JP2007317696A - Apparatus and processing method for gas processing, apparatus and method for processing gas hydrogen fluoride gas supply, method therefor, and computer-readable storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas processing apparatus that is superior in reproducibility of process and capable of supplying hydrogen fluoride gas stably into a processing container over a long term. <P>SOLUTION: COR equipment 5 comprises a chamber 50 for containing a wafer W; a line 54b for supplying hydrogen; a line 55b for supplying fluorine; a mass flow controller 54c for regulating the flow rate of hydrogen that is flowing through the hydrogen supply line 54b; a mass flow controller 55c for regulating the flow rate of fluorine flowing through the fluorine supply line 55b; a reaction container 62, connected to the hydrogen supply line 54b and the fluorine supply line 55b and producing hydrogen fluoride gas, by causing reaction of hydrogen supplied by the hydrogen supply line 54b and fluorine supplied by the fluorine supply line 55b; and a line 61 for supplying hydrogen fluoride gas, produced in the reaction container 62 to the chamber 50. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a gas processing apparatus and a gas processing method for supplying a gas containing hydrogen fluoride gas to an object to be processed, a gas processing method, and a foot for performing a predetermined process on an object to be processed disposed in a processing container. The present invention relates to a hydrogen fluoride gas supply device for supplying hydrogen fluoride gas, a hydrogen fluoride gas supply method, and a computer-readable storage medium storing a control program for executing the gas processing method.

  In a semiconductor device manufacturing process, a process gas is generally supplied into a chamber for housing a semiconductor wafer, and gas treatment is performed on the semiconductor wafer or the inner wall of the chamber. Hydrogen fluoride (HF) is used as a processing gas in various gas processing such as etching by vapor and chemical oxide removal (COR) processing, cleaning in the chamber, and the like.

The supply of HF gas into the chamber is usually performed while adjusting the flow rate by a flow rate adjusting mechanism such as a mass flow controller via a HF gas supply line connected to the chamber. However, the HF gas is composed of a mixture of multimers (HF) _n (n = 1 to 8) in which HF molecules are associated (polymerized), and the degree of association of HF molecules is very high with respect to pressure and temperature. In such a method, if a slight fluctuation occurs in the pressure or temperature of the HF gas flowing through the supply line, the ratio of multimeric components in the HF gas greatly changes in the supply line. End up. Therefore, an error is likely to occur between the set flow rate and the actual flow rate by the flow rate adjusting mechanism of HF gas, and it is difficult to ensure process reproducibility.

  Therefore, in order to suppress an error between the set flow rate and the actual flow rate by the flow rate adjustment mechanism of the HF gas, the HF flowing through the supply line is preliminarily heated by heating the flow rate adjustment valve (flow rate controller) of the flow rate adjustment mechanism. Attempts have also been made to dissociate association of HF molecules in the HF gas when the gas passes through the flow control valve, and supply HF gas composed of HF molecules in a single molecule state into the chamber (for example, Patent Documents). 1).

However, since HF has the property of reacting with most inorganic oxides to corrode inorganic oxides, in the above-described conventional technique for heating the flow rate regulating valve, the reactivity of HF is reduced at the flow rate regulating valve portion. By being raised, there is a possibility that the contact portion with the HF gas inside the flow rate adjusting valve may be corroded. In general, since the HF gas supply line is thin and the contact portion with the HF gas inside the flow rate adjusting valve is small, it is difficult to apply corrosion resistance processing to this portion in advance. Therefore, with such a technique, it is difficult to stably supply HF into the chamber for a long period of time.
JP 2004-264881 A

  The present invention has been made in view of such circumstances, and is excellent in process reproducibility, and is capable of stably supplying hydrogen fluoride gas to an object to be processed for a long period of time. An object is to provide a method, a hydrogen fluoride gas supply device, a hydrogen fluoride gas supply method, and a computer-readable storage medium storing a control program for executing the gas processing method.

  In order to solve the above problems, according to a first aspect of the present invention, there is provided a gas processing apparatus for performing gas processing by supplying a gas containing hydrogen fluoride gas to an object to be processed. A processing vessel, a hydrogen feed line for feeding hydrogen, a fluorine feed line for feeding fluorine, a hydrogen flow rate control mechanism for controlling a flow rate of hydrogen flowing through the hydrogen feed line, and the fluorine A fluorine flow rate control mechanism for controlling the flow rate of fluorine flowing through the feed line, and reacts the hydrogen fed by the hydrogen feed line with the fluorine fed by the fluorine feed line. Provided is a gas processing apparatus that generates hydrogen fluoride gas and processes an object to be processed in the processing container with the generated hydrogen fluoride gas.

  In the first aspect of the present invention, the hydrogen supply line and the fluorine supply line are respectively connected to the processing vessel, and the hydrogen supplied by the hydrogen supply line and the fluorine supply line are used for the supply. Hydrogen fluoride gas can be generated by reacting the supplied fluorine in the processing vessel.

  According to a second aspect of the present invention, there is provided a gas processing apparatus for supplying a gas containing hydrogen fluoride gas to an object to be processed to perform gas processing, a processing container in which the object to be processed is disposed, and hydrogen. A hydrogen feed line for feeding, a fluorine feed line for feeding fluorine, a hydrogen flow rate control mechanism for controlling a flow rate of hydrogen flowing through the hydrogen feed line, and a fluorine flow rate flowing through the fluorine feed line Fluorine flow rate control mechanism for controlling the flow rate, and the hydrogen supply line and the fluorine supply line are connected, hydrogen supplied by the hydrogen supply line and fluorine supplied by the fluorine supply line A gas treatment comprising: a reaction vessel that reacts to produce hydrogen fluoride gas; and a hydrogen fluoride supply line that supplies the hydrogen fluoride gas produced in the reaction vessel into the treatment vessel. To provide a location.

  In the second aspect of the present invention, it is preferable to further include a temperature control mechanism for adjusting the reaction between hydrogen and fluorine by controlling the temperature in the reaction vessel. It is preferable to further include a light irradiation mechanism for adjusting the reaction between fluorine and fluorine, and it is preferable that a catalyst part for adjusting the reaction between hydrogen and fluorine is provided in the reaction vessel.

