Patent Application
20230093323
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-153188, filed on Sep. 21, 2021, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a film forming apparatus, a film forming method, and a film forming system.
Low-resistance ruthenium (Ru) is attracting attention as a material for minute shapes of wires for interconnecting transistors, contacts, and the like formed on a substrate. For example, Patent Documents 1 and 2 propose a technique for embedding ruthenium in a recess formed in a substrate. In order to realize low resistance wires and contacts, it is important to embed ruthenium in recesses without generating voids that increase resistance.
According to one embodiment of the present disclosure, there is provided a film forming apparatus that embeds ruthenium in a substrate having a recess. The film forming apparatus includes: a processing container; a gas supplier configured to supply gas; and a gas exhauster configured to exhaust gas. The gas supplier includes a first supply line configured to supply a ruthenium raw-material gas into the processing container and a second supply line configured to supply a gas containing ozone gas into the processing container. The gas exhauster includes a first exhaust line including a first exhaust apparatus and configured to exhaust a gas containing a ruthenium raw-material gas from an interior of the processing container by using the first exhaust apparatus, and a second exhaust line including a second exhaust apparatus different from the first exhaust apparatus and configured to exhaust the gas containing ozone gas by using the second exhaust apparatus.
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.
Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.
Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In each of the drawings, the same components may be denoted by the same reference numerals, and redundant descriptions thereof may be omitted.
First, the configuration and operation of a film forming system 1 according to an embodiment will be described with reference to
The film forming system 1 includes an atmospheric transport chamber 11, load-lock chambers 12, a first substrate transport chamber 13, a second substrate transport chamber 14, and processing chambers PM. In
The numbers and arrangements of pre-cleaning apparatuses, film forming apparatuses, and annealing apparatuses are not limited to the example illustrated in
The first substrate transport chamber 13 and the second substrate transport chamber 14 are each configured in a square shape in a plan view, and are connected to each other via, for example, two delivery parts 17. The interiors of the first and second substrate transport chambers 13 and 14 and the delivery parts 17 are set to a vacuum pressure atmosphere and configured to have uniform pressures. The delivery parts 17 perform substrate delivery to and from a first transport mechanism 13a installed in the first substrate transport chamber 13 or to and from a second transport mechanism 14a installed in the second substrate transport chamber 14. The first substrate transport chamber 13 and the second substrate transport chamber 14 each include a turbo molecular pump (not illustrated) for a transport chamber to control the interior of each transport chamber to a desired pressure.
It is assumed that the direction in which the first substrate transport chamber 13 and the second substrate transport chamber 14 are arranged is referred to as a length direction, and that the first substrate transport chamber 13 is on the front side and the second substrate transport chamber 14 is on the rear side. At this time, the atmosphere transport chamber 11 set to the atmospheric pressure atmosphere is connected to the front side of the first substrate transport chamber 13 via, for example, three load-lock chambers 12. There are transport ports and gate valves for opening/closing the transport ports are provided, respectively, between the first and second substrate transport chambers 13 and 14 and the delivery parts 17, between the load-lock chambers 12 and the first substrate transport chamber 13, and between the load-lock chambers 12 and the atmospheric transport chamber 11, but the illustration thereof is omitted.
For example, four load ports 15 are connected to the atmospheric transport chamber 11, and a carrier C accommodating plural sheets of substrates is placed in each load port 15. An atmospheric transport mechanism 11a is installed in the atmospheric transport chamber 11 to transport substrates between the carriers C connected to the atmospheric transport chamber 11 and the load-lock chambers 12.
The pre-cleaning apparatuses 21 and 22 are connected, respectively, to two side walls of the first substrate transport chamber 13 at the front side. The pre-cleaning apparatuses 21 and 22 perform a pre-cleaning process for removing a metal oxide as a pre-process for a process of embedding ruthenium. For example, the pre-cleaning apparatuses 21 and 22 remove a metal oxide that is a lower layer of a recess included in a substrate. When the lower layer of the recess included in the substrate is a tungsten layer, the pre-cleaning apparatuses 21 and 22 remove a tungsten oxide due to oxidation of tungsten. In addition, for example, when the lower layer of the recess in the substrate is a ruthenium layer, the pre-cleaning apparatuses 21 and 22 remove a ruthenium oxide formed due to oxidation of ruthenium. The pre-cleaning apparatuses 21 and 22 reduce and remove a metal oxide by hydrogen plasma obtained by turning hydrogen gas into plasma.
