阅读说明：本技术 一种氮化镓高精密飞秒绿光激光加工设备 (High-precision femtosecond green laser processing equipment for gallium nitride ) 是由 刘文宇 杜金恒 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种氮化镓高精密飞秒绿光激光加工设备,包括：提供待剥离的发光机构和保护机构,其发光机构包括：激光发生器以及从下到上依次层叠设置的第一衬底、位于第一衬底一侧的多量子阱吸收层、氮化镓外延层和波导结构,激光发生器用于对第一衬底进行激光剥离,氮化镓外延层包括N型氮化镓层、有源层和P型氮化镓层；保护机构包括：从下到上依次层叠设置的第一垒层、第一变温层、第一阱层、第一变温保护层、第二垒层、第二变温层、第二阱层、第二变温保护层、第三垒层。可以通过调节孔径光闲的大小和位置来调整激光光斑的大小,进而可以采用尽可能小的光斑进行激光剥离,使得局部产生的氮化物较少,以提高衬底剥离的合格率。(The invention discloses a high-precision femtosecond green laser processing device for gallium nitride, which comprises: providing a light emitting mechanism to be peeled and a protection mechanism, the light emitting mechanism comprising: the laser device comprises a laser generator, a first substrate, a multi-quantum well absorption layer, a gallium nitride epitaxial layer and a waveguide structure, wherein the first substrate, the multi-quantum well absorption layer, the gallium nitride epitaxial layer and the waveguide structure are sequentially stacked from bottom to top; the protection mechanism includes: the first barrier layer, the first temperature-changing layer, the first well layer, the first temperature-changing protective layer, the second barrier layer, the second temperature-changing layer, the second well layer, the second temperature-changing protective layer and the third barrier layer are sequentially stacked from bottom to top. The size of the laser facula can be adjusted by adjusting the size and the position of the aperture idle, and then the facula as small as possible can be adopted for laser stripping, so that the locally generated nitride is less, and the qualification rate of the substrate stripping is improved.)

1. A high-precision femtosecond green laser processing device for gallium nitride comprises: providing a light emitting mechanism and a protection mechanism to be peeled off,

the light emitting mechanism includes: the laser device comprises a laser generator, a first substrate, a multi-quantum well absorption layer, a gallium nitride epitaxial layer and a waveguide structure, wherein the first substrate, the multi-quantum well absorption layer, the gallium nitride epitaxial layer and the waveguide structure are sequentially stacked from bottom to top;

the protection mechanism includes: the first barrier layer, the first temperature-changing layer, the first well layer, the first temperature-changing protective layer, the second barrier layer, the second temperature-changing layer, the second well layer, the second temperature-changing protective layer and the third barrier layer are sequentially stacked from bottom to top.

2. The apparatus of claim 1, wherein the apparatus comprises: and a layer of oxide layer is laid on the surface of the gallium nitride device, and the oxide layer is made of an electric insulation material.

3. The apparatus of claim 2, wherein the apparatus comprises: an angle between an oxide layer on a sidewall of a step of the gallium nitride device and a surface of the gallium nitride device is greater than 90 °.

4. The apparatus of claim 1, wherein the apparatus comprises: and depositing a transition layer on the surface of the gallium nitride layer, and manufacturing a transfer substrate on the surface of the transition layer.

5. The apparatus of claim 1, wherein the apparatus comprises: the protection mechanism further comprises: a P-type ohmic contact layer disposed on the waveguide structure.

6. The apparatus of claim 1, wherein the apparatus comprises: the multiple quantum well absorption layer is used for absorbing light leaked from the waveguide structure into the substrate.

7. The apparatus of claim 1, wherein the apparatus comprises: the quantum well number of the multiple quantum well absorption layer is 11-15.

8. The apparatus of claim 1, wherein the apparatus comprises: the laser generator is provided with an aperture diaphragm on a path of emitting laser, and the size of a light spot of the laser is adjusted through the aperture diaphragm.

Technical Field

The invention relates to the technical field of laser processing equipment research, in particular to gallium nitride high-precision femtosecond green laser processing equipment.

