CN100485884C - Substrate for electronic device and method for processing same - Google Patents

Abstract

The present invention relates to a substrate for electronic devices such as semiconductor devices and a processing method thereof. In this substrate processing method, first, a substrate for an electronic device is prepared, and an insulating film (I) made of fluorocarbon (CF) is formed on the surface of the substrate. Next, the fluorine (F) atoms exposed on ^the surface of the insulating film (I) are made to from the insulating film. At this time, the substrate is kept free from moisture at least from the step of forming the insulating film until the step of removing fluorine atoms is completed.

Description

Substrate for electronic device and processing method thereof

technical field

The present invention relates to substrates for electronic devices such as semiconductor devices, liquid crystal display devices, and organic EL elements, and their processing methods.

Background technique

As one method for achieving high integration of semiconductor devices as electronic devices, a multilayer wiring structure has been adopted. Because of the multi-layer wiring structure, the wiring layer of the nth layer and the wiring layer of the (n+1)th layer are connected by a conductive layer, and the formation of a layer other than the conductive layer is called interlayer insulation. film of film. A typical example of this interlayer insulating film is a silicon oxide film, but in order to further increase the operating speed of the semiconductor device, it is necessary to further reduce the dielectric constant of the interlayer insulating film.

Against such a background, an insulating film composed of fluorocarbon (fluorocarbon) (hereinafter referred to as "CF insulating film") attracts attention. With this CF insulating film, compared with a silicon oxide film, the Lower dielectric constant.

The CF insulating film is formed, for example, by depositing radicals generated by exciting C ₅ F ₈ , which is a source gas of fluorocarbon, on a substrate in a plasma processing apparatus. In this case, for example, a plasma gas for generating plasma such as argon gas is converted into plasma by microwaves, and the source gas is excited by the plasma (for example, refer to JP-A-11-162960).

However, when forming a CF insulating film, as shown in FIG. 10 , the fluorine atoms in the CF insulating film I are oriented toward the surface side of the film and exposed on the surface of the film. The fluorine atom has a high electronegative property and is easy to adsorb water molecules. Therefore, if the film is left in a state where fluorine atoms are exposed on the surface, water molecules will be adsorbed to the fluorine atoms on the surface, for example, during the transfer of the substrate.

Furthermore, when the substrate is heated after film formation, etc., the adsorbed water molecules react with fluorine atoms. Fluorine atoms reacted with water molecules are released from the CF insulating film I as hydrogen fluoride gas. This hydrogen fluoride gas has a property of corroding and destroying the film. For example, hydrogen fluoride gas may react with a barrier metal film formed between a conductive layer and an interlayer insulating film in a semiconductor device, thereby destroying and peeling off the barrier metal film. As a result, the multilayer wiring structure of the semiconductor device cannot be properly formed, and the production efficiency of the semiconductor device is significantly lowered.

In addition, the surface of the CF insulating film I deteriorates due to the reaction with water molecules, and the leakage characteristics of the CF insulating film I deteriorate. Therefore, the insulating property of the interlayer insulating film made of, for example, the CF insulating film I is lowered, and the performance of the semiconductor device is lowered.

Contents of the invention

The present invention was made in view of this point, and an object of the present invention is to provide a substrate for an electronic device that suppresses the reaction between fluorine atoms exposed on the surface of a CF insulating film and water molecules, and a processing method thereof.

In order to achieve the above object, the method for processing a substrate for an electronic device of the present invention is characterized in that it includes: a step of preparing a substrate for an electronic device; a step of forming an insulating film made of fluorocarbon on the surface of the substrate; and using In the step of detaching fluorine atoms exposed on the surface of the insulating film from the insulating film, the substrate is kept free from moisture at least during the period after the step of forming the insulating film until the step of detaching fluorine atoms is completed.

According to this method, by detaching the fluorine atoms exposed on the surface of the insulating film from the insulating film before they come into contact with water, the reaction of the fluorine atoms with water can be suppressed. As a result, hydrogen fluoride is not generated from the surface of the insulating film, and it is possible to prevent other films from being damaged and peeled off by hydrogen fluoride. In addition, it is possible to prevent the surface of the insulating film from deteriorating to increase the dielectric constant.

The above step of detaching fluorine atoms can be performed by colliding active species generated in plasma of a rare gas or nitrogen gas with the surface of the insulating film. In this case, the fluorine atoms on the surface of the insulating film can be detached from the insulating film by physical collision of the active species.

The above step of detaching fluorine atoms can be performed by exposing the substrate to plasma generated from a rare gas or nitrogen gas. In this case, the fluorine atoms on the surface of the insulating film can be detached by using the energy of the plasma itself generated from the rare gas or nitrogen gas as an inert gas, or the energy of photons released when the plasma returns to the gas again. The aforementioned rare gas is selected from, for example, argon, xenon, and krypton.

Such a step of exposing the substrate to plasma is preferably performed in a plasma space with an electron temperature of 2 eV or lower and an electron density of 1×10 ¹¹ electrons/cm ³ or higher. By exposing the substrate to such a high-density plasma space, fluorine atoms can be efficiently detached in a short time.

The above step of detaching fluorine atoms may be performed by irradiating electron beams or ultraviolet rays to the surface of the insulating film on the substrate. In this case, the fluorine atoms on the surface of the insulating film can be detached by energy of electron beams or ultraviolet rays. In addition, since electron rays or ultraviolet rays enter the interior of the insulating film, it is also possible to detach fluorine atoms that are not bonded and are in an unstable state in the insulating film. As a result, the film quality of the insulating film itself can also be improved.

