Method for preparing gallium nitride diamond CMOS (Complementary Metal Oxide Semiconductor) device by using adapter plate and application

Abstract

The invention provides a method for preparing a gallium nitride diamond CMOS (Complementary Metal-Oxide-Semiconductor Transistor) device by utilizing an adapter plate and application. The method comprises the following steps: (1) preparing Cu-Pads on the surface of a planar p-diamond MOSFET wafer and the surface of a planar GaN-HEMT MOSFET wafer respectively, and obtaining a planar p-diamond MOSFET device containing a first Cu-Pads and a planar GaN-HEMT MOSFET device containing a second Cu-Pads; preparing Cu-Pads on the surface of the aluminum oxide ceramic adapter plate wafer so as to obtain an aluminum oxide ceramic adapter plate containing third Cu-Pads; and (2) respectively aligning the first Cu-Pads and the second Cu-Pads with the third Cu-Pads in opposite directions, and carrying out Cu-Cu bonding connection at a preset temperature and a preset pressure. Therefore, the gallium nitride diamond CMOS device with high performance can be prepared.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a method and application of preparing a gallium nitride diamond CMOS device by using an adapter plate, and in particular to a method and application of preparing a gallium nitride diamond CMOS device by using an adapter plate and Cu-Cu bonding. Background Art

[0002] CMOS (Complementary Metal-Oxide-Semiconductor) devices are core components of modern electronic technology and are widely used in various electronic devices. The core of CMOS circuits is to use the complementary characteristics of P-type MOSFET and N-type MOSFET to realize logical functions. It is currently the most widely used integrated circuit technology. Almost all modern microprocessors, microcontrollers, memory chips and various other integrated circuits are manufactured using CMOS technology.

[0003] Among them, silicon-based materials are widely used in CMOS devices due to their excellent electrical properties, thermal stability and mature manufacturing processes. They are characterized by low cost, high integration, and miniaturization. However, silicon-based materials also have their shortcomings: 1) Silicon-based CMOS devices have low thermal conductivity and are prone to performance degradation and failure at high temperatures. 2) The physical properties of silicon materials limit high-frequency and high-power applications.

[0004] With the development of technology, gallium nitride (GaN) materials and diamond materials have also been applied to CMOS devices. Gallium nitride diamond CMOS devices (GaN diamond CMOS devices) are semiconductor devices that combine gallium nitride (GaN) and diamond materials, and are compatible with complementary metal oxide semiconductor (CMOS) processes. This device utilizes the excellent electrical properties of GaN materials and the efficient heat dissipation performance of diamond materials, aiming to achieve high-performance, high-power density and high-reliability electronic devices. However, there are very large technical bottlenecks in growing high-quality GaN films on diamond wafers. (4) The process flow for preparing GaN diamond CMOS is complex and incompatible with the existing CMOS device manufacturing process. The device preparation cost is high and the product yield is low, which limits its large-scale application. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. The present invention proposes a method for preparing a gallium nitride diamond CMOS device using an adapter plate and a Cu-Cu bonding process, the typical feature of which is that the metal pads of a planar GaN-HEMT MOSFET device and the metal pads of a p-diamond MOSFET device are integrated onto an alumina (Al2O3) ceramic adapter plate to form a CMOS by means of a high temperature and external pressure. The method provided by the present invention, with the aid of an adapter plate, can combine the high electron mobility, high breakdown voltage and high frequency characteristics of GaN with the extremely high thermal conductivity, high breakdown voltage and chemical inertness of diamond, and prepare a CMOS device with ultra-high power density, ultra-high energy conversion efficiency, high thermal stability and high frequency and high power at the same time.

[0006] Specifically, the present invention provides the following technical solutions:

[0007] A first aspect of the present invention provides a method for preparing a gallium nitride diamond CMOS device using Cu-Cu bonding, comprising:

[0008] (1) preparing Cu-Pads on the surfaces of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer, respectively, so as to obtain a planar p-diamond MOSFET device containing the first Cu-Pads and a planar GaN-HEMT MOSFET device containing the second Cu-Pads;

[0009] Preparing Cu-Pads on the surface of the alumina ceramic adapter plate to obtain an alumina ceramic adapter plate containing at least two Cu-Pads;

[0010] (2) The first Cu-Pads of the planar p-diamond MOSFET device containing the first Cu-Pads and the second Cu-Pads of the planar GaN-HEMT MOSFET device containing the second Cu-Pads are respectively aligned with the Cu-Pads of the alumina ceramic adapter plate containing at least two Cu-Pads, and Cu-Cu bonding is performed at a predetermined temperature and a predetermined pressure to obtain a gallium nitride diamond CMOS device.

