TWI412624B - A film deposition apparatus and its method for manufacturing film - Google Patents

Abstract

A film deposition apparatus includes: a cavity having an inlet that connected with a room, a plasma-producing unit having an electrode module that installed in the room, the electrode module electrically connected with a power supplied unit, the electrode module included a positive plate and a negative plate, and forming a plasma-producing area between the positive plate and the negative plate; a heating module installing in the room and to heated the film-forming gas from the inlet. Using the film deposition apparatus to fill the cavity with plasma-producing gas, and making the plasma-producing gas to transform a plasma state in the plasma-producing area, to fill the cavity with film-forming gas and to make the film-forming gas through the heating module and the plasma-producing unit, and applying the film-forming gas transformed to be ionized state in the plasma-producing area, and depositing a film on the base.

Description

Thin film deposition apparatus and method for preparing the same

The present invention relates to a thin film deposition apparatus and a method for preparing the same, and more particularly to a thin film deposition apparatus using a hybrid chemical vapor deposition reaction and a method for preparing the same.

In recent years, the rapid growth of the solar cell market, which is dominated by germanium wafers, has led to a shortage of raw material sources. Therefore, most of the companies are more eager to develop thin film solar cells to replace the past with extremely thin photoelectric conversion materials. Wafers, thereby reducing the cost of using the raw materials and improving the performance of the solar cells.

In the thin-film solar cell, the stacked solar cell has better photoelectric conversion efficiency than the amorphous germanium component, and the microcrystalline germanium film is actively developed by the industry. The carrier mobility of the microcrystalline germanium film is one to two orders of magnitude higher than that of the general amorphous germanium film. Therefore, the microcrystalline germanium film has a better light wavelength absorption range for increasing the solar cell. Photoelectric conversion efficiency.

The device for depositing a thin film is a plasma enhaced chemical vapor deposition (PECVD) device, which uses a plasma box in which a plasma chamber is disposed. An upper and lower electrode plates, and a radio frequency (RF) is connected between the upper and lower electrodes, and the decane is diluted with a large amount of hydrogen when the decane is introduced into the plasma box. The mixed gas of the reaction, followed by the RF current to excite the electrons between the two electrodes to oscillate, so that the free electrons in the plasma strike the mixed gas molecules, causing the mixed gas to be ionized and dissociated into SiH ₃ , SiH ₂ , SiH , Si, H ₂ , H, in which the active component (such as: SiH ₂ , SiH, Si) will continue to react with the mixed gas of decane and hydrogen to produce more reactive groups, but not participate in two The secondary reaction and the more stable SiH ₃ system can be partially deposited as a thin film when it reaches a surface of the substrate and loses some kinetic energy.

However, since the above reaction process uses decane as a film-forming gas mainly for forming a ruthenium film, and the decane gas system is toxic, corrosive, and explosive, it is necessary to add other gases (for example, hydrogen, helium, etc.) based on safety considerations. Diluting is used as a mixed gas for the reaction. Thus, the process of diluting the decane with other gases takes extra time, thereby affecting the efficiency of electrons striking gas molecules in the conventional device, resulting in a significant decrease in the deposition rate of the entire twin film.

Furthermore, in order to increase the deposition rate of the twinned film in the plasma-assisted chemical vapor deposition apparatus, the electrons between the two electrode plates are often excited by the higher RF current, so that the electrons generate strong oscillations and then forcefully The molecules of the mixed gas are struck to increase the deposition rate. However, the higher RF current is likely to affect other substances on the element, and increase the cost of the entire twin film during the deposition process, and even cause plasma bombing. Increase the risk of use.

In addition, the device for depositing a thin film may be selected as a hot-wire chemical vapor deposition (HWCVD) device, which is provided with a hot wire component in a chamber. And an inlet, when the decane enters the chamber through the inlet, the hot wire element is capable of decomposing the decane into an atomic radicals type product at a high temperature, and depositing on the substrate at a low pressure state The film, because the reaction process is free from the formation of a gas phase product, can shorten the reaction time to increase the deposition rate.

However, since the hot wire chemical vapor deposition apparatus must pass the decane through the hot wire element, the decane can be decomposed into an atomic type product, and therefore, due to the action efficiency of the hot wire element, decane gas decomposition is often not generated. The complete phenomenon reduces the deposition quality of the twin film.

In view of this, the conventional thin film deposition apparatus and the method for preparing the same are still necessary for improvement.

The main object of the present invention is to improve the above disadvantages to provide a thin film deposition apparatus capable of providing a high temperature gas dissociation environment to increase the dissociation rate of the film forming gas.

