JP4758938B2 - Insulating film forming method and insulating film forming apparatus - Google Patents

Description

The present invention relates to a method for forming an insulating film, and more particularly to a method for forming an insulating film having a low N—H bond content and an apparatus for forming an insulating film .

  In recent years, miniaturization of semiconductor devices has progressed, and the design rule has reached 0.13 μm. In the 0.13 μm generation, the wiring performance is dominant over the performance of the semiconductor device, and the wiring delay greatly affects the operation speed of the device. For this reason, in order to manufacture a high-speed circuit, it is necessary to suppress the wiring delay as much as possible.

  In order to reduce wiring delay, the wiring material has shifted from aluminum alloy to copper. Copper has a low specific resistance and high electromigration resistance, and is suitably used for high-speed circuit construction. However, unlike aluminum alloys, it is difficult to form a wiring pattern by chemical etching. For this reason, a so-called damascene method is employed as a method for forming copper wiring.

  The damascene method will be described below with reference to FIGS. 8 (a) to 8 (e). First, as shown in FIG. 8A, a hard mask 102 such as a silicon nitride film is formed on an interlayer insulating film 101 such as a silicon oxide film. Subsequently, as shown in FIG. 8B, an opening 103 is formed in the hard mask 102 by photolithography and etching. At this time, the etching is performed under the condition that the hard mask 102 is etched but the interlayer insulating film 101 is not etched.

  Subsequently, the interlayer insulating film 101 is etched using the hard mask 102 having the openings 103 as a mask. As a result, a trench hole 104 as shown in FIG. 8C is formed. Further, after a barrier metal film 105 such as TiN is formed on the entire surface including the inner wall of the trench hole 104, the interior of the trench hole 104 is filled with a wiring metal 106 by plating as shown in FIG. Finally, an unnecessary metal film is removed by chemical mechanical polishing (CMP) to form a copper wiring layer 107 as shown in FIG.

  In recent years, SiCN-based films have been developed as the hard mask 102 used in the damascene method. The SiCN film is composed mainly of silicon (Si), carbon (C), and nitrogen (N). The SiCN-based film is formed using, for example, hexamethyldisilazane and ammonia as starting materials. The SiCN-based film has advantages such as a relatively low relative dielectric constant and a high barrier property against copper.

  However, when the damascene method is performed using the hard mask 102 made of a SiCN-based film, a phenomenon in which the resist is not exposed according to the mask pattern is often observed when performing lithography for forming the opening 103. Such a phenomenon is called resist poisoning.

It has been confirmed that resist poisoning when using a SiCN-based film is more likely to occur as the number of nitrogen-hydrogen bonds (N—H bonds) in the film increases. This is considered to be because the N—H bond in the film is desorbed as ammonia (NH ₃ ) in the heat treatment in the lithography process. For this reason, it is necessary to obtain a SiCN-based film with few N—H bonds in the film in order to form a wiring pattern with high accuracy.

  However, there is no conventional method for forming a SiCN film having a low N—H bond content in the film, and a highly reliable semiconductor device is manufactured when the SiCN film is used as a hard mask. There was a possibility that it could not be done.

In view of the above circumstances, an object of the present invention is to provide a plasma CVD film forming method and a plasma CVD film forming apparatus that can suppress the occurrence of resist poisoning.
Another object of the present invention is to provide a plasma CVD film forming method and a plasma CVD film forming apparatus that can be suitably used for forming a buried wiring layer.

In order to achieve the above object, a method of forming an insulating film according to the first aspect of the present invention includes:
A SiCN-based film that forms a SiCN-based film containing N—H bonds at a temperature of 400 ° C. or less by plasma of a processing gas containing two types of gases, an organosilicon compound containing Si and C, and a nitrogen-containing compound. A film forming step;
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. And comprising
At least one of the organosilicon compound containing Si and C and the nitrogen-containing compound contains hydrogen,
An insulating film in which the SiCN-based films are stacked is formed by alternately repeating the SiCN-based film forming step and the hydrogen removing step.