In the substrate processing method, after the step of detaching fluorine atoms, a step of forming a pellicle film on the insulating film for preventing moisture from contacting the surface of the insulating film may be further included. In this case, since moisture does not come into contact with the insulating film due to the protective film, the reaction of fluorine atoms and water molecules can be more reliably prevented.

Another method for processing a substrate for an electronic device according to the present invention is characterized in that it includes: a step of preparing a substrate for an electronic device; a step of forming an insulating film made of fluorocarbon on the surface of the substrate; and A process of forming a protective film on an insulating film to prevent moisture from coming into contact with the surface of the insulating film.

According to this method, the pellicle prevents moisture from coming into contact with the surface of the insulating film, and fluorine atoms exposed on the surface of the insulating film do not react with water molecules. As a result, damage and peeling of other films due to generation of hydrogen fluoride gas can be prevented. In addition, it is also possible to prevent the dielectric constant of the insulating film from increasing due to deterioration of the insulating film.

In this case, it is preferable to keep the substrate free from moisture from after the step of forming the insulating film until the step of forming the pellicle film is completed.

In addition, in order to achieve the above object, the electronic device substrate of the present invention is characterized in that: an insulating film made of fluorocarbon is formed on the surface, and a surface for preventing moisture from contacting the insulating film is formed on the insulating film. Contact protective film.

According to this substrate for an electronic device, the pellicle film prevents the fluorine atoms on the surface of the insulating film from contacting and reacting with water molecules. Therefore, hydrogen fluoride gas is not generated from the surface of the insulating film, and damage to the electronic device due to the hydrogen fluoride gas can be prevented. In addition, the insulating film does not deteriorate, and an increase in the dielectric constant of the insulating film can be prevented.

The material of the above-mentioned pellicle is, for example, selected from amorphous carbon, SiN, SiCN, SiC, SiCO, and CN. By forming the pellicle film from such a material with a low dielectric constant, the dielectric constant of the entire film including the insulating film and the pellicle film can be kept low.

The above-mentioned pellicle preferably has less than thickness of. Accordingly, it is possible to suppress an increase in the dielectric constant of the entire film including the pellicle film and the insulating film.

Description of drawings

FIG. 1 is a schematic diagram of a substrate processing system used in the method of processing a substrate for an electronic device according to the present invention.

Fig. 2 is a longitudinal sectional view of an insulating film forming device in the system shown in Fig. 1 .

Fig. 3 is a plan view of a raw material gas supply structure in the apparatus shown in Fig. 2 .

Fig. 4 is a longitudinal sectional view of an insulating film processing device in the system shown in Fig. 1 .

FIG. 5 is a schematic view showing how fluorine atoms are detached from the surface of the CF insulating film.

6 is a longitudinal sectional view of an insulating film processing apparatus including an electron beam irradiator.

7 is a schematic diagram of another substrate processing system used in the method of processing a substrate for an electronic device according to the present invention.

Fig. 8 is a longitudinal sectional view of an insulating film processing device in the system shown in Fig. 7 .

FIG. 9 is a schematic view showing a state in which a pellicle film is formed on a CF insulating film.

FIG. 10 is a schematic diagram showing how fluorine atoms are exposed on the surface of the CF insulating film.

Fig. 11a is a graph showing the results of TDS measurement of a substrate of a comparative example that was not subjected to any treatment after forming a CF insulating film.

11b is a graph showing the results of TDS measurement of the substrate of the example exposed to Ar plasma for 5 seconds after the formation of the CF insulating film.

Fig. 11c is a graph showing the results of TDS measurement of the substrate of the example exposed to _N2 plasma for 5 seconds after the formation of the CF insulating film.

Detailed ways

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

First, a substrate processing system used in the method of processing a substrate for an electronic device according to the present invention will be described.

As shown in FIG. 1 , a substrate processing system 1 has a structure in which a cassette station 2 and a processing station 3 including a plurality of processing devices 32 to 35 are integrally connected in the Y direction (the left-right direction in the figure). The cassette station 2 is used for loading and unloading a plurality of substrates W between the substrate processing system 1 and the outside (for example, in a state stored in a cassette C), and for loading and unloading each substrate W from the cassette C. In addition, the processing station 3 is configured to perform sheet-by-sheet processing on the substrate W in each of the processing devices 32 to 35 .

The cassette station 2 is composed of a cassette mounting table 4 and a transport container 5 . The cartridge mounting table 4 can place two cartridges C side by side in the X direction (vertical direction in FIG. 1 ). In the transfer container 5, for example, a substrate transfer body 6 and a prealignment stage 7 constituted by an articulated robot are installed. The substrate transport body 6 can transport the substrate W between the cassette C on the cassette mounting table 4 , the stage 7 , and the load lock chambers 30 and 31 of the processing station 3 which will be described later.

The processing station 3 has a conveyance path 8 formed linearly in the Y direction from the cassette station 2 at the center thereof. The conveyance path 8 is covered with a casing (casing) 8 a capable of closing the interior of the conveyance path 8 . A gas supply pipe 21 communicating with a gas supply device 20 for dry gas is connected to the housing 8a, and dry gas can be supplied from the gas supply device 20 into the housing 8a through the gas supply pipe 21 . Furthermore, in the dry gas, inert gases such as rare gases and nitrogen are used. An exhaust pipe 23 communicating with the negative pressure generator 22 is connected to the casing 8a, and the inside of the casing 8a can be decompressed by the exhaust gas from the exhaust pipe 23. Therefore, after replacing the atmosphere in the conveyance path 8 with a predetermined dry gas, the inside of the conveyance path 8 can be decompressed to a predetermined pressure. That is, after moisture is removed from the inside of the conveyance path 8, the interior of the conveyance path 8 can be maintained in a dry atmosphere that does not contain moisture.