A second object of the present invention is to provide a method of preparing a film which is capable of shortening the time during which the film forming gas dissociates to increase the deposition rate of the film.

Still another object of the present invention is to provide a method of preparing a film which is capable of increasing the dissociation integrity of a film forming gas to enhance the deposition quality of the film.

It is still another object of the present invention to provide a method of preparing a film which is capable of reducing the occurrence of plasma bombing to reduce the risk of film deposition.

In order to achieve the foregoing object, the technical content of the present invention includes:

A thin film deposition apparatus includes: a cavity having a chamber and an air inlet, wherein the air inlet communicates with the chamber; a plasma generating unit has an electrode assembly and a power supply component, The electrode assembly is disposed in the chamber and electrically connected to the power supply component, and the electrode assembly comprises a positive electrode plate and a negative electrode plate, wherein the positive electrode plate and the negative electrode plate have a plasma generating region; and a heating The assembly is housed in the chamber and is configured to heat the film forming gas introduced by the air inlet.

Moreover, a method for preparing a thin film according to the present invention is a method for forming a plasma through a plasma deposition step, wherein a plasma is introduced into the chamber to generate a gas, and the plasma is generated into the plasma. The formation zone is dissociated to form a plasma state; a dissociation step is performed by introducing a film forming gas into the chamber of the cavity to cause ionization of the film forming gas through the heating component and the plasma generating unit, and The plasma generating region forms a film-forming gas in a dissociated state; and a film forming step is performed by depositing the dissolving film-forming gas on a substrate in the thin film deposition device to form a thin film.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Referring to FIG. 1 , a thin film deposition apparatus according to a preferred embodiment of the present invention includes a cavity 1 , a plasma generating unit 2 , and a heating assembly 3 . The plasma generating unit 2 is housed in the cavity. 1 , and the heating assembly 3 is housed in the cavity 1 and is used to heat the film forming gas that is introduced into the cavity 1 .

The cavity 1 can be selected as a cavity having any shape of withstand voltage and heat resistance. In the embodiment, the cavity 1 has a chamber 11 and an air inlet 12, and the air inlet 12 is The chamber 11 is connected to the film forming gas to enter the chamber 11 via the air inlet 12, and the chamber 11 is for receiving the plasma generating unit 2 and the heating assembly 3.

The plasma generating unit 2 has an electrode assembly 21, which is housed in the chamber 11 of the cavity 1, and the electrode assembly 21 includes two parallel positive plates 21a and negative plates 21b. A plasma generating region 211 is formed between the positive electrode plate 21a and the negative electrode plate 21b. The plasma generating region 211 is configured to supply a plasma generating gas for dissociation reaction, and the negative electrode plate 21b is further connected with a grounding wire 212 for The excess electrons generated by the action of the positive electrode plate 21a and the negative electrode plate 21b are deducted to avoid interference. The material of the electrode assembly 21 is preferably nickel, gold, silver, titanium, copper, palladium, stainless steel, beryllium copper alloy, aluminum, coated aluminum, tantalum, quartz, tantalum carbide, tantalum nitride, nitrogen. Aluminum, sapphire, polyimine or Teflon, and the positive plate 21a and the negative plate 21b can be selected to have any geometric shape (for example, circular, square, hexagonal, etc.). Further, the plasma generating unit 2 is further connected with at least one power supply element 22 for providing an electric field required for the gas to react in the plasma generating region 211. In the embodiment, the power feeding element 22 is connected by a line. The cavity 1 is connected to the positive electrode plate 21a. The power supply component 22 is preferably a radio frequency current supply, and the RF current supply is capable of providing a radio frequency (RF) current, and the supply frequency of the radio frequency current is a frequency with a pulse signal modulation ( For example: between 13MHz and 150MHz) is more appropriate. Furthermore, in order to increase the surface mobility of the gas atom during the film deposition process, the plasma generating unit 2 is further connected with a temperature rising element 23 for heating the surface of the film to be deposited. In this embodiment, the temperature increasing element The 23 series is housed in the chamber 11 of the cavity 1 and interconnected with the negative plate 21b. The temperature rising element 23 is preferably selected as an induction coil having a temperature rising function.