In order to achieve the above object, a method for forming an insulating film according to a second aspect of the present invention includes:
A SiCN-based film forming step of forming a SiCN-based film containing an N—H bond at a temperature of 400 ° C. or less by plasma of a processing gas containing one kind of gas of an organosilicon compound containing all of Si, C, and N When,
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. And comprising
The organosilicon compound containing all of Si, C, and N contains hydrogen,
An insulating film in which the SiCN-based films are stacked is formed by alternately repeating the SiCN-based film forming step and the hydrogen removing step.

In the plasma annealing treatment, an inert gas plasma of Ar, He, Ne, Xe, and N ₂ may be used .

In the SiCN-based film forming step, the plasma may be generated by any of a parallel plate type, an ECR type, an ICP type, a TCP type, and a helicon type .

The organosilicon compound containing Si and C is at least one selected from organosilane and organosilazane, and the nitrogen-containing compound is N ₂ , NF ₃ , N ₂ O, N ₂ O ₄ , NO, N _3. It may be at least one selected from H ₈ and NH ₃ .

The organosilicon compound containing all of Si, C, and N may be an organosilazane compound having a silazane bond .

The insulating film may be formed on an interlayer insulating film formed on a substrate, and the insulating film may be used as a hard mask when the interlayer insulating film is etched .

In the SiCN-based film forming step, the SiCN-based film may be formed with a thickness of 1 nm to 5 nm .

In order to achieve the above object, an insulating film forming apparatus according to a third aspect of the present invention comprises:
A chamber;
In order to form an insulating film, a raw material supply unit that supplies a processing gas containing two kinds of gases, an organosilicon compound containing Si and C, and a nitrogen-containing compound, to the chamber;
An evacuation unit for maintaining the inside of the chamber at a predetermined reduced pressure,
A heating unit for placing the object to be processed and heating it to a predetermined temperature;
A plasma generator for generating plasma to be contacted with the object to be processed in the chamber;
Control the raw material supply unit, the vacuum exhaust unit, the heating unit, the plasma generation unit,
In the chamber,
A SiCN-based film containing an N—H bond is formed at a temperature of 400 ° C. or less by plasma of a processing gas containing two kinds of gases, ie, an organosilicon compound containing Si and C and the nitrogen-containing compound. A SiCN-based film forming step;
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. When,
A control unit for forming an insulating film in which the SiCN-based films are stacked by alternately repeating
The organosilicon compound containing Si and C contains hydrogen.

In order to achieve the above object, an insulating film forming apparatus according to a fourth aspect of the present invention provides:
A chamber;
In order to form an insulating film, a raw material supply unit that supplies a processing gas containing one kind of gas of an organosilicon compound containing all of Si, C, and N to the chamber;
An evacuation unit for maintaining the inside of the chamber at a predetermined reduced pressure,
A heating unit for placing the object to be processed and heating it to a predetermined temperature;
A plasma generator for generating plasma to be contacted with the object to be processed in the chamber;
Control the raw material supply unit, the vacuum exhaust unit, the heating unit, the plasma generation unit,
In the chamber,
SiCN-based film formation for forming a SiCN-based film containing N—H bonds at a temperature of 400 ° C. or less by plasma of a processing gas containing one kind of gas of an organosilicon compound containing all of Si, C, and N Process,
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. When,
A control unit for forming an insulating film in which the SiCN-based films are stacked by alternately repeating
The organosilicon compound containing all of Si, C, and N contains hydrogen.

As described above, according to the present invention, there are provided an insulating film forming method and an insulating film forming apparatus in which damage to the film is reduced.

  Hereinafter, a method for forming an insulating film according to the present embodiment will be described with reference to the drawings. According to the method for forming an insulating film of the present embodiment, a film composed of silicon (Si), carbon (C), and nitrogen (N) as main components (hereinafter referred to as a SiCN-based film) is formed. The SiCN-based film functions as a hard mask for forming a buried wiring layer in the interlayer insulating film using a damascene method or a dual damascene method.

FIG. 1 shows a configuration example of an apparatus for carrying out the insulating film forming method of the present embodiment.
The processing apparatus according to the present embodiment is configured as a so-called parallel plate type plasma CVD apparatus having electrodes facing in parallel vertically, and forms a SiCN film on the surface of a semiconductor wafer (hereinafter referred to as wafer W) by CVD.

