阅读说明：本技术 用于氧化镓材料的微波退火改性方法 (Microwave annealing modification method for gallium oxide material ) 是由 马宏平 侯欣蓝 于 2020-12-29 设计创作，主要内容包括：本发明涉及一种用于氧化镓材料的微波退火改性方法。所述用于氧化镓材料的微波退火改性方法包括如下步骤：提供一衬底,所述衬底表面具有由氧化镓层；在预设温度下对所述氧化镓层进行微波退火处理,所述预设温度低于扩散温度,所述扩散温度为所述氧化镓层中的氧化镓材料与所述衬底之间发生热扩散的最低温度。本发明避免了现有传统的退火方式在退火过程中因退火温度过高而易发生氧化镓层与衬底之间热扩散的问题,且微波退火成本低廉,从而降低了氧化镓材料的退火处理成本,利于大规模量化生产。(The invention relates to a microwave annealing modification method for gallium oxide materials. The microwave annealing modification method for the gallium oxide material comprises the following steps: providing a substrate, wherein the surface of the substrate is provided with a gallium oxide layer; and performing microwave annealing treatment on the gallium oxide layer at a preset temperature, wherein the preset temperature is lower than a diffusion temperature, and the diffusion temperature is the lowest temperature at which thermal diffusion occurs between a gallium oxide material in the gallium oxide layer and the substrate. The invention avoids the problem that the thermal diffusion between the gallium oxide layer and the substrate is easy to occur due to overhigh annealing temperature in the annealing process of the traditional annealing mode, and the microwave annealing cost is low, thereby reducing the annealing treatment cost of the gallium oxide material and being beneficial to large-scale quantitative production.)

1. A microwave annealing modification method for gallium oxide materials is characterized by comprising the following steps:

providing a substrate, wherein the surface of the substrate is provided with a gallium oxide layer;

and performing microwave annealing treatment on the gallium oxide layer at a preset temperature, wherein the preset temperature is lower than a diffusion temperature, and the diffusion temperature is the lowest temperature at which thermal diffusion occurs between a gallium oxide material in the gallium oxide layer and the substrate.

2. The microwave annealing modification method for gallium oxide material according to claim 1, wherein the specific steps of performing microwave annealing treatment on the gallium oxide layer at a preset temperature include:

and setting a plurality of preset temperatures, and sequentially carrying out microwave annealing treatment on the gallium oxide layer at each preset temperature.

3. The microwave annealing modification method for gallium oxide material according to claim 2, wherein a plurality of the preset temperatures are arranged in order from low temperature to high temperature;

the difference values between any two adjacent preset temperatures are equal; alternatively, the first and second electrodes may be,

the higher the temperature of the preset temperature is, the smaller the difference between the adjacent preset temperatures is.

4. The microwave annealing modification method for gallium oxide material according to claim 2, wherein the specific steps of sequentially performing microwave annealing treatment on the gallium oxide layer at each of the preset temperatures include:

and sequentially carrying out microwave annealing treatment on the gallium oxide layer at each preset temperature according to the sequence of the preset temperatures.

5. The microwave annealing modification method for gallium oxide material according to claim 2, wherein the specific steps of performing microwave annealing treatment on the gallium oxide layer at each of the preset temperatures include:

placing the substrate into a cavity of a microwave annealing furnace, and vacuumizing the cavity of the microwave annealing furnace;

performing microwave annealing treatment on the gallium oxide layer by taking the preset temperature as the highest temperature;

cooling the gallium oxide layer subjected to the microwave annealing treatment in the cavity of the microwave annealing furnace;

and taking out the substrate with the gallium oxide layer from the cavity of the microwave annealing furnace.

6. The microwave annealing modification method for gallium oxide material according to claim 5, wherein before the microwave annealing treatment of the gallium oxide layer with the preset temperature as the highest temperature, the method further comprises the following steps:

and purging the cavity of the microwave annealing furnace by adopting inert gas, and removing impurity gas in the cavity of the microwave annealing furnace.

