阅读说明：本技术 一种柔性光电子器件的制备方法 (Preparation method of flexible optoelectronic device ) 是由 李兰 陈泽群 林宏焘 于 2021-08-26 设计创作，主要内容包括：本发明公开一种柔性光电子器件的制备方法,该方法采用氧化锗作为牺牲层,通过在氧化锗层上沉积、图案化多种功能材料层,采用水作为腐蚀液剥离衬底,得到柔性光电子器件。该制备方法因氧化锗可承受高温、承受等离子体轰击,所以可以实现高质量光学薄膜在高温条件下,在等离子体轰击诱导条件下的沉积和退火优化,完成高性能柔性光电子器件的制备；且在整个柔性光电子器件制备过程中,氧化锗遇水即溶,水作为腐蚀液最大可能避免了薄膜材料的损伤,保证了器件的完整性；本发明的方法可扩展到多种类光学材料柔性光电子器件,可以广泛应用于集成光学器件、空间光学器件和电子元器件的制备。此外,该方法还可用于实现柔性多层波导集成器件。(The invention discloses a preparation method of a flexible optoelectronic device, which adopts germanium oxide as a sacrificial layer, and obtains the flexible optoelectronic device by depositing and patterning a plurality of functional material layers on the germanium oxide layer and adopting water as corrosive liquid to strip off a substrate. According to the preparation method, because germanium oxide can bear high temperature and bear plasma bombardment, deposition and annealing optimization of a high-quality optical film under a plasma bombardment induction condition under a high-temperature condition can be realized, and the preparation of a high-performance flexible photoelectronic device is completed; in the whole process of preparing the flexible optoelectronic device, the germanium oxide is dissolved immediately when meeting water, and the water is used as corrosive liquid to avoid the damage of the film material to the maximum extent and ensure the integrity of the device; the method can be expanded to various optical material flexible optoelectronic devices, and can be widely applied to the preparation of integrated optical devices, space optical devices and electronic components. In addition, the method can also be used for realizing a flexible multilayer waveguide integrated device.)

1. The preparation method of the flexible optoelectronic device is characterized in that germanium oxide is used as a sacrificial layer, a plurality of functional material layers are deposited and patterned on the germanium oxide layer, and water is used as corrosive liquid to strip off a substrate, so that the flexible optoelectronic device is obtained.

2. The method for preparing a flexible optoelectronic device according to claim 1, comprising in particular the steps of:

(1) depositing a germanium oxide layer on the hard substrate;

(2) growing a functional material on the germanium oxide layer to form a functional material layer; when the functional material layer is not provided with the pattern, executing the step (3); when the functional material layer is provided with a pattern, directly executing the step (5);

(3) patterning the surface of the functional material layer;

(4) transferring the pattern to the functional material layer by a pattern transfer process to obtain the functional material layer with the pattern;

(5) depositing an adhesion layer on the surface of the functional material layer, and depositing a supporting layer on the surface of the adhesion layer;

(6) and (5) soaking the sample obtained in the step (5) in water, and dissolving the germanium oxide in the water, so that the hard substrate is peeled off, and the flexible optoelectronic device is obtained.

3. The method as claimed in claim 1, wherein the thickness of the germanium oxide layer is 100-1000 nm.

4. The method for preparing the flexible optoelectronic device according to claim 2, wherein when a device with a 3D multi-layer stacked structure as a core layer needs to be prepared, after the functional material layer with patterns is directly obtained in the step (2) or obtained through the steps (3) and (4), an isolating layer is deposited on the surface of the functional material layer; then repeating the steps (2) or (2) to (4) on the surface of the isolating layer to obtain a second functional material layer with patterns, and so on, thereby obtaining a plurality of functional material layers with patterns, and adjacent functional material layers are separated by the isolating layer; and finally, performing the steps (5) and (6).

5. The method of claim 4, wherein the spacer layer has a thickness of 50nm to 3 um.

6. The method for preparing a flexible optoelectronic device according to claim 2, wherein the temperature of soaking in water in the step (6) is between 40 and 80 ℃.

7. The method for preparing a flexible optoelectronic device according to claim 2, wherein after the step (6), the supporting layer is attached to the hard substrate, and the adhesion layer and the supporting layer on the other side are sequentially deposited.

8. The method of claim 2, wherein the adhesion layer is polydimethylsiloxane and the support layer is an epoxy film or a polyimide film.

