2.5 D / 3D photoelectric co-packaging device based on electro-absorption modulator and preparation method of 2.5 D / 3D photoelectric co-packaging device

Abstract

The invention relates to a 2.5 D / 3D photoelectric co-packaging device based on an electro-absorption modulator and a preparation method of the 2.5 D / 3D photoelectric co-packaging device. The 2.5 D / 3D photoelectric co-packaging device comprises a germanium-silicon electro-absorption modulator (1). Through the optical interconnection architecture design for high-performance calculation, the wavelength division multiplexing technology is used for widening the number of channels of a single fiber, the design of a high-performance germanium-silicon electric absorption modulator which works stably under multiple wavelengths is achieved, and the process development of an active adapter plate of a single crystal germanium-silicon material with high-quality selective epitaxial growth is achieved; therefore, the TSV active silicon adapter plate 2.5 D / 3D optical engine with high speed, large bandwidth and small volume for optical IO is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor devices, and in particular relates to a 2.5D / 3D optoelectronic co-packaging device based on an electro-absorption modulator and a preparation method thereof. Background Art

[0002] With the rapid development of emerging businesses such as cloud computing, ChatGPT, and artificial intelligence (AI), the demand for high-performance computing data transmission and processing has increased dramatically. Optical interconnection (optical IO) has emerged as the times require. It is an emerging architecture that uses optical connections to achieve interconnection between computing chips. It has the advantages of ultra-large bandwidth, ultra-fast transmission rate, and high anti-interference. The photonic integrated circuit (PICs) chip and the microelectronic integrated circuit (EICs) chip, and the packaging substrate / printed circuit board (PCB) that form this optical interconnection architecture need to form an effective signal interconnection. The 3D packaging solution is to achieve the integration of EIC and PIC by three-dimensional stacking. The EIC and PIC are connected through micro bumps. The PIC is interconnected with the PCB board through wire bonding, or TSV is directly formed in the PIC, and the substrate is directly interconnected through TSV. At this time, the PIC also plays the role of an adapter board. This solution further improves the integration and has higher reliability. Therefore, the 2.5D / 3D packaging solution based on TSV and adapter board is the most competitive advanced packaging technology for optical IO. In addition, for the PIC part, most companies use micro-ring modulators and drivers as the signal generating ends of optical interconnection. They are small in size and low in power consumption, but have a small operating wavelength range and are very sensitive to temperature changes. They require complex temperature feedback control circuits, which are more difficult. The germanium silicon detector also has the advantages of small size and low power consumption, and its operating wavelength range is larger than that of the micro-ring modulator. Using an electro-absorption modulator while broadening the number of single-fiber channels through wavelength division multiplexing technology provides a new idea for optical IO.

[0003] The 2.5D packaging structure and preparation method disclosed in CN117908200A connects the electric chip and the optical chip through a substrate, resulting in a large interconnection length of the optoelectronic chip and high loss. Therefore, it is necessary to propose a new packaging structure and preparation method. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a 2.5D / 3D optoelectronic co-packaging device based on an electro-absorption modulator and a preparation method thereof. The device adopts a germanium silicon electro-absorption modulator and a germanium detector as core components for transmission and reception, introduces wavelength division multiplexing technology to improve the single optical fiber capacity, and realizes multi-channel parallel transmission.

[0005] The present invention provides a 2.5D / 3D optoelectronic co-packaging device based on an electro-absorption modulator, comprising a germanium-silicon electro-absorption modulator; the germanium-silicon electro-absorption modulator comprises a silicon substrate, a silicon dioxide upper cladding layer located on the silicon substrate; a ridge waveguide located on the silicon dioxide upper cladding layer and covered by the silicon dioxide upper cladding layer; an intermediate ridge waveguide is provided in the middle of the ridge waveguide; a P-type silicon lightly doped region and an N-type silicon lightly doped region are provided in the middle of the intermediate ridge waveguide, as well as a P-type silicon heavily doped region and an N-type silicon heavily doped region are located at both ends of the intermediate ridge waveguide; a groove is provided in the middle of the P-type silicon lightly doped region and the N-type silicon lightly doped region, a silicon germanium waveguide and a P-type silicon germanium lightly doped region and an N-type silicon germanium lightly doped region are provided in the middle of the groove; a TiN heater and a SiN waveguide are provided above the intermediate ridge waveguide.