[0011] According to an embodiment of the present invention, step (2) further comprises:

[0012] (2-1) The first Cu-Pads of the planar p-diamond MOSFET device containing the first Cu-Pads and the second Cu-Pads of the planar GaN-HEMT MOSFET device containing the second Cu-Pads are respectively aligned with the alumina ceramic adapter plate containing at least two Cu-Pads, and a pressure of 50 N / cm3 is applied under the protection of an inert gas at a vacuum pressure of 0.1 Pa to 0.5 Pa. 2 ~150N / cm 2 The Cu-Cu bonding is performed by applying a pressure and heating at a temperature of 200 to 400°C for 20 to 50 minutes;

[0013] (2-2) Annealing is performed, and then the bonded product is heated at a temperature of 200 to 400° C. for 40 to 100 minutes under the protection of an inert gas.

[0014] According to an embodiment of the present invention, the step (1) of preparing Cu-Pads on the surface of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer respectively to obtain a planar p-diamond MOSFET device containing first Cu-Pads and a planar GaN-HEMT MOSFET device containing second Cu-Pads comprises:

[0015] (1-1) growing dielectric layers on the surfaces of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer respectively;

[0016] (1-2) etching the dielectric layers respectively so as to form vertical metal connection holes at the metal pads of the planar p-diamond MOSFET wafer and the planar GaN-HEMT MOSFET wafer respectively;

[0017] (1-3) continuing to perform etching treatment on the dielectric layers respectively to remove portions of the dielectric layers so as to form patterns in the dielectric layers respectively;

[0018] (1-4) depositing Ti and Cu on the entire surface of the planar p-diamond MOSFET wafer and the planar GaN-HEMTMOSFET wafer containing the pattern, respectively, close to the pattern side, so as to form a Ti layer and a Cu layer, wherein the Ti layer and the Cu layer are distributed in the dielectric layer, the Cu layer is located on the surface of the Ti layer, and the surface of the formed Cu layer is polished;

[0019] (1-5) repeating the above steps (1-1) to (1-4) to respectively obtain a planar p-diamond MOSFET device containing the first Cu-Pads and a planar GaN-HEMT MOSFET device containing the second Cu-Pads;

[0020] The method of preparing Cu-Pads on the surface of the alumina ceramic adapter plate to obtain an Al2O3 ceramic adapter plate containing the third Cu-Pads comprises:

[0021] (1-a) growing a dielectric layer on the surface of an alumina ceramic adapter plate;

[0022] (1-b) etching the dielectric layer to remove a portion of the dielectric layer so as to form a pattern in the dielectric layer;

[0023] (1-c) Ti and Cu are deposited on the entire surface of the alumina ceramic transfer plate containing the pattern close to the pattern side to form a Ti layer and a Cu layer, wherein the Ti layer and the Cu layer are distributed in the dielectric layer, and the Cu layer is located on the surface of the Ti layer, and the surface of the formed Cu layer is polished to obtain an alumina ceramic transfer plate containing at least two Cu-Pads.

[0024] According to an embodiment of the present invention, the thickness of the dielectric layer is 1.5-4 microns.

[0025] According to an embodiment of the present invention, the dielectric layer is obtained by oxide deposition or polymer spin coating.

[0026] According to an embodiment of the present invention, the oxide is selected from at least one of silicon dioxide, hafnium dioxide, aluminum oxide, and silicon nitride.

[0027] According to an embodiment of the present invention, the polymer is selected from at least one of polyimide, benzocyclobutene, polybenzo-bisoxazole and fluorinated aromatic AL-X 2010.

[0028] According to an embodiment of the present invention, the surface roughness Ra of the Cu surface after polishing is less than 1.0 nm.

[0029] According to an embodiment of the present invention, the polishing process is performed by chemical mechanical polishing.

[0030] According to an embodiment of the present invention, the etching process in step (1-2), step (1-3) and step (1-b) is performed by photolithography and oxide etching respectively.

[0031] According to an embodiment of the present invention, step (1-4) or step (1-c) is deposited by thermal evaporation, magnetron sputtering or electron beam evaporation to form the Ti layer and the Cu layer.

