Manufacturing method of high power component assembly

Abstract

This invention relates to a method for manufacturing a high-power device assembly, comprising the following steps: (a) forming a release layer on a first substrate, the release layer being made of a two-dimensional material; (b) forming a nucleation layer on the release layer; (c) growing a high-power device on the nucleation layer; (d) bonding a support plate to the high-power device via a bonding layer; (e) removing the first substrate and the release layer, and removing any remaining release layer from the surface of the nucleation layer; (f) bonding a second substrate to the nucleation layer; and (g) removing the bonding layer and the support plate. Therefore, this manufacturing method can use a non-silicon carbide substrate to reduce manufacturing costs, achieve commercially viable quality requirements, and can be combined with second substrates of different characteristics as needed, effectively expanding the application areas.

Description

Technical Field

[0001] This invention relates to semiconductor devices, and in particular to a method for manufacturing a high-power device assembly. Prior Technology

[0002] High-power components, such as gallium nitride high electron mobility transistors (GaN HEMTs) or gallium nitride Schottky barrier diodes used in high-frequency power applications, primarily use single-crystal silicon (Si), single-crystal silicon carbide (SiC), or single-crystal sapphire as the substrate material for epitaxy during manufacturing. Among these traditional substrate materials, the lattice constant and thermal expansion coefficient of silicon and gallium nitride differ greatly (17% and 54%, respectively), which easily leads to defects or even cracking in gallium nitride. Sapphire has poor heat dissipation. Only single-crystal silicon carbide has a lower lattice constant mismatch and better thermal conductivity, making it a better choice for epitaxial quality. However, single-crystal silicon carbide substrates are very expensive, especially for high-frequency power applications where silicon carbide epitaxial substrates must be semi-insulated. For example, the price of a 6-inch wafer is about 50 times that of a silicon substrate. Therefore, the industry has long needed to find alternative solutions. Summary of the Invention

[0003] One objective of this invention is to provide a method for manufacturing a high-power component assembly, which can use a non-silicon carbide substrate to reduce manufacturing costs, achieve commercial quality requirements, and can be combined with substrates of different characteristics as needed to effectively expand the application fields.

[0004] To achieve the above objectives, the high-power device assembly manufacturing method of the present invention includes the following steps: (a) forming a release layer on a first substrate, the release layer being made of a two-dimensional material; (b) forming a nucleation layer on the release layer; (c) growing a high-power device on the nucleation layer; (d) bonding a support plate to the high-power device via a bonding layer; (e) removing the first substrate and the release layer, and removing any remaining release layer from the surface of the nucleation layer; (f) bonding a second substrate to the nucleation layer; and (g) removing the bonding layer and the support plate. Therefore, the manufacturing method of the present invention can use a non-silicon carbide substrate to reduce manufacturing costs, achieve commercially viable quality requirements, and can be combined with second substrates of different characteristics as needed, effectively expanding the application areas. Simple Explanation of the Diagram

[0005] Figure 1 is a schematic diagram of step (a) of a high-power component assembly manufacturing method according to a preferred embodiment of the present invention; Figure 2 is a schematic diagram of steps (a) to (g) of a preferred embodiment of the high-power component assembly manufacturing method of the present invention; and Figure 3 is a schematic diagram illustrating the application of a high-power component assembly manufactured by a preferred embodiment of the present invention. Implementation

[0006] The technical content and features of the present invention will be described in detail below with reference to a preferred embodiment and accompanying drawings. As shown in Figures 1 and 2, a method for manufacturing a high-power component assembly 1 provided by a preferred embodiment of the present invention is illustrated. The manufacturing method includes the following steps:

[0007] Step (a): First, a release layer 14 is formed on a first substrate 10. The material of the first substrate 10 can be c-plane sapphire, miscut c-plane sapphire toward A, silicon wafer, silicon coated with silicon dioxide (SiO 2 / Si), silicon coated with silicon nitride (SiN x / Si), or other materials that can be easily epitaxially processed. In this embodiment, c-plane sapphire is used. The material of the release layer 14 is a two-dimensional material, such as molybdenum disulfide (MoS 2), tungsten disulfide (WS 2), molybdenum diselenide (MoSe 2), tungsten diselenide (WSe 2), or other two-dimensional layered materials with a hexagonal crystal structure. In this embodiment, molybdenum disulfide is used. There are two ways to form the release layer 14. Method 1 (a1) involves depositing an oxide layer 12 with a thickness of about 1-2 nm, such as molybdenum trioxide (MoO 3), molybdenum dioxide (MoO 2), or tungsten trioxide (WO 3), on the surface of the first substrate 10 by electron gun evaporation or sputtering. In this embodiment, molybdenum trioxide is used. Then, hydrogen sulfide (H 2S) or hydrogen selenide (H 2Se) is introduced into a low-pressure furnace tube (not shown). In this embodiment, hydrogen sulfide is used, and the gas pressure is maintained at 10-200 torr and the temperature at 500-900°C. This allows the oxide to be sulfided or selenized to form molybdenum disulfide (MoS 2) or tungsten diselenide (WSe 2). In this embodiment, molybdenum disulfide is formed. Method 2 (a2) involves directly depositing material onto the surface of the first substrate 10 using chemical vapor deposition (CVD). For example, tungsten disulfide (WS2) can be synthesized using tungsten hexafluoride (WF6) or tungsten hexacarbonyl (W(CO)6) and hydrogen sulfide (H2S) as precursors; tungsten diselenide (WSe2) can be synthesized using tungsten hexafluoride (WF6) or tungsten hexacarbonyl (W(CO)6) and hydrogen selenide (H2Se) as precursors; molybdenum disulfide (MoS2) can be synthesized using molybdenum hexafluoride (MoF6) or molybdenum hexacarbonyl (Mo(CO)6) and hydrogen sulfide (H2S) as precursors; and molybdenum diselenide (MoSe) can be synthesized using molybdenum hexafluoride (MoF6) or molybdenum hexacarbonyl (Mo(CO)6) and hydrogen selenide (H2Se) as precursors. 2) The synthesis temperature for chemical vapor deposition is 500~900°C, and the gas pressure is 1~50 torr. However, in other embodiments, the release layer 14 may be formed in other ways.