The film forming apparatuses 23 and 24 are connected, respectively, to two side walls of the first substrate transport chamber 13 at the rear side. The first transport mechanism 13a installed in the first substrate transport chamber 13 transports substrates among these four processing chambers PM 21 to 24, the delivery parts 17, and the load-lock chambers 12. In
The film forming apparatuses 25 and 26 are connected, respectively, to two side walls of the second substrate transport chamber 14 at the front side. In this example, the film forming apparatuses 25 and 26 are film forming apparatuses for embedding ruthenium.
The film forming apparatus 27 and the annealing apparatus 28 are connected, respectively, to two side walls of the second substrate transport chamber 14 at the rear side. Then, the second transport mechanism 14a transports substrates between these four processing chambers PM (25 to 28) and the delivery parts 17. In
In this example, the film forming apparatus 23 to 26 each embed ruthenium in a recess in a bottom-up manner by using a raw-material gas containing Ru3(CO)12 (hereinafter, also referred to as DCR) as a ruthenium raw-material. The film forming apparatus 27 forms ruthenium up to a field portion by using a raw-material gas containing DCR. This is a process of stacking ruthenium layers for a flattening process (CMP) in the next step.
The annealing apparatus 28 anneals the substrate after the ruthenium is formed up to the field portion. The annealing apparatus 28 may not perform the annealing. The annealing apparatus 28 is an apparatus capable of heating a substrate by a heating part such as a heater.
The film forming system 1 includes a controller 100 that controls the operation of each part constituting the film forming system 1, such as various processes in the pre-cleaning apparatuses 21 and 22, the film forming apparatuses 23 to 27, and the annealing apparatus 28, or substrate transportation. The controller 100 includes, for example, a computer having a CPU (not illustrated) and a memory (storage), and the memory stores a control program necessary for the operation of each part constituting the film forming system 1. The control program may be stored in a non-transient computer readable storage medium such as a hard disk, a compact disk, a magneto-optical disk, a memory card, or a non-volatile memory, and may be installed in the computer from the storage medium. The control program may be acquired from a network connected to the controller 100 by using communication means.
As described above as an example, the film forming system 1 includes at least one film forming apparatus for forming a ruthenium film, and the film forming apparatus is used to embed ruthenium in a substrate having a recess. In this example, the film forming apparatuses 23 to 27 have the same configuration, but the film forming apparatus 27 may not include some components of the film forming apparatuses 23 to 26 (an ozone gas supply line, a hydrogen-containing gas supply line, an ozone gas exhaust line, and the like, which will be described later).
Next, the configuration of a film forming apparatus according to an embodiment included in the film forming system 1 will be described with reference to
The film forming apparatus 23 includes a processing container 101, and the side wall of the processing container 101 is connected to the first substrate transport chamber 13 and includes a transport port 104 for carry-in/out of a substrate to and from the first substrate transport chamber 13. The transport port 104 is configured to be openable/closable by the gate valve GV1.
In the processing container 101, a stage 102 configured to horizontally support a substrate W is installed in a state of being supported by a support pillar 103 from the bottom surface side of the stage 102. The stage 102 includes a heater 105 to be capable of heating the substrate W to a preset temperature.
A shower head 110 is disposed on the ceiling of the processing container 101 to face the substrate W placed on the stage 102. The shower head 110 includes a gas diffusion space 112, and gas ejection ports 113 are dispersedly formed in the bottom surface of the shower head 110.