[0032] A second aspect of the present invention provides a gallium nitride diamond CMOS device, comprising:

[0033] A planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer, and an alumina ceramic adapter plate containing at least two Cu-Pads arranged opposite to the planar p-diamond MOSFET wafer and the planar GaN-HEMT MOSFET wafer;

[0034] A first dielectric layer and a second dielectric layer, wherein the first dielectric layer is disposed on a surface of the planar p-diamond MOSFET wafer close to the alumina ceramic adapter plate, and the second dielectric layer is disposed on a surface of the planar GaN-HEMTMOSFET wafer close to the alumina ceramic adapter plate;

[0035] A first Cu-Pad and a second Cu-Pad, wherein the first Cu-Pad is located on the surface of the planar p-diamond MOSFET wafer and is distributed in the first dielectric layer, and the second Cu-Pad is located on the surface of the planar GaN-HEMTMOSFET wafer and is distributed in the second dielectric layer, and the first Cu-Pad and the second Cu-Pad are respectively aligned with one of the at least two Cu-Pads of the alumina ceramic adapter plate, and Cu-Cu bonding is performed respectively.

[0036] According to an embodiment of the present invention, the thickness of the first dielectric layer and the second dielectric layer are respectively 3-8 microns.

[0037] According to an embodiment of the present invention, the first dielectric layer and the second dielectric layer are obtained by oxide deposition or polymer spin coating.

[0038] According to an embodiment of the present invention, the oxide is selected from at least one of silicon dioxide, hafnium dioxide, aluminum oxide, and silicon nitride.

[0039] According to an embodiment of the present invention, the polymer is selected from at least one of polyimide, benzocyclobutene, polybenzo-bisoxazole and fluorinated aromatic AL-X 2010.

[0040] According to an embodiment of the present invention, the provided GaN-diamond CMOS device is prepared according to the method described in the first aspect above.

[0041] The third aspect of the present invention provides the application of the gallium nitride diamond CMOS device described in the second aspect in the electronic field.

[0042] The beneficial effects achieved by the present invention are at least:

[0043] (1) The fabrication of GaN diamond CMOS devices was achieved by using the process technology of transfer plate and Cu-Cu bonding. The alumina ceramic transfer plate, planar GaN-HEMT MOSFET device and p-diamond MOSFET device can be manufactured separately by this technology, avoiding the technical difficulties of directly epitaxially growing GaN thin films on diamond wafers and the influence of GaN / diamond interface defects on device performance.

[0044] (2) Reduce the complexity of the GaN diamond CMOS process flow, reduce production difficulty and cost, and improve the product yield of GaN diamond CMOS.

[0045] (3) The method provided by the present invention adopts an adapter plate and Cu-Cu bonding technology to prepare a gallium nitride diamond CMOS device. With the help of a ceramic adapter plate, Cu-Cu bonding is completed, which makes it convenient to set up circuits on the ceramic adapter plate, and it is more convenient to form a circuit system; and to complete the solution of more complex CMOS circuits. The provided gallium nitride diamond CMOS device is used in high-speed digital circuits and high-frequency communication systems, which can significantly reduce signal transmission losses, improve signal integrity, and ensure the quality of high-speed data transmission. In high-power integrated circuits and power electronic devices, it can effectively dissipate heat, reduce chip junction temperature, and improve device reliability and life. In addition, the Cu-Cu bonding technology is relatively mature, and the relevant process equipment and materials are relatively complete, which is convenient for promotion and application in actual process routes. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A method for preparing Cu-Pads on the surface of a MOSFET device is provided according to an embodiment of the present invention.

[0047] Figure 2 A metal connecting wire is formed on an alumina (Al2O3) ceramic transfer plate according to an embodiment of the present invention.

[0048] Figure 3 Cu-Cu bonding is accomplished for the planar p-diamond MOSFET device and the planar GaN-HEMTMOSFET device provided according to embodiments of the present invention.

[0049] Figure 4 This is a schematic diagram of preparing a dielectric layer according to Example 1 of the present invention.

[0050] Figure 5 Schematic diagram of the preparation of metal connection holes provided according to Example 1 of the present invention.

[0051] Figure 6It is a schematic diagram of rewiring in a dielectric layer according to Embodiment 1 of the present invention.

[0052] Figure 7 Metal deposition and CMP polishing are provided according to Example 1 of the present invention.

[0053] Figure 8 Rewiring and forming Cu-Pads in the dielectric layer provided according to Example 1 of the present invention.

[0054] Fig. 9 The schematic diagram is a surface layout and cross-sectional morphology diagram of a planar GaN-HEMT MOSFET device provided according to Embodiment 1 of the present invention.

[0055] Fig.10 It is a schematic diagram of forming a dielectric layer on an alumina ceramic adapter plate substrate according to Example 1 of the present invention.

[0056] Fig.11 A pattern is formed in the dielectric layer of the alumina ceramic interposer according to Embodiment 1 of the present invention.

[0057] Fig.12 The diagram is a diagram of metal deposition and CMP polishing on an alumina ceramic transfer plate according to Example 1 of the present invention.

