A liquid-cooled radiator structure based on a diamond microfluidic channel and a manufacturing method thereof

Abstract

The present invention discloses a liquid-cooled radiator structure based on a diamond microchannel, which includes a diamond substrate and a diamond epitaxial layer stacked. A plurality of diamond microchannels with a certain interval are arranged in the diamond substrate, and the diamond epitaxial layer is used to bond the object to be cooled on its surface. The present invention also discloses a manufacturing method of the radiator, which solves the problem that traditional heat sinks cannot be applied in extreme environments such as high temperature, high radiation, and strong corrosion.

Description

Technical Field

[0001] The present invention belongs to the technical field of microelectromechanical systems, and particularly relates to a liquid-cooled radiator structure based on a diamond microchannel and a manufacturing method thereof.

Background Art

[0002] With the powerful functions of electronic devices and the significant improvement of chip processing capabilities, chips will generate astonishing heat, which will weaken the performance of the chips and even reduce their service life. Traditional heat dissipation technologies can no longer meet the heat dissipation requirements. Therefore, one of the main challenges in the semiconductor industry is how to dissipate heat from chips, circuit boards, and systems. The selection of heat dissipation materials and heat dissipation methods becomes very important, and the research and development of new heat dissipation materials have become a necessary and urgent issue.

[0003] Compared with traditional heat dissipation materials such as thermal grease, graphite, and metals reported currently, diamond has an extremely high thermal conductivity and can quickly conduct out the heat of the chips. Diamond also has excellent mechanical, optical, acoustic, electrical, and chemical properties, making it have obvious advantages over other materials in the problem of heat dissipation of high-power optoelectronic devices and being an excellent choice for working in high-temperature, high-radiation, and harsh environments. Currently, high-frequency high-power electronic devices such as gallium nitride and gallium arsenide are all trying to bond with diamond substrates for heat dissipation. If the method of using a diamond substrate to convey a coolant through a microchannel to conduct out the heat will greatly improve the heat dissipation efficiency.

[0004] Due to the extremely high hardness and excellent chemical stability of diamond, it is difficult to achieve its high-precision patterning by conventional semiconductor processes, and fabricating diamond microstructures, especially three-dimensional diamond microstructures, has always been a technical problem.

Summary of the Invention

[0005] The purpose of the present invention is to provide a liquid-cooled radiator structure based on a diamond microchannel and a manufacturing method thereof to solve the problem that traditional heat sinks cannot be applied in extreme environments such as high temperature, high radiation, and strong corrosion.

[0006] The present invention adopts the following technical solutions: A liquid-cooled radiator structure based on a diamond microchannel includes a diamond substrate and a diamond epitaxial layer stacked. A plurality of diamond microchannels with a certain interval are arranged in the diamond substrate, and the diamond epitaxial layer is used to bond an object to be cooled on its surface.

[0007] Further, the diamond substrate is a high-temperature high-pressure substrate, a self-supporting diamond film, or a CVD diamond substrate.

[0008] Further, the diamond microchannel is a groove arranged in the diamond substrate, and the opening of the diamond microchannel is closed by the diamond epitaxial layer.

[0009] Further, the channel width of the diamond microfluidic channel is 1 μm - 100 μm, and the ratio of the channel depth to the channel width of the diamond microfluidic channel is greater than 1:2.

[0010] Further, the epitaxial layer thickness of the diamond epitaxial layer is greater than half of the channel width.

[0011] Further, the object to be cooled is a semiconductor chip bonded to the diamond epitaxial layer.

[0012] The second technical solution adopted by the present invention is a manufacturing method of a liquid-cooled radiator structure based on a diamond microfluidic channel. The method includes the following steps:

[0013] Step 1: Etch a plurality of strip-shaped grooves with a certain interval on the diamond substrate. The strip-shaped grooves are the diamond microfluidic channels;

[0014] Step 2: Epitaxially grow a diamond layer on the surface of the diamond substrate where the grooves are provided.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: realizing a diamond three-dimensional microfluidic channel liquid-cooled heat dissipation structure, enabling the heat of the semiconductor chip to be quickly diffused through the diamond substrate bonded thereto and conducted out through the coolant therein, so that the chip is not affected by temperature problems in terms of working performance.

Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of a liquid-cooled radiator structure based on a diamond microfluidic channel of the present invention.