In addition, the film forming apparatus 23 includes a gas supplier 130 for supplying gas and a gas exhauster 180 for exhausting gas. The gas supplier 130 includes a first supply line 131 for supplying a gas containing a ruthenium raw-material gas and a hydrogen-containing gas to the processing container 101, and a second supply line 132 for supplying a gas containing ozone gas. The first supply line 131 includes a raw-material gas supply line 131a for supplying a gas containing a ruthenium raw-material gas and a hydrogen gas supply line 131b for supplying a hydrogen-containing gas.
The raw-material gas supply line 131a includes a carrier gas supply pipe 133 and supply pipes 140 and 135. The carrier gas supply pipe 133 extends from a CO gas source 134 and is connected to a raw-material container 161. The end of the supply pipe 133 is provided to be inserted into a raw material S. The supply pipe 133 is provided with a valve 137a, a mass flow controller 136, and a valve 137b in this order from the CO gas source 134. CO gas is supplied to the raw-material container 161 as a carrier gas from the CO gas source 134 via the supply pipe 133. However, as the carrier gas, an inert gas such as argon (Ar) gas or nitrogen (N2) gas may be used instead of the CO gas.
The raw-material container 161 accommodates the raw material S for ruthenium. In this example, DCR is accommodated in the raw-material container 161 as the raw material S for the ruthenium film, but the raw material S for the ruthenium film is not limited to DCR and may be an organic gas. The raw material S in the raw-material container 161 is heated by a heater 162 to be vaporized.
The raw-material container 161 and a gas introduction port 111 of the shower head 110 are connected to each other by the supply pipes 140 and 135. The upper end surface of the raw-material container 161 is connected to the supply pipe 140, and the supply pipe 140 is further connected to the supply pipe 135 and connected to the gas introduction port 111. The supply pipe 140 is provided with a valve 139a, a flow meter 138, and a valve 139b in this order from the raw-material container 161. The supply pipe 140 is provided with a valve 139c.
The ruthenium raw-material gas vaporized in the raw-material container 161 flows in the supply pipes 140 and 135 by using CO gas as a carrier gas, and is supplied to the processing container 101 from the gas introduction port 111. The flow meter 138 detects the flow rate of the raw-material gas. With this configuration, a ruthenium film is formed in a recess in the surface of a substrate W by the raw-material gas supplied from the first supply line 131 to the processing container 101.
When a ruthenium film can be formed from the bottom of the recess formed in the substrate W in a bottom-up manner, it is possible to avoid the generation of voids and seam to be described later so that a low resistance ruthenium layer can be formed. However, a ruthenium film (hereinafter, also referred to as a “ruthenium piece”) is formed on the side wall (side surface) of the recess during the film forming process. When the ruthenium piece formed on the side wall is removed by etching, the side surface of the recess is in the state in which no ruthenium film is formed, so that the generation of voids can be avoided. Therefore, in the film forming apparatus 23, ruthenium is grown in a bottom-up manner from the bottom of the recess by a DED method (deposition-etching-deposition method) of repeatedly executing the formation of the ruthenium film (D: deposition) and the removal of the ruthenium piece (E: etching).
When the DED method is not used, the ruthenium piece formed on the side wall of the recess closes the frontage of the recess, which may cause the generation of a void, or a minute gap (seam) may be generated in the recess by the film formation of a conformal ruthenium film. In the film forming method according to an embodiment to be described later, the DED method enables bottom-up embedding of ruthenium in a recess so that a ruthenium wire or contact can be implemented while avoiding a void and a seam.
Therefore, after forming a ruthenium film in the recess, a gas containing ozone is supplied from the second supply line 132 into the processing container 101, and the ruthenium piece formed on the side wall of the recess is etched and removed by the ozone gas.
The second supply line 132 includes supply pipes 170 and 175. The supply pipe 170 extends from the O2 gas source 174 and is connected to the supply pipe 175. The supply pipe 175 is connected to the gas introduction port 111 for introducing O2 gas. The supply pipe 170 is provided with a valve 177a, a mass flow controller 176, an ozonizer 173, and a valve 177b in this order from the O2 gas source 174. The supply pipe 175 is provided with a valve 177c.