[0006] Preferably, the P-type silicon heavily doped region, the N-type silicon heavily doped region, and the TiN heater are all connected to metal electrodes.

[0007] Preferably, through silicon vias are provided on the left and right sides of the silicon germanium electro-absorption modulator.

[0008] Preferably, the through silicon vias are deposited with micro bumps.

[0009] Furthermore, a passivation protection layer is provided on the upper and lower sides of the SiGe electro-absorption modulator.

[0010] Furthermore, an RDL layer is provided between the SiGe electro-absorption modulator and the passivation protection layer.

[0011] Furthermore, the middle portion of the silicon-germanium electro-absorption modulator also includes a blocking layer.

[0012] The present invention also provides a method for preparing a 2.5D / 3D optoelectronic co-packaging device based on an electroabsorption modulator, comprising the following steps:

[0013] (1) First, etching is performed on the SOI substrate, and the top silicon is etched into a ridge waveguide; the ridge waveguide is doped with p-Si, n-Si, p++-Si and n++-Si by an ion implantation process, a groove is etched in the doped ridge waveguide, and a silicon germanium waveguide is epitaxially grown at the groove by reduced pressure chemical vapor deposition, and polished by chemical mechanical polishing; then, a P-type silicon germanium lightly doped region and an N-type silicon germanium lightly doped region are doped in the silicon germanium waveguide, and finally, a silicon dioxide upper cladding layer is covered and a TiN heater and a SiN waveguide are prepared to obtain a silicon germanium electro-absorption modulator;

[0014] (2) The obtained SiGe electro-absorption modulator is subjected to silicon dioxide dielectric etching, followed by TSV through-hole etching, oxide dielectric passivation layer, barrier layer and seed layer deposition, TSV electroplating and planarization, through-hole etching of different metal layers, TSV and front RDL layer electroplating, front micro-bump electroplating, temporary bonding, substrate thinning, back TSV exposure, back RDL layer electroplating, back micro-bump process and debonding process to obtain a 2.5D / 3D optoelectronic co-packaging device based on the electro-absorption modulator.

[0015] The present invention also provides an application of a 2.5D / 3D optoelectronic co-packaging device based on an electro-absorption modulator in optical interconnection.

[0016] Beneficial Effects

[0017] (1) The present invention realizes a high-speed, large-bandwidth, small-volume TSV active silicon adapter board 2.5D / 3D optical engine for optical IO by designing an optical interconnection architecture for high-performance computing, using wavelength division multiplexing technology to expand the number of single-fiber channels, designing a high-performance germanium silicon electro-absorption modulator that works stably under multiple wavelengths, and developing an active adapter board process with high-quality selective epitaxially grown single-crystalline germanium silicon material.

[0018] (2) The present invention proposes a technical solution that combines a SiGe electro-absorption modulator with TSV advanced packaging technology, which has the advantages of small size and low power consumption, thereby facilitating the realization of a small-volume, highly integrated optical engine.

[0019] (3) The present invention proposes to use a differentially driven differential SiGe electro-absorption modulator to further suppress common-mode noise and interference.

[0020] (4) The present invention uses a germanium-silicon electro-absorption modulator with an integrated on-chip TiN heater to broaden the operating wavelength range, realize multi-channel transmission through wavelength division multiplexing technology, and realize stable operation of the germanium-silicon electro-absorption modulator at multiple wavelengths through adjustment of the feedback control circuit in the electronic chip.

[0021] (5) The 2.5D / 3D packaging solution proposed in the present invention has a higher degree of integration. The electrical chip is directly flip-chip bonded to the optical chip and then connected to the substrate through TSV to achieve short-distance interconnection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the electroabsorption modulator of the present invention.

[0023] Figure 2 It is a schematic structural diagram of a 2.5D / 3D optoelectronic co-packaging device based on an electro-absorption modulator according to the present invention.