On both sides of the transport path 8, load lock chambers 30, 31, insulating film forming devices 32, 33, and insulating film processing devices 34, 35 are arranged. The load lock chambers 30 , 31 and the devices 32 to 35 are connected to the conveyance path 8 via gate valves 36 . The load lock chambers 30 , 31 are adjacent to the transport container 5 of the cassette station 2 , and the load lock chambers 30 , 31 are connected to the transport container 5 via a gate valve 37 . Therefore, the substrate W in the transfer container 5 is transferred into the transfer path 8 via the load lock chambers 30 and 31 .

In the conveyance path 8 , a conveyance rail 38 extending in the Y direction and a substrate conveyance device 39 freely movable on the conveyance rail 38 are provided. The substrate transfer device 39 is configured as an articulated robot capable of transferring the substrate W between the load lock chambers 30 , 31 , insulating film forming devices 32 , 33 , insulating film processing devices 34 , 35 and the transfer path 8 through the gate valve 36 . With the above configuration, the substrate W carried from the load lock chambers 30 and 31 into the transfer path 8 can be selectively transferred to the respective devices 32 to 35 while maintaining it in a dry atmosphere. The substrate W is subjected to predetermined processing.

Next, the configurations of the above-mentioned insulating film forming apparatuses 32 and 33 will be described by taking the insulating film forming apparatus 32 as an example.

FIG. 2 schematically shows a longitudinal section of the insulating film forming device 32 . The insulating film forming apparatus 32 is a plasma CVD (chemical vapor deposition) apparatus for forming a CF insulating film made of fluorocarbon on a substrate W using plasma generated by high frequency.

The insulating film forming apparatus 32 has, for example, a bottomed cylindrical processing container 50 with an open top, as shown in FIG. 2 . The processing container 50 is formed of, for example, an aluminum alloy, and is grounded. A mounting table 51 on which the substrate W is mounted is provided substantially at the center of the bottom of the processing container 50 .

An electrode plate 52 is built in the mounting table 51 , and the electrode plate 52 is connected to a high-frequency power source 53 for a bias voltage of, for example, 13.56 MHz provided outside the processing container 50 . The high-frequency negative voltage is applied from the high-frequency power supply 53 to the surface of the mounting table 51 to attract charged particles in the plasma. In addition, the electrode plate 52 is also connected to a direct current power source (not shown) to generate an electrostatic force on the surface of the mounting table 51 to electrostatically attract the substrate W to the mounting table 51 .

Inside the mounting table 51, a heater 54 is provided. The heater 54 is connected to a power source 55 provided outside the processing container 50 , generates heat by power supplied from the power source 55 , and can heat the mounting table 51 to a predetermined temperature. In the mounting table 51, for example, a cooling jacket 56 through which a cooling medium flows is provided. The cooling jacket 56 communicates with a refrigerant supply device 57 provided outside the processing container 50 . The mounting table 51 can be cooled at a predetermined temperature by the refrigerant of a predetermined temperature supplied from the refrigerant supply device 57 to the cooling jacket 56 .

The upper opening of the processing container 50 is provided with a dielectric window 61 made of quartz glass or the like via a seal 60 such as an O-ring for ensuring airtightness. The inside of the processing container 50 is sealed by the dielectric window 61 . An RLSA (radial line slot antenna: radial line slot antenna) 62 is provided above the dielectric window 61 as a high-frequency supply unit that supplies microwaves for plasma generation.

The RLSA 62 has a substantially cylindrical antenna body 63 with an open bottom. A disk-shaped slot plate 64 in which a plurality of slots is formed is provided in an opening of the lower surface of the antenna main body 63 . On the upper portion of the slot plate 64 in the antenna main body 63, a phase slowing plate 65 formed of a low-loss dielectric material is provided. A coaxial waveguide 67 communicating with the microwave oscillator 66 is connected to the upper surface of the antenna main body 63 . The microwave oscillation device 66 is provided outside the processing container 50, and can oscillate microwaves of a predetermined frequency, for example, 2.45 GHz, to the RLSA 62. Microwaves oscillated by the microwave oscillator 66 are propagated into the RLSA 62, compressed by the slow plate 65 to shorten the wavelength, and circularly polarized waves are generated in the slot plate 64, and emitted from the dielectric window 61 into the processing container 50.

A gas supply port 70 for supplying plasma excitation gas is formed on the upper inner peripheral surface of the processing container 50 . The gas supply ports 70 are formed at multiple locations along the inner peripheral surface of the processing container 50 . A gas supply pipe 72 communicating with a gas supply source 71 provided outside the processing chamber 50 is connected to the gas supply port 70 . In the present embodiment, argon gas as a rare gas is sealed in the gas supply source 71 .

Between the mounting table 51 and the RLSA 62 in the processing container 50, a raw material gas supply structure 80 is provided. The supply structure 80 is formed in a disk shape with an outer shape at least larger than the diameter of the substrate W, and is provided so as to face the mounting table 51 and the RLSA 62. The inside of the processing chamber 50 is divided by the supply structure 80 into a plasma excitation region R1 on the RLLSA 62 side and a plasma diffusion region R2 on the stage 51 side.

As shown in FIG. 3 , the raw material gas supply structure 80 has continuous raw material gas supply pipes 81 arranged substantially in a grid on the same plane. The gas supply pipe 81 is composed of an annular pipe 81a arranged on the outer peripheral portion of the supply structure 80, and a grid-shaped pipe 81b in which a plurality of pipes are arranged to be perpendicular to each other inside the annular pipe 81a. As shown in FIG. 2 , the cross-sectional shape of the gas supply pipe 81 is rectangular.

