 during the first duration. The details of the first electrical signal VA, the second electrical signal, and the time-varying current Iac will be described in detail in FIG. FIG. 4A to FIG. 4D discussed in.

[0071] Figure 3B is a top view of a photonic device according to some embodiments. Figure 3B Similar to Figure 3A , which is different from Figure 3B In FIG. 3 , the time-varying current Iac flows through the heater 330 in different directions.

[0072] In some embodiments, the heater 330 may be configured to carry a time-varying current Iac in response to the first electrical signal VA and the second electrical signal VB. In some embodiments, the time-varying current Iac may flow through the heater 330 from the second terminal 332 to the first terminal 331 and the third terminal 333 for a second duration, wherein the voltage level of the second electrical signal VB exceeds the voltage level of the first electrical signal VA. At the same time, the time-varying current Iac may also flow through the heater 330 from the fourth terminal 334 to the first terminal 331 and the third terminal 333 for a second duration. The details of the first electrical signal VA, the second electrical signal, and the time-varying current Iac will be described in detail in FIG. 4A to FIG. 4D discussed in.

[0073] In some embodiments, the number of terminals of the heater 330 may exceed 4. The heater 330 may have one or more pairs of terminals. For example, the heater 330 may have 1 pair, 2 pairs, 3 pairs, 4 pairs, 5 pairs or more pairs of terminals (i.e., 2, 4, 6, 8, 10 or more terminals). Each of the one or more pairs of terminals includes a terminal for receiving a first electrical signal VA and another terminal for receiving a second electrical signal VB. In some embodiments, the one or more pairs of terminals may be arranged side by side along the circumference of the heater 330. That is, the terminal for receiving the first electrical signal VA may be located between the two terminals for receiving the second electrical signal VB. Similarly, the terminal for receiving the second electrical signal VB may be located between the two terminals for receiving the first electrical signal VA.

[0074] When the heater includes more terminals, the current passing through can be more uniform and thus the thermal efficiency of the heater can be improved. Under the same voltage, the heater can generate more heat with more terminals.

[0075] Figure 4A is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention. Figure 4A Contains voltage-time and current-time graphs for a rectangular AC signal.

[0076] refer to Figure 4A , the first electrical signal VA and the second electrical signal VB are rectangular AC signals. In some embodiments, the first electrical signal VA and the second electrical signal VB may fluctuate between voltage levels V1 and V2. In some embodiments, the voltage level V1 is greater than the voltage level V2. The voltage level V1 may be in the range of 0.1V to 10V. The voltage level V2 may be in the range of 0V to 1V. For example, the first electrical signal VA and the second electrical signal VB may fluctuate between 0.1V to 10V.

[0077] In some embodiments, the first electrical signal VA may ramp up to the voltage level V1 at the beginning of the first duration P1, remain at the voltage level V1 during the first duration P1, and ramp down to the voltage level V2 at the end of the first duration P1. The first electrical signal VA may ramp down to the voltage level V2 at the beginning of the second duration P2, remain at the voltage level V2, and ramp up to the voltage level V1 at the end of the second duration P2.

[0078] The second electrical signal VB may ramp down to the voltage level V2 at the beginning of the first duration P1, remain at the voltage level V2 during the first duration P1, and ramp up to the voltage level V1 at the end of the first duration P1. The second electrical signal VB may ramp up to the voltage level V1 at the beginning of the second duration P2, remain at the voltage level V1, and ramp down to the voltage level V2 at the end of the second duration P2.

[0079] In some embodiments, the first electrical signal VA is opposite to the second electrical signal VB. For example, when the first electrical signal VA is maintained at the voltage level V1 for the first duration P1, the second electrical signal VB is maintained at the voltage level V2.

[0080] In some embodiments, the electrical signal VA may have a period T1, which may be substantially equal to the period of the second electrical signal VB. The period T1 may be equal to the sum of the first duration P1 and the second duration P2. In some embodiments, the period T1 may be in the range of 1 ns to 1 ms.

[0081] refer to Figure 4AIn the current-time diagram of FIG. 1 , the time-varying current Iac may be a rectangular AC signal. The time-varying current Iac may fluctuate between current values ​​I1 and −I1. In some embodiments, the current value I1 is opposite to the current value −I1. That is, the current value −I1 is the negative value of the current value I1. The current values ​​I1 and −I1 may be in the range of 1 μA to 1 A. For example, the time-varying current Iac may fluctuate between +1 mA to −1 mA.

[0082] In some embodiments, the time-varying current Iac may ramp up to a current value I1 at the beginning of the first duration P1, remain at the current value I1 during the first duration P1, and ramp down to a current value -I1 at the end of the first duration P1. In some embodiments, the time-varying current Iac may ramp down to a current value -I1 at the beginning of the second duration P2, remain at the current value -I1, and ramp up to the current value I1 at the end of the second duration P2.