  In the first and second aspects of the present invention described above, it is preferable that a cooling mechanism for cooling the fluorine flowing through the fluorine supply line is further provided. In this case, the cooling mechanism preferably has a fluorine cooling temperature of −223 ° C. or higher, and the cooling mechanism preferably has a fluorine cooling temperature of −188 ° C. or higher.

  Furthermore, in the above first and second aspects of the present invention, it is preferable that the fluorine supply line supplies fluorine diluted by mixing with a dilution gas.

  In the first and second aspects of the present invention described above, the hydrogen flow rate control mechanism and the fluorine flow rate control mechanism can each be configured with a mass flow controller.

  According to a third aspect of the present invention, there is provided a gas processing method for performing gas processing by supplying a gas containing hydrogen fluoride gas to a target object, wherein the target object is disposed in a processing container, and hydrogen and fluorine are supplied. Each of them is supplied separately while being adjusted to a predetermined flow rate, and hydrogen and fluorine are reacted to generate hydrogen fluoride gas, and the object to be processed in the processing container is processed by the hydrogen fluoride gas. A gas treatment method is provided.

  Hydrogen and fluorine can be separately fed into the processing vessel and reacted in the processing vessel.

  According to a fourth aspect of the present invention, there is provided a gas processing method for performing gas processing by supplying a gas containing hydrogen fluoride gas to an object to be processed, wherein the object to be processed is disposed in a processing container, and hydrogen and fluorine are contained. Each of them is supplied separately while being adjusted to a predetermined flow rate, and these hydrogen and fluorine are reacted in a reaction vessel to generate hydrogen fluoride gas, and this hydrogen fluoride gas is supplied into the processing vessel to perform the treatment. Provided is a gas processing method characterized by processing an object to be processed in a container.

  According to a fifth aspect of the present invention, there is provided a hydrogen fluoride gas supply device for supplying a hydrogen fluoride gas for performing a predetermined process on an object to be processed disposed in a processing container, wherein hydrogen is supplied to the hydrogen. A feed line; a fluorine feed line that feeds fluorine; a hydrogen flow rate control mechanism that controls a flow rate of hydrogen that flows through the hydrogen feed line; and a flow rate of fluorine that flows through the fluorine feed line. A fluorine flow rate control mechanism is connected to the hydrogen supply line and the fluorine supply line, and the hydrogen supplied by the hydrogen supply line reacts with the fluorine supplied by the fluorine supply line to react. A hydrogen fluoride gas supply device comprising: a reaction vessel for producing hydrogen fluoride gas; and a hydrogen fluoride supply line for supplying the hydrogen fluoride gas produced in the reaction vessel into the treatment vessel To provide.

  According to a sixth aspect of the present invention, there is provided a hydrogen fluoride gas supply method for supplying a hydrogen fluoride gas for performing a predetermined process on an object to be processed disposed in a processing container, wherein hydrogen and fluorine are respectively predetermined. The hydrogen flow rate is adjusted separately so that hydrogen and fluorine are reacted in the reaction vessel to generate hydrogen fluoride gas, and the hydrogen fluoride gas is supplied to the object to be processed in the treatment vessel. A hydrogen fluoride gas supply method is provided.

  According to a seventh aspect of the present invention, there is provided a computer-readable storage medium storing a control program that operates on a computer, the control program being processed by a computer so that the gas processing method is performed at the time of execution. A computer-readable storage medium characterized by controlling an apparatus is provided.

  According to the first and third aspects of the present invention, hydrogen and fluorine that are extremely highly reactive and do not multimerize are separately supplied while being adjusted to a predetermined flow rate. In order to generate hydrogen fluoride gas by the reaction, and to treat the object to be processed placed in the processing container with this hydrogen fluoride gas, the flow rate set by the flow rate adjusting mechanism when hydrogen and fluorine are supplied and the actual flow rate There is almost no error, that is, there is almost no error between the set production amount of hydrogen fluoride calculated from the flow rates of hydrogen and fluorine and the actual production amount. Therefore, the process reproducibility can be sufficiently ensured, and since it is not necessary to heat the flow rate adjusting mechanism and the supply line, the corrosion of the flow rate adjusting mechanism and the supply line is avoided and the object to be processed is avoided. It becomes possible to supply hydrogen fluoride gas stably for a long period of time.

  According to the second, fourth, fifth, and sixth aspects of the present invention, hydrogen and fluorine that are extremely highly reactive and do not multimerize are separately supplied while being adjusted to a predetermined flow rate. Hydrogen and fluorine are reacted in a reaction container to generate hydrogen fluoride gas, and the hydrogen fluoride gas is supplied into the processing container to treat the object to be processed disposed in the processing container. There is almost no error between the actual flow rate and the set flow rate due to the flow rate adjustment mechanism when supplying fluorine, that is, there is also an error between the set production amount of hydrogen fluoride calculated from the hydrogen and fluorine flow rates and the actual production amount. It hardly occurs. Moreover, in order to supply the hydrogen fluoride gas generated in the reaction vessel upstream of the processing container into the processing container, even when other processing gases are supplied into the processing container in parallel, The gas can be uniformly supplied to the object to be processed in the processing container. Further, since the place where the hydrogen fluoride gas is generated, that is, the reaction container is provided separately from the place where the gas to be processed is processed, that is, the processing container, for example, the reaction container is different from the processing container. Environmental conditions that are optimal for the production of hydrogen fluoride gas, such as setting the temperature, placing the catalyst in the reaction vessel to adjust the production of hydrogen fluoride gas, or performing light irradiation in the reaction vessel And environmental conditions optimum for the gas treatment of the object to be processed can be created separately without affecting each other. Therefore, the reproducibility of the process can be remarkably improved, and it is not necessary to heat the flow rate adjusting mechanism and the feed line. It becomes possible to supply hydrogen fluoride gas stably for a long period of time.

Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.
FIG. 1 is a schematic view of a wafer processing system provided with a COR apparatus which is an embodiment of a gas processing apparatus according to the present invention.