[0024] Figure 3It is a schematic diagram of the preparation process of the electroabsorption modulator of the present invention.

[0025] Figure 4 This is a schematic diagram of the preparation process of the 2.5D / 3D optoelectronic co-packaging device based on the electroabsorption modulator of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0027] Example 1

[0028] Depend on Figure 1 As shown, this embodiment provides a 2.5D / 3D optoelectronic co-packaging device based on an electro-absorption modulator, including a germanium-silicon electro-absorption modulator 1. The germanium-silicon electro-absorption modulator 1 is the core device of the present invention, and its working principle is the FK effect, that is, under the action of an external electric field, the free carrier concentration of electron-hole pairs changes, thereby changing the absorption characteristics of the material, and finally reflecting the change of light intensity.

[0029] The SiGe electro-absorption modulator 1 comprises a silicon substrate 101, a silicon dioxide upper cladding layer 102 located on the silicon substrate 101; a ridge waveguide 112 located on the silicon dioxide upper cladding layer 102 and covered by the silicon dioxide upper cladding layer 102; an intermediate ridge waveguide 112-1 is provided in the middle of the ridge waveguide 112; a P-type silicon lightly doped region 103 and an N-type silicon lightly doped region 104 are provided in the middle of the intermediate ridge waveguide 112-1, and a A P-type silicon heavily doped region 105 and an N-type silicon heavily doped region 106 are provided at both ends of the waveguide 112-1; a groove is provided in the middle of the P-type silicon lightly doped region 103 and the N-type silicon lightly doped region 104, a silicon germanium waveguide 107 is provided in the middle of the groove, and a P-type silicon germanium lightly doped region 108 and an N-type silicon germanium lightly doped region 109 are provided at both ends of the silicon germanium waveguide 107; a TiN heater 110 and a SiN waveguide 111 are provided above the intermediate ridge waveguide 112-1.

[0030] Preferably, the P-type silicon heavily doped region 105 , the N-type silicon heavily doped region 106 , and the TiN heater 110 are all connected to a metal electrode 2 .

[0031] like Figure 2As shown, the left and right sides of the SiGe electroabsorption modulator 1 are further provided with through silicon vias 3. The through silicon vias 3 are deposited with micro bumps 7. The upper and lower sides of the SiGe electroabsorption modulator 1 are further provided with a passivation protection layer 6. An RDL layer 4 is provided between the SiGe electroabsorption modulator 1 and the passivation protection layer 6. The middle part of the SiGe electroabsorption modulator 1 also includes a barrier layer 5.

[0032] This embodiment also provides a method for preparing a 2.5D / 3D optoelectronic co-packaging device based on an electroabsorption modulator, comprising the following steps:

[0033] (1) Figure 3 As shown, firstly, etching is performed on the SOI substrate, and the top silicon is etched into a ridge waveguide 112; the ridge waveguide 112 is doped with p-Si, n-Si, p++-Si and n++-Si by an ion implantation process, a groove is etched in the doped ridge waveguide 112, and a silicon germanium waveguide 107 is epitaxially grown at the groove by reduced pressure chemical vapor deposition, and polished by chemical mechanical polishing; then, a P-type silicon germanium lightly doped region 108 and an N-type silicon germanium lightly doped region 109 are doped in the silicon germanium waveguide 107, respectively, and finally, a silicon dioxide upper cladding layer is covered and a TiN heater 110 and a SiN waveguide 111 are prepared to obtain a silicon germanium electro-absorption modulator 1;

[0034] (2) Figure 4 As shown, the obtained germanium silicon electro-absorption modulator 1 is subjected to silicon dioxide dielectric etching, followed by TSV through-hole etching, oxide dielectric passivation layer, barrier layer and seed layer deposition, TSV electroplating and planarization, through-hole etching of different metal layers, TSV and front RDL layer electroplating, front micro-bump electroplating, temporary bonding, substrate thinning, back TSV exposure, back RDL layer electroplating, back micro-bump process and debonding process, to obtain a 2.5D / 3D optoelectronic co-packaging device based on the electro-absorption modulator.

