CN115463803A - A chemical vapor deposition device and a method for preparing a high-thickness Parylene-N film - Google Patents

Abstract

The invention provides a chemical vapor deposition device and a preparation method of a high-thickness Parylene-N film, the device comprises an evaporation chamber, a cracking furnace, a deposition chamber and a cold trap connected in sequence through pipelines; the cold trap is connected to the deposition chamber by a vacuum pump The chamber is communicated; the bottom of the deposition chamber is provided with a communication port for communicating with the cold trap, and the communication port is provided with a throttling sheet, and the throttling sheet is used to adjust the size of the communication port; the A cooling platform is also provided in the deposition chamber, the cooling platform is located at the bottom of the deposition chamber, and the cooling platform is used to reduce the temperature of the substrate. The preparation method of the high-thickness Parylene-N film of the present invention, using the device, and by controlling parameters such as cracking temperature and deposition pressure, can realize the rapid deposition of the micron-scale Parylene-N film, and only needs to use common Parylene deposition equipment It can be realized by improving and adjusting parameters, which is beneficial to reduce manufacturing costs.

Description

A chemical vapor deposition device and a method for preparing a high-thickness Parylene-N film

technical field

The invention relates to the technical field of Parylene coating, in particular to a chemical vapor deposition device and a method for preparing a high-thickness Parylene-N film.

Background technique

Parylene (parylene) began to enter the Chinese market in the late 1990s. It is mainly used as a high-purity passivation layer and dielectric layer in the fields of microelectronics and semiconductors, and mixed circuit insulation and isolation protection; it is used as a passivation layer in the MEMS field. Chemical, protective, lubricating and other coatings; as isolation, curing and reinforcement materials in the fields of biomedical anticorrosion and cultural relics protection. The currently used Parylene mainly includes Parylene-N, Parylene-C and Parylene-D, which are highly inert and high-purity in common, and each type has its own characteristics, among which Parylene-N has a high impact At the same time, it has a low dielectric constant independent of frequency, but its deposition rate is low, and it is difficult to form a thick film at one time, which limits the application scenarios and functions of its Parylene-N film.

The existing method of preparing Parylene-N film is roughly as follows: in a vacuum environment, the solid powdery Parylene-N raw material is sublimated into gas after being heated in the evaporation chamber, and the gasified Parylene-N raw material moves towards the cracking under the action of pressure difference. The direction of the chamber moves, and a cracking reaction occurs under the high temperature of the cracking chamber, and the cracked Parylene-N gas enters the deposition chamber to undergo a polymerization reaction to form a Parylene-N film.

After searching found:

The Chinese invention patent with the application publication number CN113102196A discloses a chemical vapor deposition device, a parylene film and a forming method. The chemical vapor deposition device of the invention includes an evaporation chamber, a cracking chamber, a first deposition chamber, A cold well and a vacuum pump, and a second deposition chamber is embedded in the first deposition chamber, and a first through hole smaller than a predetermined size is set on the second deposition chamber. According to the relevant principles of gas flow, by controlling the first through hole The size of the hole is used to control the gas flow state and pressure in the second deposition chamber, which can accurately control the thickness of the parylene film and improve the uniformity of the parylene film.

But this invention still has the following problems: the structure of the deposition chamber is relatively complicated; what is formed is an ultra-thin parylene film with a stable thickness, which can only accurately control the thickness of the parylene film with a thickness below 50nm; and cannot simultaneously Improve deposition efficiency.

Contents of the invention

In view of the defects in the prior art, the purpose of the present invention is to provide a chemical vapor deposition device and a method for preparing a high-thickness Parylene-N film, which can realize rapid deposition of Parylene-N at the micron level, and only needs to be deposited in common Parylene-N It can be realized by improving and adjusting parameters on the equipment, which is beneficial to reduce the manufacturing cost.

