A method for supercritical treatment of semiconductor devices

Abstract

The present invention provides a supercritical treatment method for semiconductor devices. By providing a semiconductor device and a second substance, where the second substance is a compound containing carbon and hydrogen elements; obtaining the second substance in a supercritical state; and repairing crystal defects in the semiconductor structure with the supercritical second substance. It can be seen that by utilizing the permeability and fluidity of the supercritical second substance, the supercritical second substance enters the semiconductor structure, and the second substance or the elements of the second substance bond with the dangling bonds generated by the crystal defects in the semiconductor structure, playing a role in repairing the crystal defects and reducing the influence of the crystal defects on the performance of the semiconductor device.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and particularly to a method for supercritical treatment of semiconductor devices. Background Art

[0002] The third-generation wide-bandgap semiconductor materials represented by gallium nitride (GaN) and silicon carbide (SiC) have broad application prospects in the fields of aerospace, semiconductor lighting, new energy vehicles, radio frequency microwave, smart grid, etc. due to their advantages such as high electron saturation rate, high breakdown voltage, and low dielectric constant. They have irreplaceable important value and are one of the key factors to enhance the core competitiveness of the country's new generation of information technology.

[0003] At present, most GaN-based devices are fabricated on hetero-substrates (such as silicon, silicon carbide, sapphire, etc.). Problems such as lattice mismatch and thermal mismatch between the GaN epitaxial layer and the substrate will cause lattice distortion in the epitaxial layer prepared by hetero-epitaxy, resulting in problems such as high dislocation density, mosaic crystal structure, biaxial stress, and wafer warping, seriously affecting the performance and service life of GaN-based devices. Therefore, the performance of current GaN-based devices is far lower than the theoretical value.

[0004] The problem of performance degradation of semiconductor devices caused by the above crystal defects is not limited to GaN-based devices. Therefore, how to repair various crystal defects including dislocation defects has become an important means to improve the performance of semiconductor devices. Summary of the Invention

[0005] The main technical problem to be solved by the present invention is the problem that crystal defects in existing semiconductor devices lead to performance degradation of the devices.

[0006] According to a first aspect, in one embodiment, a method for supercritical treatment of a semiconductor device is provided, including:

[0007] Providing a semiconductor device, a first substance, and a second substance, where the second substance is a compound containing carbon and hydrogen elements;

[0008] Performing supercritical treatment on the first substance to obtain a supercritical state of the first substance, where the treatment temperature T satisfies T1≤T, the treatment pressure P satisfies P1≤P, T1 is the critical temperature of the first substance, and P1 is the critical pressure of the first substance;

[0009] Treating the second substance with the supercritical state of the first substance to obtain a supercritical state of the second substance;

[0010] Repairing crystal defects in the semiconductor structure of the semiconductor device with the supercritical state of the second substance.

[0011] According to a second aspect, in one embodiment, a method for supercritical treatment of a semiconductor device is provided, including:

[0012] Providing a semiconductor device and a second substance, the second substance being a compound containing carbon and hydrogen elements;

[0013] Obtaining the second substance in a supercritical state;

[0014] Repairing crystal defects of the semiconductor structure of the semiconductor device through the second substance in the supercritical state.

[0015] According to the method for supercritical treatment of a semiconductor device in the above embodiment, by providing a semiconductor device and a second substance, the second substance being a compound containing carbon and hydrogen elements; obtaining the second substance in a supercritical state; and repairing crystal defects of the semiconductor structure through the second substance in the supercritical state. It can be seen that by utilizing the permeability and fluidity of the second substance in the supercritical state, the second substance enters the semiconductor structure, and the second substance or the elements of the second substance bond with the dangling bonds generated by the crystal defects in the semiconductor structure, playing a role in repairing the crystal defects and reducing the influence of the crystal defects on the performance of the semiconductor device. Description of the Drawings

[0016] Figure 1 It is a schematic flowchart of a method for supercritical treatment of a semiconductor device provided in one embodiment;

[0017] Figure 2 It is a schematic flowchart of a method for supercritical treatment of a semiconductor device provided in another embodiment;

[0018] Figure 3 It is a schematic structural diagram of a supercritical treatment device for a semiconductor device provided in one embodiment;

[0019] Figures 4a to 4f It is a schematic diagram for comparing the electrical characteristics of a gallium nitride high electron mobility transistor before and after treatment;

[0020] Figure 5a And Figure 5b It is a comparative TEM analysis diagram of a gallium nitride high electron mobility transistor before and after treatment.