[0008] Step (b): A nucleation layer 16 is formed on the release layer 14. The nucleation layer 16 is made of aluminum nitride (AlN), aluminum gallium nitride (AlGaN), gallium nitride (GaN), or other compounds with similar properties. In this embodiment, aluminum nitride is grown by sputtering at a temperature <500°C. However, in other embodiments, the nucleation layer 16 may be formed in other ways.

[0009] Step (c): A high-power device 18 is grown on the nucleation layer 16. The high-power device 18 can be a gallium nitride high electron mobility transistor (GaN HEMTs), a gallium nitride Schottky barrier diode, a light-emitting diode (LED), a blue laser diode, a green laser diode, or other known high-power devices. In this embodiment, the gallium nitride high electron mobility transistor is grown by metal-organic chemical vapor deposition (MOCVD), including structures such as mesa, ohmic contact, source, drain, gate, and passivation layer. However, this is a known method and structure, and will not be described in detail. In addition, there are no restrictions on the method of growing the high-power device 18.

[0010] Step (d): Take a support plate 20 and attach it to the high-power component 18 via a bonding layer 22. The support plate 20 provides support and is made of copper. In other embodiments, copper alloy, titanium tungsten (TiW), gold, or other materials may also be used. The bonding layer 22 is made of epoxy resin, polyimide (PI), polymethyl methacrylate (PMMA), or other materials. It is used to combine the support plate 20 with the high-power component 18 to facilitate the subsequent cutting and removal of the first substrate 10.

[0011] Step (e): Remove the first substrate 10 and the release layer 14, and remove the remaining release layer 14 from the surface of the nucleation layer 16. The separation method is to immerse the substrate in ammonia (NH4OH) to weaken the bond between the two-dimensional material such as molybdenum disulfide and the first substrate 10, thereby easily removing the first substrate 10 and the release layer 14. Other acidic or alkaline solutions can also be used as the immersion solution, such as buffered oxide etchant (BOE), sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), formic acid (HCOOH), acetic acid (CH3COOH), or sodium hydroxide (NaOH). The remaining release layer 14 is removed by etching with carbon tetrafluoride plasma (CF4plasma) or sulfur hexafluoride plasma (SF6plasma), but other methods can also be used for removal.

[0012] Step (f): Take a second substrate 24 and bond it to the nucleation layer 16. Any conventional bonding method can be used, such as silver paste, thermally conductive adhesive, tin or other soldering materials to bond the second substrate 24 to the nucleation layer 16. The second substrate 24 is used to replace the first substrate 10 to provide better thermal conductivity or other properties. Its material can be gold (Au), gold alloy, copper (Cu), copper alloy, copper tungsten (CuW), copper tungsten alloy, copper-molybdenum copper (CuMoCu), copper-molybdenum copper alloy, polycrystalline or single crystalline diamond, aluminum nitride ceramic (AlN ceramic), silicon carbide ceramic (SiC ceramic), beryllium oxide ceramic (BeO ceramic) or other materials with support or thermal conductivity. In this way, the high-quality nucleation layer 16 and the high-power device 18 can be grown on the first substrate 10. Since the first substrate 10 cannot have high thermal conductivity or other characteristics required for the application, it is replaced by the second substrate 24. This not only gives the substrate of the high-power device 18 the required high thermal conductivity and other characteristics to improve the working efficiency of the high-power device 18, but also effectively reduces the cost.

[0013] Step (g): Remove the bonding layer 22 and the support plate 20. In practice, the bonding layer 22 is first dissolved with acetone, and then the support plate 20 can be removed. In other embodiments, chloroform, trichloroethylene or other solvents can also be used. This completes the entire preparation process of the high-power component assembly 1.

[0014] In actual mass production, the assembly of most of the high-power components 18 can be divided into most of the individual high-power components 18 before or after step (e).