[0083] During the duration P1, the time-varying current Iac can be Figure 2A and Figure 3A In contrast, during duration P2, the time-varying current Iac may be Figure 2B and Figure 3B through the heater in the direction shown.

[0084] The first electrical signal VA and the second electrical signal VB can be applied to a heater (e.g., heaters 230 and 330) and drive the heater of the light modulator to generate heat through a large current Iac. The current Iac can alternately pass through the heater in different directions. The metal atoms pushed by the momentum transfer between the conductive electrons and the metal atoms can be slightly displaced from their original positions and substantially maintain their original positions. The conductive segments can be uniform, and thus the electromigration occurring in the heater can be correspondingly eliminated. In addition, the current density passing through the heater can be reduced by using an AC signal. Therefore, electromigration of the heater can be prevented and the reliability of the heater can be enhanced. The current Iac passing through the heater can be the same as the previous practice, and thus the thermal efficiency of the heater is not affected.

[0085] Figure 4B is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention. Figure 4B Similar to Figure 4A , which is different from Figure 4B , the signals in the voltage-time diagram and the current-time diagram are sinusoidal AC signals.

[0086] Figure 4C is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention. Figure 4C Similar to Figure 4A , which is different from Figure 4CIn the voltage-time diagram and the current-time diagram, the signals are triangular AC signals.

[0087] Figure 4D is a waveform diagram of a signal for driving a heater according to some embodiments of the present invention. Figure 4D Similar to Figure 4A , which is different from Figure 4D , the signals in the voltage-time diagram and the current-time diagram are non-overlapping AC signals.

[0088] refer to Figure 4D In the voltage-time diagram of FIG. 1 , the first electrical signal VA and the second electrical signal VB are one or more pulses. In some embodiments, each pulse of the first electrical signal VA does not overlap with each pulse of the second electrical signal VB. In other words, a pulse of the first electrical signal VA is between two adjacent pulses of the second signal VB. Similarly, a pulse of the second electrical signal VB is between two adjacent pulses of the first signal VA. In some embodiments, the first pulse of the first electrical signal VA and the first pulse of the second electrical signal VB share a non-overlapping period TN, during which the first pulse of the first electrical signal VA and the first pulse of the second electrical signal VB include a predetermined voltage. For example, the predetermined voltage may be about voltage level V2.

[0089] In some embodiments, the first electrical signal VA and the second electrical signal VB may fluctuate between voltage levels V1 and V2. In some embodiments, the voltage level V1 is greater than the voltage level V2.

[0090] In some embodiments, the first electrical signal VA may ramp up to a voltage level V1 at the beginning of the first duration P1, remain at the voltage level V1 during the first duration P1, and ramp down to a voltage level V2 at the end of the first duration P1. The first electrical signal VA remains at the voltage level V2 during a first non-overlapping period TN after the first duration P1, a second duration P2, and a second non-overlapping period TN after the second duration P2.

[0091] In some embodiments, the second electrical signal VB may be maintained at the voltage level V2 for the first duration P1 and a first non-overlapping period TN after the first duration P1. The second electrical signal VB may be ramped up to the voltage level V1 at the beginning of the second duration P2, maintained at the voltage level V1 for the second duration P2, and ramped down to the voltage level V2 at the end of the second duration P2. The second electrical signal VB may be maintained at the voltage level V2 for a second non-overlapping period TN after the second duration P2.

[0092] In some embodiments, the first electrical signal VA is opposite to the second electrical signal VB. For example, when the first electrical signal VA is maintained at the voltage level V1 for the first duration P1, the second electrical signal VB will be maintained at the voltage level V2.

[0093] In some embodiments, the first electrical signal VA may have a period T4, which is from the start of the first pulse to the start of the second pulse of the first electrical signal VA. In some embodiments, the period of the second electrical signal VB may be substantially equal to the period T4. The period T4 may be equal to the sum of the first duration P1, the second duration P2, and the two non-overlapping periods TN. In some embodiments, the period T4 may be in the range of 1ns to 1ms. In some embodiments, the non-overlapping period TN may be in the range of 1% to 10% of the period T4. In another embodiment, the non-overlapping period TN may be in the range of 5% to 10% of the period T4.

[0094] refer to Figure 4D From the current-time diagram, the time-varying current Iac can fluctuate between current values ​​I1 and -I1.