  The wafer processing system 1 includes, for example, a loading / unloading unit 2 for loading / unloading a semiconductor wafer (hereinafter referred to as “wafer”) W having a disk shape, and two load locks provided adjacent to the loading / unloading unit 2. Chamber 3, a PHT apparatus 4 for performing PHT (Post Heat Treatment) on wafer W provided adjacent to each load lock chamber 3, and a wafer W provided adjacent to each PHT apparatus 4 respectively. And a COR device 5 that performs COR processing. The load lock chamber 3, the PHT device 4, and the COR device 5 are arranged on a straight line.

  The loading / unloading unit 2 includes a transfer chamber 22 in which a first wafer transfer mechanism 21 for transferring a wafer W is provided. The first wafer transfer mechanism 21 holds the wafer W substantially horizontally and moves back and forth. In addition, two transport arms 23a and 23b are provided so as to be horizontally rotatable and liftable. A mounting table 24 is provided on the side of the transfer chamber 22, and for example, three carriers C that can store a plurality of wafers W are arranged on the mounting table 24. In addition, an orienter 25 for aligning the wafer W is installed on the side of the transfer chamber 22. In the loading / unloading unit 2, the first wafer transfer mechanism 21 is configured to transfer the wafer W between the carrier C, the orienter 25 and the load lock chamber 3 on the mounting table 24 by the transfer arms 23 a and 23 b. ing.

  Each load lock chamber 3 is connected to the transfer chamber 22 via the gate valve 11 and can accommodate the wafer W and can be depressurized to a predetermined pressure. Each load lock chamber 3 is provided with a second wafer transfer mechanism 31 for transferring the wafer W. The wafer transfer mechanism 31 holds the wafer W substantially horizontally, and can move back and forth, rotate horizontally, and move up and down. A transport arm 32 is provided. In each load lock chamber 3, the second wafer transfer mechanism 31 is configured to transfer the wafer W to / from the PHT apparatus 4 and to / from the COR apparatus 5 by the transfer arm 32. ing.

  The PHT apparatus 4 includes a processing chamber 40 that can be connected to the load lock chamber 3 via the gate valve 12 and can accommodate the wafer W, and is configured to perform PHT on the wafer W in the processing chamber 40. . The COR device 5 includes a chamber 50 that is connected to the processing chamber 40 via the gate valve 13 and can accommodate the wafer W, and is configured to perform COR processing on the wafer W in the chamber 50. . The COR device 5 will be described in detail later.

  Each component of the wafer processing system 1 is connected to and controlled by a process controller 14 having a CPU. The process controller 14 includes a user interface 15 including a keyboard that allows a process manager to input commands to manage the wafer processing system 1, a display that visualizes and displays the operating status of the wafer processing system 1, and the like. A storage unit 16 that stores a control program for realizing various processes executed by the wafer processing system 1 under the control of the process controller 14 and a recipe in which processing condition data is recorded is connected. If necessary, an arbitrary recipe is called from the storage unit 16 by an instruction from the user interface 15 and is executed by the process controller 14, so that the desired processing in the wafer processing system 1 is performed under the control of the process controller 14. Is performed. The recipe may be stored in a computer-readable storage medium such as a CD-ROM, hard disk, or flash memory, or may be transmitted from another device via a dedicated line as needed. It is also possible to do.

  In the wafer processing system 1 having such a configuration, first, the carrier C in which a plurality of wafers W are stored is placed on the mounting table 24, and the first wafer transport mechanism 21 is moved from the carrier C to one sheet. The wafer W is taken out and loaded into the load lock chamber 3. When the wafer W is loaded into the load lock chamber 3, the inside of the load lock chamber 3 is sealed by the gate valves 11 and 12, and the pressure is reduced. When the pressure in the load lock chamber 3 is reduced to a predetermined pressure, the gate valves 12 and 13 are used to reduce the pressure in the load lock chamber 3, the processing chamber 40 of the PHT apparatus 4 and the chamber 50 of the COR apparatus 5 that have been reduced to the predetermined pressure. Are communicated with each other, and the second wafer transfer mechanism 31 carries the wafer W into the chamber 50 through the processing chamber 40.

  When the wafer W is loaded into the chamber 50, the inside of the chamber 50 is closed by the gate valve 13, and the wafer W is subjected to COR processing. Thereby, the natural oxide film formed on the surface of the wafer W is transformed into a reaction product. The COR processing in the COR device 5 will be described in detail later. When the COR processing is completed, the gate locks 12 and 13 allow the inside of the load lock chamber 3, the inside of the processing chamber 40 and the inside of the chamber 50 to communicate with each other, and the second wafer transfer mechanism 31 carries the wafer W into the processing chamber 40. .

  When the wafer W is loaded into the processing chamber 40, the processing chamber 40 is closed by the gate valves 12 and 13, and PHT of the wafer W is performed. Thereby, the reaction product on the surface of the wafer W is vaporized or sublimated. When the PHT is completed, the inside of the load lock chamber 3 and the inside of the processing chamber 40 are communicated with each other by the gate valve 12, and the second wafer transfer mechanism 31 unloads the wafer W from the inside of the processing chamber 40 and inside the load lock chamber 3. Carry in. Then, after the inside of the load lock chamber 3 is sealed, the inside of the load lock chamber 3 communicates with the inside of the transfer chamber 22, and the first wafer transfer mechanism 21 returns the wafer W to the carrier C on the mounting table 24. It will be.

Next, the COR device 5 will be described in detail.
2 is a schematic view of the COR device 5, FIG. 3 is a schematic view of a COR chamber constituting the COR device 5, and FIG. 4 is a schematic sectional view of a reaction part constituting the COR device 5.

The COR device 5 makes a reaction between a natural oxide film formed on the surface of the wafer W after etching and a molecule of the processing gas by contacting the wafer W with a gas containing a halogen element and a basic gas as a processing gas. A product is produced. Specifically, ammonium fluorosilicate [(NH ₄ ) ₂ SiF ₆ ] is reacted as a reaction product by causing HF gas and NH ₃ gas in the processing gas to act on a natural oxide film (SiO ₂ ) on the surface of the wafer W. Generate. The COR apparatus 5 includes the above-described chamber 50 (processing container), a mounting table 51 on which the wafer W is mounted substantially horizontally in the chamber 50, a gas supply mechanism 52 that supplies a processing gas into the chamber 50, and the chamber 50. And an exhaust gas processing mechanism 53 for exhausting the inside.