9. The method of claim 2, wherein in the step (2), titanium oxide is grown as the functional material layer by a magnetron sputtering method, or a silicon-based material is grown as the functional material layer by a vapor deposition method of plasma enhanced chemistry, or chalcogenide glass or a metal material is grown as the functional material layer by a thermal evaporation deposition method, or an oxide is grown as the functional material layer by an ink-jet printing method or a 3D printing method.

10. A flexible optoelectronic device obtainable by the method of preparation according to any one of the preceding claims.

Technical Field

The invention relates to the field of micro-nano optoelectronic device preparation, in particular to a preparation method of a flexible optoelectronic device.

Background

The flexible photoelectrons generally refer to photoelectronic devices prepared on a flexible polymer substrate, and can be mechanically deformed on the premise of not influencing optical performance, so that the rigid physical form of the traditional device is changed, and the application space of the photoelectronic devices is greatly expanded, such as flexible imaging, wearable photoelectronic equipment, short-distance optical interconnection, intelligent medical treatment and the like. The main structure of the flexible optoelectronic device comprises a core layer and a cladding layer. Polymers have long been the material of choice for the cladding of flexible optoelectronic devices, such as polyethylene films, epoxy films, polyimide films, cellulose films, silk films, due to their inherent mechanical flexibility. However, high molecular materials are generally difficult to withstand high temperatures (greater than 400 ℃) that are necessary to obtain high quality optical films (e.g., amorphous silicon, silicon nitride, oxides, etc.). Meanwhile, the high molecular material enters a physical deposition and etching device cavity such as plasma enhanced chemical vapor deposition, magnetron sputtering, plasma etching and the like for film deposition and etching, and the requirements of the CMOS industry are not met. At present, the transfer method based on etching silicon oxide sacrificial layer is mainly adopted for preparing flexible photoelectronic devices. However, the etching liquid (the main component is hydrofluoric acid) adopted in the existing transfer process corrodes the silicon oxide and also corrodes the core layer material to a certain extent at the same time, so that the optical performance is attenuated, the whole stripping and transferring process is realized by adopting multi-step etching, the process is complex and tedious, and the development of flexible optoelectronic devices is hindered. Similarly, although the polyvinyl alcohol (PVA) water-soluble adhesive tape is used as the sacrificial layer, water can be used as a corrosive agent to prevent corrosion of corrosive liquid to the core layer material, the PVA also has the problem of low high temperature resistance, so that the material requiring high-temperature annealing can not be deposited on the surface of the PVA, and the performance of an optical device is reduced.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of a flexible optoelectronic device, which adopts high-temperature-resistant water-soluble germanium oxide as a sacrificial layer to replace the traditional sacrificial layer materials such as silicon oxide, PVA and the like, and then obtains the complete flexible optoelectronic device by a stripping technology. The method can not only ensure that the whole process does not corrode the silicon-based core layer material, but also expand the core layer material to other novel materials, and the process is simple, convenient and controllable, and the obtained flexible device is reliable.

The purpose of the invention is realized by the following technical scheme:

a preparation method of a flexible optoelectronic device adopts germanium oxide as a sacrificial layer, and obtains the flexible optoelectronic device by depositing and patterning a plurality of functional material layers on the germanium oxide layer and adopting water as corrosive liquid to strip a substrate.

Further, the method specifically comprises the following steps:

(1) depositing a germanium oxide layer on the hard substrate;

(2) growing a functional material on the germanium oxide layer to form a functional material layer; when the functional material layer is not provided with the pattern, executing the step (3); when the functional material layer is provided with a pattern, directly executing the step (5);

(3) patterning the surface of the functional material layer;

(4) transferring the pattern to the functional material layer by a pattern transfer process to obtain the functional material layer with the pattern;

(5) depositing an adhesion layer on the surface of the functional material layer, and depositing a supporting layer on the surface of the adhesion layer;

(6) and (5) soaking the sample obtained in the step (5) in water, and dissolving the germanium oxide in the water, so that the hard substrate is peeled off, and the flexible optoelectronic device is obtained.

Further, for the purpose of easier stripping, the thickness of the germanium oxide layer is 100-1000 nm.