The oxygen gas supplied from the O2 gas source 174 is supplied to the ozonizer 173 while the flow rate thereof is controlled by a mass flow controller 176. The ozonizer 173 discharges the oxygen gas by electric energy to produce ozone gas, controls the concentration of ozone gas relative to oxygen gas, and outputs a mixed gas of ozone gas and oxygen gas that is controlled to a certain concentration. The mixed gas of ozone gas and oxygen gas is an example of the gas containing ozone gas. The gas containing ozone gas is supplied to the processing container 101 through the supply pipe 175. As a result, the ruthenium piece formed on the side wall of the recess is etched and removed.
The first supply line 131 further includes a supply pipe 155 branched from the supply pipe 135. The supply pipe 155 extends from a H2 gas source 154 and is connected to the supply pipe 135. The supply pipe 155 is provided with a valve 157a, a mass flow controller 156, and a valve 157b in this order from the H2 gas source 154.
The flow rate of hydrogen (H2) gas supplied from the H2 gas source 154 is controlled by the mass flow controller 156. The hydrogen gas is an example of the hydrogen-containing gas. The hydrogen gas is supplied to the processing container 101 through the supply pipes 155 and 135. As a result, the ruthenium layer is modified (reduced) by the hydrogen-containing gas. In this example, hydrogen gas, which is a reducing gas, is used as a reaction gas. As the reaction gas, H2 gas plasma, NH3 gas, NH3 plasma, monomethylhydrazine (MMH), hydrazine (N2H4), or the like may be used.
The gas exhauster 180 includes a first exhaust line 188 and a second exhaust line 189. The first exhaust line 188 and the second exhaust line 189 are connected to an exhaust pipe 108 provided in the bottom wall of the processing container 101 via a pressure adjuster (APC) 181 and a turbo molecular pump (TMP) 182.
The first exhaust line 188 includes an exhaust pipe. The exhaust pipe of the first exhaust line 188 extends from a dry pump (DP1) 185 and is connected to the turbo molecular pump (TMP) 182. The exhaust pipe of the first exhaust line 188 is provided with a valve 183b, a trap device 184, and a valve 183a in this order from the dry pump (DP1) 185 side. The dry pump (DP1) 185 roughly evacuates the interior of the processing container 101 and exhausts the residual gas of the ruthenium raw-material gas. At that time, the raw-material gas is recovered by the trap device 184. The turbo molecular pump 182 vacuumizes the interior of the processing container 101 while adjusting the pressure in the processing container 101 by the pressure adjuster 181. The first exhaust line 188 exhausts the residual gas of the ruthenium raw-material gas. In addition, the first exhaust line 188 exhausts the residual gas of the hydrogen-containing gas.
The second exhaust line 189 includes an exhaust pipe 190. The exhaust pipe 190 extends from the dry pump (DP2) 187 and is connected to the turbo molecular pump (TMP) 182. The exhaust pipe 190 is provided with a valve 186a. The dry pump (DP2) 187 roughly evacuates the interior of the processing container 101 and exhausts the residual gas of the gas containing ozone gas. The turbo molecular pump 182 vacuumizes the interior of the processing container 101 while adjusting the pressure in the processing container 101 by the pressure adjuster 181. The second exhaust line 189 exhausts the residual gas of the gas containing ozone gas.
In addition, the second exhaust line 189 includes a bypass exhaust line 179 that interconnects the second supply line 132 and the second exhaust line 189 without passing through the processing container 101. The bypass exhaust line 179 causes the gas containing ozone gas to flow from the second supply line 132 to the second exhaust line 189 during ruthenium film formation. The bypass exhaust line 179 is provided with a valve 178b.
The exhaust pipe 190 is an example of a second main exhaust line 190 that exhausts the gas containing ozone gas from the interior of the processing container 101.
The film forming apparatus 23 includes a controller 150 that controls the operation of each part constituting the film forming apparatus 23. The controller 150 includes, for example, a computer having a CPU (not illustrated) and a memory (a storage), and the memory stores a process recipe in which steps (commands) for control necessary for performing a film forming method to be described later are set. The process recipe may be stored in a non-transient computer readable storage medium such as a hard disk and installed in the computer from the storage medium, or may be acquired from a network connected to the controller 150 by using communication means. The controller 150 may control the film forming apparatus 23 and the film forming system 1 in cooperation with the controller 100.