In addition, as shown in FIGS. 2 and 3 , the raw material gas supply structure 80 has a plurality of openings 82 between the raw material gas supply pipes 81 . In FIG. 2 , the plasma generated in the upper plasma excitation region R1 of the supply structure 80 enters the lower plasma diffusion region R2 through these openings 82 .

The planar size of each opening 82 is set to be shorter than the wavelength of microwaves emitted from the RLSA 62. In this way, the microwaves emitted from the RLSA 62 are reflected by the raw material gas supply structure 80, and the entry of the microwaves into the plasma diffusion region R2 can be suppressed. By covering the surface of the supply structure 80 , that is, the surface of the source gas supply pipe 81 with a passivation film, the supply structure 80 can be prevented from being sputtered by charged particles in the plasma. Thereby, the substrate W can be prevented from being contaminated by the particle metal flying out by sputtering.

As shown in FIG. 2 , a plurality of raw material gas supply ports 83 are formed on the lower surface of the supply pipe 81 of the raw material gas supply structure 80 . These supply ports 83 are evenly arranged in the plane of the supply structure 80 . These gas supply ports 83 may be evenly arranged only in a region facing the substrate W placed on the mounting table 51 . A gas pipe 85 communicating with a raw material gas supply source 84 provided outside the processing container 50 is connected to the raw material gas supply pipe 81 . In the source gas supply source 84, a gas containing fluorine and carbon, for example, C ₅ F ₈ , is enclosed as a source gas. The raw material gas supplied from the raw material gas supply source 84 to the raw material gas supply pipe 81 through the gas pipe 85 is ejected from each raw material gas supply port 83 to the plasma diffusion region R2 below.

At the bottom of the processing container 50, an exhaust port 90 for exhausting the atmosphere in the processing container 50 is provided. An exhaust pipe 92 communicating with an exhaust device 91 such as a turbomolecular pump is connected to the exhaust port 90 . By exhausting from the exhaust port 90, the inside of the processing container 50 can be depressurized to a predetermined pressure.

In addition, the structure of the insulating film forming apparatus 33 is the same as that of the insulating film forming apparatus 32, and description thereof is omitted.

Next, taking the insulating film processing apparatus 34 as an example, the configurations of the above-mentioned insulating film processing apparatuses 34 and 35 will be described.

FIG. 4 schematically shows a longitudinal section of the insulating film processing device 34 . The insulating film forming device 34 is a plasma processing device that generates plasma from a rare gas using high frequency, and makes active species in the plasma collide with the substrate W to process the insulating film on the substrate W.

As shown in FIG. 4 , the insulating film processing apparatus 34 has a bottomed cylindrical processing container 100 formed of, for example, an aluminum alloy and having an open top. A mounting table 101 is provided substantially at the center of the bottom of the processing container 100 . An electrode plate 102 is built in the mounting table 101 , and the electrode plate 102 is connected to a high-frequency power source 103 for a bias voltage of, for example, 13.56 MHz provided outside the processing container 100 . A negative high voltage is applied to the surface of the mounting table 101 by the high-frequency power supply 103 . Thereby, positive ions serving as active species in the plasma generated in the processing chamber 100 can be attracted to the mounting table 101 side, and the positive ions can be collided with the surface of the substrate W on the mounting table 101 at high speed. In addition, the electrode plate 102 is also connected to a DC power supply (not shown), and generates electrostatic force on the surface of the mounting table 101 , so that the substrate W can be electrostatically attracted to the mounting table 101 .

A shower plate 111 is attached to the upper opening of the processing container 100 through a seal 110 such as an O-ring for ensuring airtightness. The shower plate 111 is made of a dielectric such as Al ₂ O ₃ , for example. The upper opening of the processing container 100 is closed by the shower plate 111 . On the upper side of the shower plate 111, an RLSA 113 for supplying microwaves for plasma generation is provided with a cover plate 112 interposed therebetween.

The shower plate 111 is formed in, for example, a disk shape, and is arranged to face the mounting table 101 . A plurality of gas supply holes 114 penetrating in the vertical direction are formed in the shower plate 111 . A gas supply pipe 115 penetrating horizontally from the side surface of the processing chamber 100 to the center through the inside of the shower plate 111 and opening on the upper surface of the shower plate 111 is formed. A gas flow path 116 is formed between the shower plate 111 and the cover plate 112 by the recess formed on the upper surface of the shower plate 111 . The gas flow path 116 communicates with the gas supply pipe 115 and each gas supply hole 114 . Therefore, the plasma gas supplied to the gas supply pipe 115 is sent to the gas flow path 116 through the gas supply pipe 115 , and is supplied from the gas flow path 116 into the processing chamber 100 through each gas supply hole 114 .

The gas supply pipe 115 communicates with a gas supply source 117 provided outside the processing chamber 100 . In the gas supply source 117, krypton gas is enclosed as a rare gas. Therefore, krypton gas is supplied into the processing chamber 110 as a gas for plasma excitation.

The cover plate 112 is bonded to the upper surface of the shower plate 111 through a sealing member 118 such as an O-ring. The cover plate 112 is made of a dielectric such as Al ₂ O ₃ .

