High-heat-conductivity amorphous nitride coating as well as preparation method and application thereof

Abstract

The invention relates to a high-heat-conductivity amorphous nitride coating as well as a preparation method and application thereof. The high-heat-conductivity amorphous nitride coating is composed of crystals and an amorphous matrix, the crystals are distributed in the amorphous matrix in a dispersed mode, the amorphous matrix is SiNx amorphous, and the crystals comprise TiN, BN and AlN. Compared with the prior art, the double-phase nitride coating is prepared by adopting a microstructure precise control technology, the limitation that an amorphous material is generally low in thermal conductivity at 2W / mK is broken through, the highest thermal conductivity of the nitride coating of a SiNx / TiN, SiNx / BN or SiNx / AlN double-phase structure can reach 100W / mK, and the nitride coating can be widely applied to the fields of electronic chips, LEDs, optical devices, lasers and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, and particularly to a high-thermal-conductivity amorphous nitride coating, a preparation method thereof, and an application thereof. Background Art

[0002] Silicon nitride (Si 3 N 4 ) coatings have been widely used in the semiconductor field due to their excellent physical, chemical, and mechanical properties. In chip manufacturing, silicon nitride is often used as a passivation layer to protect the semiconductor surface from environmental pollution; in the lithography process, silicon nitride is used as an anti-reflection coating (ARC) to reduce optical interference and improve the clarity and resolution of patterns; in crystalline silicon solar cells, silicon nitride is used as a surface passivation layer and an anti-reflection coating to improve light absorption and cell efficiency; in metal-oxide-semiconductor (MOS) devices, silicon nitride is used as a gate oxide layer or a dielectric layer to provide excellent electrical insulation.

[0003] In metal-oxide-semiconductor devices, heat dissipation of the gate dielectric is an important issue, especially in high-performance and high-power-density application scenarios. Since the gate dielectrics of MOS devices are usually insulating materials (such as amorphous silicon dioxide, amorphous silicon nitride, hafnium dioxide, etc.), the thermal conductivities of these materials are extremely low, 2-5 W / mK, so effective heat dissipation is crucial for maintaining the performance and reliability of the devices.

[0004] Therefore, there is an urgent need for a new type of gate dielectric coating material, especially a coating with high thermal conductivity while acting as an insulating property, so as to help semiconductor devices dissipate heat faster, avoid the influence of too high operating temperature on device performance, and even cause device damage.

[0005] Chinese Patent CN201710312291.1 discloses a nanocomposite material, a nanocomposite coating for surface strengthening of an aluminum alloy die-casting mold, and an application thereof. The nanocomposite material includes titanium nitride nanocrystals; and a coating layer wrapping the titanium nitride nanocrystals; the coating layer includes amorphous silicon nitride and amorphous nickel, and the amorphous nickel is in a free metal state and is uniformly dispersed in the amorphous silicon nitride. The coating of this patent adds a conductive material nickel and cannot be used as a dielectric layer in semiconductor devices, especially this patent is a coating for surface strengthening of aluminum alloy. Summary of the Invention

[0006] The purpose of the present invention is to provide a high-thermal-conductivity amorphous nitride coating, a preparation method thereof, and an application thereof. The thermal conductivity of the amorphous nitride coating is as high as 100 W / mK, and the high-thermal-conductivity amorphous nitride coating can be applied to devices represented by metal-oxide-semiconductors, significantly improving the heat dissipation characteristics of the devices.

[0007] The object of the present invention can be achieved by the following technical solutions:

[0008] A high thermal conductivity amorphous nitride coating, which is composed of crystals and an amorphous matrix, and the crystals are dispersedly distributed in the amorphous matrix.

[0009] The amorphous matrix is SiNx amorphous, and the range of x is 1 to 1.5.

[0010] The crystals include TiN, BN, and AlN.

[0011] Furthermore, the volume fraction percentages of the crystals and the amorphous matrix are 1 to 100:1 to 100, and the high thermal conductivity of the nitride coating is achieved by precisely regulating the dual-phase structure and the proportion of each element.

[0012] The present invention also provides a preparation method for a high thermal conductivity amorphous nitride coating, and the specific steps are as follows:

[0013] S1. Pretreat the substrate;

[0014] S2. Prepare a high thermal conductivity amorphous nitride coating: deposit a high thermal conductivity amorphous nitride coating on the surface of the substrate pretreated in step S1 by magnetron sputtering.