Next, an example of a film forming method according to an embodiment executed by the film forming system 1 will be described with reference to
The film forming method illustrated in
As illustrated in
In order to remove the metal oxide film 50a, the controller 100 first takes out the substrate accommodated in the carrier C by the atmospheric transport mechanism 11a illustrated in
Next, in step S3, the metal oxide film 50a at the bottom of the recess 52 illustrated in
Gas: H2
Flow rate of H2 gas: 2,000 sccm
Pressure in processing container: 5 Torr (667 Pa)
Next, the controller 100 transports the substrate to any of the film forming apparatuses 23 and 24 via the first transport mechanism 13a illustrated in
In the film forming apparatus 23, the controller 150 forms a ruthenium layer in a region including the bottom of the recess 52. Specifically, the controller 150 carries the substrate into the processing container 101, places the substrate on the stage 102, heats the substrate with the heater 105, and evacuates the interior of the processing container 101 by the gas exhauster 180.
In step S5 of
Gas: DCR raw-material gas, CO gas
Flow rate of CO gas: 100 sccm
Pressure in processing container: 16.6 mTorr (2.21 Pa)
Temperature of stage: 100 degrees C. to 200 degrees C.
In the raw material container 161 illustrated in
The operation of gas supply and gas exhaust in the ruthenium embedding step (during film formation) is illustrated in
While the ruthenium film is being formed in step S5, the first exhaust line 188 exhausts the gas containing the ruthenium raw-material gas in the processing container 101. Specifically, as illustrated in
Step S7 in
Next, in step S9 of
Next, in step S11 of
Gas: Mixed gas of O3 and O2
Flow rate of O3 gas): 300 g/m3
Pressure in processing container: 3 Torr (400 Pa)
Temperature of stage: 100 degrees C. to 200 degrees C.
As illustrated in
In step S11, the state in which the valve 178b is opened and the valve 177c and 186a are closed, as illustrated in
In step S13, the interior of the processing container 101 is vacuumized by using the exhaust apparatus of the second exhaust line 189. As a result, the gas containing ozone gas is exhausted. Purge may be performed together with the above-mentioned vacuumizing. In the purge step, an inert gas is supplied into the processing container 101, and the gas containing ozone gas in the processing container 101 is replaced with the inert gas.
Next, in step S15 of
In step S15, the ruthenium layer 55 is modified (reduced) by supplying a hydrogen-containing gas, which is controlled to the following process conditions, from the hydrogen gas supply line 131b into the processing container 101.
Gas: H2 gas
Flow rate of H2 gas: 2,000 sccm
Pressure in processing container: 5 Torr
Temperature of stage: 100 degrees C. to 200 degrees C.
This makes it possible to reduce and return a ruthenium oxide layer formed on the surface layer of the ruthenium layer 55 into the ruthenium layer 55. During the supply of H2 gas, as illustrated in
At this time, the valve 139b of the raw-material gas supply line 131a is closed. As illustrated in
Next, in step S17 of
Next, the controller 150 determines whether the ruthenium embedding process (steps S5 to S17) has been executed a predetermined set number of times. When the controller 150 determines that the ruthenium embedding process has not been executed the set number of times, the controller 150 returns to step S5 and executes steps S5 to S17. As a result, the film formation illustrated in
When the controller 150 determines that the ruthenium embedding process has been executed the set number of times, the substrate W is carried out, and the controller 100 transmits the substrate to the film forming apparatus 27 via the first transport mechanism 13a, the delivery part 17, and the second transport mechanism 14a.
Next, in step S21 of
Gas: DCR raw-material gas, CO gas
Flow rate of CO gas: 100 sccm
Pressure in processing container: 16.6 mTorr (2.21 Pa)
Temperature of stage: 100 degrees C. to 250 degrees C.
Next, when annealing the formed ruthenium layer, the controller 100 transports the substrate to the annealing apparatus 28 via the second transport mechanism 14a, and the annealing apparatus 28 is controlled to the following process conditions and heats the transported wafer W at a predetermined temperature. Thereafter, this process is terminated.