The RLSA 113 has a substantially cylindrical antenna body 120 with an open bottom. A slot plate 121 is provided at the opening of the lower surface of the antenna main body 120 , and a phase retardation plate 122 is provided at the top of the slot plate 121 . The coaxial waveguide 124 communicated with the microwave oscillator 123 is connected to the antenna main body 120 . The microwave oscillation device 123 is installed outside the processing container 100, and can oscillate microwaves of a predetermined frequency, for example, 2.45 GHz, to the RLSA 113. The microwave oscillated by the microwave oscillator 123 is propagated into the RLSA 113, compressed by the slow-phase plate 122 to shorten the wavelength, and then circularly polarized wave is generated in the slot plate 121, and then passes through the cover plate 112 and the spray plate 111 to the processing container Launch within 100.

At the bottom of the processing container 100, an exhaust port 130 for exhausting the atmosphere in the processing container 100 is provided. An exhaust pipe 132 communicating with an exhaust device 131 such as a turbomolecular pump is connected to the exhaust port 130 . The inside of the processing container 100 can be decompressed to a predetermined pressure by exhausting from the exhaust port 130 . By this decompression, the moisture existing in the processing container 100 is removed, and the inside of the processing container 100 can be maintained in a dry atmosphere free of moisture.

As described above, the insulating film processing apparatus 34 is different from the insulating film forming apparatus 32 shown in FIG. In addition, since the insulating film processing apparatus 35 has the same structure as the insulating film processing apparatus 34, description is abbreviate|omitted.

Next, a method of processing the substrate W using the substrate processing system 1 configured as above will be described by taking the case of processing a substrate for a semiconductor device having a multilayer structure as an electronic device as an example.

For example, in another processing apparatus, a substrate W on which a conductive film is formed as a wiring layer is accommodated in a cassette C, and the cassette C is placed on the cassette mounting table 4 of the substrate processing system 1 as shown in FIG. 1 . . At this time, the inside of the conveyance path 8 of the substrate processing system 1 is replaced with dry gas by, for example, the gas supplied from the gas supply pipe 21 and then depressurized to a predetermined pressure by exhaust from the exhaust pipe 23 . Then, the inside of the conveyance path 8 is maintained as a depressurized atmosphere that does not contain moisture.

When the cassette C is placed on the cassette mounting table 4 , the substrate W is taken out from the cassette C by the substrate transport body 6 and transported to the pre-alignment table 7 . The substrate W aligned on the stage 7 is transported by the substrate transport body 6 to, for example, the load lock chamber 30 through the gate valve 37 . The substrate W in the load lock chamber 30 is transferred to the insulating film forming device 32 by the substrate transfer device 39 through the transfer path 8 .

The substrate W conveyed to the insulating film forming apparatus 32 is sucked and held on the mounting table 51 in the processing chamber 50 as shown in FIG. 2 . At this time, the substrate W is maintained at, for example, about 350° C. by heat generated by the heater 54 . Next, the exhaust device 51 starts to exhaust the inside of the processing container 50, and the inside of the processing container 50 is depressurized to a predetermined pressure, for example, about 13.3 Pa (100 mTorr). This reduced pressure maintains the inside of the processing container 50 in a dry atmosphere free of moisture.

When the pressure in the processing chamber 50 is reduced, argon gas is supplied from the gas supply port 70 to the plasma excitation region R1. For example, microwaves of 2.45 GHz are emitted from the RLSA 62 to the plasma excitation region R1 directly below. By emitting this microwave, argon gas is plasmaized in the plasma excitation region R1. At this time, microwaves emitted from the RLSA 62 are reflected by the raw material gas supply structure 80 and remain in the plasma excitation region R1. As a result, a so-called high-density plasma space is formed in the plasma excitation region R1.

On the other hand, a negative voltage is applied to the mounting table 51 from the high-frequency power supply 53 for bias. As a result, the plasma generated in the plasma excitation region R1 diffuses into the plasma diffusion region R2 through the opening 82 of the source gas supply structure 80 . C ₅ F ₈ gas is supplied from the source gas supply port 83 of the source gas supply structure 80 to the plasma diffusion region R2 . The C ₅ F ₈ gas is activated by, for example, plasma diffused from the plasma excitation region R1 , and a CF insulating film composed of fluorine atoms and carbon atoms is formed on the substrate W by the active species of the C ₅ F ₈ gas. At this time, as shown in FIG. 10, on the surface of the CF insulating film I, fluorine (F) atoms are exposed side by side.

The CF insulating film formed in this way does not contain H atoms in the gas used for film formation, so it is possible to prevent the F atoms in the film from combining with the H atoms to generate HF, and it becomes an insulating film with extremely excellent quality.

When the CF insulating film I of a predetermined thickness is formed on the substrate W, the emission of microwaves and the supply of source gas and plasma gas are stopped, and the substrate W on the stage 51 is carried out of the processing container 50 by the substrate transfer device 39 . The substrate W carried out from the insulating film forming apparatus 32 is conveyed to the insulating film processing apparatus 34 through the conveyance path 8 . During this period, since the interior of the conveyance path 8 is maintained in a dry atmosphere, moisture does not come into contact with the surface of the CF insulating film I on the substrate W.

The insulating film processing apparatus 34 is maintained in a reduced pressure atmosphere, for example, 33.3 Pa (250 mTorr) by exhausting from the exhaust port 130 . Therefore, even if the substrate W is carried in, the substrate W is continuously maintained in the dry atmosphere. The substrate W conveyed to the insulating film processing apparatus 34 is adsorbed and held on the mounting table 101 whose temperature is adjusted to, for example, 30° C. When the substrate W is held on the mounting table 101 , a negative high voltage is applied to the mounting table 101 by the high-frequency bias power supply 103 . On the other hand, krypton gas is supplied downward from the shower plate 111 at, for example, 50 cm ³ /min, and microwaves at 2.45 GHz are emitted from the RLSA 113 at a power of, for example, 500 W. By emitting this microwave, krypton gas is turned into plasma, and krypton ions Kr ⁺ , which are active species in the plasma, are attracted to the negative potential on the side of the mounting table 101 . Thus, the krypton ions Kr ⁺ collide with the surface of the substrate W on the mounting table 101 at high speed. As shown in FIG. 5 , the fluorine (F) atoms exposed on the surface of the insulating film I on the substrate detach from the insulating film I due to the collision of Kr ⁺ .