[0058] Fig.13 This is a schematic diagram of the surface layout and cross-sectional morphology of the Al2O3 ceramic transfer plate provided according to Example 1 of the present invention, wherein the left figure is a top view of the prepared alumina ceramic transfer plate, and the right figure is a front view of the prepared alumina ceramic transfer plate.

[0059] Fig.14 It is a schematic structural diagram of a gallium nitride diamond CMOS device provided according to an embodiment of the present invention, wherein reference numeral 1 is an alumina ceramic adapter board, reference numeral 2 is a dielectric layer on the alumina ceramic adapter board, reference numeral 3 is Cu-Pads on the alumina ceramic adapter board, reference numeral 4 is a second Cu-Pads, reference numeral 5 is a second dielectric layer, reference numeral 6 is a planar GaN-HEMTMOSFET wafer, reference numeral 7 is a planar p-diamond MOSFET wafer, reference numeral 8 is a first dielectric layer, and reference numeral 9 is a first dielectric layer. DETAILED DESCRIPTION

[0060] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0061] In this article, the terms "first", "second" and "third" are used for descriptive purposes only and are not used to indicate order or importance.

[0062] The present invention provides a method for preparing a gallium nitride diamond CMOS device by using Cu-Cu bonding, comprising:

[0063] (1) preparing Cu-Pads on the surfaces of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer, respectively, so as to obtain a planar p-diamond MOSFET device containing the first Cu-Pads and a planar GaN-HEMT MOSFET device containing the second Cu-Pads;

[0064] Preparing Cu-Pads on the surface of the alumina ceramic adapter plate substrate to obtain an alumina ceramic adapter plate containing third Cu-Pads;

[0065] (2) The first Cu-Pads of the planar p-diamond MOSFET device containing the first Cu-Pads and the second Cu-Pads of the planar GaN-HEMT MOSFET device containing the second Cu-Pads are respectively aligned with the Cu-Pads of an alumina ceramic adapter plate containing at least two Cu-Pads, and Cu-Cu bonding is performed at a predetermined temperature and a predetermined pressure to obtain a gallium nitride diamond CMOS device.

[0066] With the help of a ceramic adapter board, the connection of a CMOS circuit can be completed, and the connection of a more complex circuit can be completed more conveniently on the ceramic adapter board. The provided method, after completing the circuit connection on the ceramic adapter board, "covers" the Cu-Pads of the gallium nitride and diamond devices on the Cu-Pads of the ceramic adapter board to complete the preparation of the CMOS device.

[0067] According to an embodiment of the present invention, step (2) further comprises:

[0068] (2-1) The first Cu-Pads of the planar p-diamond MOSFET device containing the first Cu-Pads and the second Cu-Pads of the planar GaN-HEMT MOSFET device containing the second Cu-Pads are respectively aligned with the alumina ceramic adapter plate containing at least two Cu-Pads, and a pressure of 50 N / cm3 is applied under the protection of an inert gas at a vacuum pressure of 0.1 Pa to 0.5 Pa. 2 ~150N / cm 2 The Cu-Cu bonding is performed by applying a pressure and heating at a temperature of 200 to 400°C for 20 to 50 minutes;

[0069] (2-2) Annealing is performed, and then the bonded product is heated at a temperature of 200 to 400° C. for 40 to 100 minutes under the protection of an inert gas.

[0070] According to an embodiment of the present invention, the step (1) of preparing Cu-Pads on the surface of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer respectively to obtain a planar p-diamond MOSFET device containing first Cu-Pads and a planar GaN-HEMT MOSFET device containing second Cu-Pads comprises:

[0071] (1-1) growing dielectric layers on the surfaces of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer respectively;

[0072] (1-2) etching the dielectric layers respectively so as to form vertical metal connection holes at the metal pads of the planar p-diamond MOSFET wafer and the planar GaN-HEMT MOSFET wafer respectively;

[0073] (1-3) continuing to perform etching treatment on the dielectric layers respectively to remove portions of the dielectric layers so as to form patterns in the dielectric layers respectively;

[0074] (1-4) depositing Ti and Cu on the entire surface of the planar p-diamond MOSFET wafer and the planar GaN-HEMTMOSFET wafer containing the pattern, respectively, close to the pattern side, so as to form a Ti layer and a Cu layer, wherein the Ti layer and the Cu layer are distributed in the dielectric layer, the Cu layer is located on the surface of the Ti layer, and the surface of the formed Cu layer is polished;

[0075] (1-5) repeating the above steps (1-1) to (1-4) to respectively obtain a planar p-diamond MOSFET device containing the first Cu-Pads and a planar GaN-HEMT MOSFET device containing the second Cu-Pads;