The heating unit 3 is disposed in the chamber 11 for heating the film forming gas introduced by the air inlet 12. In the embodiment, the heating unit 3 includes a heating element 31 and at least one temperature. The control element 32 is located between the plasma generating region 211 and the air inlet 12, and the heating element 31 is preferably selected as a material having high melting point characteristics (for example: tungsten, molybdenum, niobium, graphite) , 铼, 锇...etc.). The temperature control element 32 can be selected as any object having a heating function (for example, a heater, an infrared ray, an induction coil, etc.) for raising the temperature of the heating element 31. In this embodiment, the temperature control element Preferably, the two heaters are respectively connected to the two ends of the heating element 31 by two heaters, and are disposed on two adjacent sides of the air inlet 12 of the cavity 1.

In addition, in order to ensure that the thin film deposition apparatus of the present invention is not affected by external gases and affect the deposition quality of the thin film, the present invention is connected to a vacuum unit 4, which is preferably selected as a vacuum pump, and the vacuum is selected. The unit 4 is connected with a connecting member 41, and the connecting member 41 is connected to the chamber 11 of the cavity 1. Thereby, the chamber 1 is evacuated by the vacuum unit 4, thereby regulating the chamber 1. The pressure value in the chamber 11. In this embodiment, the pressure value of the cavity 1 is controlled by the vacuum unit 4 to be preferably between 10 and 760 torr, thereby maintaining the cavity 1 in a preferred vacuum environment for film formation. Deposition.

Referring to FIG. 2, a preferred embodiment of the present invention is a film deposition apparatus for preparing a film, which comprises a plasma generating step S1, a dissociating step S2, and a film forming step S3.

A thin film deposition apparatus of the present invention is provided, and a substrate 5 is provided in the thin film deposition apparatus, and the substrate 5 can be selected from quartz, glass, plastic, and the like. More specifically, the substrate 5 is placed on the cathode plate 21b of the plasma generating unit 2 to heat the substrate 5 by the temperature rising element 23 connected to the cathode plate 21b, so that the temperature of the substrate 5 is controlled in Celsius. Between 200 and 250 degrees, thereby increasing the surface mobility of the gas atoms on the substrate 5. In the present embodiment, the temperature of the substrate 5 controlled by the temperature increasing element 23 is preferably 225 degrees.

The plasma generating step S1 is to pass a plasma generating gas into the cavity 1 to cause the plasma generating gas to dissociate in the plasma generating region 211 to form a plasma state, wherein the plasma generating gas system It can be selected from argon, nitrogen, hydrogen, and the like. More specifically, the cavity 1 is first evacuated by the vacuum unit 4, so that the chamber 11 of the cavity 1 is in a vacuum state, and then the air inlet 12 of the thin film deposition apparatus of the present invention is connected to the electricity. The slurry generating gas is in the plasma generating region 211, and the RF current is input to the electrode assembly 21 by the power feeding element 22, so that the electrode assembly 21 can generate an electric field required for the reaction in the plasma generating region 211 to utilize the electricity. The electrons in the slurry generating region 211 strike the plasma generating gas to destroy the plasma generating gas atoms or intermolecular bonds to form a plasma state. For example, the vacuum unit 4 adjusts the pressure value in the chamber 11 of the cavity 1 between 10 and 760 Torr to ensure that no external gas is present in the chamber 11. This embodiment is Selecting and adjusting the pressure value in the chamber 11 of the cavity 1 is 350 Torr, and then introducing argon gas into the plasma generating region 211 from the air inlet 12, and controlling the flow rate of the argon gas to be 10 to 25 sccm (sccm) : In the standard state of temperature 0 ° C and pressure 760 Torr, how many cubic centimeters of gas flow per minute), in order to maintain a better plasma generation efficiency, in this embodiment, the flow rate of the argon gas is preferably selected. It is 15sccm. The power supply element 22 is further turned on to input an RF current with a frequency of 13 MHz to 150 MHz between the electrode assemblies 21, and the RF current of the embodiment is preferably selected to be 75 MHz. Thus, the RF current can be utilized in the plasma generation region. The electrons generated by 211 strike the argon or nitrogen to destroy the molecular bonding of the argon or nitrogen to form a plasma state.