The present invention is achieved through the following technical solutions:

According to one aspect of the present invention, a kind of chemical vapor deposition device is provided, comprising an evaporation chamber, a cracking furnace, a deposition chamber and a cold trap connected in sequence through pipelines; the cold trap communicates with the deposition chamber through a vacuum pump; the deposition chamber The bottom of the tank is provided with a communication port for communicating with the cold trap, and the communication port is provided with a throttling plate, and the throttle plate is used to adjust the size of the communication port; the deposition chamber is also provided with a cooling platform , the cooling platform is located at the bottom of the deposition chamber, and the cooling platform is used to reduce the temperature of the substrate.

Preferably, the communication port is a circular hole, the throttling plate is provided with a circular hole, and the diameter of the circular hole is smaller than that of the communication port.

Preferably, the diameter of the circular hole is 3-10mm.

Preferably, the throttling piece is square.

Preferably, it also includes an object stage arranged in the deposition chamber, and the cooling platform is located on the object stage.

Preferably, the height of the stage is 0-12cm.

According to another aspect of the present invention, a method for preparing a high-thickness Parylene-N film is provided, which is realized by using the above-mentioned chemical vapor deposition device, including:

Put the Parylene-N raw material in the evaporation chamber, heat the Parylene-N raw material to vaporize and evaporate, and form Parylene-N gas;

The Parylene-N gas enters the cracking furnace, where a cracking reaction occurs at 630-660°C and is cracked into active monomers;

The active monomer enters the deposition chamber, and the pressure in the deposition chamber is controlled to be 4-5.8KPa. The active monomer is deposited and polymerized on the substrate in the deposition chamber to form a Parylene-N film.

Preferably, the heating to vaporize the Parylene-N raw material includes: heating to 175° C. to vaporize the Parylene-N raw material.

Preferably, the active monomer is deposited and polymerized on the substrate in the deposition chamber, including: controlling the temperature of the substrate to be -5-10° C. through a cooling platform.

Preferably, the thickness of the Parylene-N film is on the order of microns, and the single deposition thickness of the active monomer is above 15um.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention can control the deposition rate of Parylene-N by setting a throttling plate and a cooling platform in the deposition chamber, and optimize the deposition parameters such as the temperature of the cracking furnace and the pressure of the deposition chamber, so that the deposition rate of Parylene-N is relatively low. Slow materials can also achieve faster deposition rates, and the film composition is pure, good uniformity and excellent performance.

2. The present invention does not make major changes to the vapor deposition equipment. It only needs to improve and adjust parameters on the existing common Parylene deposition equipment, and the deposition efficiency can be greatly improved under the premise of ensuring the performance of the film layer. The deposition thickness can reach more than 15um.

3. The deposition rate of the present invention is stable, and the thickness of the Parylene-N film can be controlled by controlling the deposition parameters and the diameter of the throttle plate, thereby reducing the difficulty of controlling the film thickness of the Parylene-N film.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

FIG. 1 is a schematic structural view of the interior of a deposition chamber according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a chemical vapor deposition device according to an embodiment of the present invention;

3 is a schematic structural view of the bottom of the deposition chamber according to an embodiment of the present invention;

FIG. 4 is a schematic structural view of a throttle plate according to an embodiment of the present invention;

In the figure: 1 is a throttling plate, 2 is a cooling platform, 3 is a stage, and 4 is a deposition chamber.

detailed description

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

The Parylene-N vapor deposition technology in the prior art does not give clear suggestions on the deposition process parameters of the Parylene-N type. The present invention improves its process parameters by starting from the deposition principle and process of the Parylene-N type. The deposition efficiency is improved under the premise of Parylene-N film performance.

The embodiment of the present invention provides a kind of chemical vapor deposition device, with reference to Fig. 1-2, this device comprises the evaporation chamber, cracking furnace, deposition chamber 4 and cold trap that are connected successively by pipeline; Cold trap communicates with deposition chamber 4 through vacuum pump; The bottom of the chamber 4 is provided with a communication port for communicating with the cold trap, and the communication port is provided with a throttling piece 1, which is used to adjust the size of the communication port, and the throttling piece 1 is used to control the size of the communication port, thereby The deposition rate of the Parylene-N film can be controlled; a cooling platform 2 is also provided in the deposition chamber 4, and the cooling platform 2 is located at the bottom of the chamber of the deposition chamber 4, and the cooling platform 2 is used to reduce the temperature of the substrate, because the lower the substrate temperature , the higher the deposition rate, the lower the surface temperature of the substrate through the cooling platform 2, without affecting the performance and uniformity of the Parylene-N film, the deposition rate of the Parylene-N film can be increased, so that the control of the Parylene-N film can be achieved. purpose of film thickness.