  With reference to FIG. 1, the processing apparatus 11 includes a cylindrical chamber 12. The chamber 12 is made of a conductive material such as aluminum that has been anodized (anodized). The chamber 12 is grounded.

  An exhaust port 13 is provided at the bottom of the chamber 12. An exhaust device 14 including a vacuum pump such as a turbo molecular pump is connected to the exhaust port 13. The exhaust device 14 exhausts the inside of the chamber 12 to a predetermined pressure. A gate valve 15 is provided on the side wall of the chamber 12. With the gate valve 15 opened, the wafer W is carried into and out of the chamber 12.

  A substantially cylindrical susceptor support 16 is provided at the bottom of the chamber 12. On the susceptor support 16, a susceptor 17 is provided as a mounting table for the wafer W. The susceptor 17 has a function as a lower electrode, and the susceptor support 16 and the susceptor 17 are insulated by an insulator 18 such as ceramic.

  A lower coolant channel 19 is provided inside the susceptor support 16. A refrigerant circulates in the lower refrigerant flow path 19. As the coolant circulates through the lower coolant channel 19, the susceptor 17 and the wafer W are controlled to a desired temperature.

  The susceptor support 16 is provided with lift pins 20 for transferring the semiconductor wafer W, and the lift pins 20 can be moved up and down by a cylinder (not shown). Further, the susceptor 17 is formed in a disc shape having a convex upper center portion, and an electrostatic chuck (not shown) having substantially the same shape as the wafer W is provided thereon. The wafer W placed on the susceptor 17 is electrostatically attracted by applying a DC voltage.

  A first high frequency power supply 21 is connected to the susceptor 17 functioning as the lower electrode via a first matching unit 22. The first high frequency power supply 21 has a frequency in the range of 0.1 to 13 MHz. By applying a frequency in the above range to the first high-frequency power source 21, effects such as reducing damage to the object to be processed can be obtained.

  A shower head 23 is provided above the susceptor 17 so as to face the susceptor 17 in parallel. An electrode plate 25 made of aluminum or the like having a large number of gas holes 24 is provided on the surface of the shower head 23 facing the susceptor 17. The shower head 23 is supported on the ceiling portion of the chamber 12 by an electrode support 26. Inside the shower head 23, an upper refrigerant channel 27 is provided. The refrigerant circulates in the upper refrigerant flow path 27, and the shower head 23 is controlled to a desired temperature.

Further, a gas introduction pipe 28 is connected to the shower head 23. The gas introduction pipe 28 is connected to a hexamethyldisilazane (HMDS) gas source 29, an ammonia (NH ₃ ) gas source 30, and an argon (Ar) gas source 31 through a mass flow controller, a valve, etc. (not shown). Has been.

  Process gases from the gas sources 29 to 31 are mixed and supplied to a hollow portion (not shown) formed inside the shower head 23 via the gas introduction pipe 28. The gas supplied into the shower head 23 is diffused in the hollow portion and supplied from the gas hole 24 of the shower head 23 to the surface of the wafer W.

  A second high frequency power source 32 is connected to the shower head 23, and a second matching unit 33 is interposed in the power supply line. The second high-frequency power source 32 has a frequency in the range of 13 to 150 MHz. By applying such a high frequency, the shower head 23 functions as an upper electrode and is in a preferable dissociated state in the chamber 12. In addition, high-density plasma is formed.

  The controller 34 controls the operation of the entire processing apparatus 11 including a film forming process on the wafer W. The detailed operation of the controller 34 is omitted for easy understanding.

  Hereinafter, a method for forming an insulating film using the processing apparatus 11 will be described. FIG. 2 shows a timing chart of the manufacturing method of the present embodiment. Note that the timing diagram shown in FIG. 2 is an example, and any timing diagram may be used as long as the same effect can be obtained.