[0017] Figure 2 It is a schematic diagram of the use state of a liquid-cooled radiator structure based on a diamond microfluidic channel of the present invention.

[0018] Wherein, 1. Diamond substrate, 2. Diamond microfluidic channel, 3. Diamond epitaxial layer, 4. Semiconductor chip, 5. Microfluidic channel depth, 6. Microfluidic channel width, 7. Diamond epitaxial layer thickness.

Detailed Embodiments

[0019] Next, through the drawings and embodiments, the technical solutions of the present invention will be further described in detail.

[0020] The present invention provides a liquid-cooled radiator structure based on a diamond microfluidic channel, as shown in Figure 1 and Figure 2As shown in the figure, it includes a diamond substrate 1 and a diamond epitaxial layer 3 arranged in a stacked manner. A number of diamond microfluidic channels 2 are arranged in the diamond substrate 1. The diamond epitaxial layer 3 is used to bond the object to be cooled on its surface. The object to be cooled is a semiconductor chip 4 or an integrated circuit bonded to the diamond epitaxial layer 3. The heat sink of the present invention uses all-diamond materials, which enables the diamond microfluidic channels 2 not to need other materials such as adhesives to cap and bond them, and diamond has extremely high thermal conductivity, which can ensure good heat dissipation efficiency.

[0021] Among them, the diamond substrate 1 can be a high-temperature and high-pressure substrate, a self-supporting diamond film, or a CVD diamond substrate. The shape of the diamond substrate 1 can be rectangular, circular, elliptical or other shapes.

[0022] The diamond microfluidic channel 2 is a groove arranged in the diamond substrate 1, and the opening of the groove is closed by the diamond epitaxial layer 3. First, deep channels are obtained by selective dry etching, and then the diamond epitaxial layer 3 is laterally epitaxially grown by MPCVD technology to cap the channels, so as to form a complete diamond microfluidic channel 2. This manufacturing process can ensure that no other sacrificial layer materials are introduced when manufacturing the diamond microfluidic channel 2, ensuring the thermal conductivity of the heat sink.

[0023] The channel width 6 of the diamond microfluidic channel 2 is 1 μm - 100 μm, and the ratio of the channel depth 5 to the channel width 6 of the diamond microfluidic channel 2 is greater than 1:2. If the width of the diamond microfluidic channel 2 is too small, it will affect the flow rate of the cooling liquid and thus affect the heat dissipation efficiency; if the width of the diamond microfluidic channel 2 is too large, the epitaxial layer 3 may start to grow from the bottom of the diamond microfluidic channel 2, thus unable to form a microfluidic channel structure; if the aspect ratio of the diamond microfluidic channel 2 is less than 1:2, the epitaxial layer 3 may start to grow from the bottom of the diamond microfluidic channel 2, thus unable to form a microfluidic channel structure.

[0024] The epitaxial layer thickness 7 of the diamond epitaxial layer 3 is greater than half of the channel width 6. If the thickness of the epitaxial layer 3 is less than half of the width of the diamond microfluidic channel 2, the diamond microfluidic channel 2 cannot be closed by lateral epitaxy to form a complete diamond microfluidic channel 2.

[0025] The present invention also provides a manufacturing method for a liquid-cooled heat sink structure based on diamond microfluidic channels, and this method includes the following steps:

[0026] Step 1: Etch a number of strip-shaped grooves with a certain interval on the diamond substrate 1, and the strip-shaped grooves are the diamond microfluidic channels 2. The etching method can be inductively coupled plasma etching, reactive ion etching, focused ion beam etching, etc.

[0027] Step 2: Epitaxially grow a diamond layer 3 on the surface of the diamond substrate 1 where the groove is set. The epitaxial method is MPCVD epitaxy. MPCVD is vapor phase epitaxial growth.

[0028] As Figure 2 shown, after fabricating a liquid-cooled radiator structure based on diamond microchannels, bonding the semiconductor chip to the epitaxial layer 3 enables heat dissipation from the semiconductor chip.