  The chamber 50 includes a cylindrical chamber main body 50a having an upper opening, and a lid 50b that closes the upper opening of the chamber main body 50a. The lid 50b is mounted on the chamber main body 50a via a seal member (not shown), thereby ensuring airtightness in the chamber 50.

  As shown in FIG. 3, a loading / unloading port 50 c for loading / unloading the wafer W into / from the chamber 50 is provided on the side wall of the chamber body 50 a.

  As shown in FIG. 3, the lid 50b has a lid main body 50d and a shower head 50e attached to the lid main body 50d for discharging the processing gas from the gas supply mechanism 52 into the chamber 50. Yes. The shower head 50e is formed in a substantially plate shape having a flat space 50g inside, and is attached to the lower part of the lid body 50d to constitute the inner surface (lower surface) of the lid body 50b. The shower head 50e has a plurality or a plurality of discharge ports 50f for discharging the processing gas on the lower surface, diffuses the processing gas from the gas supply mechanism 52 in the space 50g, and the inside of the chamber 50 from above by the discharge port 50f. Alternatively, it is configured to discharge into the chamber body 50a.

  As shown in FIG. 3, the mounting table 51 is fixed to the bottom of the chamber body 50 a, and a mounting table temperature controller 51 a that adjusts the temperature of the mounting table 51 is provided inside the mounting table 51. . The mounting table temperature controller 51a has, for example, a flow path (not shown) that circulates a temperature control fluid such as water, and heat exchange is performed with the temperature control fluid that flows through the flow path. Temperature adjustment, that is, temperature adjustment of the wafer W on the mounting table 51 is performed.

As shown in FIG. 2, the gas supply mechanism 52 includes a hydrogen fluoride gas supply mechanism 59 (hydrogen fluoride gas supply device) that supplies hydrogen fluoride (HF) gas into the chamber 50 via the shower head 50e, An ammonia gas supply mechanism 56 that supplies ammonia (NH ₃ ) gas, an argon gas supply mechanism 57 that supplies argon (Ar) gas that is an inert gas, and a nitrogen gas supply mechanism 58 that supplies nitrogen (N ₂ ) gas. I have.

  The ammonia gas supply mechanism 56 adjusts the ammonia gas supply source 56a, the supply path 56b for introducing the ammonia gas from the ammonia gas supply source 56a into the space 50g of the shower head 50e, and the flow rate of the ammonia gas flowing through the supply path 56b. A mass flow controller 56c and a valve 56d for branching, and a branch supply path 56e for branching the ammonia gas from the ammonia gas supply source 56a provided in the supply path 56b into a reaction vessel 62 described later of the hydrogen fluoride gas supply mechanism 59. And a mass flow controller 56f and a valve 56g for adjusting the flow rate of the ammonia gas flowing through the branch supply path 56e. The argon gas supply mechanism 57 adjusts the argon gas supply source 57a, the supply path 57b for introducing the argon gas from the argon gas supply source 57a into the space 50g of the shower head 50e, and the flow rate of the argon gas flowing through the supply path 57b. A mass flow controller 57c and a valve 57d for branching, and a branch supply path 57e for branching the argon gas from the argon gas supply source 57a provided in the supply path 57b into a reaction vessel 62 described later of the hydrogen fluoride gas supply mechanism 59. And a mass flow controller 57f and a valve 57g for adjusting the flow rate of the argon gas flowing through the branch supply path 57e. The nitrogen gas supply mechanism 58 adjusts the nitrogen gas supply source 58a, the supply path 58b for introducing the nitrogen gas from the nitrogen gas supply source 58a into the space 50g of the shower head 50e, and the flow rate of the nitrogen gas flowing through the supply path 58b. A mass flow controller 58c and a valve 58d for branching, and a branch supply path 58e for branching the nitrogen gas from the nitrogen gas supply source 58a provided in the supply path 58b into a reaction vessel 62 described later of the hydrogen fluoride gas supply mechanism 59. And a mass flow controller 58f and a valve 58g for adjusting the flow rate of nitrogen gas flowing through the branch supply path 58e.

The hydrogen fluoride gas supply mechanism 59 includes a hydrogen fluoride supply line 61 having one end connected to the chamber 50, a reaction unit 60 connected to the other end of the hydrogen fluoride supply line 61, and a hydrogen in the reaction unit 60. A hydrogen supply mechanism 54 for supplying (H ₂ ) gas, and a fluorine supply mechanism 55 for supplying fluorine (F ₂ ) gas (or fluorine or liquid fluorine) to the reaction unit 60. Hydrogen gas is generated by reacting hydrogen gas with fluorine gas from the fluorine supply mechanism 55 in the reaction unit 60, and the generated hydrogen fluoride gas is supplied into the chamber 50 through the hydrogen fluoride supply line 61. Is configured to do.

As shown in FIG. 4, the reaction unit 60 includes a reaction vessel 62 provided so as to communicate with the space 50 g in the chamber 50 or the shower head 50 e via the hydrogen fluoride supply line 61, and the temperature of the reaction vessel 62. A temperature adjusting mechanism 63 for adjusting the temperature, a light 64 as a light irradiation mechanism for illuminating the inside of the reaction vessel 62, and a casing 65 for housing the reaction vessel 62, from the hydrogen gas and fluorine supply mechanism 55 from the hydrogen supply mechanism 54. Each of the fluorine gases is sent into the reaction vessel 62, and hydrogen fluoride gas is generated in the reaction vessel 62. The temperature adjustment mechanism 63 includes, for example, a heater 63a that heats the reaction vessel 62, a fan 63b that cools the reaction vessel 62, and the like. The reaction vessel 62 is made of, for example, an aluminum material. The inner wall of the reaction vessel 62 is preferably subjected to surface oxidation treatment or surface nitridation treatment so as not to be corroded by reaction with fluorine gas or hydrogen fluoride gas. Alternatively, at least the inner wall of the reaction vessel 62 may be formed of a polyethylene material, and a Teflon (registered trademark) coating may be applied to the inner wall. Further, if the temperature of the reaction vessel 62 by the temperature adjusting mechanism 63 is 500 ° C. or less, the reaction vessel 62 may be formed of gold (Au) or platinum (Pt) at least on the inner wall. The reaction vessel 62 is made of cordierite, alumina, alumina so that the reaction of hydrogen gas and fluorine gas supplied by the hydrogen supply line 54b and the fluorine supply line 55b does not proceed suddenly or moderately. Silica, mullite, silicon carbide, silicon nitride, zeolite, zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), platinum, palladium (Pd), rhodium (Rh), copper (Cu), nickel (Ni), cobalt (Co), silver (Ag), molybdenum (Mo), tungsten (W), vanadium (V), formed of a material containing at least one substance selected from substances having a catalytic action, such as lanthanum (La). A catalyst layer 66 as a catalyst (positive catalyst or negative catalyst) portion is provided on a part of the inner wall. .