In some embodiments, the communication port at the bottom of the deposition chamber 4 is a circular hole, as shown in Figure 3-4, correspondingly, the throttle plate 1 is provided with a circular hole to ensure uniform air flow, and the diameter of the circular hole is less than The diameter of the communication port, and the diameter of the circular hole is controllable.

In order to better control the size of the communication port, in some preferred embodiments, the diameter of the circular hole is 3-10mm, and the throttling plate 1 is square. The larger the diameter of the circular hole of the throttle plate 1, the higher the deposition efficiency.

Of course, in order to cover the circular hole at the bottom of the deposition chamber, in some other embodiments, the throttling plate 1 can also adopt other shapes, and setting a circular hole on the throttle plate 1 of other shapes can realize the same effect as that of the present invention. The same function as in the embodiment, the embodiment of the present invention does not specifically limit the shape of the throttle plate 1 .

In some embodiments, a stage 3 disposed in the deposition chamber 4 is also included, and the cooling platform 2 is located on the stage 3 . The object stage 3 includes an object stage and a plurality of support columns for supporting the object stage; according to the actual situation and the specific requirements of deposition, the height of the object stage 3 can be adjusted through different heights of the support columns. The higher the height of the stage 3, the lower the roughness of the deposited Parylene-N film, that is, the higher the quality of the deposited Parylene-N film, but the rate of deposition will slow down, and the stage 3 will be raised every 1cm. The surface roughness of the deposited Parylene-N film will be reduced by 5nm, but the deposition rate will be reduced by about 100nm/hour. By setting the appropriate height of the stage 3, the deposition efficiency can be improved while ensuring the performance of the film layer.

The lower the height of the substrate in the deposition chamber 4, the higher the deposition efficiency. The higher the height of the substrate in the deposition chamber 4, the better the film quality. , In some preferred embodiments, the height of the stage 3 is 0-12cm.

The embodiment of the present invention also provides a method for preparing a high-thickness Parylene-N film, which is realized by using the chemical vapor deposition device in the above embodiment, and the method includes:

S1. Put the Parylene-N raw material in the evaporation chamber, and heat to vaporize the Parylene-N raw material to form Parylene-N gas;

S2. Parylene-N gas enters the cracking furnace, where a cracking reaction occurs at 630-660°C and is cracked into active monomers;

S3. The active monomer enters the deposition chamber, and the pressure in the deposition chamber is controlled to be 4-5.8KPa, which can ensure the quality of the Parylene-N film while increasing the deposition rate. The active monomer is deposited and polymerized on the substrate in the deposition chamber to form Parylene-N film.

In order to vaporize the Parylene-N raw material, in some embodiments, heating to vaporize the Parylene-N raw material includes: heating to 175° C. to vaporize the Parylene-N raw material.

By lowering the surface temperature of the substrate through the cooling platform, the deposition rate of the Parylene-N film can be increased without affecting the performance and uniformity of the Parylene-N film. In some embodiments, the active monomer is deposited and polymerized on the substrate in the deposition chamber, comprising: controlling the temperature of the substrate to be -5˜10° C. through a cooling platform.

In this embodiment, by controlling the temperature of the cracking furnace, the pressure of the deposition chamber, the temperature of the substrate, and setting a throttling plate at the communication port of the deposition chamber, while improving the deposition efficiency of the Parylene-N film, the Parylene-N film can also be maintained Excellent performance and uniformity, and the single deposition thickness of the active monomer can be more than 15um, the thickness of the Parylene-N film is micron, in some preferred embodiments, the thickness of the Parylene-N film is more than 5um.

In addition, the embodiments of the present invention can accurately control the thickness of the Parylene-N film by controlling the pressure of the deposition chamber, the temperature of the substrate, the height of the substrate in the deposition chamber, and the diameter of the circular hole of the throttle plate, so that the Parylene-N film can be realized high efficiency and high quality deposition.