[0029] Example

[0030] As Figure 1 , for the diamond microchannel liquid-cooled radiator, the diamond substrate 1 is an intrinsically grown diamond synthesized under high temperature and high pressure. The diamond microchannels 2 are first fabricated on the diamond substrate 1 by means of magnetron sputtering thin film deposition process, standard photolithography process and dry etching process to form an Al strip array with a thickness of 6 μm, a width of 30 μm and a pitch of 30 μm. Then, through the ICP etching process, the Al strip array is transferred to the surface of the diamond substrate 1. The etching conditions are as follows: the etching gases are oxygen and argon, with gas flow rates of 50 sccm and 20 sccm respectively, the etching power is 800 W, the chamber pressure is 10 mTorr, the etching depth is 20 μm, and the Al strip array is removed with sulfuric acid and nitric acid to form diamond deep grooves on the surface of the diamond substrate 1. Finally, a 100-μm-thick diamond epitaxial layer 3 is laterally epitaxially grown through MPCVD technology to cap the channels, forming a complete diamond microchannel. The growth conditions are as follows: the reaction gases are methane and hydrogen, with gas flow rates of 300 sccm and 300 sccm respectively, the growth pressure is 120 Torr, and the substrate temperature is 900 °C. After growth, the diamond microchannel system is bonded to the semiconductor chip.

[0031] If one wants to apply diamond microchannels in a liquid-cooled radiator, the first difficulty to overcome is how to fabricate diamond microchannels. Therefore, to obtain better heat dissipation performance, the present invention uses an etching method and a lateral growth method to fabricate a liquid-cooled radiator based on diamond microchannels. This radiator, as a heat dissipation substrate for the chip, can greatly improve the heat dissipation efficiency and is also an ideal heat dissipation device for working in extreme environments such as high temperature, high radiation, and strong corrosion. Thus, it solves the problems of overheating and explosion of semiconductor chips caused by heat dissipation problems.

[0032] The present invention realizes a diamond three-dimensional microchannel liquid-cooled heat dissipation structure through an etching method and a lateral growth method. This system, as a heat dissipation substrate for the chip, enables the heat of the chip to be quickly diffused through the diamond substrate and conducted out through the coolant therein, which can greatly improve the heat dissipation efficiency and is also an ideal radiator for working in extreme environments such as high temperature, high radiation, and strong corrosion.

[0033] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A liquid-cooled radiator structure based on a diamond microfluidic channel, characterized in that, It includes a diamond substrate (1) and a diamond epitaxial layer (3) arranged in a stacked manner. A plurality of diamond microfluidic channels (2) with a certain interval are arranged in the diamond substrate (1), and the diamond epitaxial layer (3) is used to bond the object to be cooled on its surface; Among them, the diamond epitaxial layer (3) is epitaxially grown on the surface of the diamond substrate (1) where grooves are provided. Its growth conditions are: the reaction gases are methane and hydrogen, the gas flow rates are 300 sccm and 30 sccm respectively, the growth pressure is 120 Torr, and the substrate temperature is 900 °C; The channel width (6) of the diamond microfluidic channel (2) is 1 μm - 100 μm, and the ratio of the channel depth (5) to the channel width (6) of the diamond microfluidic channel (2) is greater than 1:

2.

2. The liquid-cooled radiator structure based on a diamond microfluidic channel according to claim 1, wherein, The diamond substrate (1) is a high-temperature and high-pressure substrate, a self-supporting diamond film, or a CVD diamond substrate.

3. The liquid-cooled radiator structure based on a diamond microfluidic channel according to claim 1 or 2, characterized in that, The diamond microfluidic channel (2) is a groove arranged in the diamond substrate (1), and the opening of the diamond microfluidic channel (2) is closed by the diamond epitaxial layer (3).

4. The liquid-cooled radiator structure based on a diamond microfluidic channel according to claim 3, wherein, The epitaxial layer thickness (7) of the diamond epitaxial layer (3) is greater than half of the channel width (6).

5. A liquid-cooled radiator structure based on a diamond microfluidic channel according to claim 3 or 4, characterized in that The object to be cooled is a semiconductor chip (4) or an integrated circuit bonded to the diamond epitaxial layer (3).

6. The manufacturing method of a liquid-cooled radiator structure based on a diamond microfluidic channel according to any one of claims 1-5, characterized in that, This method includes the following steps: Step 1: Etch a plurality of strip-shaped grooves with a certain interval on the diamond substrate (1), and the strip-shaped grooves are the diamond microfluidic channels (2); Step 2: Epitaxially grow a diamond epitaxial layer (3) on the surface of the diamond substrate (1) where grooves are provided.

Images