  First, an unprocessed wafer W having an insulating film on its surface is carried into the chamber 12 through an open gate valve 15 held by a transfer arm (not shown). The transfer arm transfers the wafer W to the lift pins 20 at the raised position and exits from the chamber 12. Thereafter, the wafer W is placed on the susceptor 17 as the lift pins 20 are lowered. The wafer W is fixed on the susceptor 17 by an electrostatic chuck.

Next, the controller 34 sets the inside of the chamber 12 to, for example, 1.3 × 10 ⁻² Pa (1 × 10 ⁻⁴ Torr) by the exhaust device 14. At the same time, the controller 34 sets the temperature of the susceptor 17 to a temperature of 400 ° C. or lower, for example, 350 ° C.

Thereafter, HMDS, NH ₃ and Ar gas are supplied from the gas sources 29 to 31 into the chamber 12 at a predetermined flow rate. The mixed gas of the processing gas is uniformly discharged toward the wafer W from the gas hole 24 of the shower head 23. The supply of HMDS, NH ₃ and Ar is performed at a flow rate ratio (each sccm) of HMDS / NH ₃ / Ar = 30/10/100, for example.

  Thereafter, a high frequency power of 60 MHz, for example, is applied from the second high frequency power supply 32 to the upper electrode (shower head 23). Thereby, a high-frequency electric field is generated between the upper electrode and the lower electrode (susceptor 17), and mixed gas plasma is generated. On the other hand, from the first high frequency power supply 21, for example, high frequency power of 2 MHz is applied to the lower electrode. Thereby, ions in the plasma are drawn to the susceptor 17 side, and the plasma density near the surface of the wafer W is increased. Application of high-frequency power to the upper and lower electrodes 23 and 17 generates plasma of a processing gas, and a SiCN-based film is formed on the surface of the wafer W by a chemical reaction on the surface of the wafer W by the plasma. .

Here, the controller 34 applies high-frequency power to the upper and lower electrodes 23 and 17 for several seconds, and forms a thin film of a SiCN film having a thickness of, for example, 1 nm to 5 nm (10 to 50 mm) on the surface of the wafer W. . After a predetermined time from the start of the application of the high-frequency power, the controller 34 stops the application of the high-frequency power to the upper electrode and the lower electrode and stops the introduction of HMDS and NH ₃ from the HMDS gas source 29 and the NH ₃ gas source 30. To do. Thus, the film forming process is completed. At this time, Ar flows in the chamber 12.

The controller 34 purges the chamber 12 with Ar gas for a predetermined time, and removes the remaining HMDS and NH ₃ from the chamber 12. At this time, the controller 34 sets the temperature of the susceptor 17 to a temperature of 450 ° C. or lower, for example, 400 ° C., and sets the pressure to, for example, 1.3 × 10 ⁻³ Pa (1 × 10 ⁻⁵ Torr). And

The controller 34 performs annealing by heating the susceptor 17 at 400 ° C. for a predetermined time. In the annealing step, NH bonds existing in the SiCN film formed on the surface of the wafer W are excited, whereby the NH bonds are dissociated and hydrogen (H) is desorbed. The desorbed H is discharged out of the chamber 12 as H ₂ or the like as exhaust gas. Here, the formed SiCN-based film is a thin film of several atomic layers having a thickness of about 1 nm to 5 nm. For this reason, desorption of H occurs easily even on the surface other than the film surface, and the removal of N—H bonds from the SiCN film is sufficiently performed.

Here, for example, FTIR (Fourier Transform Infrared Spectroscopic Analysis) shows that the N—H bond absorption peak in the vicinity of 1200 cm ^−1, which was present in the thin film immediately after film formation, has completely disappeared after annealing. ). Therefore, it can be seen that the N—H bond is reliably removed from the formed thin film.

The controller 34 performs the annealing process for a time sufficient to remove H from the N—H bonds in the film. After a predetermined time, the controller 34 lowers the temperature of the susceptor 17 to the temperature at the time of film formation (350 ° C.) while flowing Ar into the chamber 12, and the pressure is reduced to 1.3 × 10 ⁻² Pa (1 × 10 ⁻⁴ Torr).