For example, when microwaves are irradiated for 5 seconds and the fluorine atoms on the surface of the CF insulating film I on the substrate W are sufficiently detached, the supply of microwaves and the supply of krypton gas are stopped. Then, the substrate W is carried out from the insulating film processing device 34 by the substrate transfer device 39 . The unloaded substrate W is transported to the load lock chamber 31 through the transport path 8 , and is accommodated in the cassette C on the cassette mounting table 4 by the substrate transport body 6 . Then, in another processing apparatus, after patterning the CF insulating film I on the substrate W by photolithography, a conductive film, a protective film, and the like are formed in a predetermined pattern, thereby manufacturing a semiconductor device.

According to the above embodiment, after the CF insulating film I is formed on the substrate W, the active species collides with the surface of the CF insulating film I at a high speed while keeping moisture from contacting the CF insulating film I, thereby insulating the fluorine atoms from the CF. The surface of Membrane I detached. As a result, the fluorine atoms exposed on the surface of the CF insulating film I disappear, and the fluorine atoms and water molecules do not react thereafter. Therefore, hydrogen fluoride gas can be prevented from being released from the CF insulating film I, and film damage and peeling of other layers in the semiconductor device, for example, do not occur. In addition, the surface of the CF insulating film I is not deteriorated to increase the dielectric constant of the CF insulating film I. Furthermore, in the above embodiments, krypton gas is used as the gas for generating plasma in the insulating film processing apparatus 34 , but other rare gases such as helium, xenon, and argon may be used, and nitrogen gas may also be used.

In the above embodiments, the active species generated in the plasma of the rare gas or nitrogen gas actively collides with the CF insulating film I to detach the fluorine atoms on the surface of the CF insulating film I. Alternatively, fluorine atoms may be detached by exposing the substrate W on which the CF insulating film I is formed to plasma generated from a rare gas or nitrogen gas.

In this case, in the insulating film processing apparatus 34 of FIG. 4 , for example, nitrogen gas which is a rare gas is supplied from the shower plate 111 . Then, by supplying microwaves from the RLSA 113 , the krypton gas is turned into a plasma to form a high-density plasma space in the processing chamber 100 , for example, with an electron temperature of 2 eV or less and an electron density of 1×10 ¹¹ electrons/cm ³ or more. By exposing the substrate W to this high-density plasma space, the surface of the CF insulating film 1 on the substrate W is exposed using, for example, the energy of the krypton ion itself or the energy of photons released when the krypton ion returns to krypton gas. The fluorine atom is detached. In this case, since krypton gas with high excitation energy is used, fluorine atoms can be desorbed efficiently in a short time. In addition, in this example, a rare gas other than krypton gas, such as xenon gas or argon gas, or nitrogen gas may be used as the gas for generating plasma.

Instead of the detachment method of fluorine atoms described in the above embodiments, the substrate W on which the CF insulating film I is formed may be irradiated with electron beams to detach fluorine atoms.

In this case, for example, the insulating film processing apparatus 150 shown in FIG. 6 is used instead of the insulating film processing apparatus 34 of FIG. 4 . This insulating film forming apparatus 150 has a process container 151 that can be closed. In the center of the bottom of the processing container 151, a mounting table 152 is provided. A plurality of electron beam irradiators 153 are installed at positions facing the mounting table 152 in the upper portion of the processing container 151 . These irradiators 153 are arranged so as to be able to uniformly irradiate electron beams to, for example, the surface of the substrate W placed on the mounting table 152 . The electron beam irradiator 153 can irradiate electron beams by applying a high voltage from a high voltage power supply 154 provided outside the processing container 151 . In addition, the irradiation amount of electron beams can be adjusted by, for example, the control unit 155 that controls the operation of the high-voltage power supply 154 .

At the bottom of the processing container 151, an exhaust port 156 for exhausting the atmosphere in the processing container 151 is provided. An exhaust pipe 158 communicating with an exhaust device 157 such as a turbomolecular pump is connected to the exhaust port 156 . By exhausting the air from the exhaust port 156, the inside of the processing container 151 can be decompressed to a predetermined pressure, and the inside of the processing container 151 can be maintained in a depressurized atmosphere free of moisture.

Then, when the fluorine atoms are desorbed, the inside of the processing container 151 is maintained in a dry atmosphere by exhausting from the exhaust port 156 , and then the substrate W is loaded into the processing container 151 . The loaded substrate W is placed on the mounting table 152 , and the CF insulating film I on the substrate W is irradiated with electron beams from the electron beam irradiator 153 . The fluorine atoms exposed on the surface of the CF insulating film 1 are disconnected from the carbon atoms by the energy of the electron beams and detached. In this case, fluorine atoms can be efficiently desorbed by irradiation with high-energy electron beams. In addition, since the electron beams are transmitted into the CF insulating film 1, fluorine atoms existing in an unstable state without bonding are also detached inside the CF insulating film 1, and the film quality of the CF insulating film 1 itself can be improved.