[0015] Furthermore, in step S1, the substrate material is selected from substrates such as silicon wafers, metals, or ceramics.

[0016] Furthermore, in step S1, the method for pretreating the substrate is as follows:

[0017] Fix the substrate in the sample fixture of the magnetron sputtering chamber, evacuate the air and then introduce argon and nitrogen, and obtain the pretreated substrate after heating.

[0018] In the above further step, the vacuum degree is less than or equal to 8.0×10 -6 mBar.

[0019] In the above further step, the flow rate of argon is 20 to 40 sccm, and the flow rate of nitrogen is 10 to 30 sccm.

[0020] In the above further step, the heating temperature is 20 to 500 °C.

[0021] Furthermore, in step S2, the target materials for magnetron sputtering deposition are selected from any one combination of Si target and Ti target, Si target and B target, or Si target and Al target.

[0022] In the above further step, the RF sputtering power of the Si target is 50 - 1000 W.

[0023] The RF sputtering power of the Ti target is 50 - 1000 W,

[0024] The RF sputtering power of the B target is 50 - 1000 W,

[0025] The RF sputtering power of the Al target is 50 - 1000 W.

[0026] Further, in step S2, the thickness of the high - thermal - conductivity amorphous nitride coating deposited on the surface of the pretreated substrate is 1 - 5000 nanometers.

[0027] In addition, the present invention also provides an application of the high - thermal - conductivity amorphous nitride coating in the fields of electronic chips, LEDs, optical devices, lasers, etc.

[0028] Further, the high - thermal - conductivity amorphous nitride coating is used to prepare a mask layer for semiconductor silicon wafers.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. The present invention deposits a nitride coating with a SiNx / TiN, SiNx / BN, or SiNx / AlN biphasic structure with a thickness of 1 - 5000 nanometers on a semiconductor Si wafer or any substrate by using magnetron sputtering.

[0031] 2. The present invention uses a precise microstructure control technology to prepare a biphasic nitride coating, breaking through the limitation of the generally low thermal conductivity of 2 W / mK for amorphous materials. The present invention can achieve a maximum thermal conductivity of 100 W / mK for the nitride coating with a SiNx / TiN, SiNx / BN, or SiNx / AlN biphasic structure, and can be widely applied in the fields of electronic chips, LEDs, optical devices, lasers, etc.

[0032] 3. The preparation method of the high - thermal - conductivity amorphous nitride coating in the present invention is simple and suitable for large - scale industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic structural diagram of the high - thermal - conductivity amorphous nitride coating in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be described in detail below with reference to the drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and gives a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0035] Some embodiments of the present invention will be described in detail below with reference to the drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0036] Example 1:

[0037] This example provides a method for preparing a high-thermal-conductivity amorphous nitride coating, and the specific steps are as follows:

[0038] S1. Pretreat the substrate:

[0039] Place the silicon wafer in the sample fixture of the magnetron sputtering chamber and fix it. Pump the vacuum to 8.0×10 -6 mBar, and introduce argon at a flow rate of 20 sccm and nitrogen at a flow rate of 10 sccm. At the same time, set the heating temperature of the substrate to 300 °C to obtain a pretreated substrate.

[0040] S2. Deposit a SiNx / TiN coating on the surface of the silicon wafer pretreated in step S1 by magnetron sputtering:

[0041] Set the powers applied to the Si target and the Ti target to 80 W and 400 W respectively. The silicon wafer rotates self at a speed of 5 r / min to achieve the co-deposition of Si and Ti. After 1 hour, turn off the power supply to obtain the SiNx / TiN coating.

[0042] Measure the thermal conductivity of the SiNx / TiN coating on the surface of the silicon wafer by the time-domain thermoreflectance method. The thermal conductivity of the SiNx / TiN coating is 23.5 W / mK.

[0043] Example 2:

[0044] This example provides a method for preparing a high-thermal-conductivity amorphous nitride coating, and the specific steps are as follows:

[0045] S1. Pretreat the substrate:

[0046] Place the silicon wafer in the sample fixture of the magnetron sputtering chamber and fix it. Pump the vacuum to 8.0×10 -6 mBar, and introduce argon at a flow rate of 35 sccm and nitrogen at a flow rate of 25 sccm. At the same time, set the heating temperature of the substrate to 500 °C to obtain a pretreated substrate.