7. The microwave annealing modification method for gallium oxide material according to claim 5, wherein the specific step of performing microwave annealing treatment on the gallium oxide layer with the preset temperature as the highest temperature comprises:

setting microwave annealing parameters and introducing annealing atmosphere into the cavity of the microwave annealing furnace to carry out annealing treatment, wherein the highest annealing temperature in the microwave annealing parameters is the preset temperature.

8. The microwave annealing modification method for gallium oxide material according to claim 5, wherein the annealing atmosphere is argon atmosphere or nitrogen atmosphere.

9. The microwave annealing modification method for gallium oxide material according to claim 5, wherein the specific step of cooling the gallium oxide layer subjected to the microwave annealing treatment in the microwave annealing furnace cavity comprises:

and blowing the cavity of the microwave annealing furnace by adopting inert gas to reduce the temperature of the cavity of the microwave annealing furnace.

10. The microwave annealing modification method for gallium oxide material according to claim 1, wherein the preset temperature is 200-600 ℃.

Technical Field

The invention relates to the technical field of semiconductor manufacturing, in particular to a microwave annealing modification method for gallium oxide materials.

Background

Gallium oxide as a third generation wide band gap semiconductor material has the advantages of larger forbidden band width and higher breakdown field strength. The ultra-wide forbidden band characteristic of the gallium oxide material enables the gallium oxide material to have wide application prospect in the manufacturing field of high-power and high-frequency devices.

Annealing is an important step in semiconductor processing engineering for modifying material layers. The conventional annealing processes include tube furnace annealing, laser annealing, rapid thermal annealing (RTP), and the like. In the tube furnace annealing mode and the rapid thermal annealing mode, the required temperature is high in the implementation process of the annealing process, the thermal diffusion effect is easily induced, diffusion occurs between the gallium oxide thin film material and the substrate, and the performance of the final device is seriously influenced by the diffusion. The laser annealing method mainly used in the industry at present has the disadvantages of high equipment cost and being not suitable for large-scale mass production.

Therefore, how to avoid the problem that the gallium oxide material is easy to generate heat diffusion in the annealing process, improve the performance of the finally formed device, and reduce the annealing cost of the gallium oxide material is a technical problem to be solved at present.

Disclosure of Invention

The invention provides a microwave annealing modification method for a gallium oxide material, which is used for solving the problem that the heat diffusion is easy to occur in the annealing treatment process of the gallium oxide material in the prior art, so as to improve the performance of a finally formed semiconductor device and reduce the annealing cost of the gallium oxide material.

In order to solve the above problems, the present invention provides a microwave annealing modification method for gallium oxide material, comprising the following steps:

providing a substrate, wherein the surface of the substrate is provided with a gallium oxide layer;

and performing microwave annealing treatment on the gallium oxide layer at a preset temperature, wherein the preset temperature is lower than a diffusion temperature, and the diffusion temperature is the lowest temperature at which thermal diffusion occurs between a gallium oxide material in the gallium oxide layer and the substrate.

Optionally, the specific step of performing microwave annealing treatment on the gallium oxide layer at a preset temperature includes:

and setting a plurality of preset temperatures, and sequentially carrying out microwave annealing treatment on the gallium oxide layer at each preset temperature.

Optionally, the preset temperatures are arranged in sequence from low temperature to high temperature;

the difference values between any two adjacent preset temperatures are equal; alternatively, the first and second electrodes may be,

the higher the temperature of the preset temperature is, the smaller the difference between the adjacent preset temperatures is.

Optionally, the specific steps of sequentially performing microwave annealing treatment on the gallium oxide layer at each preset temperature include:

and sequentially carrying out microwave annealing treatment on the gallium oxide layer at each preset temperature according to the sequence of the preset temperatures.