[0021] Reference numerals: 100 - carbon dioxide supply source; 200 - gas pressure pump; 300 - valve; 400 - reaction chamber; 401 - temperature adjustment component; 500 - gallium nitride high electron mobility transistor. Detailed Embodiments

[0022] The present invention will be further described in detail below in conjunction with the specific embodiments and the accompanying drawings. Similar elements in different embodiments are denoted by related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification, which is to avoid overwhelming the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0023] In addition, the features, operations, or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in an obvious manner by those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for clearly describing a certain embodiment, and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0024] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0025] Embodiment 1

[0026] A semiconductor device includes multiple semiconductor structure layers and insulating dielectric layers. There are certain crystal defects in the preparation process of the semiconductor structure with a single crystal structure, and the crystal defects will affect the electrical characteristics of the semiconductor structure.

[0027] Supercritical technology has been gradually applied to traditional industrial production, such as extraction, particle manufacturing, environmental governance, chemical reactions, energy conservation, etc. Taking supercritical extraction technology as an example, the extraction process mainly uses supercritical carbon dioxide as the extraction solvent. By utilizing the unique physical properties of supercritical fluids, organic compounds can be extracted from parts such as plant seeds, fruits, and leaves. The application fields of supercritical fluid technology are extensive, but due to the fact that the principle of supercritical fluids has not been thoroughly studied, the operating pressure of supercritical fluids is relatively high, and high requirements are imposed on the equipment. At the same time, the manufacturing threshold of semiconductor processes is high, and there are problems such as the cross-professional and cross-industry understanding of supercritical technology practitioners. The application of supercritical technology in the semiconductor integrated circuit industry has always been very limited.

[0028] After a semiconductor device is usually fabricated, it needs to be packaged to isolate the device from factors such as water and oxygen. In addition, most defects in the device exist inside the device, and it is difficult for ordinary substances to enter it. Therefore, the embodiments of the present invention provide a supercritical treatment method for semiconductor devices. By utilizing the unique physical properties of supercritical fluids, which have both high solubility and high permeability, and applying them to the treatment of semiconductor devices, the crystal defects of semiconductor devices can be effectively repaired, and the comprehensive performance of the devices can be improved.

[0029] As Figure 1 shown, the supercritical treatment method for semiconductor devices provided by the embodiments of the present invention includes:

[0030] Step 1: Provide a semiconductor device and a second substance, where the second substance is a compound containing carbon and hydrogen elements.

[0031] The above semiconductor device can be a semiconductor device in any process step, that is to say, it can be a semi-finished product during the manufacturing process or a finished product after packaging.

[0032] Step 2: Obtain the second substance in a supercritical state.

[0033] Step 3: Repair the crystal defects of the semiconductor structure through the second substance in a supercritical state.

[0034] Place the semiconductor device in the second substance in a supercritical state, and use the second substance in a supercritical state to treat the semiconductor structure of the semiconductor device. The second substance in a supercritical state repairs the crystal defects, especially the dislocation and crystal cleavage defects.

[0035] More specifically, by utilizing the permeability and fluidity of the second substance in a supercritical state, the second substance in a supercritical state can penetrate into the semiconductor structure (single crystal structure) of the semiconductor device. Since the second substance is a compound containing carbon and hydrogen elements, the carbon-hydrogen bonds and unsaturated bonds (if any) of the second substance are easily broken, especially the bonds between carbon and hydrogen elements. Therefore, after the carbon-hydrogen bonds or unsaturated bonds of the second substance are broken, they will bond with the dangling bonds generated by the crystal defects (especially dislocations and crystal cleavages) in the semiconductor structure, thereby achieving the repair of crystal defects. As a result, its semiconductor structure tends to an ideal crystal structure, the crystal defects are reduced, and the influence brought by the defects is also reduced. Thus, the electrical characteristics of the semiconductor device are more in line with the ideal model.

[0036] In practical applications, the semiconductor structures that affect the electrical performance of semiconductor devices include, but are not limited to, the substrate, buffer layer, active layer, and channel layer. The above crystal defects often lead to a large number of dangling bonds in the semiconductor structure of the single crystal structure. The second substance in a supercritical state can bond with these dangling bonds to reduce the influence brought by the dangling bonds.