[0015] As shown in Figure 3, there are two packaged samples of the high-power component assembly 1 manufactured according to the above method: Packaged sample one (p1) connects the high-power component assembly 1 to the contact 32 on a circuit board 30 with a passive component matching circuit using wire bonding technology. The second substrate 24 is bonded to the circuit board 30. The second substrate 24 with good thermal conductivity can quickly conduct heat to the circuit board 30. Packaged sample two (p2) connects the high-power component assembly 1 directly to the contact 32 on the circuit board 30 using flip-chip bonding. This method is particularly suitable for circuits with a large proportion of passive components, because passive components do not require expensive substrates, and flip-chip bonding can be performed after confirming that the characteristics of the passive circuit are not problematic. This packaging method can effectively improve the yield and significantly reduce the cost.

[0016] Because the layers of two-dimensional materials are bonded by weak van der Waals forces and are easy to peel off, the concept of van der Waals epitaxy eliminates the need for expensive silicon carbide substrates for epitaxy. The high-power device 18 formed on the first substrate 10, such as sapphire, can also meet commercial requirements in terms of quality. Furthermore, the high-power device 18 can be replaced by the second substrate 24 with specific characteristics instead of the first substrate 10 on which it was originally grown. On the one hand, the first substrate 10 can be reused, and on the other hand, the second substrate 24 can be made of materials with different properties as needed. This makes the high-power device assembly 1 not only have good heat dissipation and low cost, but also applicable to passive circuits, silicon integrated circuits, or other circuits, effectively expanding the application field and thus achieving the purpose of this invention.

[0017] Based on the design spirit of this invention, the manufacturing method of the high-power component assembly 1 may have other variations. All variations that can be easily conceived should be covered by the scope of the patent application of this invention.

[0018] 1 High-power component assembly 10 First substrate 12 Oxide layer 14 Release layer 16 nucleation layers, 18 high-power components, 20 support plates 22 Bonding layer 24 Second substrate 30 circuit boards with 32 contacts

Claims

1. A method for manufacturing a high-power device assembly, comprising the following steps: (a) forming a release layer on a first substrate, the release layer being made of a two-dimensional material; (b) forming a nucleation layer on the release layer; (c) growing a high-power device on the nucleation layer; (d) bonding a support plate to the high-power device via a bonding layer; (e) removing the first substrate and the release layer, and removing any remaining release layer from the surface of the nucleation layer; (f) bonding a second substrate to the nucleation layer, the second substrate being made of gold (Au), gold alloy, copper (Cu), copper alloy, copper-tungsten (CuW), copper-tungsten alloy, copper-molybdenum-copper (CuMoCu), copper-molybdenum-copper alloy, polycrystalline or single-crystalline diamond, aluminum nitride ceramic (AlN ceramic), silicon carbide ceramic (SiC ceramic), or beryllium oxide ceramic (BeO ceramic); and (g) removing the bonding layer and the support plate.

2. The high-power component assembly manufacturing method as described in claim 1, wherein the material of the first substrate is c-plane sapphire, miscut c-plane sapphire toward A, silicon wafer, silicon plated with silicon dioxide (SiO2 / Si), or silicon plated with silicon nitride (SiNx / Si).

3. The method for manufacturing a high-power component assembly as described in claim 1, wherein the two-dimensional material is molybdenum disulfide (MoS2), tungsten disulfide (WS2), molybdenum diselenide (MoSe2), or tungsten diselenide (WSe2).

4. The method for manufacturing a high-power component assembly as described in claim 1, wherein the two-dimensional material has a hexagonal crystal structure.

5. The method for manufacturing a high-power device assembly as described in claim 1, wherein the nucleation layer is made of aluminum nitride (AlN), aluminum gallium nitride (AlGaN), gallium nitride (GaN), or a combination thereof.

6. A method for manufacturing a high-power device assembly as described in claim 1, wherein the high-power device is a gallium nitride high electron mobility transistor (GaN HEMTs), a gallium nitride Schottky barrier diode, a light-emitting diode (LED), a blue laser diode, or a green laser diode.

7. The method for manufacturing a high-power component assembly as described in claim 1, wherein the support plate is made of copper, copper alloy, titanium tungsten (TiW), or gold.

8. The high-power component assembly manufacturing method as described in claim 1, wherein in step (e), ammonia (NH4OH), buffered oxide etchant (BOE), sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), formic acid (HCOOH), acetic acid (CH3COOH), or sodium hydroxide (NaOH) is used to weaken the bond between the first substrate and the release layer.

9. In the high-power component assembly manufacturing method as described in claim 1, the release layer is removed by plasma etching in step (e).

10. The method for manufacturing a high-power component assembly as claimed in claim 1, wherein the bonding layer is made of epoxy resin, polyimide (PI), or polymethyl methacrylate (PMMA).

11. The method for manufacturing a high-power component assembly as described in claim 1, wherein in step (f) the second substrate is bonded to the nucleation layer by means of silver paste, thermally conductive adhesive, tin or a combination thereof.

12. In the high-power component assembly manufacturing method as described in claim 1, in step (g), the bonding layer is first dissolved using acetone, chloroform, or trichloroethylene to remove the support plate.

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