In addition, according to this example, electron beams are irradiated to the surface of the CF insulating film I, but ultraviolet rays may be irradiated instead of electron beams. In this case, in the insulating film processing apparatus 150 shown in FIG. 6 , an ultraviolet irradiator 160 is provided instead of the electron beam irradiator 153 . Also when ultraviolet rays are irradiated to the CF insulating film I, fluorine atoms can be desorbed efficiently by high-energy ultraviolet rays. In addition, fluorine atoms existing in an unstable state inside the CF insulating film I can also be detached.

In the above embodiments, the reaction between the fluorine atoms and the water molecules is prevented by detaching the fluorine atoms exposed on the surface of the CF insulating film I. Alternatively, the reaction between fluorine atoms and water molecules may be prevented by forming a protective film for preventing contact with moisture on the CF insulating film formed on the substrate W.

In this case, as shown in FIG. 7 , a substrate processing system 1 provided with insulating film processing devices 170 and 171 for forming a pellicle instead of the insulating film processing devices 34 and 35 of the processing system 1 shown in FIG. 1 is used. '. As the insulating film processing apparatuses 170 and 171, a plasma CVD apparatus for forming a film using plasma is used.

As shown in FIG. 8, the insulating film processing apparatus 170 has first, second, and third gas supply sources 202, 203, 204 and a raw material gas supply source 215, respectively, instead of the gas supply source 71 and raw material gas supply source 71 shown in FIG. Supply source 84. Other configurations of the insulating film processing apparatus 170 are substantially the same as those of the insulating film forming apparatus 32 shown in FIG. 2 .

In this embodiment, for example, in order to form a pellicle film made of SiN on the substrate W, hydrogen gas is sealed in the first gas supply source 202 , argon gas is sealed in the second gas supply source 203 , and the third gas supply source 203 is filled with hydrogen gas. Nitrogen gas is enclosed in source 204 . In addition, silane gas as a source gas is sealed in the source gas supply source 215 .

In addition, since the structure of the insulating film processing apparatus 171 is the same as that of the insulating film processing apparatus 170, description is abbreviate|omitted.

In the substrate processing system 1' configured as above, first, the CF insulating film I is formed on the surface of the substrate W in the insulating film forming apparatus 32 or 33 in the same manner as in the above-mentioned embodiment. Then, the substrate W is transported through the transport path 8 to the insulating film processing apparatus 170 or 171 , for example, the insulating film processing apparatus 170 while keeping the CF insulating film I from contacting moisture. The inside of the insulating film processing apparatus 170 is preliminarily decompressed by exhausting from the exhaust port 90 to maintain a dry atmosphere. The substrate W conveyed into the insulating film processing apparatus 170 is placed on the mounting table 51 .

The substrate W is maintained at, for example, about 350° C. by the heater 54 inside the mounting table 51 . A mixed gas of argon, hydrogen, and nitrogen is supplied from the gas supply port 70 to the plasma excitation region R1. The microwave of 2.45 GHz is emitted from the RLSA 62 to the plasma excitation region R1 directly below, and the mixed gas in the plasma excitation region R1 is plasmaized.

优选小于

例如

左右的厚度的SiN膜(氮化硅膜)构成的防护膜D。When a negative voltage is applied to the mounting table 51 by the high-frequency bias power supply 53 , the plasma in the plasma excitation region R1 diffuses into the plasma diffusion region R2 through the source gas supply structure 80 . A silane gas is supplied from the source gas supply port 83 to the plasma diffusion region R2, and the silane gas is activated by the plasma diffused from the plasma excitation region R1. SiN is deposited and grown on the surface of the CF insulating film I of the substrate W by radicals of the silane gas and nitrogen gas, and the like. Thus, as shown in FIG. 9, on the CF insulating film I, formed by less than

preferably less than

For example

The pellicle D made of a SiN film (silicon nitride film) having a thickness of about 100 Å.

的由SiN构成的防护膜D，所以可以维持包括CF绝缘膜I与防护膜D的膜整体的绝缘性。According to this embodiment, the substrate W on which the CF insulating film I is formed is transported to the insulating film processing device 170 without contacting moisture, and in the processing device 170, a pellicle film made of SiN can be formed on the surface of the CF insulating film I. d. Therefore, the fluorine atoms exposed on the surface of the CF insulating film 1 can be prevented from reacting with water molecules. As a result, hydrogen fluoride gas is not released from the CF insulating film I, and it is possible to prevent, for example, other films in the semiconductor device from being damaged and peeled off by the hydrogen fluoride gas. In addition, it is possible to prevent the CF insulating film I itself from deteriorating due to the reaction with water molecules, resulting in an increase in the dielectric constant. Moreover, since the CF insulating film I is formed with a thickness less than

Since the protective film D made of SiN is used, the insulation properties of the entire film including the CF insulating film I and the protective film D can be maintained.

左右的厚度。另外，形成防护膜D的绝缘膜处理装置也可以是利用电子回旋加速器共振的等离子体CVD装置、溅射装置、ICP等离子体装置或平行平板型等离子体装置等其它成膜装置。The material of the pellicle D is not limited to SiN, and other materials with a low dielectric constant such as amorphous carbon, SiCN, SiC, SiCO, or CN may be used. Here, amorphous carbon includes hydrogenated amorphous carbon. In the case of using these amorphous carbon, SiCN, SiC, SiCO, or CN materials, since the dielectric constant is lower than that of SiN, the thickness of the pellicle D can be further increased, and the pellicle D can be formed more easily. For example, when the material of the pellicle D is amorphous carbon, SiCN, SiC, SiCO, CN, it is preferably

About the thickness. In addition, the insulating film processing apparatus for forming the pellicle D may be another film forming apparatus such as a plasma CVD apparatus utilizing electron cyclotron resonance, a sputtering apparatus, an ICP plasma apparatus, or a parallel plate plasma apparatus.