[0037] In a practical application, in the method for supercritical treatment of a semiconductor device provided by an embodiment of the present invention, the second substance may be an alkane, an alkene or an alkyne. Regardless of whether the semiconductor structure uses silicon, group III and group V elements, or group II and group VI elements, the difficulty of bonding the carbon element in group IV in the middle with the above elements is lower than that of elements in other groups. At the same time, the carbon-hydrogen bond or the carbon-carbon unsaturated bond of the unsaturated hydrocarbon is easy to break, so that the carbon element can bond with the dangling bond of the semiconductor structure. Based on the intermediate valence state, the carbon element has strong repair ability for all semiconductor structures.

[0038] For example, the second substance may be methane, ethylene or acetylene. The preparation processes of methane, ethylene and acetylene are simple. For example, acetylene can be generated by using calcium carbide and water, and it is easy to be supercriticalized. Among them, the critical temperature of acetylene is 35.7 °C and the critical pressure is 6.19 MPa.

[0039] In a practical application, gallium nitride is a direct-bandgap semiconductor material and has been widely used in various optoelectronic devices and power electronic devices. Currently, most gallium nitride-based devices are fabricated on hetero-substrates (such as silicon, silicon carbide, sapphire, etc.). Problems such as lattice mismatch and thermal mismatch between the gallium nitride epitaxial layer and the substrate will cause lattice distortion in the epitaxial layer prepared by heteroepitaxy, resulting in a high dislocation density, mosaic crystal structure, biaxial stress and wafer warping, etc., seriously affecting the performance and service life of gallium nitride-based devices. Therefore, the performance of current gallium nitride-based devices is far lower than the theoretical value. Therefore, in the method for supercritical treatment of a semiconductor device provided by an embodiment of the present invention, the semiconductor device may be a gallium nitride-based semiconductor device, and the material of the semiconductor structure may be gallium nitride. For gallium nitride composed of group III and group V elements, such as unsaturated bond compounds containing carbon elements such as acetylene, the carbon element is easy to bond with the nitrogen element and the gallium element, and the hydrogen element will also undergo a condensation reaction with the nitrogen element, and finally the carbon element is bonded with the nitrogen element and the gallium element.

[0040] For example, the semiconductor device may be a gallium nitride high electron mobility transistor. The active layer materials of the gallium nitride high electron mobility transistor are gallium aluminum nitride and gallium nitride. The preparation processes of gallium aluminum nitride and gallium nitride are not yet very mature compared with other semiconductor materials, and more dislocation crystal cracks are generated than other semiconductor materials.

[0041] Embodiment 2

[0042] Existing methods for supercriticalizing substances use a single means of increasing temperature and pressure, and for a substance to reach the supercritical state, it also needs to meet the conditions of high concentration or even being a pure substance. Many substances (such as acetylene, ethylene, and hydrogen sulfide) are themselves combustible or toxic. High concentrations of combustible gases are prone to explosion, and there are also difficulties in the preparation and storage of these substances. Evidently, the supercriticalization operation of these substances is difficult and has a high risk factor. Therefore, achieving the supercriticalization of such substances is restricted in various aspects. At the same time, for a substance to reach the supercritical state, it needs to meet the temperature and pressure conditions, and energy is required to maintain these conditions. For example, the critical pressure of water is 21.76 MPa and the critical temperature is 374.2 °C, while the critical pressure of carbon dioxide is 7.38 MPa and the critical temperature is 31.06 °C. Evidently, achieving the supercriticalization of water requires a relatively high energy consumption.

[0043] For example, the critical pressure of ammonia is 11.25 MPa and the critical temperature is 132.4 °C. At low concentrations of ammonia, people will feel an irritating smell, and there will be a burning and irritating sensation in places such as the eyes, nose, and throat; the higher the concentration of ammonia, the greater the harm to the human body. In the existing technology, for a substance to reach the supercritical state, it is necessary to heat and pressurize a substance with a high concentration (even a pure substance). Evidently, there are many limiting conditions for the supercriticalization of nitrogen compounds such as ammonia.

[0044] Also, for example, when the second substance is a flammable and explosive gas (such as acetylene), for a high concentration (even a pure) second substance to reach the supercritical state, heating and pressurization are required, which is very dangerous, prone to explosion, and difficult to operate.

