This application claims priority to Chinese application No. 202110883036.9, filed on Aug. 2, 2021, the content of which is hereby incorporated by reference in its entirety and made a part of this specification.
The invention belongs to the field of photodetection device preparation, in particular to a laser rapid fabrication method for flexible gallium nitride (GaN) photodetector.
Exposure is the most critical process link in chip manufacturing lithography technology, which requires a certain intensity of ultraviolet (UV) light to selectively irradiate the photoresist through the mask. The UV exposure dose will directly affect the surface and edge accuracy of the photoresist developed pattern, and ultimately affect the chip manufacturing quality. UV photodetector can effectively monitor UV exposure during the lithography process, and improve the lithography accuracy through feedback adjustment. At present, non-flexible UV photodetectors silicon-based UV photodiodes and photomultiplier tubes are mainly widely used, which are bulky and easily damaged. As a new generation of UV photodetectors, flexible GaN photodetectors have stable physical and chemical properties, small size and wide applicability compared to traditional rigid substrate detectors, and are more suitable for monitoring in high-end complex industrial environments such as chip production. Chinese patent application CN201811189141.1 adopts the method of tool peeling and mechanical transfer to separate GaN film from the substrate material to prepare a flexible GaN photodetector. This method has a high product damage rate and limited process controllability and precision. Chinese patent application CN202011106989.6 uses a pre-grown sacrificial layer and then chemical solution etching to transfer the prepared GaN functional device to a flexible substrate. Chemical solution etching is easy to cause environmental pollution, low removal efficiency, complex process, and is not suitable for mass production. Flexible photodetectors made by traditional methods have weak detection capabilities, and often need to be coated with nanoparticles to improve their detection performance with the help of plasmon polaritons enhancement effect. Therefore, the development of a new technology for rapid fabrication of high-performance GaN flexible photodetectors is of great significance for improving the lithography accuracy and even the quality of chip production in the semiconductor chip manufacturing process.
In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a laser rapid fabrication method for flexible GaN photodetector. The invention adopts the laser technology to realize the transfer of GaN film to flexible substrate while controlling the precipitation of in-situ growth of Ga metal nanoparticles, and prepares a flexible GaN photodetector with an in-situ distribution detection surface of the Ga metal nanoparticles in one step. The invention simplifying the device preparation process, and greatly enhance the light absorption and light response capabilities of the detector, and is suitable for large-scale batch industrial production.
The specific technical scheme of the present invention is: a laser rapid fabrication method for flexible GaN photodetector, comprising the following steps:
the combination of process parameters with low single pulse energy, low laser scanning speed and small scanning spacing can realize the precipitation of Ga metal nanoparticles between GaN film and rigid transparent substrate without any separation or damage, at the same time, the release rate of gas products produced by GaN decomposition is slowed down, and the influence of gas products on the distribution uniformity of Ga metal nanoparticles is reduced;
high single pulse energy can rapidly release the decomposition gas products of GaN, which is beneficial to destroy the micro connection between GaN film and rigid transparent substrate, and realize the separation of the interface between GaN film and rigid transparent substrate. High scanning speed and large scanning spacing can reduce the overlap rate between pulse points, and reduce the interference of gas product coupling between adjacent pulse points on the distribution of Ga metal nanoparticles formed in step 3). Reverse scanning can further homogenize the distribution of Ga metal nanoparticles precipitated in step 3);
Further, in step 3), the laser wavelength should be selected in the range where its photon energy is less than the band gap of the corresponding rigid transparent substrate.
Further, in step 6), the material of the interdigital electrode is a metal with a metal work function higher than the semiconductor affinity of the GaN and forms a Schottky contact with the GaN film.
Compared with the prior art, the present invention has the beneficial effects of: it provides a laser rapid fabrication method for flexible GaN photodetector. By using laser technology to transfer GaN films on rigid substrates to flexible substrates rapidly with high quality, the rapid fabrication of flexible GaN photodetector is realized. In addition, through the regulation of the laser process, the surface of the detector is covered with uniformly distributed Ga metal nanoparticles, which further enhances the light absorption and light response capabilities of the detector. The invention optimizes device performance on the basis of simplifying fabrication process of the flexible GaN photodetector, and is suitable for large-scale batch industrial production.
Where, 1. rigid transparent substrate, 2. GaN epitaxial wafer, 3. Ga metal nanoparticles, 4. interdigital electrode, 5. flexible substrate, 6. ultrafast laser beam.
In order to make the purposes, technical schema and advantages of the present invention clearer, the technical schema of the present invention will be described clearly and completely below with the embodiments and the accompanying drawings. Obviously, the described embodiments are one embodiment of the invention and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
Referring to
Referring to
The above embodiment 1 and embodiment 2 are only examples, wherein the selection of rigid transparent substrate and flexible substrate, the setting of various parameters of laser beam are only examples, and not limitations of the present invention. For example, PI or PDMS can also be selected for flexible substrates, SiC can also be selected for rigid transparent substrates, and Pt can be selected for interdigital electrode materials.
Number | Date | Country | Kind |
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202110883036.9 | Aug 2021 | CN | national |
Number | Name | Date | Kind |
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8772144 | Zhu | Jul 2014 | B2 |
20070093037 | Zhu | Apr 2007 | A1 |
20080041434 | Adriani | Feb 2008 | A1 |
20140318611 | Moslehi | Oct 2014 | A1 |
Number | Date | Country |
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101246820 | Aug 2008 | CN |
102790137 | Nov 2012 | CN |
103824905 | May 2014 | CN |
103839777 | Jun 2014 | CN |
108015410 | May 2018 | CN |
201811189141.7 | Feb 2019 | CN |
109411552 | Mar 2019 | CN |
110047760 | Jul 2019 | CN |
111496384 | Aug 2020 | CN |
112382688 | Feb 2021 | CN |
202011106989.6 | Feb 2021 | CN |
Entry |
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Search Report of the priority application CN202110883036.9. |
Supplemental Search Report of the priority application CN202110883036.9. |
International Search Report of the corresponding international application PCT/CN2021/121981. |
Number | Date | Country | |
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20230032584 A1 | Feb 2023 | US |