[0095] In some embodiments, the time-varying current Iac may ramp up to a current value I1 at the beginning of the first duration P1, remain at the current value I1 during the first duration P1, and ramp down to a value of 0 at the end of the first duration P1. The time-varying current Iac remains at a value of 0 during a first non-overlapping period TN after the first duration P1. The time-varying current Iac may ramp down to a current value -I1 at the beginning of the second duration P2, remain at the current value -I1, and ramp up to a value of 0 at the end of the second duration P2. The time-varying current Iac remains at a value of 0 during a second non-overlapping period TN after the second duration P2.

[0096] During the duration P1, the time-varying current Iac can be Figure 2A and Figure 3A In contrast, during duration P2, the time-varying current Iac may be Figure 2B and Figure 3B through the heater in the direction shown.

[0097] The non-overlap period TN is shared between the pulse of the first electrical signal VA and the pulse of the second electrical signal VB, and thus the induced current Iac can be more stable. Therefore, the reliability of the heater can be improved.

[0098] Figure 5 5 is a flow chart 500 showing a method for adjusting the resonant wavelength of an optical modulator according to some embodiments of the present invention. In some embodiments, the method may be performed by a semiconductor device. In some embodiments, the method may be performed by a photonic device. In some embodiments, the method may be performed by Figure 1B , Figure 2A to Figure 2C and FIG. 3A to FIG. 3B The modulator shown in is implemented.

[0099] In operation 510, an optical modulator is provided on a substrate and adjacent to a waveguide optically coupled to the optical modulator. In some embodiments, the waveguide includes an optical input terminal and an optical output terminal.

[0100] In operation 520, an optical signal may be received at an optical input terminal of a waveguide. In some embodiments, the optical signal may be transmitted through the waveguide.

[0101] In operation 530, a heater driven by an alternating current may be used to adjust the resonant wavelength of the light modulator to a predetermined wavelength. In some embodiments, the heater may be Figure 2A to Figure 2C The heater 230 and Figure 3A and Figure 3B The heater 330 in the embodiment of the present invention can be used to determine the predetermined wavelength as required.

[0102] In operation 540, a portion of the optical signal may be absorbed by the optical modulator. When a wavelength of the portion of the optical signal corresponds to a resonant wavelength of the optical modulator, the portion of the optical signal may be optically coupled to the optical modulator.

[0103] In operation 550, the conditioned optical signal may be output at the optical output terminal of the waveguide. Since a portion of the optical signal is optically coupled to the optical modulator, the conditioned optical signal will lack this portion of the optical signal. Thus, the conditioned optical signal may be conditioned to be a desired signal (light) output at the optical output terminal of the waveguide.

[0104] According to some embodiments, a semiconductor device is provided. The semiconductor device includes: a substrate; a first waveguide disposed on the substrate; a second waveguide disposed on the substrate and separated from the first waveguide by a first distance; and a heater disposed on the second waveguide and having a first terminal and a second terminal. In addition, the first terminal of the heater is configured to receive a first electrical signal; the second terminal of the heater is configured to receive a second electrical signal; and the heater is configured to carry a time-varying current in response to the first electrical signal and the second electrical signal.

[0105] According to other embodiments, a photonic circuit is provided. The photonic circuit includes: a first waveguide; a second waveguide, which is placed on the substrate and separated from the first waveguide; and a heater, which is placed on the second waveguide and includes one or more pairs of terminals. In addition, each of the one or more pairs of terminals includes a first terminal and a second terminal. The first terminal of the heater is configured to receive a first electrical signal and the second terminal of the heater is configured to receive a second electrical signal, so that an alternating current passes through the heater from the first terminal to the second terminal in a first duration and from the second terminal to the first terminal in a second duration, and wherein the first electrical signal has a frequency equal to the frequency of the second electrical signal.

[0106] According to other embodiments, a method for adjusting the resonant wavelength of an optical modulator includes providing the optical modulator on a substrate and adjacent to a waveguide optically coupled to the optical modulator, wherein the waveguide includes an optical input terminal and an optical output terminal; receiving an optical signal at the optical input terminal of the waveguide; adjusting the resonant wavelength of the optical modulator to a predetermined wavelength by a heater driven by an alternating current; absorbing a portion of the optical signal by the optical modulator; and outputting the adjusted optical signal at the optical output terminal of the waveguide.

[0107] The method and components of the present disclosure have been fully described in the examples and descriptions. It should be understood that any modification or change that does not depart from the spirit of the present disclosure is intended to be included in the protection scope of the present disclosure.

[0108] In addition, the scope of the present application is not intended to be limited to the particular embodiments of the processes, machines, manufactures, and material compositions, components, methods, and steps described in this specification. Those skilled in the art will readily appreciate from this disclosure that currently existing or later developed processes, machines, manufactures, material compositions, components, methods, or steps that perform substantially the same functions as the corresponding embodiments described herein or achieve substantially the same results as the corresponding embodiments described herein may be utilized according to the present disclosure.

