CN-121995660-A - Optical modulator, method of manufacturing optical modulator, and apparatus including optical modulator

Abstract

Optical modulators, methods of fabricating optical modulators, and electronic devices including optical modulators are disclosed. The optical modulator according to an embodiment includes a first semiconductor layer, a second semiconductor layer disposed on the first semiconductor layer in a micro disk shape and including a high doping region having a relatively high doping concentration and a low doping region having a relatively low doping concentration, a first optical waveguide disposed adjacent to the second semiconductor layer, and a first electrode layer and a second electrode layer disposed spaced apart from each other on the high doping region, wherein the second semiconductor layer includes at least one recess, and the second semiconductor layer has at least one step due to the at least one recess, and the high doping region, the low doping region, and the recess are concentric.

Inventors

• Li Douxuan
• NanGong Jue
• Pu Zaiche

Assignees

• 三星电子株式会社

Dates

Publication Date

20260508

Application Date

20251105

Priority Date

20241105

Claims (20)

1. 1. An optical modulator, comprising: a first semiconductor layer; a second semiconductor layer disposed on the first semiconductor layer in a micro disk shape and including a high doping region having a relatively high doping concentration and a low doping region having a relatively low doping concentration; A first optical waveguide disposed adjacent to the second semiconductor layer, and A first electrode layer and a second electrode layer disposed spaced apart from each other on the highly doped region, Wherein the second semiconductor layer comprises at least one recess, The second semiconductor layer has at least one step due to the at least one recess, and The highly doped region, the lowly doped region, and the recess are concentric.
2. 2. The light modulator of claim 1 wherein, The second semiconductor layer includes a first recess, The bottom surface of the first recess includes the upper surface of the highly doped region and the upper surface of the lowly doped region, the side surface of the first recess includes the inner surface of the lowly doped region, and Due to the first recess, a first step is present in the low doped region.
3. 3. The light modulator of claim 2 wherein, The highly doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The low doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The bottom surface of the first concave part comprises the upper surface of the N-type doped region of the high doped region, the upper surface of the P-type doped region of the high doped region and the first upper surface of the P-type doped region of the low doped region, The side surface of the first recess comprises the inner surface of the P-type doped region of the low doped region, and The first step corresponds to a difference in height between a first upper surface of the P-type doped region of the low doped region and a second upper surface located higher than the first upper surface.
4. 4. The light modulator of claim 2 wherein, The highly doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The low doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The bottom surface of the first concave part comprises the upper surface of the N-type doped region and the upper surface of the P-type doped region of the high doped region and the first upper surface of the P-type doped region of the low doped region, The side surface of the first recess includes an inner surface of a P-type doped region of the low doped region and an inner surface of an N-type doped region of the low doped region, The first step corresponds to a difference in height between a first upper surface of a P-type doped region of the low doped region and an upper surface of an N-type doped region of the low doped region, The N-type doped region of the low doped region is between the P-type doped region of the low doped region and the first semiconductor layer, and is in the form of a P-type doped region completely surrounding the low doped region around the first recess, and The outer surface of the N-type doped region of the low doped region is a side surface of the second semiconductor layer.
5. 5. The light modulator of claim 3 wherein, The P-type doped region and the N-type doped region of the high doped region are concentric, and a step difference exists between the center and the edge of the N-type doped region of the high doped region, The thickness of the edge of the N-type doped region of the highly doped region is smaller than the thickness of the center of the N-type doped region of the highly doped region, The P-type doped region of the high doped region overlaps with the edge of the N-type doped region of the high doped region, and the upper surface of the P-type doped region and the upper surface of the N-type doped region of the high doped region are the same plane.
6. 6. The light modulator of claim 2 wherein, The second semiconductor layer includes a second recess disposed inside and concentric with the first recess, The side surfaces and bottom surfaces of the second recess include the surfaces of the highly doped region, Due to the second recess, there is a second step inside the first recess, and The first step and the second step are spaced apart from each other in a horizontal direction parallel to an upper surface of the first semiconductor layer, and the first step and the second step have different heights.
7. 7. The light modulator of claim 6 wherein, The highly doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The N-type doped region and the P-type doped region are concentric, The bottom surface of the second recess includes an upper surface of the N-type doped region, The side surface of the second recess comprises the side surface of the P-type doped region, and The second step corresponds to a difference in height between an upper surface of an N-type doped region of the highly doped region and an upper surface of a P-type doped region of the highly doped region.
8. 8. The light modulator of claim 6 wherein, The highly doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The N-type doped region and the P-type doped region are concentric, The N-type doped region and the P-type doped region are spaced apart from each other in a direction perpendicular to an upper surface of the first semiconductor layer, The bottom surface of the second recess includes an upper surface of the N-type doped region, The side surface of the second recess includes the side surface of the P-type doped region, The second step corresponds to a difference in height between an upper surface of an N-type doped region of the highly doped region and an upper surface of a P-type doped region of the highly doped region, A portion of the low doped region exists between the N-type doped region and the P-type doped region spaced apart from each other, The side surfaces of the second recess include a side surface of a portion of the low doped region and a side surface of the P-type doped region, The low doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The N-type doped region of the lowly doped region and the P-type doped region of the lowly doped region are concentric, The bottom surface of the first recess comprises the upper surface of the P-type doped region of the low doped region, and The inner surface of the first recess part comprises a side surface of a P-type doped region of the low doped region.