Further, in order to realize efficient information transmission between layers, when a device with a 3D multi-layer stacked structure as a core layer needs to be prepared, a layer of isolation layer is deposited on the surface of the functional material layer directly in the step (2) or after the functional material layer with patterns is obtained through the steps (3) and (4); then repeating the steps (2) or (2) to (4) on the surface of the isolating layer to obtain a second functional material layer with patterns, and so on, thereby obtaining a plurality of functional material layers with patterns, and adjacent functional material layers are separated by the isolating layer; and finally, performing the steps (5) and (6).

Further, in order to realize efficient information transmission between layers, the thickness of the isolation layer is 50nm-3 um.

Further, in order to shorten the device peeling time, the temperature of soaking in water in the step (6) is between 40 and 80 ℃.

Further, in order to obtain a device with a symmetrical or asymmetrical structure, after the step (6), the supporting layer is attached to the hard substrate, and the adhesion layer and the supporting layer on the other side are sequentially deposited.

Furthermore, in order to improve the success rate of device peeling and the mechanical strength of the peeled flexible device, the adhesion layer is polydimethylsiloxane, and the support layer is an epoxy resin film or a polyimide film.

Further, since germanium oxide can withstand high temperature and plasma bombardment, it is possible to realize the optimization of deposition and annealing of a high quality optical thin film under high temperature conditions under plasma bombardment-induced conditions, and in the step (2), titanium oxide may be grown as a functional material layer by a magnetron sputtering method, or a silicon-based material may be grown as a functional material layer by a plasma-enhanced chemical vapor deposition method, or chalcogenide glass or a metal material may be grown as a functional material layer by a thermal evaporation deposition method, or an oxide may be grown as a functional material layer by an ink-jet printing method or a 3D printing method.

A flexible optoelectronic device obtained by the preparation method.

The invention has the following beneficial effects:

(1) in the preparation method, because the germanium oxide can bear high temperature and bear plasma bombardment, the deposition and annealing optimization of the high-quality optical film under the high-temperature condition and the plasma bombardment induction condition can be realized, and the preparation of the high-performance flexible photoelectronic device is completed;

(2) in the whole process of preparing the flexible photonic device, the germanium oxide is dissolved when meeting water, and the water is used as corrosive liquid to avoid the damage of the film material to the maximum extent and ensure the integrity of the device;

(3) the process technology can be expanded to various optical material flexible optoelectronic devices, and can be widely applied to integrated optical devices, such asSuch as flexible optical waveguide, resonant cavity, grating, detector, modulator, etc., applied to the fields of sensing, detection, flexible optical interconnection, etc. of multiple physical quantities such as novel optical mechanics, temperature, etc.; it can also be used for preparing space optical elements, such as superlens, holographic grating, diffraction element, and AR，VR, holographic imaging, etc.; the preparation method can also be used for preparing flexible electronic devices such as transistors, memristors and the like, and is used in the fields of flexible display screens and flexible integrated circuits; in addition, the technology can also be used for preparing a multilayer photoelectric device structure, and the flexible 3D device photoelectric monolithic integration process which is difficult to complete by the traditional method is realized.

Drawings

FIG. 1 is a process flow diagram of a method of making a flexible optoelectronic device of the present invention;

FIG. 2 is a schematic view of a flexible optoelectronic device of example 2 of fully symmetric structure;

fig. 3 is a perspective view of the flexible optoelectronic device obtained in example 2.

Fig. 4 is a schematic diagram of the flexible optoelectronic device of the asymmetric structure of the embodiment 3.

Fig. 5 is a schematic view of the flexible multilayer coupled optoelectronic device obtained in example 4.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments, and the objects and effects of the present invention will become more apparent, it being understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

According to the preparation method of the flexible optoelectronic device, the germanium oxide is used as a sacrificial layer, water is used as corrosive liquid, and the preparation of the complete flexible optoelectronic device is realized through the processes of film coating, patterning, pattern transfer and stripping. The overall process flow diagram of the preparation method is shown in figure 1. The method specifically comprises the following steps:

the method comprises the following steps: and depositing a germanium oxide layer on the hard substrate.

The hard substrate can be a silicon wafer, and a germanium oxide film can be prepared on the silicon wafer as a sacrificial layer by adopting the technologies of a magnetron sputtering method, an electron beam evaporation method, an atomic layer deposition method, a chemical deposition method and the like, wherein the deposition thickness of the germanium oxide film is 100-1000 nm.