[0045] Therefore, the existing supercritical technologies have the following deficiencies:

[0046] 1. The means of supercriticalization are single; 2. Safety issues in the supercriticalization of combustible or toxic fluids; 3. Substances such as water and ammonia require relatively high energy consumption for supercriticalization; 4. For a substance to reach the supercritical state, it needs to be of high concentration or a pure substance.

[0047] In the embodiments of the present invention, on the basis of Embodiment 1, a method for supercriticalizing a second substance by using a first substance in a supercritical state is proposed and applied to the semiconductor device supercritical treatment method provided in the embodiments of the present invention. Among them, the supercriticalization of the second substance alone has at least one of the deficiencies in the existing supercritical technologies described above. By using the method provided in the embodiments of the present invention, at least one of the above problems can be solved. This enables the semiconductor device supercritical treatment method provided in the embodiments of the present invention to have more advantages.

[0048] To avoid the above limitations and achieve the supercriticalization of substances such as acetylene at lower temperatures and pressures or under safer conditions for crystal defect repair of semiconductor devices, such asFigure 2 As shown in Figure 2 , the supercritical treatment method for semiconductor devices provided by the embodiments of the present invention may include:

[0049] Step 10: Provide a semiconductor device, a first substance, and a second substance, where the second substance is a compound containing carbon and hydrogen elements.

[0050] Step 20: Perform supercritical treatment on the first substance to obtain a supercritical first substance, where the treatment temperature T satisfies T1 ≤ T, and the treatment pressure P satisfies P1 ≤ P, T1 is the critical temperature of the first substance, and P1 is the critical pressure of the first substance.

[0051] The above treatment temperature T and treatment pressure P may also be the temperature and pressure for subsequent treatment of the semiconductor device. Under these temperature and pressure conditions, the first substance achieves supercriticalization.

[0052] Step 30: Treat the second substance with the supercritical first substance to obtain a supercritical second substance.

[0053] Specifically, the second substance and the supercritical first substance are introduced into a reaction chamber. The order of introducing the two into the reaction chamber is not limited. After standing for a certain time, based on the high solubility and high permeability of the supercritical fluid, the second substance will dissolve in the supercritical first substance, and the second substance thus achieves supercriticalization.

[0054] Step 40: Repair crystal defects of the semiconductor structure with the supercritical second substance.

[0055] Here, the supercritical second substance refers to the second substance dissolved in the supercritical first substance. For example, when the semiconductor device is placed in the reaction chamber, the second substance and the supercritical first substance are introduced. After the second substance is supercriticalized, the supercritical second substance and the supercritical first substance coexist in the reaction chamber. It can be that the supercritical second substance repairs the crystal of the semiconductor structure, and the supercritical first substance can act as a solvent or a protective gas. However, it does not exclude the possibility that both the first substance and the second substance play a role in repairing the crystal of the semiconductor structure.

[0056] It can be seen that this embodiment is a further improvement based on Embodiment 1. The various technical solutions mentioned in Embodiment 1 can be adopted. For example, the selection criteria for the second substance, in addition to having the technical effects mentioned in Embodiment 1, also have the following technical effects:

[0057] Through the above-mentioned supercritical treatment method for semiconductor devices, when the supercritical temperature and pressure of the second substance are greater than those of the first substance, the supercritical state of the second substance can be achieved under the conditions of lower temperature and pressure. At the same time, the supercritical state of the second substance with a lower concentration can also be achieved. When the second substance is a flammable, explosive, or toxic fluid, the safety of the second substance with a lower concentration can be guaranteed during actual operation.

[0058] Since the first substance needs to reach the supercritical state under the premise of a high concentration, it is required that the first substance is non-flammable and even non-toxic. At the same time, it is preferably to achieve the supercritical state under lower temperature and pressure conditions. Therefore, the first substance is preferably a gas.

[0059] In practical applications, the first substance can be a saturated bond compound containing carbon elements or an inert gas. Saturated bond compounds containing carbon elements and inert gases have high chemical stability, are not easily reactive with the second substance, and are not likely to cause adverse effects on semiconductor devices.

[0060] For example, the first substance can be carbon dioxide, carbon tetrafluoride, or nitrogen. The critical pressure of carbon dioxide is 7.38 MPa, and the critical temperature is 31.06 °C; the critical pressure of carbon tetrafluoride is 3.74 MPa, and the critical temperature is -45.67 °C. It can be seen that both of the above two substances can reach the supercritical state under lower temperature and pressure conditions (compared with ammonia), and they are non-flammable and non-toxic gases. The critical temperature and pressure of nitrogen are even lower, and it can also be used as the first substance.