Referring to FIG. 3, the dissociation step S2 is to pass a film forming gas into the chamber 11 of the cavity 1, and the film forming gas is passed through the heating assembly 3 and enters the plasma generating unit 2. Ionization, and forming a film-forming gas in a dissociated state in the plasma generating region 211, wherein the film forming gas system may be selected from the group consisting of an anthracene hydrogen compound (for example, decane, ethane, propane, etc.), a hydrogen compound, and Hydrocarbons. More specifically, the temperature of the heating element 31 is raised by the temperature control element 32 such that the temperature of the heating element 31 can reach a high temperature at which the film forming gas is decomposed, and then the air inlet 12 is introduced into the Membrane gas, when the film forming gas enters the chamber 11 of the cavity 1 and passes through the heating element 31, since the heating element 31 maintains a temperature sufficient to dissociate the film forming gas, the film forming gas system The dissociated film forming gas is formed via the high temperature action of the heating element 31 to enter the plasma generating region 211, thereby increasing the dissociation rate of the film forming gas. Moreover, as shown in FIG. 4, the film-forming gas that has been dissociated by the heating element 31 also enters the plasma generating region 211, and the RF element is supplied with the RF current to the electrode assembly 21 to utilize the electrode. The potential difference between the positive electrode plate 21a and the negative electrode plate 21b of the module 21 accelerates the electrons in the plasma generating region 211, and the accelerated high-energy electrons are transferred to the film forming gas molecules by collision, so that the film forming gas has secondary dissociation. Opportunity. Thus, the step of secondary dissociation can enhance the dissociation integrity of the film forming gas to improve the quality of film deposition. For example, referring to the third and fourth figures, the temperature of the heating element 31 is raised to 1600 degrees Celsius or higher by the temperature control element 32, and the decane gas is introduced from the air inlet 12, and The flow rate of the decane gas is controlled to be 50 to 80 sccm to maintain a better decane gas dissociation efficiency. The flow rate of the decane gas in the embodiment is preferably 65 sccm, so that the decane gas passes through the heating element 31 at a temperature of 1600 degrees. The ionization causes dissociation of the decane gas into SiH ₃ , SiH ₂ , SiH, Si, H ₂ , and H. The gas molecules are accompanied by a portion of the un-ionized decane gas to enter the plasma generating region 211, and are input to the electrode assembly 21 by the power supply element 22 at a frequency of 75 MHz to utilize the electrode assembly 21. The potential difference generated in the plasma generating region 211 accelerates the electrons from striking the decane gas, so that the high-energy electrons transfer energy to the decane gas molecules to form a decane gas in a dissociated state. Thus, the decane gas system introduced into the thin film deposition apparatus can have better dissociation integrity to enhance the film formation quality of the thin film deposition apparatus.

Referring to FIG. 5, the film forming step S3 deposits the dissociated film forming gas on the substrate 5 to form a thin film. More specifically, the dissociated film forming gas is obtained through the dissociation step S2, and the film forming gas system is dissociated into other gas molecules or atoms, wherein the gas molecules or atomic systems having stronger active components continue to undergo a second reaction. More reactive radicals are obtained, while the more stable gas molecules or atoms lose some of their kinetic energy before reaching the substrate 5, and deposit as a thin film on the surface of the substrate 5. For example, the dissociated decane gas system obtained through the dissociation step S2 described above contains SiH ₃ , SiH ₂ , SiH, Si, H ₂ , H, and molecules having stronger active components (for example, SiH ₂ , SiH, Si) Generally, the second reaction with the decane gas is continued to generate more reactive radicals, and the relatively stable SiH ₃ system that does not participate in the secondary reaction can lose part of the kinetic energy when reaching the surface of the substrate 5, and the substrate The surface of 5 is deposited as a twin film.

By the above-mentioned thin film deposition apparatus and a method for preparing the same, the decane gas introduced into the air inlet 12 can be subjected to high temperature action on the decane gas by the heating unit 3, so that the decane gas is rapidly ionized. The decane gas forming the dissociated state enters the plasma generating region 211, and the decane gas system that has not completely dissociated through the heating assembly 3 can be dissociated again after entering the plasma generating region 211. At this time, the plasma is generated. The power supply element 22 of the unit 2 provides a radio frequency current to the electrode assembly 21 to generate a potential difference between the positive electrode plate 21a and the negative electrode plate 21b of the electrode assembly 21, and the potential difference is used to accelerate the electrons of the plasma generating region 211 to be fast and high-energy. Electrons strike the decane gas to transfer energy to the decane gas to form a dissociation. Thus, the high temperature of the heating assembly 3 is used to assist the electron impact of the plasma generating unit 2 to dissociate the decane gas first, thereby eliminating the time required for the hydrogen to mix with the decane gas. Therefore, the thin film deposition apparatus of the present invention is capable of accelerating the deposition rate of the decane gas in the plasma generation region 211. Furthermore, the dissociation of the decane gas by the high temperature of the heating unit 3 can slow down the high-speed electron-generating plasma bombing of the plasma generating unit 2, thereby reducing the risk of use. In addition, the high temperature of the heating unit 3 and the electron impact of the plasma generating unit 2 enable the decane gas passing into the chamber 11 of the chamber 1 to have a second dissociation opportunity, thereby enhancing the decane gas. Better and complete ionization stabilizes the quality of the film deposition.