[0076] The step of epitaxially growing Cu-Pads on the surface of the alumina ceramic adapter plate substrate to obtain an alumina ceramic adapter plate containing at least two Cu-Pads comprises:

[0077] (1-a) growing a dielectric layer on the surface of an alumina ceramic adapter plate substrate;

[0078] (1-b) etching the dielectric layer to remove a portion of the dielectric layer so as to form a pattern in the dielectric layer;

[0079] (1-c) Ti and Cu are deposited on the entire surface of the alumina ceramic transfer plate substrate containing the pattern, which is close to the pattern side, to form a Ti layer and a Cu layer, wherein the Ti layer and the Cu layer are distributed in the dielectric layer, and the Cu layer is located on the surface of the Ti layer, and the surface of the formed Cu layer is polished to obtain an alumina ceramic transfer plate containing at least two Cu-Pads.

[0080] The thickness of the dielectric layer mentioned is 1.5 to 4 micrometers; it can be prepared by various methods, for example, by oxide deposition or polymer spin coating.

[0081] The oxides mentioned include but are not limited to silicon dioxide, hafnium dioxide (HfO2), aluminum oxide (Al2O3), silicon nitride (Si3N4), etc. The polymers mentioned include but are not limited to polyimide (PI), such as PWDC 1000 (DowCorning), which is a high-performance polyimide material with excellent high temperature resistance and mechanical properties; benzocyclobutene (BCB), such as cyclotene 4024-40 (Dow Chemical); polybenzo-bisoxazole (PBO), such as HD-8930 (HD Micro Systems); fluorinated aromatic AL-X 2010 (Asahi Glass Corporation), etc.

[0082] According to a specific embodiment, the surface roughness Ra of the Cu surface after polishing is less than 1.0 nm. The polishing process can be carried out by a method commonly used in the art, for example, the polishing process can be carried out by chemical mechanical polishing. Chemical mechanical polishing (CMP) is an ultra-precision polishing technology that combines mechanical friction and chemical corrosion. Its basic principle is to achieve the flattening and smoothing of the workpiece surface through the combined effect of mechanical grinding and chemical liquid dissolution. The main process includes: (1) Chemical corrosion: The oxidant and catalyst in the polishing liquid react chemically with the workpiece surface material to form a layer of easily removable chemical reaction film on the workpiece surface; (2) Mechanical grinding: The abrasive particles and polymer materials in the polishing pad remove the chemical reaction film through mechanical action, so that the workpiece surface is exposed again; (3) Repeated alternation: Chemical action and mechanical action are performed alternately to finally complete the polishing of the workpiece surface. The polishing liquid used can be purchased commercially and usually includes: ultrafine abrasive particles (such as SiO2, used for physical grinding); chemical corrosive agents (such as nitric acid, hydrofluoric acid, etc., used for chemical corrosion); dispersants and stabilizers (used to maintain the stability and uniformity of the polishing liquid) and pH adjusters (to control the pH value of the polishing liquid).

[0083] According to a specific embodiment of the present invention, the etching process is performed by photolithography and oxide etching in step (1-2), step (1-3), and step (1-b), respectively;

[0084] The deposition of the metal layer Ti layer and the Cu layer can be carried out by methods commonly used in the art, including but not limited to thermal evaporation, magnetron sputtering or electron beam evaporation. Thermal evaporation can be achieved by a high-temperature wire rod or a boat-type evaporator, with simple equipment requirements and low cost. Magnetron sputtering is a technology that uses a magnetic field to control the movement of metal ions. This method can achieve deposition in a high vacuum environment, avoid gas collisions and reactions, and thus obtain high-quality films. Electron beam evaporation uses an electron beam to heat the material, causing it to evaporate and condense into a thin film on a substrate.

[0085] The thickness of the formed Ti layer may be 25 nm, and the thickness of the Cu layer may be 1.5 micrometers.

[0086] A second aspect of the present invention provides a gallium nitride diamond CMOS device, comprising:

[0087] A planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer, and an alumina ceramic adapter plate containing at least two Cu-Pads arranged opposite to the planar p-diamond MOSFET wafer and the planar GaN-HEMT MOSFET wafer;

[0088] A first dielectric layer and a second dielectric layer, wherein the first dielectric layer is disposed on a surface of the planar p-diamond MOSFET wafer close to the alumina ceramic adapter plate, and the second dielectric layer is disposed on a surface of the planar GaN-HEMTMOSFET wafer close to the alumina ceramic adapter plate;

[0089] A first Cu-Pad and a second Cu-Pad, wherein the first Cu-Pad is located on the surface of the planar p-diamond MOSFET wafer and is distributed in the first dielectric layer, and the second Cu-Pad is located on the surface of the planar GaN-HEMTMOSFET wafer and is distributed in the second dielectric layer, and the first Cu-Pad and the second Cu-Pad are respectively aligned with one of the at least two Cu-Pads of the alumina ceramic adapter plate, and Cu-Cu bonding is performed respectively.