Optionally, the specific step of performing microwave annealing treatment on the gallium oxide layer at each preset temperature includes:

placing the substrate into a cavity of a microwave annealing furnace, and vacuumizing the cavity of the microwave annealing furnace;

performing microwave annealing treatment on the gallium oxide layer by taking the preset temperature as the highest temperature;

cooling the gallium oxide layer subjected to the microwave annealing treatment in the cavity of the microwave annealing furnace;

and taking out the substrate with the gallium oxide layer from the cavity of the microwave annealing furnace.

Optionally, before performing microwave annealing on the gallium oxide layer with the preset temperature as the highest temperature, the method further includes the following steps:

and purging the cavity of the microwave annealing furnace by adopting inert gas, and removing impurity gas in the cavity of the microwave annealing furnace.

Optionally, the specific step of performing microwave annealing treatment on the gallium oxide layer by using the preset temperature as the highest temperature includes:

setting microwave annealing parameters and introducing annealing atmosphere into the cavity of the microwave annealing furnace to carry out annealing treatment, wherein the highest annealing temperature in the microwave annealing parameters is the preset temperature.

Optionally, the annealing atmosphere is an argon atmosphere or a nitrogen atmosphere.

Optionally, the specific step of cooling the gallium oxide layer subjected to the microwave annealing treatment in the cavity of the microwave annealing furnace includes:

and blowing the cavity of the microwave annealing furnace by adopting inert gas to reduce the temperature of the cavity of the microwave annealing furnace.

Optionally, the preset temperature is 200 ℃ to 600 ℃.

According to the microwave annealing modification method for the gallium oxide material, provided by the invention, the gallium oxide layer on the surface of the substrate is annealed by adopting a microwave annealing treatment method, the annealing temperature (namely the preset temperature) in the microwave annealing treatment process is controlled to be lower than the diffusion temperature, and the diffusion temperature is the lowest temperature at which thermal diffusion occurs between the gallium oxide material in the gallium oxide layer and the substrate, so that the problem that thermal diffusion between the gallium oxide layer and the substrate is easy to occur due to overhigh annealing temperature in the annealing process in the traditional annealing mode is solved, the microwave annealing cost is low, the annealing treatment cost of the gallium oxide material is reduced, and the large-scale quantitative production is facilitated.

Drawings

FIG. 1 is a flow chart of a microwave annealing modification method for gallium oxide materials in an embodiment of the present invention;

fig. 2 is a schematic structural view of a substrate having a gallium oxide layer in an embodiment of the present invention.

FIG. 3 is a surface topography of unannealed and microwave annealed gallium oxide films taken with an Atomic Force Microscope (AFM).

Detailed Description

The following describes in detail a specific embodiment of the microwave annealing modification method for gallium oxide material provided by the present invention with reference to the accompanying drawings.

The present embodiment provides a microwave annealing modification method for gallium oxide materials, fig. 1 is a flowchart of the microwave annealing modification method for gallium oxide materials in the present embodiment, and fig. 2 is a schematic structural diagram of a substrate having a gallium oxide layer in the present embodiment. As shown in fig. 1, the method for microwave annealing modification of a gallium oxide material according to this embodiment includes the following steps:

step S11, providing a substrate 20, where the surface of the substrate 20 has a gallium oxide layer 21, as shown in fig. 2.

In the present embodiment, the material of the substrate 20 may be Si, SiC, or GaN. The gallium oxide layer 21 may be formed on the surface of the substrate 20 by using a chemical vapor deposition process, a physical vapor deposition process, or an atomic layer deposition process.

Step S12, performing microwave annealing treatment on the gallium oxide layer 21 at a preset temperature, where the preset temperature is lower than a diffusion temperature, and the diffusion temperature is a lowest temperature at which thermal diffusion occurs between a gallium oxide material in the gallium oxide layer 21 and the substrate 20.