[0061] In another practical application, without considering the safety of the first substance and the second substance, in order to achieve the supercritical state of the second substance with lower energy consumption, the selection conditions for the first substance can be: T1 < T2, and / or, P1 < P2, where T2 is the critical temperature of the second substance and P2 is the critical pressure of the second substance. That is to say, when it is difficult to achieve one of the treatment conditions of temperature or pressure when the second substance reaches the supercritical state, the above method can be used to achieve the supercritical state of the second substance.

[0062] In a possible implementation manner, when the second substance reaches the supercritical state alone, its mass fraction or volume fraction in the reaction chamber is 100%. In the method provided in this embodiment, the second substance is dissolved in the supercritical first substance. The closer the treatment conditions in the reaction chamber are to the critical conditions of the second substance, the higher the solubility of the second substance in the supercritical first substance, that is, the higher the mass fraction or volume fraction of the second substance. For the second substance that will cause explosion, toxicity, or corrosion at high concentrations, a low concentration is required. At the same time, under low temperature and low pressure conditions, the concentration of the second substance is also low. For example, the mass fraction of the second substance can be less than or equal to 5%, or the volume fraction of the second substance is less than or equal to 5%.

[0063] In summary, the specific implementation of the first substance actually needs to be selected according to the second substance that needs to be supercriticalized. That is to say, in an ideal state (without considering issues such as toxicity and flammability), under normal temperature and pressure conditions, the first substance can be water, gaseous inorganic substances, gaseous organic substances, or liquid organic substances.

[0064] In a practical application, the first substance can be a gaseous non-metallic inorganic substance. For example, when the first substance can be a gaseous non-metallic single substance such as nitrogen or inert gas, or it can also be a gaseous non-metallic compound such as carbon dioxide or ammonia. The critical temperature and pressure of the gaseous non-metallic inorganic substance are reduced, which can be used corresponding to the case where the critical temperature and pressure of the second substance are higher. For example, when the second substance is a liquid substance. Another example is that when the first substance is an inert gas, the inert gas has chemical stability, is inactive, does not react with the second substance, and does not react with the device that needs to be processed.

[0065] In a practical application, the first substance can be a fluid organic substance. For example, the first substance can be an alkane, an alkene, or an alkyne. Among them, the critical temperature of methane is -82.6 °C, and the critical pressure is 4.59 Mpa. The critical pressure of such substances is relatively low (compared with carbon dioxide), and the critical temperature of some substances (such as methane and ethylene) is lower than that of carbon dioxide. At this time, when the second substance is carbon dioxide, such substances can be used as the first substance to achieve the supercriticalization of the second substance.

[0066] Another example is that the first substance can be a fluid saturated halogenated hydrocarbon. Among them, the first substance can be carbon tetrafluoride. The critical pressure of carbon tetrafluoride is 3.74 MPa, and the critical temperature is -45.67 °C, and it is an incombustible and non-toxic substance. It has the characteristics of being easy to supercriticalize, non-toxic, non-combustible, and high safety.

[0067] Still another example is that the first substance can be an organic substance such as alcohol, aldehyde, ester, ketone, phenol, ether, acyl, or carboxylic acid, and the first substance is a fluid. The organic substance is preferably a substance with 1 to 2 carbon atoms, and at this time, the corresponding critical temperature and pressure are relatively low.

[0068] Example Three

[0069] Due to the limitations of many factors such as material growth quality, fabrication and processing technology, and device structure, the overall performance and electrical reliability of gallium nitride high electron mobility transistors are severely restricted by problems such as large gate leakage current and high-density defect states on the material surface (or interface). There is still a large gap between their characteristic indicators and the theoretical limit values of the material. Currently, there are various explanatory models for the degradation of the electrical characteristics of gallium nitride high electron mobility transistors, including the virtual gate model, hot carrier effect, inverse piezoelectric effect, etc. By analyzing the mechanisms of different explanatory models, it is considered that the theoretical assumptions of most influencing factors fundamentally lie in the generation of various defects such as interface defects and lattice defects, that is, defects are the root cause of the problems in gallium nitride high electron mobility transistor devices.