[0090] The gallium nitride diamond CMOS device provided by the present invention combines the high power and high frequency characteristics of GaN with the excellent heat dissipation capability of diamond, and can achieve extremely high power density and high frequency operation; and the low on-resistance of GaN and the good heat dissipation of diamond jointly improve the energy conversion efficiency; through effective heat dissipation and material stability, the reliability of the device in high power and high temperature environments is jointly ensured. Both GaN and diamond have very high breakdown voltage, which further improves the voltage resistance of the device.

[0091] The thickness of the first dielectric layer and the second dielectric layer mentioned above are 3-8 micrometers respectively; the first dielectric layer and the second dielectric layer are obtained by oxide deposition or polymer spin coating.

[0092] The oxides mentioned include but are not limited to at least one of silicon dioxide, hafnium dioxide, aluminum oxide, and silicon nitride; the polymer is selected from at least one of polyimide, benzocyclobutene, polybenzo-bisoxazole, and fluorinated aromatic AL-X 2010.

[0093] The gallium nitride diamond CMOS device provided by the present invention is characterized by electrical properties, thermal properties (such as thermal conductivity, junction temperature peak), reliability (such as radiation tolerance, long-term stability, etc.) and physical properties (such as X-ray diffraction). The results show that the gallium nitride diamond CMOS device provided by the present invention, with the help of an adapter plate and Cu-Cu bonding, shows faster switching speed and higher efficiency in high-frequency and high-voltage applications compared to simple unbonded gallium nitride or unbonded diamond devices. Moreover, due to the integration of diamond devices, the heat dissipation capacity of the gallium nitride device is significantly improved, so that the provided gallium nitride diamond CMOS device can still maintain a low junction temperature at high power density.

[0094] The provided GaN-diamond CMOS devices can be applied to multiple fields, including but not limited to high power amplifiers, switching power supplies and RF power amplifiers, 5G base stations, satellite communications and radar systems, electric vehicle power conversion systems and charging infrastructure, solar inverters and wind power generation systems, laptop high-efficiency chargers, military communications, navigation, electronic warfare and aerospace applications, as well as oil drilling and deep space exploration.

[0095] The technical solution of the present invention is described below by specific embodiments. It should be noted that these embodiments are only used to facilitate the understanding of those skilled in the art and should not be regarded as limiting the scope of protection of the present invention.

[0096] Example 1

[0097] Example 1 Gallium nitride diamond CMOS devices are prepared using an adapter plate and Cu-Cu bonding process. First, Cu-Pads are prepared on the surfaces of planar GaN-HEMT MOSFET devices and planar p-diamond MOSFET devices respectively; metal connecting wires are formed on an aluminum oxide (Al2O3) ceramic adapter plate. Then, the planar GaN-HEMT MOSFET device and the planar p-diamond MOSFET device are integrated on the Al2O3 ceramic adapter plate through a Cu-Cu bonding process to complete the preparation of the CMOS device.

[0098] (1) Reference Figure 1 As shown, Cu-Pads are prepared on the surface of planar GaN-HEMT MOSFET devices and planar p-diamond MOSFET devices.

[0099] The details include:

[0100] 1) Prepare an 8-inch planar GaN-HEMT MOSFET (planar p-diamond MOSFET) wafer.

[0101] 2) A 5 μm thick SiO2 dielectric layer is grown on the surface of a planar GaN-HEMT MOSFET (planar p-diamond MOSFET) wafer by plasma enhanced chemical vapor deposition (PECVD); the schematic diagram of the structure is shown in FIG. Figure 4 shown.

[0102] 3) Through photolithography and oxide etching processes, vertical metal connection holes are formed at the metal pads of the n-type GaN MOSFET (p-type diamond MOSFET) wafer. Figure 5 shown.

[0103] 4) Again through the photolithography and oxide etching process, a pattern is formed in the dielectric layer to facilitate rewiring in the dielectric layer. Its structure is as follows Figure 6 shown.

[0104] 5) Sputter Ti and Cu and electrochemically deposit (ECD) Cu on the entire wafer to complete the wiring in the dielectric layer. The wafer surface is polished using a chemical mechanical polishing (CMP) process. The process diagram is shown in the figure below. Figure 7 shown.