  The hydrogen supply mechanism 54 includes a hydrogen gas supply source 54a, a hydrogen supply line 54b for introducing hydrogen gas from the hydrogen gas supply source 54a into the reaction vessel 62, that is, supplying or supplying the hydrogen gas into the reaction vessel 62, and a hydrogen supply line. It has a mass flow controller 54c and a bubble 54d (hydrogen flow rate adjusting mechanism) for adjusting the flow rate of hydrogen gas flowing through the supply line 54b. The fluorine supply mechanism 55 includes a fluorine gas supply source 55a, a fluorine supply line 55b for introducing the fluorine gas from the fluorine gas supply source 55a into the reaction vessel 62, that is, supplying or supplying the fluorine gas into the reaction vessel 62, and a fluorine supply. A mass flow controller 55c and a valve 55d (fluorine flow rate adjusting mechanism) for adjusting the flow rate of the fluorine gas flowing through the supply line 55b are provided.

  Fluorine has a very high reactivity and has the property of oxidizing most elemental elements other than helium, neon, and argon, so that the fluorine supply mechanism 55 does not corrode by reacting with fluorine gas. It is preferable to provide a cooling mechanism for cooling the fluorine gas, and to reduce the reactivity of the fluorine gas in the fluorine supply mechanism 55 by the cooling mechanism. For example, in the case where a cooling mechanism is provided in the fluorine supply line 55b, the cooling mechanism is disposed on the outer periphery of the fluorine supply line 55b, and a refrigerant flow path through which a cooling fluid such as nitrogen gas cooled to a predetermined temperature flows. 55e. Moreover, you may comprise a cooling mechanism using a Peltier device. Although the cooling mechanism can lower the reactivity of the fluorine gas as the cooling temperature is lower, the fluorine gas from the fluorine gas supply source 55a is reliably guided into the space 50g of the shower head 50e by the fluorine supply line 55b. Thus, it is preferable to cool the fluorine gas to a temperature of −223 ° C. or higher, which is the melting point, and to cool to a temperature of −188 ° C. or higher of the boiling point so as to be surely guided into the space 50g of the shower head 50e. It is preferable.

  The exhaust gas processing mechanism 53 includes an exhaust passage 53a provided so as to communicate with the chamber 50, a dry pump (DP) 53b for forcibly exhausting the chamber 50 through the exhaust passage 53a, and an exhaust gas flowing through the exhaust passage 53a. A trap device (TR) 53c for removing solid components (precipitates) contained in the gas and an open / close valve 53d for opening and closing the exhaust passage 53a are provided. The exhaust path 53a is connected to the bottom of the chamber 50 or the chamber body 50a, for example. The on-off valve 53d, the dry pump (DP) 53b, and the trap device (TR) 53c are provided in order from the upstream side to the downstream side in the exhaust passage 53a.

Various members such as the chamber 50 and the mounting table 51 constituting the COR device 5 are formed of an aluminum (Al) material. The inner surface of the chamber 50 (the inner surface of the chamber main body 50a, the lower surface of the shower head 50e, the mounting table 51, etc.) is subjected to surface oxidation treatment or surface nitridation treatment so as not to be corroded by reaction with fluorine gas or hydrogen fluoride gas. It is preferable to keep. Surface oxidation treatment that forms an oxide film (Al ₂ O ₃ ) on the surface or surface nitridation treatment that forms a nitride film (AlN) improves surface hardness, corrosion resistance, and durability, and provides corrosion and impact. Can be protected from etc.

Next, the COR process performed on the wafer W by the COR apparatus 5 will be described in detail.
When the wafer W is unloaded from the load lock chamber 3 by the second wafer transfer mechanism 31 (see FIG. 1), loaded into the chamber 50 from the loading / unloading port 50c, and placed on the mounting table 51, the gate The inlet / outlet port 50c is closed by the valve 13, and the inside of the chamber 50 is sealed. Ammonia gas supply mechanism 56, argon gas supply mechanism 57, and nitrogen gas supply mechanism 58 supply ammonia gas, argon gas, and nitrogen gas, respectively, into chamber 50 or chamber body 50a through shower head 50e. In the ammonia gas supply mechanism 56, the argon gas supply mechanism 57, and the nitrogen gas supply mechanism 58, ammonia gas, argon gas, and nitrogen gas are supplied from the ammonia gas supply source 56a, the argon gas supply source 57a, and the nitrogen gas supply source 58a, respectively. The gas is supplied through the passages 56b, 57b and 58b while being adjusted to a predetermined flow rate by the mass flow controllers 56c, 57c and 58c and the valves 56d, 57d and 58d. At this time, the wafer W on the mounting table 51 is adjusted to a predetermined temperature, for example, about 25 ° C. by the mounting table temperature controller 51a.

  Thereafter, hydrogen gas and fluorine gas are supplied into the reaction vessel 62 of the reaction unit 60 by the hydrogen supply mechanism 54 and the fluorine supply mechanism 55, respectively. In the hydrogen supply mechanism 54 and the fluorine supply mechanism 55, the hydrogen gas and the fluorine gas from the hydrogen gas supply source 54a and the fluorine gas supply source 55a flow through the hydrogen supply line 54b and the fluorine supply line 55b, respectively, and the mass flow controller 54c. , 55c and valves 54d and 55d while being adjusted to a predetermined flow rate. The mass flow controller 54c, the valve 54d, and the process controller 14 constitute a hydrogen flow rate control mechanism that controls the flow rate of hydrogen flowing through the hydrogen supply line 54b, and the mass flow controller 55c, the valve 55d, and the process controller 14 include the fluorine supply line. A fluorine flow rate control mechanism for controlling the flow rate of the fluorine gas flowing through 55b is configured.