[0070] Taking the application of gallium nitride high electron mobility transistors as an example, the supercritical treatment method for semiconductor devices provided by the embodiments of the present invention is further elaborated below. However, the supercritical treatment method for semiconductor devices provided by the embodiments of the present invention is not limited to this application example. At this time, the second substance is selected as acetylene, and the first substance is selected as carbon dioxide.

[0071] Step 1: Perform characteristic tests on the gallium nitride high electron mobility transistor before treatment.

[0072] For example, perform basic electrical characteristic tests, including but not limited to characteristics such as threshold voltage, current magnitude, and leakage current.

[0073] Step 2: Treat the gallium nitride high electron mobility transistor with supercritical acetylene to repair crystal defects. The supercritical treatment method for semiconductor devices provided in Example 1 or Example 2 can be used.

[0074] For example, use the Figure 3 shown semiconductor device supercritical treatment equipment for treatment, and adopt the following treatment process:

[0075] 1. Charge acetylene and carbon dioxide into the gas pressure pump 200 with a certain concentration. The concentration of acetylene is 1% (which can be mass fraction or volume fraction). Then, close the gas pressure pump 200 through the valve 300 and increase the pressure to above the critical pressure of carbon dioxide, for example, 2500 psi. Among them, carbon dioxide can be provided by the carbon dioxide supply source 100, and this carbon dioxide is mixed with acetylene, or acetylene can be provided by the acetylene supply source.

[0076] 2. Place the gallium nitride high electron mobility transistor 500 in the reaction chamber 400, close the reaction chamber 400, and raise the temperature to above the critical temperature of carbon dioxide through the temperature adjustment component 401, for example, raise the temperature to 90°C.

[0077] 3. Pass the gas in the air pressure pump 200 into the reaction chamber 400, so that the reaction chamber 400 is under a pressure of 90 °C and 2500 psi. At this time, since carbon dioxide reaches the critical pressure and temperature, it enters the supercritical state, and acetylene therein dissolves in the supercritical carbon dioxide and also enters the supercritical state.

[0078] 4. After placing for a period of time (such as one hour) in the environment of the supercritical fluid of carbon dioxide and acetylene, the supercritical treatment is completed, and the reaction chamber 400 is cooled and depressurized to complete the supercritical treatment of the gallium nitride high electron mobility transistor 500.

[0079] Step 3: Conduct characteristic tests and analyses on the processed gallium nitride high electron mobility transistors.

[0080] For example, characteristics such as the threshold voltage, current magnitude, and leakage current are tested. Then, it is compared with the characteristics of the gallium nitride high electron mobility transistor before treatment.

[0081] As Figure 4a shown, it can be seen that the drain leakage current in the off state of the processed gallium nitride high electron mobility transistor is significantly reduced compared with that before treatment, by one order of magnitude.

[0082] As Figure 4b shown, it can be seen that the on-state current of the drain of the processed gallium nitride high electron mobility transistor is increased compared with that before treatment.

[0083] As Figure 4c and Figure 4d shown, it can be seen that the on-state current of the drain of the processed gallium nitride high electron mobility transistor is increased compared with that before treatment. Under different gate voltage conditions (shown as 6 gate voltages), at the same drain voltage, the on-state current of the drain after treatment is greater than that before treatment. ( Figure 4c and Figure 4d The curves in correspond one by one from bottom to top)

[0084] As Figure 4e and Figure 4f shown, it can be seen that the initial slope of the output characteristics of the processed gallium nitride high electron mobility transistor increases, indicating a reduction in the equivalent contact resistance.

[0085] As Figures 4a to 4f shown, after the gallium nitride high electron mobility transistor is treated with supercritical acetylene, the comprehensive performance of the device is improved.

[0086] As Figure 5a and Figure 5bAs shown, it can be seen that before the gallium nitride high electron mobility transistor is treated with supercritical acetylene, there are many dislocations and crystal cracks in the gallium nitride buffer layer, which extend from the buffer layer to the upper active layer. The more dislocations and crystal cracks there are, the greater the impact on the gallium nitride high electron mobility transistor, and the worse the comprehensive performance. Ideally, there are no dislocations and crystal cracks, but in actual manufacturing, dislocations and crystal cracks will inevitably be introduced, which limits the performance of the gallium nitride high electron mobility transistor. After the gallium nitride high electron mobility transistor passes through supercritical acetylene treatment, it can be seen that the number of dislocations and crystal cracks in the gallium nitride buffer layer is significantly less, indicating that the dislocations and crystal cracks have been effectively repaired and can be directly observed microscopically.