[0105] 6) Repeat steps 2) to 5) to rewire the dielectric layer and obtain Cu-Pads on the wafer surface. The process steps are as follows: Figure 8 shown.

[0106] 7) The wafer is cut into individual devices, and the rewiring is completed in the dielectric layer to prepare the surface layout and cross-sectional morphology of the planar GaN-HEMT MOSFET device (planar p-diamond MOSFET device) with Cu-Pads. Fig. 9 (a) and 9(b).

[0107] (2) Reference Figure 2 As shown, metal connecting wires are formed on an alumina (Al2O3) ceramic transfer plate.

[0108] Specifically include:

[0109] 1) Prepare an 8-inch Al2O3 ceramic adapter plate.

[0110] 2) A 5 μm thick SiO2 dielectric layer is grown on the Al2O3 ceramic transfer plate by plasma enhanced chemical vapor deposition (PECVD); the schematic diagram of the structure is shown in Fig.10 shown.

[0111] 3) Through photolithography and oxide etching processes, a dielectric layer pattern is formed on the Al2O3 ceramic adapter to facilitate wiring in the dielectric layer. Fig.11 shown.

[0112] 4) Sputter Ti and Cu and electrochemically deposit (ECD) Cu on the entire Al2O3 ceramic transfer board to complete the wiring in the dielectric layer. The surface of the alumina transfer board is polished using a chemical mechanical polishing (CMP) process. The process diagram is shown in the figure below. Fig.12 shown.

[0113] 5) The surface layout and cross-sectional morphology of the adapter board with Cu-Pads after wiring and preparation on the Al2O3 ceramic substrate are shown in the figure. Fig.13 (a) and 13(b).

[0114] (3) Reference Figure 3 As shown, the planar GaN-HEMTMOSFET device and the planar p-diamond MOSFET device are integrated on the Al2O3 ceramic adapter plate through the Cu-Cu bonding process to complete the preparation of the CMOS device.

[0115] The Cu-Pads of GaN and diamond MOSFETs were aligned with the Cu-Pads on the alumina ceramic adapter plate, and a pressure of 25kN was applied to the wafer under the protection of N2 atmosphere with a pressure of 0.1Pa, and the wafer was heated at 300℃ for 30min. After bonding, the wafer was annealed and heated at 300℃ for 60min under the protection of N2 atmosphere. The prepared GaN diamond CMOS device is shown in FIG. Fig.14 shown.

[0116] Characterization shows that the GaN-diamond CMOS device provided has faster switching speed and higher efficiency in high-frequency and high-voltage applications compared to simple unbonded GaN or unbonded diamond devices. In addition, due to the integration of diamond devices, the heat dissipation capacity of GaN devices is significantly improved, so that the GaN-diamond CMOS device provided can still maintain a low junction temperature at high power density.

[0117] In the description of this specification, the description with reference to the terms "one embodiment", "specific implementation", "implementation", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations on the present invention. Those of ordinary skill in the art can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a gallium nitride diamond CMOS device using an adapter plate, characterized in that: include: (1) preparing Cu-Pads on the surfaces of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer, respectively, so as to obtain a planar p-diamond MOSFET device containing the first Cu-Pads and a planar GaN-HEMT MOSFET device containing the second Cu-Pads; Preparing Cu-Pads on the surface of the alumina ceramic adapter plate substrate to obtain an alumina ceramic adapter plate containing at least two Cu-Pads; (2) The first Cu-Pads of the planar p-diamond MOSFET device containing the first Cu-Pads and the second Cu-Pads of the planar GaN-HEMT MOSFET device containing the second Cu-Pads are respectively aligned with the Cu-Pads of the alumina ceramic adapter plate containing at least two Cu-Pads, and Cu-Cu bonding is performed at a predetermined temperature and a predetermined pressure to obtain a gallium nitride diamond CMOS device.

2. The method according to claim 1, characterized in that Step (2) further comprises: (2-1) The first Cu-Pads of the planar p-diamond MOSFET device containing the first Cu-Pads and the second Cu-Pads of the planar GaN-HEMT MOSFET device containing the second Cu-Pads are respectively aligned with the alumina ceramic adapter plate containing at least two Cu-Pads, and a pressure of 50 N / cm3 is applied under the protection of an inert gas at a vacuum pressure of 0.1 Pa to 0.5 Pa. 2 ~150N / cm 2 The Cu-Cu bonding is performed by applying a pressure and heating at a temperature of 200 to 400°C for 20 to 50 minutes; (2-2) Annealing is performed, and then the bonded product is heated at a temperature of 200 to 400° C. for 40 to 100 minutes under the protection of an inert gas.