  When hydrogen gas and fluorine gas are supplied by the hydrogen supply mechanism 54 and the fluorine supply mechanism 55, the fluorine gas of the fluorine supply mechanism 55, for example, the fluorine gas flowing through the fluorine supply line 55b, is cooled by a cooling mechanism, for example, a refrigerant flow path. Cooled to a predetermined temperature by the cooling fluid flowing through 55e. Thereby, the reactivity of the fluorine gas in the fluorine supply mechanism 55 decreases, and corrosion of the fluorine supply mechanism 55 by the fluorine gas is prevented.

  Hydrogen gas and fluorine gas supplied by the hydrogen supply mechanism 54 and the fluorine supply mechanism 55 are joined and reacted in the reaction vessel 62 to generate hydrogen fluoride gas. At this time, the reaction vessel 62 is adjusted to a predetermined temperature, for example, about 850 ° C. by the temperature adjusting mechanism 63 so that the reaction between the hydrogen gas and the fluorine gas does not proceed rapidly or moderately. Alternatively, the inside of the reaction vessel 62 is illuminated by the light 64. By illuminating the inside of the reaction vessel 62 with the light 64, energy required for the reaction is given as an energy form other than heat, and the reaction is promoted. At this time, ammonia gas is supplied into the reaction vessel 62 via the branch supply path 56e of the ammonia gas supply mechanism 56, and this ammonia gas is allowed to act as a catalyst for adjusting the reaction of hydrogen gas and fluorine gas. Also good.

  The hydrogen fluoride gas generated in the reaction vessel 62 is guided to the space 50g in the shower head 50e by the hydrogen fluoride supply line 61 and discharged into the chamber 50 or the chamber body 50a from the discharge port 50f of the shower head 50e. Is done. As a result, the chamber 50 or the chamber body 50a is filled with a processing atmosphere containing ammonia gas and hydrogen fluoride gas, and the COR processing on the wafer W is started. As a result, the natural oxide film chemically reacts with the hydrogen fluoride gas molecules and the ammonia gas molecules to be converted into reaction products. During the COR process, the inside of the chamber 50 is maintained at a predetermined pressure reduced from the atmospheric pressure, for example, a vacuum state of about 13.3 Pa. As the reaction product, ammonium fluorosilicate, moisture and the like are generated. When supplying hydrogen gas and fluorine gas into the reaction vessel 62, the argon gas is introduced into the reaction vessel 62 via the branch supply passage 57 e of the argon gas supply mechanism 57 and the branch supply passage 58 e of the nitrogen gas supply mechanism 58. And nitrogen gas are supplied, and the hydrogen fluoride gas generated in the reaction vessel 62 is diluted with the argon gas and nitrogen gas as dilution gases, the corrosion of the hydrogen fluoride supply line 61 can be effectively suppressed. it can. In this case, it is preferable to supply hydrogen and fluorine at the same flow rate so that unreacted hydrogen and fluorine are prevented from being supplied into the chamber 50. Alternatively, when the hydrogen fluoride supply line 61 is formed of a material that hardly corrodes, the processing gas flowing through the hydrogen fluoride supply line 61 may be heated.

  In this embodiment, focusing on the point that hydrogen and fluorine are not polymerized like hydrogen fluoride, and the reactivity of hydrogen and fluorine is extremely high, respectively, hydrogen gas and fluorine gas are mass-flowed. While the flow rate is adjusted by the controllers 54c and 55c, the hydrogen is fed into the reaction vessel 62 through the hydrogen feed line 54b and the fluorine feed line 55b, and the hydrogen generated by reacting hydrogen gas and fluorine gas in the reaction vessel 62 is generated. Since the hydrogen fluoride gas is supplied into the chamber 50, a desired amount of hydrogen fluoride gas can be supplied into the chamber 50.

  In the conventional technology for supplying hydrogen fluoride gas consisting of multimers into a processing vessel through a supply line while adjusting the flow rate by a flow adjustment mechanism such as a mass flow controller, the pressure of the hydrogen fluoride gas flowing through the supply line Or, even if the temperature fluctuates even slightly, the ratio of the multimeric components in the hydrogen fluoride gas will change greatly in the feed line. There was a problem that an error would occur. However, in the present embodiment, hydrogen and fluorine, which are raw materials of hydrogen fluoride gas and are not polymerized, are supplied while individually adjusting the flow rate, so that the hydrogen supply line 54b and the fluorine supply line 55b are respectively provided. Even if the pressure or temperature of the flowing hydrogen gas and fluorine gas changes, the flow rate set by the mass flow controllers 54c and 55c of the hydrogen gas and fluorine gas in the hydrogen feed line 54b and the fluorine feed line 55b and the actual flow rate There is almost no error, and hydrogen gas and fluorine gas can be supplied into the reaction vessel 62 almost at a set flow rate. In addition, since the hydrogen and fluorine reactivities are extremely high, the hydrogen gas and fluorine gas react almost 100% in the reaction vessel 62 to become hydrogen fluoride gas. Therefore, the flow rate and mass flow of hydrogen gas by the mass flow controller 54c are as follows. There is almost no error between the set supply amount of hydrogen fluoride gas into the chamber 50 calculated from the flow rate of fluorine gas by the controller 55c and the actual supply amount. Therefore, this embodiment can greatly improve the reproducibility of the process as compared with the conventional technique in which hydrogen fluoride gas is supplied into the processing vessel while adjusting the flow rate.