Thereafter, the controller 34 starts to form a thin film of the above-described SiCN-based film again. That is, the controller 34 starts supplying HMDS and NH ₃ from the gas source. Next, high frequency power is applied to the upper electrode and the lower electrode. By performing the film formation process for a predetermined time in the same manner as described above, a thin SiCN-based film having a thickness of 1 nm to 5 nm is newly formed on the already formed thin film.

After the film forming process, the controller 34 stops the application of the high frequency power to the upper electrode and the lower electrode, and stops the supply of HMDS and NH ₃ . Next, the temperature of the susceptor 17 is set to 400 ° C., the pressure in the chamber 12 is set to 1.3 × 10 ⁻³ Pa (1 × 10 ⁻⁵ Torr), and the inside of the chamber 12 is purged with Ar gas.

  The controller 34 again holds the susceptor 17 at 400 ° C. for a predetermined time and performs an annealing process. Thereby, H of the N—H bond in the SiCN-based film, particularly in the newly formed film is desorbed. In this way, N—H bonds are removed from the newly formed SiCN-based film.

Thereafter, the controller 34 reduces the temperature of the susceptor 17 to 350 ° C., and the pressure in the chamber 12 is set to 1.3 × 10 ⁻² Pa (1 × 10 ⁻⁴ Torr). In this way, the controller 34 repeats the film forming process, the annealing process, and the purge between the processes. The controller 34 repeats the above processes as many times as the total thickness of the SiCN-based film formed by stacking the thin films reaches a predetermined thickness, for example, 500 nm (5000 mm).

  After the above processes are repeated a predetermined number of times, the controller 34 stops heating the susceptor 17 and returns the pressure in the chamber 12 to the pressure outside the chamber 12. Thereafter, the electrostatic chuck is released and the lift pin 20 is raised. Next, the gate valve 15 is opened, and the transfer arm enters the chamber 12. The wafer W is carried out of the chamber 12 by the transfer arm.

  The SiCN-based film forming process using the processing apparatus 11 is thus completed, and a resultant product in which the SiCN-based film 41 is formed on the insulating film 40 as shown in FIG. 3 is obtained. The wafer W is then subjected to patterning of the SiCN-based film 41, and then etching of the insulating film 40 using the patterned SiCN-based film 41 as a hard mask. For example, the embedded wiring as shown in FIGS. Layer 42 is formed.

  4 to 6, the wiring layer 42 is provided via a barrier layer 42a. Here, the wiring layer 42 shown in FIG. 4 is an example formed using the damascene method. Further, the wiring layer 42 shown in FIGS. 5 and 6 is an example in which a trench hole 43 and a via hole 44 are formed using a dual damascene method. The wiring layer 42 shown in FIG. 5 is formed using one hard mask (SiCN-based film 41), and the wiring layer 42 shown in FIG. 6 is formed using two hard masks.

  As described above, according to the present invention, the SiCN-based film is formed by laminating a thin film having a thickness of several nm. During the thin film formation process, N—H bonds in the thin film (particularly the film surface) are removed by thermal annealing. As a result, a SiCN-based film having a low N—H bond content in the film is finally formed.

By forming a SiCN-based film having a low N—H bond content, generation of NH ₃ during heating in the lithography process can be suppressed. FIG. 7 shows a result of detecting NH ₃ generated under resist processing conditions by gas analysis from a thin film in which the amount of N—H bonds remaining in the film is changed by changing the annealing time. As shown in FIG. 7, the NH bond and generate NH ₃ intensity present in the film showed a positive correlation with a decrease in the NH bond, NH ₃ intensity generated also decreases. From this, it is possible to reduce resist alteration (so-called resist poisoning) by using an insulating film formed by sufficiently removing N—H bonds from a thin film by appropriate annealing treatment, and reliability. It can be seen that high lithography processing (patterning) is possible. Therefore, highly reliable wiring layer formation processing (particularly, damascene processing) using the SiCN-based film as a hard mask becomes possible. The quantification of resist poisoning can be performed, for example, by taking an SEM (scanning electron microscope) image of the patterned substrate surface and using the distance between the patterned lines of the image. This is because when the resist poisoning occurs, the line edge is shaved and the depth of focus of the microscope does not match, and the line edge is in a so-called defocused state, so the measurement interval is smaller than the design interval.