Gas: N2 gas
Flow rate of CO gas: 100 sccm
Pressure in processing container: 5 Torr
Temperature of stage: 300 degrees C. to 500 degrees C.
The actions of the film forming method described above will be described with reference to
In addition, the chemical reaction (2), which is one of the reactions between the ruthenium layer 55 and ozone gas, is represented by Ru+4/3O3→Rua′. In this chemical reaction (2), Gibbs free energy is −350 kJ/mol, and the chemical reaction (2) proceeds.
In addition, the chemical reaction (3) between the ruthenium oxide layer (RuO2) 55b and ozone gas is represented by RuO2+2/3O3→RuO4. In this chemical reaction (3), Gibbs free energy is −5.36 kJ/mol, and a reaction is unlikely to occur, but the chemical reaction (2) occurs. RuO4 formed by these chemical reactions (2) and (3) is volatized. As a result, as illustrated in
The chemical reaction (4) for reducing the remaining ruthenium oxide layer 55b with hydrogen gas is represented by RuO2+2H2→Ru+H2O. In this chemical reaction (4), Gibbs free energy is −215 kJ/mol, and the chemical reaction (4) proceeds. As a result, as illustrated in
From the foregoing, in the film forming method according to the present embodiment, after forming a ruthenium layer, a gas containing ozone gas is supplied in the same film forming apparatus, and film formation and etching of Ru are repeated so that the ruthenium layer can be formed in a recess of a substrate in a bottom-up manner without generating a void. In addition to the film formation and etching of Ru, by reducing a RuOx film by supplying a hydrogen-containing gas in the same film forming apparatus, it is possible to form a ruthenium layer having a lower resistance.
In the film forming method of
During the step of supplying the gas containing the ruthenium raw-material gas (step S5), the gas containing ozone gas is exhausted by the dry pump (DP2) 187 through the bypass exhaust line 179. Since ozone gas is generated by discharging oxygen gas, in order to stabilize the discharge, it is necessary to keep the ozone gas flowing even during the film formation of ruthenium to stabilize the flow rate and concentration of the ozone gas. Therefore, in the film forming method according to the present embodiment, when ozone gas is not used for processing in the processing container 101, for example, when forming a ruthenium film, the gas containing ozone gas is caused to continuously flow through the bypass exhaust line 179. This makes it possible to stabilize the flow rate and concentration of ozone gas. The continuous flowing is necessary.
In the film forming method of
However, respective steps are not limited to repeating in this order. For example, after executing the ruthenium film forming step, the ruthenium etching step and the ruthenium reduction step may be repeated multiple times, and then the process may return to the ruthenium film forming step.
When the ruthenium etching step and the ruthenium reduction step are repeated multiple times after executing the ruthenium film forming step, the ruthenium etching step may be divided into plural times and the gas containing ozone gas may be intermittently supplied multiple times. According to this, since the gas containing ozone gas having a certain flow rate is stored in a separate chamber and then supplied multiple times, it is possible to inject the high-pressure ozone gas into the processing container 101, and the ozone gas easily reaches the bottom of the recess. This enables the formation of a ruthenium film with higher embedding performance.
In the film forming method of
Hereinafter, the configuration and operation of a film forming apparatus according to a second embodiment will be described with reference to
The configuration that differs from the first embodiment is that a new exhaust line is provided in the second exhaust line 189. The exhaust pipe 190 will also be referred to as a second main exhaust line 190. The second exhaust line 189 includes, as a line separate from the second main exhaust line 190, an exhaust pipe 289 that connects the processing container 101 and the dry pump (DP2) 187 to each other and exhausts a gas containing ozone gas from the processing container 101. The exhaust pipe 289 will also be referred to as a second sub-exhaust line 289. That is, the film forming apparatus according to the second embodiment is different from the film forming apparatus according to the first embodiment in that the second exhaust line 189 further includes the second sub-exhaust line 289. In other configurations, the film forming apparatus according to the second embodiment is the same as the film forming apparatus according to the first embodiment. The film forming apparatus according to the second embodiment does not have to be provided with the second main exhaust line 190. The bypass exhaust line 179 is connected to the exhaust pipe 289 of the second sub-exhaust line.