Background

Gallium nitride, a semiconductor with a large forbidden band width, belongs to the so-called wide forbidden band semiconductor. It is an excellent material of microwave power transistor, and also a semiconductor with important application value in blue light emitting device. The research and application of gallium nitride is the leading edge and hot spot of the current global semiconductor research, is a novel semiconductor material for developing microelectronic devices and optoelectronic devices, is praised as a third-generation semiconductor material following the first-generation Ge, Si semiconductor materials, second-generation GaAs and InP compound semiconductor materials together with semiconductor materials such as SIC, diamond and the like. The material has the properties of wide direct band gap, strong atomic bond, high thermal conductivity, good chemical stability (hardly corroded by any acid) and the like, and strong irradiation resistance, and has wide prospects in the application aspects of photoelectrons, high-temperature high-power devices and high-frequency microwave devices.

The gallium nitride material has the properties of wide direct band gap, strong atomic bond, high thermal conductivity, good chemical stability and the like, and strong anti-irradiation capability, and has wide prospects in the application aspects of photoelectrons, high-temperature high-power devices and high-frequency microwave devices. The manufacturing process of most gallium nitride devices comprises the following steps: epitaxially growing an aluminum nitride crystal nucleus on a substrate material, growing gallium nitride epitaxy on a nucleation layer, growing a gallium nitride layer on the gallium nitride epitaxy, then growing a layer of silicon-doped aluminum gallium nitride on the gallium nitride layer, forming a two-dimensional electron gas and heterojunction channel between the aluminum gallium nitride channel and the gallium nitride channel, and finally protecting the surfaces of the two-dimensional electron gas and the heterojunction channel by using a thin passivation layer. At present, the growth of gallium nitride film on sapphire substrate is the most widely used growth technique of gallium nitride material. Because the sapphire substrate is insulated and poor in heat-conducting property, the performance of a gallium nitride-based photoelectric device made of a gallium nitride film growing on the sapphire substrate is restricted, and therefore the technology of replacing the sapphire substrate with a new substrate is widely researched. The laser lift-off technology can separate the gallium nitride film from the sapphire substrate, and provides a good solution for solving the technical problem of replacing the sapphire substrate. However, when the laser peels off the gallium nitride film on the decomposition interface, nitrogen is generated, a large shock wave is formed, and the periphery of the gallium nitride film receiving laser spots is cracked, so that the gallium nitride film with large area and continuity without damage cannot be obtained.

In order to ensure that the gallium nitride film does not generate cracks, the area of the light spot must be set to be very small, so that the processing time and the processing cost are greatly prolonged, and the square laser stripping method cannot be used for the actual production of stripping the large-area continuous gallium nitride film.

Disclosure of Invention

The invention overcomes the defects of the prior art and provides the gallium nitride high-precision femtosecond green laser processing equipment.

In order to achieve the purpose, the invention adopts the technical scheme that: a high-precision femtosecond green laser processing device for gallium nitride comprises: providing a light emitting mechanism to be peeled and a protection mechanism, the light emitting mechanism comprising: laser generator and from the bottom up stack gradually the first substrate that sets up, be located the multiple quantum well absorbed layer, gallium nitride epitaxial layer and the waveguide structure of first substrate one side, laser generator is used for right laser stripping are carried out to first substrate, the gallium nitride epitaxial layer includes N type gallium nitride layer, active layer and P type gallium nitride layer.

The protection mechanism includes: the first barrier layer, the first temperature-changing layer, the first well layer, the first temperature-changing protective layer, the second barrier layer, the second temperature-changing layer, the second well layer, the second temperature-changing protective layer and the third barrier layer are sequentially stacked from bottom to top.

In a preferred embodiment of the present invention, an oxide layer is deposited on the surface of the gan device, and the oxide layer is made of an electrically insulating material.

In a preferred embodiment of the present invention, an angle between an oxide layer on a sidewall of a step of the gallium nitride device and a surface of the gallium nitride device is greater than 90 °.

In a preferred embodiment of the present invention, a transition layer is deposited on the surface of the gallium nitride layer, and a transfer substrate is fabricated on the surface of the transition layer.

In a preferred embodiment of the present invention, the protection mechanism further comprises: a P-type ohmic contact layer disposed on the waveguide structure.

In a preferred embodiment of the present invention, the multiple quantum well absorption layer is for absorbing light leaked from the waveguide structure into the substrate.

In a preferred embodiment of the invention, the number of quantum wells of the multiple quantum well absorption layer is 11-15.

In a preferred embodiment of the present invention, the laser generator has an aperture stop on the path of the laser beam, and the spot size of the laser beam is adjusted by the aperture stop.