Combining with the chemical vapor deposition apparatus in the above-mentioned examples, the preparation method of the high-thickness Parylene-N film in the examples of the present invention will be further described in detail through examples and comparative examples.

Example

This embodiment provides a method for preparing a high-thickness Parylene-N film. In order to prepare a high-thickness Parylene-N film with low surface roughness, high shape retention and no bubbles, the method includes the following steps:

S1. Put the Parylene-N raw material in the evaporation chamber and heat it to 175°C to make it sublime until the gas enters the cracking furnace.

S2. The Parylene-N gas that enters the cracking furnace from the evaporation chamber is in the cracking furnace at 630-660°C, after a cracking reaction occurs, an active monomer is formed.

S3. The active monomer enters the deposition chamber, and the pressure of the deposition chamber is set to 4-5.8Kpa. The active monomer is deposited and polymerized. Due to the restrictive effect of the throttle plate on the gas flow, only a small amount of Parylene-N gas will be sucked in by the vacuum pump. Near the cold trap, in the deposition chamber, the cooling platform lowers the substrate temperature to -5~10°C, which can accelerate the deposition rate of Parylene-N at the same time. In this embodiment, the thickness of a single deposition can reach more than 15um, and the deposition rate can reach 1um /per hour.

The Parylene-N film prepared by the above method can be formed in a single deposition in a short time, which solves the problem that multiple depositions are required when preparing a high-thickness Parylene-N film, which leads to the problem of film delamination. At the same time, the surface roughness of the film is less than 40nm, and good shape retention, without any bubbles inside the film.

In some preferred embodiments, the cracking furnace temperature is controlled at 650°C, the deposition chamber pressure is at 4-5.8KPa, the substrate temperature is -5°C to 10°C, and a throttling plate is set at the communication port of the deposition chamber for deposition. The diameter of the round hole of the throttling sheet is 3-10mm. Through the setting of these process parameters and the setting of the throttle plate, the thickness of a single deposition can reach more than 15um, the deposition rate can reach 1um/hour, the roughness of the Parylene-N film is about 40nm, and there is no bubble inside the film.

During the deposition process, keeping other parameters constant, by controlling the pressure of the deposition chamber in the range of 4-5.8KPa, increasing the pressure of the deposition chamber can prevent the Parylene-N gas from being pumped into the cold trap too quickly, the higher the pressure , the higher the deposition efficiency, the deposition rate will increase by 0.08um/hour for every increase in pressure of 0.1KPa.

During the deposition process, keep other parameters constant, and control the temperature through the cooling platform to reduce the temperature of the substrate, thereby controlling the thickness of the Parylene-N film. The lower the substrate temperature, the higher the deposition efficiency, at -5 ~ 10 ° C Within the range, the deposition rate will increase by 0.12um/hour for every 1°C decrease in the substrate temperature.

During the deposition process, keeping other parameters constant, by controlling the height of the substrate on the stage and controlling the thickness of the Parylene-N film, the lower the height of the substrate in the deposition chamber, the higher the deposition efficiency. In addition, the deposition The higher the height of the substrate in the chamber, the better the film quality.

During the deposition process, keeping other parameters constant, through different throttle plates, each type of throttle plate has a different circular hole diameter, the larger the circular hole diameter of the throttle plate, the higher the deposition efficiency, and the diameter range of the circular hole is 3 Within -10mm, the deposition rate will increase by 0.15um/hour for every 1mm increase in the diameter of the circular hole.

comparative example

This comparative example provides a method for preparing a Parylene-N film, including: gasification and evaporation of raw materials, pyrolysis in a cracking furnace, deposition of a polymerized Parylene-N film in a deposition chamber, and no throttle plate is provided at the communication port of the deposition chamber.

It was found that: without a throttling plate and without taking control of the process parameters in the above examples, Parylene-N is difficult to deposit normally, and the deposition rate is about 60nm/hour, which is much lower than the deposition rate in the above examples; And it is difficult to achieve a single film thickness of more than 1um.