Hereinbelow, the configuration of the second sub-exhaust line 289 will be mainly described. The second sub-exhaust line 289 includes, between the processing container 101 and the dry pump (DP2) 187, a pressure adjuster 281 without including an evacuation apparatus that enables vacuumizing, such as a turbo molecular pump. The pressure adjuster 281 is connected to an exhaust pipe (not illustrated) provided in the side wall or bottom wall of the processing container 101.
The opened/closed state of each valve is the same during the film formation (embedding) of ruthenium in
In addition, the valves 183a and 183b of the first exhaust line 188 are opened, and the valve 178b of the bypass exhaust line 179 of the second exhaust line 189 is opened. The valve 186a of the second main exhaust line 190 of the second exhaust line 189 and the valve 283a of the second sub-exhaust line 289 are closed. As a result, the gas containing the ruthenium raw-material gas is exhausted from the first exhaust line 188 during the ruthenium film formation in
During the supply of ozone gas in
With the film forming apparatus according to the second embodiment, as in the film forming apparatus according to the first embodiment, after the ruthenium layer is formed in the same film forming apparatus, the supply of the gas containing ozone gas and the supply of the hydrogen-containing gas are repeated. As a result, the film formation and etching of Ru are repeated, so that a ruthenium layer can be formed in a recess of a substrate in a bottom-up manner without generating a void.
In addition, with the film forming apparatus according to the second embodiment, when supplying ozone gas, it is possible to cause the gas containing ozone gas to pass from the pressure adjuster 381 to the dry pump (DP2) 187 without causing the gas containing ozone gas to flow through the turbo molecular pump 182. The flow rate of gas that is capable of flowing through the turbo molecular pump 182 is limited to be less than the flow rate of gas that is capable of flowing through the dry pump (DP2) 187. Therefore, with the film forming apparatus according to the second embodiment, it is possible to use a relatively large flow rate of ozone gas.
Next, the configuration and operation of a film forming apparatus according to a third embodiment will be described with reference to
The configuration that differs from the second embodiment is that a new exhaust line is provided in the first exhaust line 188. The exhaust pipe 195 of the first exhaust line 188 will also be referred to as a first main exhaust line 195. The first exhaust line 188 includes, as a line separate from the first main exhaust line 195, an exhaust pipe 389 that connects the processing container 101 and the dry pump (DP1) 185 to each other and exhausts a gas containing a raw-material gas and a hydrogen-containing gas from the processing container 101. The exhaust pipe 389 will also be referred to as a first sub-exhaust line 389. That is, the film forming apparatus according to the third embodiment is different from the film forming apparatus according to the second embodiment in that the first exhaust line 188 further includes the first sub-exhaust line 389. In other configurations, the film forming apparatus according to the third embodiment is the same as the film forming apparatus according to the second embodiment. The film forming apparatus according to the third embodiment does not have to be provided with the second main exhaust line 190.
Hereinbelow, the configuration of the first sub-exhaust line 389 will be mainly described. The second sub-exhaust line 289 includes, between the processing container 101 and the dry pump (DP1) 185, a pressure adjuster 381 without including an evacuation apparatus that enables vacuumizing, such as a turbo molecular pump. The pressure adjuster 381 is connected to an exhaust pipe (not illustrated) provided in the side wall or bottom wall of the processing container 101.
In the film forming apparatus according to the third embodiment, during the film formation (embedding) of ruthenium in
At this time, the valve 178b of the bypass exhaust line 179 is opened, and the valve 186a of the second main exhaust line 190 and the valve 283a of the second sub-exhaust line 289 are closed. Therefore, a gas containing ozone gas is exhausted through the bypass exhaust line 179.