3. The method according to claim 1, characterized in that The step (1) of preparing Cu-Pads on the surface of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer respectively to obtain a planar p-diamond MOSFET device containing first Cu-Pads and a planar GaN-HEMT MOSFET device containing second Cu-Pads comprises: (1-1) growing dielectric layers on the surfaces of a planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer respectively; (1-2) etching the dielectric layers respectively so as to form vertical metal connection holes at the metal pads of the planar p-diamond MOSFET wafer and the planar GaN-HEMT MOSFET wafer respectively; (1-3) continuing to perform etching treatment on the dielectric layers respectively to remove portions of the dielectric layers so as to form patterns in the dielectric layers respectively; (1-4) depositing Ti and Cu on the entire surface of the planar p-diamond MOSFET wafer and the planar GaN-HEMT MOSFET wafer containing the pattern, respectively, close to the pattern side, so as to form a Ti layer and a Cu layer, wherein the Ti layer and the Cu layer are distributed in the dielectric layer, the Cu layer is located on the surface of the Ti layer, and the surface of the formed Cu layer is polished; (1-5) repeating the above steps (1-1) to (1-4) to respectively obtain a planar p-diamond MOSFET device containing the first Cu-Pads and a planar GaN-HEMT MOSFET device containing the second Cu-Pads; The method of preparing Cu-Pads on the surface of the alumina ceramic adapter plate substrate to obtain an alumina ceramic adapter plate containing at least two Cu-Pads comprises: (1-a) growing a dielectric layer on the surface of an alumina ceramic adapter plate substrate; (1-b) etching the dielectric layer to remove a portion of the dielectric layer so as to form a pattern in the dielectric layer; (1-c) Ti and Cu are deposited on the entire surface of the alumina ceramic transfer plate substrate close to the pattern side including the pattern to form a Ti layer and a Cu layer, wherein the Ti layer and the Cu layer are distributed in the dielectric layer, and the Cu layer is located on the surface of the Ti layer, and the surface of the formed Cu layer is polished to obtain an alumina ceramic transfer plate containing at least two Cu-Pads.

4. The method according to claim 3, characterized in that The thickness of the dielectric layer is 1.5 to 4 microns; Optionally, the dielectric layer is obtained by oxide deposition or polymer spin coating; Optionally, the oxide is selected from at least one of silicon dioxide, hafnium dioxide, aluminum oxide, and silicon nitride; Optionally, the polymer is selected from at least one of polyimide, benzocyclobutene, polybenzo-bisoxazole and fluorinated aromatic AL-X 2010.

5. The method according to claim 3, characterized in that: The surface roughness Ra of the Cu surface after polishing is less than 1.0 nm; Optionally, the polishing process is performed by chemical mechanical polishing.

6. The method according to claim 3, characterized in that: Step (1-2), step (1-3), and step (1-b) are respectively subjected to the etching process by photolithography and oxide etching; Optionally, step (1-4) or step (1-c) is deposited by thermal evaporation, magnetron sputtering or electron beam evaporation to form a Ti layer and a Cu layer.

7. A gallium nitride diamond CMOS device, characterized in that: include: A planar p-diamond MOSFET wafer and a planar GaN-HEMT MOSFET wafer, and an alumina ceramic adapter plate containing at least two Cu-Pads arranged opposite to the planar p-diamond MOSFET wafer and the planar GaN-HEMT MOSFET wafer; A first dielectric layer and a second dielectric layer, wherein the first dielectric layer is disposed on a surface of the planar p-diamond MOSFET wafer close to the alumina ceramic adapter plate, and the second dielectric layer is disposed on a surface of the planar GaN-HEMT MOSFET wafer close to the alumina ceramic adapter plate; The first Cu-Pads and the second Cu-Pads are respectively aligned with one of the at least two Cu-Pads of the alumina ceramic adapter plate, and Cu-Cu bonding is performed respectively.

8. The GaN-diamond CMOS device according to claim 7, characterized in that: The thickness of the first dielectric layer and the second dielectric layer are 3 to 8 microns respectively; Optionally, the first dielectric layer and the second dielectric layer are obtained by oxide deposition or polymer spin coating; Optionally, the oxide is selected from at least one of silicon dioxide, hafnium dioxide, aluminum oxide, and silicon nitride; Optionally, the polymer is selected from at least one of polyimide, benzocyclobutene, polybenzo-bisoxazole and fluorinated aromatic AL-X 2010.

9. The GaN-diamond CMOS device according to claim 7, characterized in that: Prepared according to the method according to any one of claims 1 to 6.

10. Application of the gallium nitride diamond CMOS device according to any one of claims 7 to 9 in the field of electronics.

Images