  Further, in the present embodiment, hydrogen gas and fluorine gas that do not become multimerized are supplied while individually adjusting the flow rate, so that hydrogen fluoride gas is supplied into the processing vessel while adjusting the flow rate. Thus, since it is not necessary to heat the feed line or the flow rate adjusting mechanism, it is avoided that the fluorine supply mechanism 55 such as the fluorine feed line 55b and the valve 55d can increase the reactivity of the fluorine gas. Corrosion of the fluorine supply mechanism 55 by gas can be suppressed. In particular, it is possible to reliably prevent corrosion of the fluorine supply mechanism 55 by cooling the fluorine supply mechanism 55, for example, the fluorine supply line 55b, by the cooling mechanism, for example, the refrigerant flow path 55e.

  Furthermore, in this embodiment, in order to supply the hydrogen fluoride gas generated in the reaction vessel 62 in the previous stage of the chamber 50 into the chamber 50, ammonia gas is supplied into the chamber 50 in parallel with the hydrogen fluoride gas. However, the hydrogen fluoride gas can be uniformly supplied to the wafer W in the chamber 50. In addition, conditions such as the temperature in the reaction vessel 62 and conditions such as the temperature in the chamber 50 can be set separately without affecting each other. For this reason, even if the catalyst layer and the light 64 for finely adjusting the reaction of fluorine and hydrogen are provided in the reaction vessel 62, the COR treatment in the chamber 50 is not directly affected. While it is possible to create an optimum environmental condition for the production of hydrogen fluoride gas, it is possible to create an optimum environmental condition for the COR process in the chamber 50. Therefore, this embodiment can remarkably improve process reproducibility.

  In addition, if the pressure in the chamber 50 is reduced and maintained at a predetermined pressure before supplying the hydrogen gas and the fluorine gas by the hydrogen supply mechanism 54 and the fluorine supply mechanism 55, the pressure of the processing atmosphere is easily stabilized, and the processing atmosphere The uniformity of the concentration of hydrogen fluoride gas and ammonia gas in the inside can be improved, and the occurrence of processing unevenness on the wafer W can be prevented. Further, the hydrogen fluoride gas is liable to be liquefied and easily adheres to the inner surface of the chamber 50 or the like, but the adhesion can be suppressed by supplying the hydrogen fluoride gas into the chamber 50 immediately before the COR treatment.

When the COR process ends, the inside of the chamber 50 is forcibly exhausted by the exhaust gas processing mechanism 53. Thereby, hydrogen fluoride gas and ammonia gas are forcibly discharged out of the chamber 50. At this time, ammonium fluoride (NH ₄ F) is also generated as a reaction product (by-product) by the reaction between hydrogen fluoride and ammonia, and is discharged from the chamber 50 together with the exhaust gas. Ammonium fluoride is carried along with the exhaust gas by the dry pump 53b through the exhaust passage 53a to the trap device 53c, where it is deposited and collected by the trap device 53c. When forced evacuation is completed, the loading / unloading port 50 c is opened by the gate valve 13, and the wafer W is unloaded from the chamber 50 by the second wafer transfer mechanism 31 (see FIG. 1), and inside the processing chamber 40 of the PHT apparatus 4. It will be carried in.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made. In the above embodiment, since the present invention is applied to the COR process, supply mechanisms (ammonia gas supply mechanism, argon gas supply mechanism, and nitrogen gas supply) of other processing gases (ammonia gas, argon gas, and nitrogen gas) other than fluorine gas and hydrogen gas are used. However, the present invention is mainly intended to perform a predetermined treatment on the object to be treated with hydrogen fluoride gas generated by reacting fluorine gas and hydrogen gas. Supply and supply mechanisms are not essential. When other processing gas that reacts with fluorine gas and hydrogen gas is not supplied into the processing vessel, the hydrogen supply line and the fluorine supply line are directly connected to the processing vessel, and hydrogen from the hydrogen supply line is removed. The hydrogen flow rate control mechanism supplies the process vessel with a predetermined flow rate, and supplies fluorine from the fluorine feed line to the process vessel while the fluorine flow rate control mechanism controls the flow rate to a predetermined flow rate. A predetermined treatment may be applied to the object to be treated with hydrogen fluoride gas generated by reacting hydrogen with fluorine.

In this case, the inner wall of the processing vessel may be formed of a polyethylene material, the inner wall of the processing vessel may be coated with Teflon (registered trademark), or the temperature of the reaction vessel 62 by the temperature adjusting mechanism 63 may be used. If the temperature is 500 ° C. or less, the inner wall of the processing vessel may be formed of gold or platinum, and gas treatment in which silicon tetrafluoride (SiF ₄ ) generated by reaction with fluorine does not adversely affect the process and the apparatus. If so, the inner wall of the processing vessel may be formed of silicon dioxide (SiO ₂ ). In addition, a temperature control mechanism that adjusts the temperature in the processing container may be provided so that the reaction of hydrogen and fluorine does not proceed rapidly or moderately, and the above-described inner wall surface of the processing container may be provided. A catalyst (positive catalyst or negative catalyst) layer similar to that provided in the reaction vessel may be provided, or a light irradiation mechanism for illuminating the inside of the processing vessel may be provided.

  The hydrogen flow rate adjustment mechanism and the fluorine flow rate adjustment mechanism are not limited to a thermal flow rate adjustment mechanism such as a mass flow controller, but may be configured by a pressure type flow rate adjustment mechanism. Further, the fluorine gas may be supplied into the processing vessel or the reaction vessel through the fluorine supply line in a state diluted by mixing with other diluent gas or inert gas such as helium (He) or neon (Ne). Good. Thereby, corrosion of fluorine supply mechanisms, such as a fluorine supply line and a fluorine flow rate adjustment mechanism, can be controlled more effectively.

  The present invention is not limited to COR processing, and can be widely applied to gas processing including hydrogen fluoride gas, such as wafer cleaning of a wafer and cleaning of an inner wall (object to be processed) of a processing container for storing a wafer.

1 is a schematic plan view of a wafer processing system including a COR device that is an embodiment of a gas processing apparatus according to the present invention. It is the schematic of a COR apparatus. It is a schematic sectional drawing of the COR chamber which comprises a COR apparatus. It is a schematic sectional drawing of the reaction part which comprises a COR apparatus.