The thin film deposition apparatus of the present invention is capable of providing a high temperature gas dissociation environment to achieve an effect of increasing the dissociation rate of the film forming gas.

The method for preparing a film of the present invention is capable of shortening the time of film-forming gas dissociation and achieving the effect of increasing the deposition rate of the film.

The method for preparing a film of the invention can increase the dissociation integrity of the film forming gas and achieve the effect of improving the deposition quality of the film.

The method for preparing a film of the present invention is capable of reducing the occurrence of plasma bombing to reduce the risk of film deposition.

While the invention has been described in connection with the preferred embodiments described above, it is not intended to limit the scope of the invention. The technical scope of the invention is protected, and therefore the scope of the invention is defined by the scope of the appended claims.

[this invention]

1. . . Cavity

11. . . Room

12. . . Air inlet

2. . . Plasma generating unit

twenty one. . . Electrode assembly

21a. . . Positive plate

21b. . . Negative plate

211. . . Plasma generation zone

212. . . Ground wire

twenty two. . . Power supply component

twenty three. . . Heating element

3. . . Heating component

31. . . Heating element

32. . . Temperature control element

4. . . Vacuum unit

41. . . Connecting piece

5. . . Substrate

Fig. 1 is a view showing the apparatus of the thin film deposition apparatus of the present invention.

Fig. 2 is a flow chart showing the film deposition apparatus of the present invention for preparing a film.

Fig. 3 is a schematic view showing the operation of the thin film deposition apparatus of the present invention for preparing a film.

Fig. 4 is a schematic view showing the operation of the thin film deposition apparatus of the present invention for preparing a film.

Fig. 5 is a schematic view showing the operation of the thin film deposition apparatus of the present invention for preparing a film.

1. . . Cavity

11. . . Room

12. . . Air inlet

2. . . Plasma generating unit

twenty one. . . Electrode assembly

21a. . . Positive plate

21b. . . Negative plate

211. . . Plasma generation zone

212. . . Ground wire

twenty two. . . Power supply component

twenty three. . . Heating element

3. . . Heating component

31. . . Heating element

32. . . Temperature control element

4. . . Vacuum unit

41. . . Connecting piece

Claims (11)

A thin film deposition apparatus includes: a cavity having a chamber and an air inlet, wherein the air inlet communicates with the chamber; a plasma generating unit has an electrode assembly and a power supply component, The electrode assembly is disposed in the chamber and electrically connected to the power supply component, and the electrode assembly comprises a positive electrode plate and a negative electrode plate, wherein the positive electrode plate and the negative electrode plate have a plasma generating region; and a heating The assembly is housed in the chamber and is configured to heat the film forming gas introduced by the air inlet. The thin film deposition apparatus of claim 1, wherein the heating element comprises a heating element and at least one temperature control element, the heating element is located between the plasma generating area and the air inlet, and the temperature is A control element is coupled to the heating element and is located adjacent the air inlet. The thin film deposition apparatus of claim 1, wherein the plasma generating unit is further connected with a temperature rising element disposed in the cavity and interconnected with the negative electrode plate. The thin film deposition apparatus of claim 1, further comprising a vacuum unit, and the vacuum unit is connected to the chamber of the cavity for regulating the pressure in the chamber of the cavity. The thin film deposition apparatus of claim 1, wherein the power supply element is an RF current supply. A method for preparing a film, comprising the steps of: the plasma generating step of introducing a plasma generating gas into the cavity, wherein the film forming device according to claim 1 is configured to: The plasma generating gas is dissociated in the plasma generating region to form a plasma state; a dissociating step is performed by introducing a film forming gas into the chamber of the cavity to generate the film forming gas through the heating component and the plasma The unit is ionized to form a dissociated film forming gas in the plasma generating region; and a film forming step is performed by depositing the dissociated film forming gas on a substrate in the thin film deposition device to form a thin film. A method of preparing a film according to claim 6 wherein the pressure value in the chamber is between 10 and 760 Torr. The method for preparing a film according to claim 6, wherein the temperature of the heating element is 1600 degrees Celsius or more. The method for producing a film according to claim 6, wherein the plasma generating gas has a flow rate of 10 to 25 sccm. The method for producing a film according to claim 6, wherein the film forming gas has a flow rate of 50 to 80 sccm. The method for producing a film according to claim 6, wherein the substrate is further heated in the plasma generating step.