The reason for the above phenomenon is that if there is no throttling plate, Parylene-N will be decomposed into gas at high temperature. Unlike Parylene-C gas, the gas density of Parylene-N is small, and the gasified Parylene-N is deposited During the process, it will be sucked away by a vacuum pump, causing a large amount of Parylene-N raw materials to adhere to the cold trap, making it difficult to increase the deposition rate and deposit a thicker Parylene-N film in a single pass. For deposition process parameters such as cracking furnace temperature, substrate temperature, and deposition chamber pressure, it is difficult to achieve high efficiency and high-quality deposition of Parylene-N films without using the parameters in the above examples, and the deposition rate is difficult to achieve 1um/hour.

The chemical vapor deposition device and the preparation method of the high-thickness Parylene-N film in the above-mentioned embodiments of the present invention can be controlled by controlling the temperature of the cracking furnace, the pressure of the deposition chamber, the temperature of the substrate, and setting the throttling plate at the communication port of the deposition chamber. While significantly improving the deposition efficiency of the Parylene-N film, the excellent performance and uniformity of the Parylene-N film are maintained; in addition, by controlling the pressure of the deposition chamber, the temperature of the substrate, the height of the substrate in the deposition chamber and the round hole of the throttle plate Diameter, the thickness of Parylene-N film can be precisely controlled. Compared with the traditional Parylene-N deposition method, the Parylene-N deposition rate in the embodiment of the present invention is significantly improved, and can achieve micron-level Parylene-N rapid deposition, and only needs to be improved on the existing common Parylene deposition equipment It can be realized by adjusting and adjusting parameters, which is beneficial to reduce the manufacturing cost.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The above-mentioned preferred features can be used in any combination if they do not conflict with each other.

Claims (10)

1. A chemical vapor deposition device is characterized by comprising an evaporation chamber, a cracking furnace, a deposition chamber and a cold trap which are connected in sequence through pipelines; the cold trap is communicated with the deposition chamber through a vacuum pump; the bottom of the deposition chamber is provided with a communication port communicated with the cold trap, and a throttle sheet is arranged at the communication port and used for adjusting the size of the communication port; still be equipped with the cooling platform in the deposit room, the cooling platform is located the cavity bottom of deposit room, the cooling platform is used for reducing the temperature of substrate.

2. The chemical vapor deposition apparatus according to claim 1, wherein the communication port is a circular hole, and a circular hole is formed in the throttle plate, and the diameter of the circular hole is smaller than that of the communication port.

3. The chemical vapor deposition apparatus of claim 2, wherein the circular aperture has a diameter of 3-10mm.

4. The chemical vapor deposition apparatus of claim 2, wherein the throttle plate is square.

5. The chemical vapor deposition apparatus of any of claims 1-4, further comprising a stage disposed within the deposition chamber, wherein the cool-down stage is positioned on the stage.

6. The chemical vapor deposition apparatus according to claim 5, wherein the stage has a height of 0 to 12cm.

7. A method for preparing a high thickness Parylene-N film using the chemical vapor deposition apparatus of any one of claims 1 to 6, comprising:

putting the Parylene-N raw material into an evaporation chamber, heating to evaporate the Parylene-N raw material to form Parylene-N gas;

the Parylene-N gas enters a cracking furnace, and is subjected to cracking reaction at 630-660 ℃ in the cracking furnace to be cracked into active monomers;

and the active monomer enters a deposition chamber, the pressure in the deposition chamber is controlled to be 4-5.8KPa, and the active monomer is deposited and polymerized on the substrate in the deposition chamber to form a Parylene-N film.

8. The method of producing a high thickness Parylene-N film in accordance with claim 7, wherein the heating vaporizes the Parylene-N feedstock including: heating to 175 ℃ vaporizes the Parylene-N feedstock.

9. The method of claim 7, wherein the depositing and polymerizing the reactive monomer onto the substrate in the deposition chamber comprises: the temperature of the substrate is controlled to be-5-10 ℃ by the cooling platform.

10. The method for preparing a high thickness Parylene-N film according to claim 9, wherein the thickness of the Parylene-N film is in the micron order, and the single deposition thickness of the reactive monomer is above 15 um.

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