[0109] Therefore, the appended claims are intended to include within their scope the process, machine, manufacture, composition of matter, means, methods, or steps. In addition, each claim constitutes a separate embodiment, and the combination of various claims and embodiments are within the scope of the present disclosure.

[0110] Explanation of symbols

[0111] 10: Optical Communication Systems

[0112] 11: Light Source

[0113] 12: Modulator

[0114] 12A: Modulator

[0115] 12B: Modulator

[0116] 13: Receiver

[0117] 14: Driver

[0118] 15: Processor

[0119] 16: Waveguide

[0120] 17:Light signal

[0121] 17': modulated optical signal

[0122] 100:Semiconductor structure

[0123] 121: Electrical coupling part

[0124] 122: Electrical coupling part

[0125] 123: Waveguide / optical coupling part

[0126] 126: Waveguide

[0127] 127: Dielectric layer

[0128] 128: Semiconductor layer

[0129] 129: Substrate

[0130] 210: Waveguide

[0131] 210a: Area

[0132] 210b: Area

[0133] 211: Electrical coupling part

[0134] 211a: Area

[0135] 211b: Area

[0136] 212: Electrical coupling part

[0137] 212a: Area

[0138] 212b: Area

[0139] 215a: Groove

[0140] 215b: Groove

[0141] 216: Waveguide

[0142] 217: Dielectric layer

[0143] 219: Substrate

[0144] 230: Heater

[0145] 231:Terminal

[0146] 232:Terminal

[0147] 235: Dielectric layer

[0148] 330: Heater

[0149] 331:Terminal

[0150] 332:Terminal

[0151] 333:Terminal

[0152] 334:Terminal

[0153] 500:Flowchart

[0154] 510: Operation

[0155] 520: Operation

[0156] 530: Operation

[0157] 540: Operation

[0158] 550: Operation

[0159] D1: Distance

[0160] I1: Current value

[0161] Iac: time-varying current

[0162] P1: First duration

[0163] P2: Second duration

[0164] T1: Cycle

[0165] T4: Cycle

[0166] TN: Non-overlapping cycles

[0167] V1: voltage level

[0168] V2: voltage level

[0169] VA: First electrical signal

[0170] VB: second electrical signal.

Claims

1. A semiconductor device, characterized in that The semiconductor device comprises: substrate; A first waveguide disposed on the substrate; a second waveguide disposed on the substrate and spaced a first distance from the first waveguide; and a heater placed on the second waveguide and having a first terminal and a second terminal, wherein The first terminal of the heater is configured to receive a first electrical signal; The second terminal of the heater is configured to receive a second electrical signal; and The heater is configured to carry a time-varying current in response to the first electrical signal and the second electrical signal.

2. The semiconductor device according to claim 1, characterized in that Further included is a dielectric layer positioned between the heater and the second waveguide.

3. The semiconductor device according to claim 2, characterized in that The second waveguide has at least one groove, and wherein the dielectric layer fills the at least one groove of the second waveguide.

4. The semiconductor device according to claim 1, characterized in that The heater covers a portion of the second waveguide.

5. The semiconductor device according to claim 1, wherein The time-varying current flows through the heater from the first terminal to the second terminal for a first duration and flows through the heater from the second terminal to the first terminal for a second duration.

6. The semiconductor device according to claim 1, wherein The heater further includes a third terminal and a fourth terminal, wherein the first terminal is opposite to the third terminal and the second terminal is opposite to the fourth terminal, wherein the third terminal is configured to receive the first electrical signal and the fourth terminal is configured to receive the second electrical signal.

7. The semiconductor device according to claim 1, characterized in that The second waveguide includes an annular profile, and wherein the heater covers a first portion of the second waveguide and exposes a second portion of the second waveguide.

8. A photonic circuit, characterized in that The photonic circuit comprises: first waveguide; and a second waveguide spaced apart from the first waveguide; and a heater placed on the second waveguide and comprising one or more pairs of terminals, wherein each of the one or more pairs of terminals comprises a first terminal and a second terminal, wherein the first terminal of the heater is configured to receive a first electrical signal and the second terminal of the heater is configured to receive a second electrical signal such that alternating current passes through the heater from the first terminal to the second terminal for a first duration and from the second terminal to the first terminal for a second duration, and wherein the first electrical signal has a frequency equal to the frequency of the second electrical signal.

9. The photonic circuit according to claim 8, characterized in that The heater covers a portion of the second waveguide.

10. The photonic circuit according to claim 8, characterized in that Further comprising a dielectric layer positioned between the heater and the second waveguide, wherein the second waveguide comprises at least one groove, and wherein the dielectric layer is located within the at least one groove of the second waveguide.

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