Specifically, the essence of microwave annealing is to directly heat the stacked structure (i.e., the stacked structure of the substrate 20 and the gallium oxide layer 21) with microwaves. The existence of the microwave field reduces the crystallization activation energy of the grain boundary of the gallium oxide material, so that the amorphous gallium oxide layer 21 film can form crystal nuclei and be rapidly crystallized by annealing under the lower temperature condition (namely, under the preset temperature condition lower than the diffusion temperature), and meanwhile, the mutual diffusion effect of elements is effectively controlled under the lower temperature condition, and the gallium oxide film with less interface diffusion is finally prepared. Compared with the traditional annealing technology, the microwave annealing technology can effectively reduce the thermal budget, avoid the thermal diffusion effect and achieve the effect of low-temperature annealing, and the annealing efficiency is higher.

Optionally, the specific step of performing microwave annealing treatment on the gallium oxide layer 21 at a preset temperature includes:

and setting a plurality of preset temperatures, and sequentially carrying out microwave annealing treatment on the gallium oxide layer 21 at each preset temperature.

Specifically, in order to further improve the effect of the microwave annealing treatment, a plurality of different preset temperatures may be preset, and the microwave annealing treatment may be performed on the gallium oxide layer 21 sequentially at each preset temperature condition with the preset temperature being the highest temperature in the microwave annealing process. The maximum temperature refers to the maximum temperature to which the cavity of the microwave annealing furnace rises during the microwave annealing treatment.

Optionally, the preset temperatures are arranged in sequence from low temperature to high temperature;

the difference values between any two adjacent preset temperatures are equal; alternatively, the first and second electrodes may be,

the higher the temperature of the preset temperature is, the smaller the difference between the adjacent preset temperatures is.

Specifically, specific values of a plurality of the preset temperatures can be set by those skilled in the art according to actual needs, for example, according to the physical property requirements of the gallium oxide layer 21 after the required annealing. In order to simplify the step of setting the preset temperature, a plurality of preset temperatures may be arranged in an arithmetic progression from low to high. The difference between adjacent preset temperatures may be 50 ℃, 100 ℃ or other values.

In order to further improve the efficiency of microwave annealing, a plurality of preset temperatures are arranged in the order from low temperature to high temperature, and the higher the temperature of the preset temperature is, the smaller the difference between the adjacent preset temperatures is.

Optionally, the specific steps of sequentially performing microwave annealing treatment on the gallium oxide layer 21 at each preset temperature include:

and sequentially carrying out microwave annealing treatment on the gallium oxide layer at each preset temperature according to the sequence of the preset temperatures.

For example, according to the sequence from low temperature to high temperature of the plurality of preset temperatures, the gallium oxide layer is sequentially subjected to microwave annealing treatment at each preset temperature. The plurality in the present embodiment means two or more.

Optionally, the specific step of performing microwave annealing treatment on the gallium oxide layer 21 at each preset temperature includes:

placing the substrate into a cavity of a microwave annealing furnace, and vacuumizing the cavity of the microwave annealing furnace;

performing microwave annealing treatment on the gallium oxide layer by taking the preset temperature as the highest temperature;

cooling the gallium oxide layer subjected to the microwave annealing treatment in the cavity of the microwave annealing furnace;

and taking out the substrate with the gallium oxide layer from the cavity of the microwave annealing furnace.

Optionally, before performing microwave annealing on the gallium oxide layer with the preset temperature as the highest temperature, the method further includes the following steps:

and purging the cavity of the microwave annealing furnace by adopting inert gas, and removing impurity gas in the cavity of the microwave annealing furnace.

Optionally, the specific step of performing microwave annealing treatment on the gallium oxide layer by using the preset temperature as the highest temperature includes:

setting microwave annealing parameters and introducing annealing atmosphere into the cavity of the microwave annealing furnace to carry out annealing treatment, wherein the highest annealing temperature in the microwave annealing parameters is the preset temperature.

Specifically, during the microwave annealing treatment, the temperature in the cavity of the microwave annealing furnace is gradually increased, and the preset temperature used as the highest temperature of the microwave annealing treatment in the present embodiment means the highest temperature that can be reached inside the cavity of the microwave annealing furnace during a single microwave annealing treatment. And after the cavity of the microwave annealing furnace rises to the preset temperature, keeping the preset temperature for a preset time to realize the microwave annealing treatment on the gallium oxide layer. The preset time is preset annealing duration.

