CN104746036B - Thin film packaging method - Google Patents

Abstract

The invention relates to a thin film encapsulation method, comprising the following steps: depositing an organic functional layer by a PECVD method; depositing an inorganic functional layer by a pulse flow PECVD method, wherein the pulse flow PECVD method is to input a precursor in the PECVD method through a pulse input method ; Deposit several thin films with alternating structure of organic functional layers and inorganic functional layers. The controllable speed and rapid deposition of high-quality films are realized.

Description

A kind of film encapsulation method

technical field

The invention relates to the field of device packaging, in particular to a film packaging method.

Background technique

Electronic devices, especially organic electronic devices, are particularly sensitive to moisture and oxygen in the air, so organic devices need to be packaged to ensure the performance and service life of the device. At present, the main method of flexible organic electronic device packaging is to directly fabricate a flexible film structure with excellent water and oxygen permeability on the surface of the device. Since the flexible polymer film has a very limited ability to block water and oxygen penetration, while the dense and pinhole-free inorganic film has a high ability to block water and oxygen, but when it reaches a certain thickness, it shows a rigid structure and is easily broken. Most of the research on flexible packaging is based on the Barix ^TM packaging technology with organic/inorganic multilayer alternate composite structure. The main methods to realize the organic/inorganic alternating structure are: (1) PECVD method, such as the PECVD method adopted by Suzhou Nanotechnology Institute of the Chinese Academy of Sciences, by changing the composition of the process gas during the deposition process, thereby depositing an organic/inorganic alternating structure without a clear interface; (2) ) ALD method, such as BENEQ company using ALD method to deposit Al ₂ O ₃ /ZrO ₂ multilayer film to realize the packaging of organic electronic devices. Among the above two methods, the PECVD method has a faster film deposition rate, but because the PECVD method is based on island growth, there will be defects at the island boundary, etc., so the quality of the deposited inorganic film is relatively poor; the ALD method is based on the atomic layer growth without defects, although high-quality inorganic thin films can be deposited, but the deposition rate is too slow, generally not exceeding 2nm/min, and multilayer films such as Al ₂ O ₃ /ZrO ₂ prepared by ALD method are due to Al ₂ O _{3 Both} ZrO2 and ZrO2 are inorganic thin films, which show rigidity when the thickness is constant, so they are not strictly flexible packaging. Therefore, high-efficiency, high-quality, and flexible thin-film packaging has become the most important bottleneck restricting the development of organic electronic devices.

Contents of the invention

In order to solve the above technical problems, the present invention provides a thin film encapsulation method, which deposits organic functional layers by PECVD method and deposits inorganic functional layers by pulse flow PECVD method, which realizes the controllable speed and rapid deposition of higher quality thin films.

The method includes the following steps: depositing an organic functional layer by PECVD method; depositing an inorganic functional layer by a pulse flow PECVD method, wherein the pulse flow PECVD method is to input the precursor in the PECVD method through pulse input; depositing several organic functional layers and inorganic functional layers thin film with alternating layers.

In the above technical scheme, the plasma material for depositing the organic functional layer includes SiO _x C _{y Hz} , SiN _x C _{y Hz} or SiO _x N _y C _z H _m , and the precursor used in the PECVD method includes HMDSO , TEOS, the precursor is continuously injected during the deposition process.

In the above technical solution, the thickness of each organic functional layer deposited is 100-2000 nm.

In the above technical solution, the plasma material for depositing the inorganic functional layer includes SiO _x , SiN _x , SiO _x N _y or SiO _x C _y H _z , and the precursors used in the pulse flow PECVD method include HMDSO, TEOS, the HMDSO or TEOS is fed into the deposition chamber in the form of pulse output, the pulse duration is 10-200ms, and the pulse period is 0.5-5s.

In the above technical solution, each inorganic functional layer is deposited to a thickness of 10-300 nm.

In the above technical solution, the organic functional layer and the inorganic functional layer alternate once as a cycle, and the cycle is 2-20.

The present invention controls the thin film deposition process by combining the PECVD method and the pulse flow PECVD method, so that the thin film is deposited in an island shape by the PECVD method, and the pulse flow PECVD method is used to transform the island shape deposition into a layered deposition, filling the gaps at the edges of each island in the island shape deposition The depression makes up for the defects of island-like deposition, realizes the switching between island-like growth and layered growth of the controllable film growth mode, and realizes the method of controlling the speed and rapidly depositing high-quality thin films.

Description of drawings

Fig. 1 is the flow chart of the film encapsulation method provided by the embodiment of the present invention;

Fig. 2 is a schematic structural view of the device used in the thin film encapsulation method provided by the embodiment of the present invention;

FIG. 3 is a structural diagram of a thin film obtained by a thin film encapsulation method provided by an embodiment of the present invention;

Fig. 4 is a data graph of the water and oxygen permeability of the film obtained by the film encapsulation method provided by the embodiment of the present invention.

detailed description

The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Example 1

Referring to Fig. 1, a thin film encapsulation method includes the following steps:

Step 1: Deposit organic functional layer by PECVD method (PECVD method has been disclosed in the prior art, refer to A. Bieder, A. Gruniger, Ph. Rudolf von Rohr, Surface & Coatings Technology, 200, 928-931, 2005.) used for deposition The plasma material is SiO _x C _y H _z , the precursor used is HMDSO, and the reactive gas used is O ₂ . The precursor and reactive gas are continuously fed into the deposition chamber 3 during the deposition process. 1 and flow meter 4 monitor and control, the thickness of organic functional layer deposition is 300nm.