[0047] S2. Deposit a SiNx / BN coating on the surface of the silicon wafer pretreated in step S1 by magnetron sputtering:

[0048] Set the powers applied to the Si target and the B target to 120 W and 600 W respectively. The silicon wafer rotates self at a speed of 5 r / min to achieve the co-deposition of Si and B. After 2 hours, turn off the power supply to obtain the SiNx / BN coating.

[0049] Measure the thermal conductivity of the SiNx / BN coating on the surface of the silicon wafer by the time-domain thermoreflectance method. The thermal conductivity of the SiNx / BN coating is 103.2 W / mK.

[0050] Example 3:

[0051] This embodiment provides a method for preparing a high thermal conductivity amorphous nitride coating, and the specific steps are as follows:

[0052] S1. Pretreat the substrate:

[0053] Place the silicon wafer in the sample fixture of the magnetron sputtering chamber and fix it. Evacuate to 8.0×10 -6 mBar, introduce argon at a flow rate of 40 sccm, introduce nitrogen at a flow rate of 18 sccm, and at the same time set the heating temperature of the substrate to 50 °C to obtain a pretreated substrate.

[0054] S2. Deposit a metal SiNx / AlN coating on the surface of the silicon wafer pretreated in step S1 by magnetron sputtering:

[0055] Set the powers applied to the Si target and the Al target to 150 W and 400 W respectively. The silicon wafer rotates self - rotationally at a speed of 5 r / min to achieve the co - deposition of Si and Al. After 1 hour, turn off the power supply to obtain the SiNx / AlN coating.

[0056] Measure the thermal conductivity of the SiNx / AlN coating on the surface of the silicon wafer by the time - domain thermoreflectance method. The thermal conductivity of the SiNx / AlN coating is 68.3 W / mK.

[0057] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A high thermal conductivity amorphous nitride coating, characterized in that: The high thermal conductivity amorphous nitride coating is composed of crystals and an amorphous matrix, wherein the crystals are dispersed in the amorphous matrix. The amorphous matrix is ​​SiNx amorphous, and the range of x is 1 to 1.

5. The crystals include TiN, BN and AlN.

2. The high thermal conductivity amorphous nitride coating according to claim 1, characterized in that: The volume fraction percentage of the crystal and the amorphous matrix is ​​1-100:1-100.

3. A method for preparing a high thermal conductivity amorphous nitride coating according to claim 1 or claim 2, characterized in that: The specific steps are as follows: S1, pretreatment of substrate; S2. Preparation of high thermal conductivity amorphous nitride coating: Deposition of high thermal conductivity amorphous nitride coating on the surface of the substrate pretreated in step S1 by magnetron sputtering.

4. The method for preparing a high thermal conductivity amorphous nitride coating according to claim 3, characterized in that: In step S1, the substrate material is selected from a silicon wafer, a metal or a ceramic substrate.

5. The method for preparing a high thermal conductivity amorphous nitride coating according to claim 3, characterized in that: In step S1, the method for pretreating the substrate is as follows: The substrate is fixed in a sample holder of a magnetron sputtering chamber, argon gas and nitrogen gas are introduced after vacuuming, and the pretreated substrate is obtained after heating.

6. The method for preparing a high thermal conductivity amorphous nitride coating according to claim 5, characterized in that: The vacuum degree is less than or equal to 8.0×10 -6 mBar; The flow rate of the argon gas is 20 to 40 sccm, and the flow rate of the nitrogen gas is 10 to 30 sccm; The heating temperature is 20-500°C.

7. The method for preparing a high thermal conductivity amorphous nitride coating according to claim 3, characterized in that: In step S2, the target material for magnetron sputtering deposition is selected from any combination of Si target material and Ti target material, Si target material and B target material, or Si target material and Al target material.

8. The method for preparing a high thermal conductivity amorphous nitride coating according to claim 7, characterized in that: The RF sputtering power of the Si target is 50-1000W, The radio frequency sputtering power of the Ti target is 50-1000W, The RF sputtering power of the B target is 50-1000W, The radio frequency sputtering power of the Al target is 50-1000W.

9. The method for preparing a high thermal conductivity amorphous nitride coating according to claim 3, characterized in that: In step S2, a high thermal conductivity amorphous nitride coating is deposited on the pretreated substrate surface with a thickness of 1 to 5000 nanometers.

10. Use of the high thermal conductivity amorphous nitride coating according to claim 1 or claim 2 in the fields of electronic chips, LEDs, optical devices and lasers.

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