Optionally, the annealing atmosphere is an argon atmosphere or a nitrogen atmosphere.

Optionally, the specific step of cooling the gallium oxide layer subjected to the microwave annealing treatment in the cavity of the microwave annealing furnace includes:

and blowing the cavity of the microwave annealing furnace by adopting inert gas to reduce the temperature of the cavity of the microwave annealing furnace.

Optionally, the preset temperature is 200 ℃ to 600 ℃.

For example, the specific steps of performing microwave annealing treatment on the gallium oxide layer 21 at a preset temperature include: step a, placing a sample: putting the substrate 20 with the gallium oxide layer 21 into the middle position of a cavity of a microwave annealing furnace, closing a cavity door, and then vacuumizing the cavity of the microwave annealing furnace; step b, purging a cavity: firstly, purging and cleaning the cavity of the microwave annealing furnace by using sufficient argon to remove residual oxygen in the cavity of the microwave annealing furnace and on the inner wall of the cavity, and keeping an argon purging state for a period of time, wherein the sufficient argon refers to the amount of argon capable of completely exhausting the residual oxygen in the cavity of the microwave annealing furnace and on the inner wall of the cavity; step c, setting annealing parameters: setting technological parameters such as annealing power, the highest temperature in the annealing process, an annealing temperature step and the like, introducing annealing atmosphere, and taking the preset temperature as the highest temperature in the annealing process; step d, annealing is started: setting the annealing time length and starting annealing; step e: and taking out the sample, keeping sufficient argon to continuously purge the cavity of the microwave annealing furnace after the microwave annealing is finished, naturally cooling the temperature in the cavity, and taking out the substrate with the gallium oxide layer, which is subjected to the microwave annealing treatment, from the cavity. And repeating the steps a to e, so that the gallium oxide layer is subjected to multiple annealing treatments at different preset temperatures, thereby improving the annealing efficiency and the annealing quality.

In other specific embodiments, a person skilled in the art can also achieve the effect of batch annealing treatment on the gallium oxide material sample by replacing the gallium oxide material sample and repeating the steps a to e according to actual needs. The gallium oxide material sample is a semiconductor sample with a substrate and a gallium oxide layer positioned on the surface of the substrate.

In the microwave annealing modification method for the gallium oxide material provided by the specific embodiment, the gallium oxide layer on the surface of the substrate is annealed by a microwave annealing method, and the annealing temperature (i.e. the preset temperature) in the microwave annealing process is controlled to be lower than the diffusion temperature, wherein the diffusion temperature is the lowest temperature at which thermal diffusion occurs between the gallium oxide material in the gallium oxide layer and the substrate, so that the problem that thermal diffusion between the gallium oxide layer and the substrate is easily caused due to overhigh annealing temperature in the annealing process in the conventional annealing method is solved, the microwave annealing cost is low, the annealing cost of the gallium oxide material is reduced, and the large-scale quantitative production is facilitated.

FIG. 3 is a surface topography of unannealed and microwave annealed gallium oxide films taken with an Atomic Force Microscope (AFM). The morphology characterization was performed before and after annealing of the gallium oxide sample, and the surface microstructure morphology of the films subjected to different treatments was tested by using an atomic force microscope for the unannealed gallium oxide film and the gallium oxide film subjected to microwave annealing at 250, 350 and 450 ℃, respectively, as shown in fig. 3. It can be seen that the ALD grown gallium oxide thin film is an amorphous disordered structure, as shown in a in fig. 3, with small surface roughness. The surface roughness of the gallium oxide film is gradually increased along with the increase of the annealing temperature from 250 ℃ to 450 ℃, the surface appearance is gradually changed from a needle-point disordered amorphous structure to a coagulated pellet granular crystalline structure, and the size of the microcrystalline particles is gradually increased, which shows that the microwave annealing process really and effectively changes the crystallization and microstructure of the gallium oxide film.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.