Step 2: Deposit the inorganic functional layer by the pulse flow PECVD method. The plasma material used for deposition is SiO _x C _{y Hz} , the precursor used is HMDSO, and the reaction gas used is O ₂ . The precursor HMDSO is input by pulse Input, the pulse duration is 50ms, and the pulse period is 2s. The reaction gas _O2 is continuously fed during the deposition process. The amount of feed can be monitored and controlled by the ordinary valve 1 and the flow meter 4. The thickness of the inorganic functional layer deposited is 50nm. The completion of the pulse input is accomplished by connecting a pulse valve 2 in parallel to the precursor input pipeline of the existing PECVD equipment, and controlling the input of the required precursor through the pulse valve 2, see Figure 2 for details.

Repeat step 1 and step 2 for a total of three times to deposit three thin films with alternating structures of organic functional layers and inorganic functional layers. One cycle is one cycle, and the prepared film has four cycles in total. Refer to Figure 3 for the finished product.

After testing, the average water-oxygen permeability of the structure with 4 cycles of alternating organic functional layers and inorganic functional layers prepared in this example can be as low as 5.0×10 ^-5 g/m ² ·day, see Figure 4 for the specific test data.

Example 2

Referring to Fig. 1, a thin film encapsulation method includes the following steps:

Step 1: Deposit organic functional layer by PECVD method (PECVD method has been disclosed in the prior art, refer to A. Bieder, A. Gruniger, Ph. Rudolf von Rohr, Surface & Coatings Technology, 200, 928-931, 2005.) used for deposition The plasma material is SiN _x C _y H _z , the precursor used is TEOS, and the reaction gas is N ₂ . The precursor and reaction gas are continuously fed into the deposition chamber 3 during the deposition process. The flowmeter 4 monitors and controls, and the thickness of organic functional layer deposition is 400nm.

Step 2: Deposit the inorganic functional layer by the pulse flow PECVD method. The plasma material used for deposition is SiN _x , the precursor used is TEOS, and the reaction gas is N ₂ . The precursor TEOS is input by pulse input, and the pulse duration is 100ms , the pulse period is 1s, the reaction gas O2 is continuously fed during the deposition process, and the feeding amount can be monitored and controlled by the ordinary valve 1 and the flow meter 4, and the thickness of the inorganic functional layer deposited is 90nm. The completion of the pulse input is accomplished by connecting a pulse valve 2 in parallel to the precursor input pipeline of the existing PECVD equipment, and controlling the input of the required precursor through the pulse valve 2, see Figure 2 for details.

Repeat step 1 and step 2 for a total of three times to deposit three thin films with alternating structures of organic functional layers and inorganic functional layers. One cycle is one cycle, and the prepared film has four cycles in total. Refer to Figure 3 for the finished product.

According to the test, the average water and oxygen permeability of the structure with 4 cycles of alternating organic functional layers and inorganic functional layers prepared in this example can be as low as 4.7×10 ^-5 g/m ² ·day.

The traditional PECVD technology is a rapid deposition technology based on the island-like growth mechanism. It is characterized by fast deposition speed, but the edge of each island in the island-like deposition is prone to defects, resulting in poor film quality. ALD technology is a layer-by-layer deposition technology based on the self-limiting growth mechanism. It is characterized by high-quality deposition film, but the deposition speed is too slow. Pulse flow PECVD technology is a technology between traditional PECVD technology and ALD technology. Through the control of pulse time and cycle by pulse valve 2, when pulse gas is input to pulse valve 2, the film is deposited in an island-like mode. When the pulse valve is intermittent for 2 cycles and no precursor is input, the film growth process can be transformed from island deposition to layer deposition, filling the depressions on the edge of each island in island deposition, making up for the defects of island deposition, and realizing a controllable film growth mode Switching between island growth and layer growth can control the film quality and film growth speed according to actual production needs, and can achieve faster deposition of higher quality films.

Finally, it should be noted that the above examples are only used to illustrate the technical implementation of the material without limitation, although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the present invention can be Modifications or equivalent replacements of the technical solutions without departing from the spirit and scope of the technical solutions of the present invention shall fall within the scope of the claims of the present invention.

Claims (4)

1. A thin film encapsulation method, characterized in that: comprises the steps: Deposition of organic functional layers by PECVD method; The inorganic functional layer is deposited by a pulse flow PECVD method, wherein the pulse flow PECVD method is to input the precursor in the PECVD method through a pulse input mode; Deposit several thin films with alternating structure of organic functional layers and inorganic functional layers; Wherein, the deposited thickness of the organic functional layer is 300 nm, and the deposited thickness of the inorganic functional layer is 50 nm; or, the deposited thickness of the organic functional layer is 400 nm, and the deposited thickness of the inorganic functional layer is 90 nm. 2. The thin film encapsulation method according to claim 1, characterized in that: the plasma material for depositing the organic functional layer comprises SiOxCyHz, SiNxCyHz or SiOxNyCzHm, the precursor used in the PECVD method comprises HMDSO, TEOS, and the precursor The body continues to pass through during the deposition process. 3. The thin film encapsulation method according to claim 1, characterized in that: the plasma material for depositing the inorganic functional layer comprises SiOx, SiNx, SiOxNy or SiOxCyHz, and the precursor used in the method of pulse flow PECVD comprises HMDSO , TEOS, the HMDSO or TEOS is passed into the deposition chamber (3) in the form of pulse output, the duration of the pulse is 10-200ms, and the pulse period is 0.5-5s. 4. The thin film encapsulation method according to claim 1, characterized in that: the organic functional layer and the inorganic functional layer alternate once as a cycle, and the cycle is 2-20.