Step two: growing a functional material on the germanium oxide layer to form a functional material layer; when the functional material layer is not provided with the pattern, executing a third step; when the functional material layer is provided with a pattern, directly executing a fifth step;

in this step, desired materials are grown on the sacrificial layer, including but not limited to:

growing titanium oxide as a functional material layer by a magnetron sputtering method, or growing a silicon-based material (such as amorphous silicon, silicon nitride and the like) as a functional material layer by a Plasma Enhanced Chemical Vapor Deposition (PECVD) method, or growing chalcogenide glass (such as germanium antimony sulfide, germanium antimony selenium and the like) or a metal material (such as indium tin alloy, iron-based alloy and the like) as a functional material layer by a thermal evaporation deposition method, or growing an oxide (such as lead titanate, titanium oxide, silicon oxide, indium tin oxide, zinc oxide, indium gallium zinc oxide and the like) as a functional material layer by an ink-jet printing method or a 3D printing method. In addition, other functional ceramics and glass materials can be used as the functional material layer. Wherein, the functional material layer with patterns can be directly obtained by an ink-jet printing method or a 3D printing method, and the subsequent steps of three and four can be directly skipped at the moment.

Step three: patterning the surface of the functional material layer;

in this step, the patterning process includes lithography machine exposure, electron beam exposure, nanoimprint, laser direct writing, and the like.

Step four: transferring the pattern to the functional material layer by a pattern transfer process to obtain the functional material layer with the pattern;

in this step, the pattern transfer process includes dry etching, wet etching, lift-off process (lift-off), and the like. And soaking the sample wafer after the pattern transfer in a corresponding organic solvent to remove the mask in the patterning process. The organic solvent includes: acetone, N-methyl pyrrolidone, isopropanol, and the like.

Secondly, when a device with a 3D multilayer stack structure as a core layer needs to be prepared, directly obtaining a functional material layer with patterns in the second step or obtaining the functional material layer with the patterns through the third step and the fourth step, and depositing an isolation layer on the surface of the functional material layer; and then repeating the second or second to fourth steps on the surface of the isolating layer to obtain a second functional material layer with patterns, and so on, thereby obtaining a plurality of functional material layers with patterns, and adjacent functional material layers are separated by the isolating layer.

The isolating layer can be deposited by adopting the processes of magnetron sputtering, PECVD, LPCVD, thermal evaporation deposition, spin-coating and the like, the isolating layer can be made of materials such as silicon oxide, aluminum oxide, titanium oxide, silicon oxynitride, silicon nitride, SU8, polyimide and the like, and the thickness of the isolating layer is between 50nm and 3 um. And finally, flattening the surface by chemical polishing. And repeating the steps of the isolation layer and the functional material layer with the pattern according to the required layer number of the device.

Step five: and depositing an adhesion layer on the surface of the functional material layer, and depositing a support layer on the surface of the adhesion layer.

The adhesion layer can be made of polymer material such as silicone oil, Polydimethylsiloxane (PDMS), and silica gel; but also metallic materials such as titanium, chromium, etc. The support layer may be a polyethylene film, an epoxy resin film, a polyimide film, a cellulose film, a polypropylene film, a polystyrene film, a silk film, or the like. The polymer films in the adhesion layer and the supporting layer can be prepared by adopting a spin coating method, and the metal in the adhesion layer can be prepared by adopting a thermal evaporation method, a magnetron sputtering method and the like.

Step six: and D, soaking the sample obtained in the fifth step in water, and dissolving the germanium oxide in the water, so that the hard substrate is peeled off, and the flexible optoelectronic device is obtained.

In the step, the stripping process is to soak the substrate coated with the adhesion layer and the supporting layer in warm water at the temperature of 40-80 ℃ for 1-10 hours to completely dissolve the sacrificial layer in the water, so that the flexible optoelectronic device can be obtained.

Finally, according to different application occasions, the device can be attached to the hard substrate on the supporting layer surface of the device subsequently, and the deposition of the corresponding adhesion layer and the corresponding supporting layer on the other surface is carried out.

Example 1

Preparing 800nm germanium oxide on a silicon wafer by adopting a magnetron sputtering method. After plating a silicon nitride film on the germanium oxide film, the photolithography process was patterned with NR 91000 py photoresist. And carrying out dry etching on the photoetched sample to realize pattern transfer. And removing photoresist on the surface of the etched substrate, and respectively and sequentially carrying out spin coating preparation on the PDMS and the polyimide film by a spin coating method. And soaking the substrate coated with the PDMS and the polyimide film in water at 60 ℃ for 10 hours to completely dissolve the sacrificial layer in the water, thus obtaining the complete flexible optoelectronic device.