[0087] In summary, after the gallium nitride high electron mobility transistor is treated with supercritical acetylene, carbon elements successfully enter the device, repair dislocations and crystal cracks, reduce the number of dislocations and crystal cracks, and lower the defect concentration. The reduction of the number of dislocations and crystal cracks and the defect concentration at the micro level are manifested at the macro level as an increase in the device's on-state current, a decrease in the leakage current, and a decrease in the device's equivalent contact resistance, resulting in a significant improvement in the device's comprehensive performance.

[0088] Combining the above three embodiments, it can be seen that the semiconductor device supercritical treatment method provided by the embodiments of the present invention at least further has the following technical effects:

[0089] 1. Compatibility: Taking the gallium nitride high electron mobility transistor as an example, for the supercritical treatment of semiconductor devices, due to the unique physical properties of supercritical fluids, which have both high permeability and solubility, supercritical treatment can be carried out in the middle and at the end of the process manufacturing flow. That is, the above semiconductor device can be a semiconductor device in any process step from the completion of the preparation of the buffer layer, active layer, or channel layer to the end of packaging, that is to say, it can be a semi-finished product during the manufacturing process or a finished product after packaging.

[0090] 2. Extensiveness: According to the semiconductor device to be actually processed, by adjusting the types of fluids selected for the first substance and the second substance, during actual processing, multiple conditions such as processing temperature, pressure, time, and fluid flow rate can be adjusted, and the optimal processing condition parameters can be explored through multiple experiments.

[0091] 3. Safety: When using the semiconductor device supercritical treatment method provided in Embodiment 2, the supercriticalization of the second substance can be achieved under safe and controllable conditions.

[0092] 4. Repair effect: Defects are an inevitable problem in semiconductor manufacturing and an important problem that needs to be addressed. The present invention can penetrate deep into the device and repair the defects of the device, improving the comprehensive performance of the device.

[0093] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art to which the present invention pertains, based on the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. A supercritical processing method for semiconductor devices, characterized in that, Including: Providing a semiconductor device, a first substance, and a second substance, wherein the second substance is a compound containing carbon and hydrogen elements; Performing supercritical treatment on the first substance to obtain the first substance in a supercritical state, where the treatment temperature T satisfies T1 ≤ T, and the treatment pressure P satisfies P1 ≤ P, T1 being the critical temperature of the first substance and P1 being the critical pressure of the first substance; Treating the second substance with the supercritical first substance to obtain a supercritical second substance; Repairing crystal defects of the semiconductor structure of the semiconductor device with the supercritical second substance.

2. The supercritical processing method of a semiconductor device according to claim 1, wherein, Under normal temperature and pressure, the first substance is a gaseous inorganic substance, a gaseous organic substance, or a liquid organic substance.

3. The supercritical processing method of a semiconductor device according to claim 2, characterized in that, The first substance is an alkane, an alkene, an alkyne, a saturated halogenated hydrocarbon, an alcohol organic substance, an aldehyde organic substance, an ester organic substance, a ketone organic substance, a phenol organic substance, an ether organic substance, an acyl organic substance, or a carboxylic acid organic substance, and the first substance is a fluid.

4. The supercritical processing method of a semiconductor device according to claim 1, characterized in that, The first substance is carbon dioxide, carbon tetrafluoride, water, nitrogen, ammonia, or an inert gas.

5. The supercritical processing method of a semiconductor device according to claim 1, wherein, The second substance is an alkane, an alkene, or an alkyne.

6. The supercritical processing method of a semiconductor device as described in claim 5, characterized in that, The second substance is methane, ethylene, or acetylene.

7. The supercritical processing method of a semiconductor device according to claim 1, wherein The material of the semiconductor structure is gallium nitride.

8. The supercritical processing method of a semiconductor device according to claim 7, wherein The semiconductor device is a gallium nitride high electron mobility transistor.

9. The supercritical processing method of a semiconductor device according to claim 1, characterized in that, The mass fraction of the second substance in the supercritical reaction chamber is less than or equal to 5%, or the volume fraction of the second substance in the supercritical reaction chamber is less than or equal to 5%.

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