During the supply of ozone gas in
During the supply of hydrogen in
At this time, the valve 178b of the bypass exhaust line 179 is opened, and the valve 186a of the second main exhaust line 190 and the valve 283a of the second sub-exhaust line 289 are closed. Therefore, the gas containing ozone gas is exhausted through the bypass exhaust line 179.
With the film forming apparatus according to the third embodiment, as in the film forming apparatuses according to the first and second embodiments, after the ruthenium layer is formed in the same film forming apparatus, the supply of the gas containing ozone gas and the supply of the hydrogen-containing gas are repeated. As a result, the film formation and etching of Ru are repeated, so that a ruthenium layer can be formed in a recess of a substrate in a bottom-up manner without generating a void.
In addition, with the film forming apparatus according to the third embodiment, when supplying the gas containing ozone gas, the gas containing ozone gas is exhausted from the second sub-exhaust line 289, and when supplying the hydrogen-containing gas, the hydrogen-containing gas is exhausted from the first sub-exhaust line 389. Accordingly, with the film forming apparatus according to the third embodiment, when supplying the gas containing ozone gas, it is possible to cause the gas containing ozone gas to pass from the pressure adjuster 381 to the dry pump (DP2) 187 without causing the gas containing ozone gas to flow through the turbo molecular pump 182. In addition, when supplying hydrogen gas, it is possible to cause hydrogen gas to pass from the pressure adjuster 381 to the dry pump (DP1) 185 without causing the hydrogen gas to flow through the turbo molecular pump 182. The flow rate of gas that is capable of flowing through the turbo molecular pump 182 is limited to be less than the flow rate of gas that is capable of flowing through the dry pump (DP1) 185 and the dry pump (DP2) 187. Therefore, with the film forming apparatus according to the third embodiment, it is possible to use a relatively large flow rate of ozone gas, and to use a relatively large flow rate of hydrogen gas.
Furthermore, with the film forming apparatus according to the third embodiment, in the film forming method in which the supply of ozone gas and the supply of hydrogen-containing gas are repeated once or multiple times during the film formation of ruthenium, it is possible to improve throughput by switching the supply of ozone gas and the supply of hydrogen-containing gas at high speed. The reason is that the exhaust amounts of the dry pumps DP1 and DP2 and the turbo molecular pump TMP are different. Therefore, when an exhaust line passing through a turbo molecular pump is used to supply the gas containing ozone gas and the hydrogen-containing gas, it takes time to stabilize the pressure. Since the dry pump DP1 and the dry pump DP2 have the same or similar exhaust amounts, at the time of switching between the gas containing ozone gas and the hydrogen-containing gas when the supply of the gas containing ozone gas and the supply of the hydrogen-containing gas are repeated, the pressure change in the processing container 101 is small so that the pressure can be controlled in the same order. Therefore, with the film forming method using the apparatus according to the third embodiment, it does not take time to stabilize the pressure in the processing container 101 only by switching between the opening and closing of the valve 283a and the valve 383a. As a result, it is possible to shorten the film formation time of a ruthenium layer so that the throughput can be improved.
As described above, according to the film forming apparatus, the film forming method, and the film forming system of the present embodiment, it is possible to execute the film formation and etching of ruthenium in the same film forming apparatus, and to embed the ruthenium in a bottom-up manner.
It should be considered that the film forming apparatuses, film forming methods, and the film forming systems according to the embodiments disclosed herein are exemplary in all aspect and are not restrictive. The embodiments may be modified and improved in various forms without departing from the scope and spirit of the appended claims. The matters described in the above embodiments may take other configurations within the non-contradictory range, and may be combined within the non-contradictory range.
For example, in the film forming apparatus of the present disclosure, it is also possible to clean the processing container 101 when supplying a gas containing ozone gas. By the ozone gas supplied from the ozonizer 173 to the processing container 101, it is possible to perform not only etching of ruthenium that has adhered to the side wall of a recess, but also cleaning of ruthenium deposited on a wall surface or the like of the processing container 101.
According to an aspect, it is possible to execute film formation and etching of ruthenium in the same film forming apparatus, and to embed ruthenium in a bottom-up manner
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosures. Indeed, the embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-153188 | Sep 2021 | JP | national |