In addition, after detaching fluorine atoms from the surface of the CF insulating film on the substrate W as in the previous embodiment ( FIGS. 1 to 6 ), carbonitridation of the surface of the CF insulating film may be performed directly. In this case, the surface of the CF insulating film functions as a protective film.

Alternatively, the protective film D may be formed on the CF insulating film I after fluorine atoms are detached from the surface of the CF insulating film I on the substrate W as in the previous embodiment ( FIGS. 1 to 6 ). In this way, the reaction of the fluorine atoms on the surface of the CF insulating film 1 with the water molecules can be more reliably prevented.

11a to 11c show the experimental results for confirming the properties of the CF insulating film processed according to the foregoing embodiment (FIGS. 1 to 5). Among them, Fig. 11a shows the results of measuring the substrate of the comparative example without any treatment after the formation of the CF insulating film by TDS (thermal desorption spectroscopy), and Fig. 11b shows the measurement of the Ar plasma after the formation of the CF insulating film by TDS Figure 11c shows the results of measuring the substrate of the example exposed to _N2 plasma for 5 seconds after the formation of the CF insulating film by TDS.

From these figures, it can be seen that by exposing the CF insulating film to plasma, outgassing (especially of F) from the film is reduced. In these figures, only representative outgassing components are shown, but actually, reductions in components such as C, CF, CF ₂ , and SiF ₃ due to exposure to plasma are also observed. This means that the amount of outgassing from the CF insulating film is reduced when annealing the substrate after the CF insulating film is formed. Therefore, it is possible to prevent voids from being generated at the interface between the CF insulating film and the barrier layer, wiring layer, protective layer, etc. laminated thereon, and to maintain good adhesion between the two.

In addition, in the above description, some examples of the embodiment of the present invention have been described, but the present invention is not limited to these examples, and various forms can be employed. For example, in the above embodiments, the substrate W on which the CF insulating film I is formed is used for a semiconductor device as a semiconductor device, but it may also be used for other electronic devices such as liquid crystal display devices and organic EL elements.

Industrial availability

The present invention is useful for forming a high-quality insulating film made of fluorocarbon on the surface of a substrate for electronic devices in the manufacture of electronic devices such as semiconductor devices, liquid crystal display devices, and organic EL elements.

Claims (12)

1. the processing method of an electronic device substrate is characterized in that:

Comprise: the operation of preparing the substrate of use for electronic equipment;

On the surface of this substrate, form the operation of the dielectric film that constitutes by fluorocarbon; With

The operation that the fluorine atom that exposes on the surface of described dielectric film is broken away from from this dielectric film,

The described operation that fluorine atom is broken away from is undertaken by the surface irradiation electron ray to described dielectric film,

At least after the operation of described formation dielectric film up to the described operation that fluorine atom is broken away from finish during, keep described substrate and do not contact with moisture.

2. the method for claim 1 is characterized in that:

Described make the operation that fluorine atom breaks away from after,

Also be included in the operation of the protecting film that is formed on the described dielectric film preventing that moisture from contacting with the surface of this dielectric film.

3. method as claimed in claim 2 is characterized in that:

The material of described protecting film is selected from amorphous carbon, SiN, SiCN, SiC, SiCO and CN.

4. method as claimed in claim 2 is characterized in that:

Described protecting film have less than

Thickness.

5. the method for claim 1 is characterized in that:

Described make the operation that fluorine atom breaks away from after,

Also comprise the surfaces nitrided operation that directly makes described dielectric film.

6. the processing method of an electronic device substrate is characterized in that, comprising:

Prepare the operation of the substrate of use for electronic equipment;

On the surface of this substrate, form the operation of the dielectric film that constitutes by fluorocarbon; With

The operation that the fluorine atom that exposes on the surface of described dielectric film is broken away from from this dielectric film,

The described operation that fluorine atom is broken away from is undertaken by the surface irradiation ultraviolet ray to described dielectric film,

At least after the operation of described formation dielectric film up to the described operation that fluorine atom is broken away from finish during, keep described substrate and do not contact with moisture.

7. method as claimed in claim 6 is characterized in that:

Described make the operation that fluorine atom breaks away from after,

Also be included in the operation of the protecting film that is formed on the described dielectric film preventing that moisture from contacting with the surface of this dielectric film.

8. method as claimed in claim 7 is characterized in that:

The material of described protecting film is selected from amorphous carbon, SiN, SiCN, SiC, SiCO and CN.

9. method as claimed in claim 7 is characterized in that:

Described protecting film have less than

Thickness.

10. method as claimed in claim 6 is characterized in that:

Described make the operation that fluorine atom breaks away from after,

Also comprise the surfaces nitrided operation that directly makes described dielectric film.

11. an electronic device substrate is characterized in that:

Form the dielectric film that constitutes by fluorocarbon in its surface, and, by the irradiation electron ray fluorine atom that exposes on the surface of this dielectric film is broken away from, on this dielectric film, be formed with and be used to the protecting film that prevents that moisture from contacting with the surface of this dielectric film.

12. an electronic device substrate is characterized in that:

Form the dielectric film that constitutes by fluorocarbon in its surface, and, by irradiation ultraviolet radiation the fluorine atom that exposes on the surface of this dielectric film is broken away from, on this dielectric film, be formed with and be used to the protecting film that prevents that moisture from contacting with the surface of this dielectric film.

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