9. 9. The light modulator of claim 1 wherein, The second semiconductor layer includes a first recess, The bottom surface of the first recess includes the upper surface of the low doped region, the side surface of the first recess includes the inner surface of the low doped region, and Due to the first recess, a first step is present in the low doped region.
10. 10. The light modulator of claim 9 wherein, The second semiconductor layer includes a second recess disposed inside and concentric with the first recess, The bottom surface of the second recess includes the surface of the highly doped region, the side surface of the second recess includes the inner surface of the lowly doped region, Due to the second recess, there is a second step inside the first recess, and The first step and the second step are spaced apart from each other in a horizontal direction parallel to an upper surface of the first semiconductor layer, and the first step and the second step have different heights.
11. 11. The light modulator of claim 10 wherein, The highly doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The N-type doped region and the P-type doped region are concentric, The N-type doped region and the P-type doped region are spaced apart from each other in a direction perpendicular to an upper surface of the first semiconductor layer, The bottom surface of the second recess includes an upper surface of the N-type doped region, The P-type doped region is on the bottom surface of the first recess, and the inner surface of the P-type doped region and the side surface of the second recess form the same side surface, The second step corresponds to a difference in height between an upper surface of the N-type doped region of the highly doped region and a bottom surface of the first recess, The low doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The N-type doped region and the P-type doped region of the low doped region are concentric, The bottom surface of the first recess comprises the upper surface of the P-type doped region of the low doped region, and The inner surface of the first recess part comprises a side surface of a P-type doped region of the low doped region.
12. 12. The light modulator of claim 1 wherein, The second semiconductor layer includes a first recess, The side surfaces and the bottom surface of the first recess include the surface of the highly doped region, and Due to the first concave part, a first step difference exists in the high doped region.
13. 13. The light modulator of claim 12 wherein, The highly doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, The bottom surface of the first recess includes an upper surface of the N-type doped region, The side surface of the first recess includes the side surface of the P-type doped region, The N-type doped region and the P-type doped region are disposed to overlap each other around the first recess portion, The low doped region is disposed to completely surround the high doped region in a plan view, The low doped region includes an N-type doped region doped with an N-type dopant and a P-type doped region doped with a P-type dopant, and The N-type doped region and the P-type doped region of the low doped region are sequentially disposed in a direction perpendicular to an upper surface of the first semiconductor layer.
14. 14. The light modulator of claim 1 wherein, The second semiconductor layer includes a first recess, The bottom surface of the first recess includes an upper surface of a first doped region of the highly doped region, The side surfaces of the first recess include the side surface of the low doped region and the side surface of the second doped region of the high doped region, The first doped region, the second doped region and the first recess are concentric, Due to the first recess, a step difference exists between the upper surface of the first doped region and the upper surface of the second doped region, The first doped region and the second doped region include opposite types of dopants and are spaced apart from each other in a direction perpendicular to an upper surface of the first semiconductor layer, The outer diameter of the first doped region and the inner diameter of the second doped region are equal to each other, and The upper surface of the second doped region and the upper surface of the low doped region form the same surface.
15. 15. The light modulator of claim 1, further comprising: A second optical waveguide spaced apart from the second semiconductor layer, Wherein the second semiconductor layer is disposed between the first optical waveguide and the second optical waveguide.
16. 16. A method of fabricating an optical modulator, the method comprising: forming a second semiconductor layer in the form of a micro disk on the first semiconductor layer; Forming a first doped region in a region of the second semiconductor layer; Forming a second doped region in the second semiconductor layer around the first doped region to be concentric with the first doped region and surround the first doped region in a plan view; Forming a first step in one of the first doped region and the second doped region, and An electrode layer is formed on the first doped region, the first doped region having a higher doping concentration than the second doped region.
17. 17. The method of claim 16, wherein the first step is formed in the first doped region.
18. 18. The method of claim 17, further comprising forming a second step in the second doped region.
19. 19. The method of claim 18, wherein forming the second doped region further comprises: Forming a first doped layer; Forming a second doped layer on the first doped layer to include the second step difference, and Forming a third doped layer covering an outside of the second step difference of the second doped layer and in contact with the first doped layer, Wherein the first doped layer and the third doped layer comprise the same type of dopant.
20. 20. An electronic device, comprising: A light source; an optical waveguide through which light emitted from the light source is transmitted; a semiconductor layer disposed adjacent to the optical waveguide, in the form of a microdisk, and including a plurality of doped regions, an An amplifier configured to amplify light transmitted through the optical waveguide, Wherein the semiconductor layer includes a first doped region and a second doped region included in the plurality of doped regions at a center of the semiconductor layer, The remaining doped regions of the plurality of doped regions other than the first doped region and the second doped region are disposed around the first doped region and the second doped region, The first doped region and the second doped region are regions doped with opposite types of dopants, The first doped region and the second doped region have a higher doping concentration than the remaining doped regions, and The semiconductor layer includes at least one step.