  The present invention is not limited to the above-described embodiment, and various modifications and applications are possible. Hereinafter, modifications of the above-described embodiment applicable to the present invention will be described.

In the above embodiment, the SiCN-based film is formed using HMDS and NH ₃ as source gas compounds. However, the raw material compound may be any compound containing Si, C, and N, as long as the SiCN film is formed by a single reaction or a combination of these appropriately.

For example, three kinds of raw material gas compounds each containing Si, C, and N can be used. In this case, SiH ₄ is used as the Si-containing compound, C ₂ H ₄ , CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₂ H _{2 and the} like may be appropriately combined with N ₂ , NF ₃ , N ₂ O, N ₂ O ₄ , NO, N ₃ H _{8 and the} like as the N-containing compound.

Alternatively, a film may be formed by mixing two kinds of gases, a raw material compound containing Si and C, and a raw material compound containing N. In this case, the above-described compounds may be used as the N-containing compound, and organic silanes such as alkylsilane and alkoxysilane may be used as the compound containing Si and C, and these may be combined appropriately. Examples of the alkylsilane include methylsilane (SiH ₃ (CH ₃ )), dimethylsilane (SiH ₂ (CH ₃ ) ₂ ), trimethylsilane (SiH (CH ₃ ) ₃ ), and tetramethylsilane (Si (CH ₃ ) _4. ), And examples of the alkoxysilane include methoxylated silanes such as trimethoxymethylsilane (Si (CH ₃ ) (OCH ₃ ) ₃ ). On the contrary, a source gas containing Si and N and a source gas containing C may be mixed. In this case, the C-containing compound is selected from those described above, and the compound containing Si and N may be appropriately combined using, for example, disilazane (SiH ₃ —NH—SiH ₃ ).

Furthermore, it is also possible to use a compound other than HMDS containing all of Si, C, and N as a raw material gas. As such a compound, an organic silazane compound having a silazane bond (—Si—N—) can be used. In the case of using an organic silazane compound, for example, the film can be formed by thermal polymerization by a plasma CVD method. Examples of usable organic silazane compounds include triethylsilazane (SiEt ₃ NH ₂ ), tripropylsilazane (SiPr ₃ NH ₂ ), triphenylsilazane (SiPh ₃ NH ₂ ), and tetramethyldisilazane (SiMe ₂ H—NH). -SiMe ₂ H), hexaethyl disilazane _{(SiEt 3 -NH-SiEt 3)} , hexaphenyl disilazane _{(SiPh 3 -NH-SiPh 3)} , heptamethyldisilazane _{(SiMe 3 -NMe-SiMe 3)} , dipropyl - tetramethyldisilazane _{(SiPrMe 2 -NH-SiPrMe 2)} , di -n- butyl - tetramethyl disilazane _{(SiBuMe 2 -NH-SiBuMe 2)} , di -n- octyl - tetramethyl disilazane (SiOcMe ₂ -NH- SiOcMe ₂ ), Divinyl - tetramethyl disilazane _{(CH 2 = CH-SiMe 2} -NH-SiMe 2 -CH = CH 2) chain silazane compounds such as triethyl - trimethylcyclotrisiloxane silazane _{((SiEtH-NMe) 3)} , 1,1 , 3,3,5,5-hexamethylcyclotrisilazane (HMCTS) and 1,2,3,4,5,6-hexamethylcyclotrisilazane including isomers such as hexamethylcyclotrisilazane ((SiMe _{2 -NH)} 3), hexaethyl cyclotrisiloxane silazane _{((SiEt 2 -NH) 3)} , hexaphenyl cyclotrisiloxane silazane _{((SiPh 2 -NH) 3)} , octamethylcyclotetrasilazane _((SiMe 2 _{-NH) 4)} , octaethyl cyclotetrasiloxane disilazane _{((SiEt 2 -NH) 4)} , tetraethyl - tetra Chill cyclotetrasiloxane disilazane _{((SiHEt-NMe) 4)} , cyanopropyl methylcyclopentadienyl silazane _{(SiMeNC (CH 2) 3 -NH} ), tetraphenyl dimethyl disilazane _{(SiMePh 2 -NH-SiMePh 2)} , diphenyl - tetramethyldisilazane ((SiMe ₂ Ph) ₂ —NH), trivinyl-trimethylcyclotrisilazane ((CH ₂ ═CH—SiMe—NH) ₃ ), tetravinyl-tetramethylcyclotetrasilazane (CH ₂ ═CH—SiMe—NH) ₄ And cyclic silazane compounds such as In the above formula, Me is a methyl group (CH ₃ ), Et is an ethyl group (C ₂ H ₅ ), Pr is a propyl group (C ₃ H ₇ ), Oc is an n-octyl group (n—C ₈ H ₁₇ ), Ph represents a phenyl group (C ₆ H ₅ ).