Example 2

Preparing 1000nm germanium oxide on a silicon wafer by adopting an electron beam evaporation method. Preparing a titanium oxide material with a certain pattern on the germanium oxide film by adopting an ink-jet printing method, carrying out spin coating on the 2um SU8 and 2um polyimide film on the surface of the pattern by a spin coating method, and heating and curing. Soaking the substrate coated with SU8 and polyimide film in 70 deg.C water for 5 hr to dissolve the sacrificial layer in water completely, blow-drying the stripped device with nitrogen gun, adhering the polyimide film to the glass sheet with water soluble adhesive tape, spin-coating 2um SU8 and 2um polyimide film on the other side, and heating for curing. And finally, removing the water-soluble adhesive tape by using water to obtain the complete flexible optoelectronic device with the completely symmetrical structure, as shown in figure 2. The structure can be widely applied to space optical devices. The resulting perspective view of the flexible optoelectronic device is shown in fig. 3.

Example 3

Preparing 600nm germanium oxide on a silicon wafer by adopting a magnetron sputtering method. After a germanium antimony sulfide film with the thickness of 500nm is plated on the germanium oxide film, patterning is carried out on the germanium antimony sulfide film by adopting an electron beam exposure technology, and pattern transfer is further realized by a dry etching process. And removing photoresist on the surface of the etched substrate, respectively carrying out spin coating on 5um PDMS and 2um SU8 films by a spin coating method, and heating for curing. The substrate coated with PDMS and SU8 film was soaked in water at 50 ℃ for 7 hours to completely dissolve the sacrificial layer in water. And (3) drying the stripped device by using a nitrogen gun, flatly attaching and fixing the SU8 film surface on a glass sheet by using a water-soluble adhesive tape, respectively carrying out spin coating on the 2um PDMS and the 2um SU8 film on the other side, and heating and curing. And finally, removing the water-soluble adhesive tape by using water to obtain the complete flexible optoelectronic device with the asymmetric structure, as shown in fig. 4.

Example 4

Preparing 1500nm germanium oxide on a silicon wafer by adopting a chemical deposition method. After the germanium oxide film is plated with the 220nm amorphous silicon film, patterning is carried out on the amorphous silicon film by adopting an electron beam exposure technology, and pattern transfer is further realized by a dry etching process. And removing photoresist on the surface of the etched substrate, plating a 300nm silicon oxide film on the surface of the amorphous silicon device by a PECVD (plasma enhanced chemical vapor deposition) method to serve as a first isolation layer, and flattening the surface by chemical polishing. Preparing a 500nm thick silicon nitride film on the flattened surface by PECVD, patterning the silicon nitride film by adopting an electron beam exposure technology, and further realizing pattern transfer and photoresist removal by a dry etching process. And plating 700nm silicon oxynitride on the surface of the silicon nitride device by a magnetron sputtering method to serve as a second isolation layer, and flattening the surface by chemical polishing. And preparing a 250nm titanium dioxide film on the surface of the flattening device by a spin coating method. Patterning is carried out on the titanium dioxide film by adopting an electron beam exposure technology, and pattern transfer and photoresist removal are further realized by a dry etching process. And respectively carrying out spin coating of PDMS and polyimide films on the surface of the titanium dioxide device, and heating and curing. The substrate coated with PDMS and polyimide films was soaked in water at 50 ℃ for 7 hours to completely dissolve the sacrificial layer in the water. And (3) drying the stripped device by using a nitrogen gun, flatly attaching and fixing the polyimide film surface on a glass sheet by using a water-soluble adhesive tape, respectively carrying out spin coating on PDMS and the polyimide film on the other side, and heating and curing. And finally, removing the water-soluble adhesive tape by using water to obtain the complete flexible multilayer coupling optoelectronic device, as shown in fig. 5. And performing process stacking and material stacking with corresponding layers according to the layer number of the device and the design requirement, and selecting and matching the processes. The present example is illustrated only by way of a three-layer stacked device fabrication process to illustrate the process scheme of the present invention.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and although the invention has been described in detail with reference to the foregoing examples, it will be apparent to those skilled in the art that various changes in the form and details of the embodiments may be made and equivalents may be substituted for elements thereof. All modifications, equivalents and the like which come within the spirit and principle of the invention are intended to be included within the scope of the invention.