Description

Optical modulator, method of manufacturing optical modulator, and apparatus including optical modulator Cross Reference to Related Applications The present application is based on and claims priority of korean patent application No.10-2024-0155686, filed on the korean intellectual property office on day 11, 2024, and korean patent application No.10-2025-0085378, filed on the korean intellectual property office on day 26, 2025, the entire disclosures of which are incorporated herein by reference. Technical Field Embodiments of the present disclosure relate to optical devices, and more particularly, to optical modulators of Photonic Integrated Circuits (PICs), methods of fabricating optical modulators, and devices including optical modulators. Background In silicon (Si) -based PICs, mach-zehnder interferometers (MZI) and micro-ring modulators (MRMs) are mainly used as optical modulators. For broadband information transmission, a technology for increasing the modulation speed of an optical modulator and for processing signals in parallel, and a Wavelength Division Multiplexing (WDM) technology in which a plurality of wavelength signals are simultaneously transmitted through a single waveguide are being applied. Since the MRM modulates only light whose wavelength matches the micro-ring resonance wavelength, it is possible to construct a WDM optical path relatively simply, and since high-speed modulation is possible, the MRM is widely used. To expand the WDM bandwidth, the diameter of the micro-ring should be gradually reduced, but in the process the curvature of the micro-ring increases, which may lead to optical loss. Thus, a method of configuring a resonator in the form of a micro-disk (as an alternative to a micro-ring) has been introduced, but may include elements defining the speed of light modulation. Disclosure of Invention One or more embodiments provide an optical modulator capable of increasing an optical modulation speed. One or more embodiments also provide an optical modulator capable of mode filtering. One or more embodiments also provide a method of manufacturing a light modulator. One or more embodiments also provide an apparatus including an optical modulator. Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the embodiments presented herein. According to aspects of one or more embodiments, an optical modulator includes a first semiconductor layer, a second semiconductor layer disposed on the first semiconductor layer in a micro disk shape and including a high doping region having a relatively high doping concentration and a low doping region having a relatively low doping concentration, a first optical waveguide disposed adjacent to the second semiconductor layer, and a first electrode layer and a second electrode layer disposed spaced apart from each other on the high doping region, wherein the second semiconductor layer includes at least one recess. The second semiconductor layer may have at least one step difference due to the at least one recess, and the high doping region, the low doping region, and the recess may be concentric. In one example, the second semiconductor layer may include a first recess, a bottom surface of the first recess may include an upper surface of the high doping region and an upper surface of the low doping region, a side surface of the first recess may include an inner surface of the low doping region, and a first step may be present in the low doping region due to the first recess. In one example, the high doping region may include an N-type doping region doped with an N-type dopant and a P-type doping region doped with a P-type dopant, the low doping region may include an N-type doping region doped with an N-type dopant and a P-type doping region doped with a P-type dopant, a bottom surface of the first recess may include an upper surface of the N-type doping region of the high doping region, an upper surface of the P-type doping region of the high doping region, and a first upper surface of the P-type doping region of the low doping region, a side surface of the first recess may include an inner surface of the P-type doping region of the low doping region, and the first step may correspond to a difference in height between the first upper surface of the P-type doping region of the low doping region and a second upper surface located higher than the first upper surface. In one example, the high doping region may include an N-type doping region doped with an N-type dopant and a P-type doping region doped with a P-type dopant, the low doping region may include an N-type doping region doped with an N-type dopant and a P-type doping region doped with a P-type dopant, a bottom surface of the first recess may include an upper surface of the N-type doping region and an upper surface of the P-type doping region of the high doping region, and a first upper sur