In the above example, only one source gas containing Si, C, and N is sufficient. However, the present invention is not limited to this. For example, C ₂ H ₂ is added in addition to organosilane and N ₂ . A gas or a gas obtained by adding N ₂ in addition to organic silazane may be used.

  In the above embodiment, a parallel plate type plasma CVD apparatus is used for the film forming process. However, the present invention is not limited to this, and plasma processing such as ECR type, ICP type, TCP type, and helicon type may be used. Moreover, not only plasma CVD but thermal CVD may be used. Furthermore, so-called ALD (Atomic Layer Deposition) or ALE (Atomic Layer Epitaxy), in which a reactant is adsorbed one atomic layer at a time to form a film at the atomic layer level, may be applied.

In the above embodiment, the N—H bond removal treatment is performed by exciting the N—H bond by heating under reduced pressure. However, the method for exciting the N—H bond is not limited to this. For example, plasma annealing may be used. In this case, the SiCN-based thin film may be exposed to plasma of an inert gas such as Ar, He, Ne, Xe, or N ₂ . By using plasma annealing, the N—H bond can be activated and removed not only by desorption of H from the N—H bond but also by extraction of H by active species such as Ar ions.

  In the above embodiment, the SiCN-based film is used as a hard mask for etching. However, the present invention is not limited to this, and it may be used as another application film such as a barrier layer provided on the wiring layer to suppress diffusion of the wiring material.

  In the above embodiment, the SiCN-based film has been described as an example. However, the present invention is not limited to this, and the present invention can be applied to an insulating film including an N—H bond, such as a SiN-based film including at least nitrogen and hydrogen.

  The processing apparatus 11 of the above embodiment may be combined with an etcher or the like. In this case, a clustering system including the processing device 11 or an inline system can be used.

It is a figure which shows the structure of the processing apparatus concerning embodiment of this invention. It is a timing chart of the formation method of the insulating film concerning an embodiment of the invention. It is a figure which shows the structure of the result formed by the formation method of the insulating film of embodiment of this invention. It is the figure which formed the wiring layer in the result formed by the formation method of the insulating film of embodiment of this invention. It is the figure which formed the wiring layer in the result formed by the formation method of the insulating film of embodiment of this invention. It is the figure which formed the wiring layer in the result formed by the formation method of the insulating film of embodiment of this invention. Is a diagram showing a relationship between detected intensity of the NH ₃ gas during the NH bond amount and the resist process of a thin film formed by changing the annealing conditions. It is a figure which shows the formation process of the wiring layer using a damascene method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Processing apparatus 12 Chamber 13 Exhaust port 14 Exhaust apparatus 15 Gate valve 16 Susceptor support stand 17 Susceptor 18 Insulator 19 Lower refrigerant | coolant flow path 20 Lift pin 21 1st high frequency power supply 22 1st matching device 23 Shower head 24 Gas hole 25 Electrode Plate 26 Electrode support 27 Upper refrigerant flow path 28 Gas introduction pipe 29 HMDS gas source 30 NH ₃ gas source 31 Ar gas source 32 Second high frequency power source 33 Second matching unit 34 Controller

Claims (10)