Explanation of symbols

5: COR device (gas processing device)
14: Process controller 50: Chamber (processing vessel)
54b: Hydrogen supply line 54c: Mass flow controller (hydrogen flow rate adjustment mechanism)
54d: Valve (hydrogen flow rate adjusting mechanism)
55b: Fluorine supply line 55c: Mass flow controller (fluorine flow rate adjustment mechanism)
55d: Valve (fluorine flow rate adjustment mechanism)
55e: Refrigerant flow path (cooling mechanism)
59: Hydrogen fluoride gas supply mechanism (hydrogen fluoride gas supply device)
61: Hydrogen fluoride supply line 62: Reaction vessel 63: Temperature adjustment mechanism 64: Light (light irradiation mechanism)
W: Wafer (object to be processed)

Claims (17)

A gas processing apparatus that performs gas processing by supplying a gas containing hydrogen fluoride gas to an object to be processed,
A processing container in which an object to be processed is disposed;
A hydrogen supply line for supplying hydrogen;
A fluorine feed line for feeding fluorine;
A hydrogen flow rate control mechanism for controlling the flow rate of hydrogen flowing through the hydrogen supply line;
A fluorine flow rate control mechanism for controlling the flow rate of fluorine flowing through the fluorine supply line,
Hydrogen supplied by the hydrogen supply line reacts with fluorine supplied by the fluorine supply line to generate hydrogen fluoride gas, and the generated hydrogen fluoride gas generates a hydrogen fluoride gas. A gas processing apparatus for processing a processing body. The hydrogen supply line and the fluorine supply line are each connected to the processing vessel,
The hydrogen fluoride gas is generated by reacting hydrogen supplied by the hydrogen supply line and fluorine supplied by the fluorine supply line in the processing container. Gas processing equipment. A gas processing apparatus that performs gas processing by supplying a gas containing hydrogen fluoride gas to an object to be processed,
A processing container in which an object to be processed is disposed;
A hydrogen supply line for supplying hydrogen;
A fluorine feed line for feeding fluorine;
A hydrogen flow rate control mechanism for controlling the flow rate of hydrogen flowing through the hydrogen supply line;
A fluorine flow rate control mechanism for controlling the flow rate of fluorine flowing through the fluorine supply line;
The hydrogen supply line and the fluorine supply line are connected, and hydrogen supplied by the hydrogen supply line reacts with fluorine supplied by the fluorine supply line to generate hydrogen fluoride gas. A reaction vessel;
A gas treatment apparatus comprising: a hydrogen fluoride supply line for supplying hydrogen fluoride gas generated in the reaction vessel into the treatment vessel.   The gas processing apparatus according to claim 3, further comprising a temperature control mechanism that adjusts a reaction between hydrogen and fluorine by controlling a temperature in the reaction vessel.   The gas processing apparatus according to claim 3, further comprising a light irradiation mechanism that adjusts a reaction between hydrogen and fluorine by irradiating light into the reaction vessel.   The gas processing apparatus according to any one of claims 3 to 5, wherein a catalyst unit for adjusting a reaction between hydrogen and fluorine is provided in the reaction vessel.   The gas processing apparatus according to any one of claims 1 to 6, further comprising a cooling mechanism that cools fluorine flowing through the fluorine supply line.   The gas processing apparatus according to claim 7, wherein the cooling mechanism sets a cooling temperature of fluorine to −223 ° C. or higher.   The gas processing apparatus according to claim 7, wherein the cooling mechanism sets a cooling temperature of fluorine to −188 ° C. or higher.   The gas processing apparatus according to any one of claims 1 to 9, wherein the fluorine supply line supplies fluorine diluted by mixing with a dilution gas.   11. The gas processing apparatus according to claim 1, wherein each of the hydrogen flow rate control mechanism and the fluorine flow rate control mechanism includes a mass flow controller. A gas treatment method for performing gas treatment by supplying a gas containing hydrogen fluoride gas to an object to be treated,
Place the object to be processed in the processing container,
Hydrogen and fluorine are separately supplied while being adjusted to a predetermined flow rate, and hydrogen and fluorine are reacted to generate hydrogen fluoride gas, and the object to be processed in the processing container is processed by the hydrogen fluoride gas. And a gas processing method.   The gas processing method according to claim 11, wherein hydrogen and fluorine are separately fed into the processing container and reacted in the processing container. A gas treatment method for performing gas treatment by supplying a gas containing hydrogen fluoride gas to an object to be treated,
Place the object to be processed in the processing container,
Hydrogen and fluorine are separately supplied while being adjusted to a predetermined flow rate, and hydrogen and fluorine are reacted in a reaction vessel to generate hydrogen fluoride gas, and this hydrogen fluoride gas is supplied into the processing vessel. And the to-be-processed object in the said processing container is processed, The gas processing method characterized by the above-mentioned. A hydrogen fluoride gas supply device for supplying hydrogen fluoride gas for performing a predetermined process on an object to be processed disposed in a processing container,
A hydrogen supply line for supplying hydrogen;
A fluorine feed line for feeding fluorine;
A hydrogen flow rate control mechanism for controlling the flow rate of hydrogen flowing through the hydrogen supply line;
A fluorine flow rate control mechanism for controlling the flow rate of fluorine flowing through the fluorine supply line;
The hydrogen supply line and the fluorine supply line are connected, and hydrogen supplied by the hydrogen supply line reacts with fluorine supplied by the fluorine supply line to generate hydrogen fluoride gas. A reaction vessel;
A hydrogen fluoride gas supply device comprising: a hydrogen fluoride supply line for supplying hydrogen fluoride gas generated in the reaction vessel into the processing vessel. A hydrogen fluoride gas supply method for supplying hydrogen fluoride gas for performing a predetermined process on an object to be processed disposed in a processing container,
Hydrogen and fluorine are separately supplied while being adjusted to a predetermined flow rate, and these hydrogen and fluorine are reacted in a reaction vessel to generate hydrogen fluoride gas. This hydrogen fluoride gas is treated in the treatment vessel. A method for supplying hydrogen fluoride gas, characterized by being supplied to a body. A computer-readable storage medium storing a control program that runs on a computer,
15. A computer-readable storage medium, wherein the control program causes a computer to control a processing apparatus so that the gas processing method according to any one of claims 12 to 14 is performed at the time of execution.

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