The invention solves the defects in the background technology, and has the following beneficial effects:

(1) the invention adopts the long-strip flat-top laser spot for scanning, and under the condition of the same laser spot area, compared with the traditional square laser spot, the impact moment generated on two sides of a stripping interface is much smaller, thus not only ensuring that a large-area gallium nitride film sample is stripped without cracks, but also obtaining acceptable processing speed. Meanwhile, the invention can be used for quickly and effectively preparing the crack-free continuous gallium nitride film with large area.

(2) According to the invention, the laser generator is adopted to strip the first substrate of the light-emitting device, such as a sapphire substrate, and the aperture diaphragm is arranged on the path of laser emitted by the laser generator in the stripping process, so that the size of a laser spot can be adjusted by adjusting the size and position of the aperture idle, and further, the laser stripping can be carried out by adopting the spot as small as possible, so that the locally generated nitride is less, and the qualification rate of the substrate stripping is improved.

(3) The angle between the oxide layer on the side wall of the step and the surface of the gallium nitride device is far larger than 90 degrees. When the metal layer padded on the surface of the gallium nitride device is etched, the metal layers on the front side and the rear side of the step can be completely removed, and the metal residues on the side walls on the front side and the rear side of the step in metal etching are avoided. Effectively prevent short circuit interconnection between the source electrode and the drain electrode of the gallium nitride device.

(4) The invention effectively isolates the grid metal and the conductive channel of the gallium nitride device, thereby protecting the conductive channel of the gallium nitride device and preventing the leakage of the gallium nitride device.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram of a simple structure of a preferred embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the invention, the meaning of "a plurality" is two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

A high-precision femtosecond green laser processing device for gallium nitride comprises: providing a light emitting mechanism to be peeled and a protection mechanism, the light emitting mechanism comprising: laser generator and from the bottom up stack gradually the first substrate that sets up, be located multiple quantum well absorbed layer, gallium nitride epitaxial layer and the waveguide structure of first substrate one side, laser generator is used for carrying out laser to first substrate and peels off, and the gallium nitride epitaxial layer includes N type gallium nitride layer, active layer and P type gallium nitride layer.

The protection mechanism includes: the first barrier layer, the first temperature-changing layer, the first well layer, the first temperature-changing protective layer, the second barrier layer, the second temperature-changing layer, the second well layer, the second temperature-changing protective layer and the third barrier layer are sequentially stacked from bottom to top.

In a preferred embodiment of the present invention, an oxide layer is formed on the surface of the gan device, and the oxide layer is made of an electrically insulating material; and depositing a transition layer on the surface of the gallium nitride layer, and manufacturing a transfer substrate on the surface of the transition layer.

In a preferred embodiment of the present invention, the protection mechanism further comprises: and a P-type ohmic contact layer disposed on the waveguide structure. The multiple quantum well absorption layer is used to absorb light leaked from the waveguide structure into the substrate. The quantum well number of the multiple quantum well absorption layer is 11-15. The laser generator is provided with an aperture diaphragm on the path of emitting laser, and the size of the laser spot is adjusted through the aperture diaphragm.

In a preferred embodiment of the invention, the elongated flat-top laser spot is adopted for scanning, and under the condition of the same laser spot area, compared with the traditional square laser spot, the impact moment generated on two sides of a stripping interface is much smaller, so that the large-area gallium nitride film sample can be ensured to be stripped without cracks, and the acceptable processing rate can be obtained. Meanwhile, the invention can be used for quickly and effectively preparing the crack-free continuous gallium nitride film with large area.

In a preferred embodiment of the invention, the laser generator is adopted to strip the first substrate of the light-emitting device, such as a sapphire substrate, and an aperture diaphragm is arranged on a path of laser emitted by the laser generator in the stripping process, so that the size of a laser spot can be adjusted by adjusting the size and the position of the aperture, and further, the laser stripping can be carried out by adopting the spot as small as possible, so that the locally generated nitride is less, and the qualification rate of the substrate stripping is improved.

In a preferred embodiment of the present invention, an angle between an oxide layer on a sidewall of a step of a gallium nitride device and a surface of the gallium nitride device is greater than 90 °. When the metal layer padded on the surface of the gallium nitride device is etched, the metal layers on the front side and the rear side of the step can be completely removed, and the metal residues on the side walls on the front side and the rear side of the step in metal etching are avoided. Effectively prevent short circuit interconnection between the source electrode and the drain electrode of the gallium nitride device.

In a preferred embodiment of the present invention, the gate metal and the conductive channel of the gan device can be effectively isolated, thereby protecting the conductive channel of the gan device and preventing the leakage of the gan device.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.