A SiCN-based film that forms a SiCN-based film containing N—H bonds at a temperature of 400 ° C. or less by plasma of a processing gas containing two types of gases, an organosilicon compound containing Si and C, and a nitrogen-containing compound. A film forming step;
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. And comprising
At least one of the organosilicon compound containing Si and C and the nitrogen-containing compound contains hydrogen,
An insulating film forming method, wherein an insulating film in which the SiCN-based films are stacked is formed by alternately repeating the SiCN-based film forming step and the hydrogen removing step. The organosilicon compound containing Si and C is at least one selected from organosilane and organosilazane, and the nitrogen-containing compound is N ₂ , NF ₃ , N ₂ O, N ₂ O ₄ , NO, N _3. The method for forming an insulating film according to claim 1, wherein the insulating film is at least one selected from H ₈ and NH ₃ . A SiCN-based film forming step of forming a SiCN-based film containing an N—H bond at a temperature of 400 ° C. or less by plasma of a processing gas containing one kind of gas of an organosilicon compound containing all of Si, C, and N When,
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. And comprising
The organosilicon compound containing all of Si, C, and N contains hydrogen,
An insulating film forming method, wherein an insulating film in which the SiCN-based films are stacked is formed by alternately repeating the SiCN-based film forming step and the hydrogen removing step.   4. The method for forming an insulating film according to claim 3, wherein the organosilicon compound containing all of Si, C, and N is an organosilazane compound having a silazane bond. 5. The insulating film formation according to claim 1, wherein the plasma annealing treatment uses plasma of an inert gas of any one of Ar, He, Ne, Xe, and N _2. Method.   The said plasma is produced | generated by any of a parallel plate type, an ECR type, an ICP type, a TCP type, and a helicon type in the said SiCN type | system | group film formation process. The insulating film formation method as described. The insulating film is formed on an interlayer insulating film formed on a substrate,
The method for forming an insulating film according to claim 1, wherein the insulating film is used as a hard mask when the interlayer insulating film is etched.   The method for forming an insulating film according to claim 1, wherein, in the SiCN-based film forming step, the SiCN-based film is formed with a thickness of 1 nm to 5 nm. A chamber;
In order to form an insulating film, a raw material supply unit that supplies a processing gas containing two kinds of gases, an organosilicon compound containing Si and C, and a nitrogen-containing compound, to the chamber;
An evacuation unit for maintaining the inside of the chamber at a predetermined reduced pressure,
A heating unit for placing the object to be processed and heating it to a predetermined temperature;
A plasma generator for generating plasma to be contacted with the object to be processed in the chamber;
Control the raw material supply unit, the vacuum exhaust unit, the heating unit, the plasma generation unit,
In the chamber,
A SiCN-based film containing an N—H bond is formed at a temperature of 400 ° C. or less by plasma of a processing gas containing two kinds of gases, ie, an organosilicon compound containing Si and C and the nitrogen-containing compound. A SiCN-based film forming step;
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. And a control unit that forms an insulating film in which the SiCN-based films are stacked, by alternately repeating
With
The organosilicon compound containing Si and C contains hydrogen,
An insulating film forming apparatus. A chamber;
In order to form an insulating film, a raw material supply unit that supplies a processing gas containing one kind of gas of an organosilicon compound containing all of Si, C, and N to the chamber;
An evacuation unit for maintaining the inside of the chamber at a predetermined reduced pressure,
A heating unit for placing the object to be processed and heating it to a predetermined temperature;
A plasma generator for generating plasma to be contacted with the object to be processed in the chamber;
Control the raw material supply unit, the vacuum exhaust unit, the heating unit, the plasma generation unit,
In the chamber,
SiCN-based film formation for forming a SiCN-based film containing N—H bonds at a temperature of 400 ° C. or less by plasma of a processing gas containing one kind of gas of an organosilicon compound containing all of Si, C, and N Process,
A hydrogen removal step of exciting and dissociating NH bonds in the SiCN-based film by removing heat from the SiCN-based film by heat-treating or annealing the SiCN-based film at a temperature of 450 ° C. or lower. And a control unit that forms an insulating film in which the SiCN-based films are stacked, by alternately repeating
With
The organosilicon compound containing all of Si, C, and N contains hydrogen,
An insulating film forming apparatus.

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