Claims

1. A 2.5D / 3D optoelectronic co-packaging device based on an electroabsorption modulator, characterized in that: The invention comprises a germanium silicon electro-absorption modulator (1); the germanium silicon electro-absorption modulator (1) comprises a silicon substrate (101), a silicon dioxide upper cladding layer (102) located on the silicon substrate (101); a ridge waveguide (112) located on the silicon dioxide upper cladding layer (102) and covered by the silicon dioxide upper cladding layer (102); an intermediate ridge waveguide (112-1) is provided in the middle of the ridge waveguide (112); a P-type silicon lightly doped region (103) and an N-type silicon lightly doped region (104) are provided in the middle of the intermediate ridge waveguide (112-1); and A P-type silicon heavily doped region (105) and an N-type silicon heavily doped region (106) are located at both ends of the middle ridge waveguide (112-1); a groove is provided in the middle of the P-type silicon lightly doped region (103) and the N-type silicon lightly doped region (104); a silicon germanium waveguide (107) and a P-type silicon germanium lightly doped region (108) and an N-type silicon germanium lightly doped region (109) are provided in the middle of the groove; and a TiN heater (110) and a SiN waveguide (111) are provided above the middle ridge waveguide (112-1).

2. The 2.5D / 3D optoelectronic co-packaging device according to claim 1, characterized in that: The P-type silicon heavily doped region (105), the N-type silicon heavily doped region (106), and the TiN heater (110) are all connected to metal electrodes (2).

3. The 2.5D / 3D optoelectronic co-packaging device according to claim 1, characterized in that: Through-silicon vias (3) are also provided on the left and right sides of the silicon-germanium electro-absorption modulator (1).

4. The 2.5D / 3D optoelectronic co-packaging device according to claim 1, characterized in that: The through silicon via (3) is deposited with micro bumps (7).

5. The 2.5D / 3D optoelectronic co-packaging device according to claim 1, characterized in that: The upper and lower sides of the germanium silicon electroabsorption modulator (1) are also provided with a passivation protection layer (6).

6. The 2.5D / 3D optoelectronic co-packaging device according to claim 5, characterized in that: An RDL layer (4) is provided between the germanium silicon electroabsorption modulator (1) and the passivation protection layer (6).

7. The 2.5D / 3D optoelectronic co-packaging device according to claim 1, characterized in that: The middle part of the germanium silicon electroabsorption modulator (1) also includes a blocking layer (5).

8. A method for preparing a 2.5D / 3D optoelectronic co-packaging device based on an electroabsorption modulator, comprising the following steps: (1) First, etching is performed on an SOI substrate, and a top layer of silicon is etched into a ridge waveguide (112); p-Si, n-Si, p++-Si and n++-Si are doped into the ridge waveguide (112) by an ion implantation process, a groove is etched in the doped ridge waveguide (112), and a silicon germanium waveguide (107) is epitaxially grown at the groove by reduced pressure chemical vapor deposition, and polished by chemical mechanical polishing; then a P-type silicon germanium lightly doped region (108) and an N-type silicon germanium lightly doped region (109) are doped in the silicon germanium waveguide (107), and finally a silicon dioxide upper cladding layer is covered and a TiN heater (110) and a SiN waveguide (111) are prepared to obtain a silicon germanium electro-absorption modulator (1); (2) The obtained SiGe electro-absorption modulator (1) is subjected to silicon dioxide dielectric etching, followed by TSV through-hole etching, oxide dielectric passivation layer, barrier layer and seed layer deposition, TSV electroplating and planarization, through-hole etching of different metal layers, TSV and front RDL layer electroplating, front micro-bump electroplating, temporary bonding, substrate thinning, back TSV exposure, back RDL layer electroplating, back micro-bump process and debonding process, to obtain a 2.5D / 3D optoelectronic co-packaging device based on the electro-absorption modulator.

9. Application of a 2.5D / 3D optoelectronic co-packaging device based on an electro-absorption modulator as claimed in any one of claims 1 to 7 in optical interconnection.

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