JP2012124227A - Substrate cleaning method and substrate processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technology which can satisfactorily remove foreign matter stuck to a substrate (e.g., particles and residues at etching time) by dry cleaning.SOLUTION: A silicon oxide film 8 formed on the surface of a wafer W by oxidation at ashing time is etched by hydrogen fluoride gas to remove particles P stuck to the wafer W together with the silicon oxide film 8. At the time of etching by hydrogen fluoride, the wafer W is set with its surface down, and further the wafer W is heated to be electrically charged, whereby heat migration and electrostatic forces, in addition to gravity, are made to act upon particles P. Also, after the silicon oxide film 8 is etched at ashing time, the surface of the wafer W is further oxidized by, for example, ozone gas and then etched by hydrogen fluoride gas. These successive steps are carried out once or twice or more, making it possible to remove the particles P more surely than ever.

Description

  The present invention relates to a technique for removing foreign matter adhering to a substrate.

  In a series of steps for manufacturing a semiconductor device on a substrate, foreign particles may adhere to the substrate during the process performed in the process module or during the transfer of the substrate. When the semiconductor device is manufactured, the yield decreases. For this reason, measures are taken to suppress dust generation, but the substrate after dry etching, where particles are likely to adhere, is carried into a cleaning station and subjected to a cleaning process to remove particles. .

  Cleaning methods aimed at particle removal include wet cleaning using lift-off with a mixture of ammonia water and hydrogen peroxide water, wet cleaning physically removed by ultrasonic waves, etc., and chemically reactive gas. Examples thereof include dry cleaning for removing particles and dry cleaning (aerosol cleaning) using an impact force of gas. In wet cleaning, the particles after lift-off move into the chemical and are discharged, so there is no concern about reattachment, but a complicated recipe is required to avoid the generation of watermarks, and the pattern line width is narrow. Then, there is a problem that the pattern collapses due to the surface tension when the cleaning liquid is dried. Chemical particle removal can be applied only when the composition of the particles is known, and only particles of a specific material can be removed. For cleaning using the impact force of gas, there are trade-offs between the ability to remove particles and the probability of pattern collapse due to impact, so the processes that can be applied together are limited.

  Patent Document 1 describes particle removal using Maxwell stress, gas shock wave, thermal stress and thermophoretic force, and mechanical vibration. Patent Document 2 describes physical removal of particles by gas clusters. However, both patent documents do not describe particle removal by dry cleaning using lift-off described in the present invention.

JP 2005-101539 A JP 2001-137797 A

  The present invention has been made under such a background, and an object of the present invention is to provide a technique capable of satisfactorily removing foreign matters (particles, residues during etching, etc.) adhering to a substrate by dry cleaning. There is to do.

The substrate cleaning method in the present invention is:
Holding the substrate in the holding portion so that the surface faces downward;
Supplying an oxidizing gas to the surface of the substrate to oxidize the surface of the substrate;
Removing the foreign matter attached to the surface of the substrate together with the oxide film by supplying an etching gas to the downward surface of the substrate held by the holding unit and etching the oxide film oxidized by the process Including a process,
This removal step is performed by using at least one of the step of heating the substrate and the step of charging the substrate in order to cause at least one of thermophoretic force and electrostatic repulsive force to act on the foreign matter in addition to the action of gravity. It is characterized by that.

In addition, the substrate cleaning method of the present invention is
In the method of removing foreign matter adhering to the surface of the substrate after etching with an etching gas in a vacuum atmosphere using an etching mask,
Holding the substrate in a holding portion so that the surface faces downward without breaking the vacuum after the etching;
An etching process is performed by supplying an etching gas to the downward surface of the substrate held by the holding unit, and etching the surface layer portion of the substrate to remove foreign matter adhering to the surface of the substrate together with the surface layer portion; Including
This removal step is performed by using at least one of the step of heating the substrate and the step of charging the substrate in order to cause at least one of thermophoretic force and electrostatic repulsive force to act on the foreign matter in addition to the action of gravity. It is characterized by that.

The substrate processing apparatus in the present invention is
A processing container having a holding part for holding the substrate so that the surface faces downward;
An oxidizing gas supply unit that supplies an oxidizing gas to oxidize the surface of the substrate held by the holding unit;
An etching gas supply unit that etches the surface of the substrate oxidized by the oxidizing gas while facing downward, and supplies an etching gas to the surface of the substrate in order to remove foreign matter adhering to the surface of the substrate together with the oxide film When,
And at least one of a heating mechanism for heating the substrate to apply a thermophoretic force to the foreign matter on the substrate and a charging mechanism for charging the substrate to cause an electrostatic repulsive force to the foreign matter on the substrate. It is characterized by.

In addition, the substrate processing apparatus in another aspect of the present invention is
An etching module having a processing container for etching, and etching the surface of the substrate with an etching gas using an etching mask;
A vacuum transfer chamber that is airtightly connected to the processing container for etching and has a substrate transfer mechanism for transferring a substrate;
A processing container for cleaning, which is hermetically connected to the vacuum transfer chamber and has a holding unit for holding the substrate so that the surface faces downward,
An etching gas supply unit for supplying an etching gas to the surface of the substrate in order to remove the entire surface layer of the foreign matter adhering to the surface of the substrate held by the holding unit;
And at least one of a heating mechanism for heating the substrate to apply a thermophoretic force to the foreign matter on the substrate and a charging mechanism for charging the substrate to cause an electrostatic repulsive force to the foreign matter on the substrate. It is characterized by.

  The present invention lifts off the surface of the substrate to which the foreign substance has adhered in a dry environment, so that the generation of a watermark or pattern collapse, which is a problem in wet cleaning, does not occur from the substrate. Can be liberated and removed. At this time, the surface of the substrate is directed downward and gravity is used to suppress the reattachment of the large foreign matter released from the substrate to the substrate, and the small foreign matter released from the substrate is caused by thermophoresis or static electricity. The reattachment is suppressed. As a result, a good foreign matter removal process can be performed on the substrate.

It is a schematic diagram showing the composition of the substrate processing device concerning the embodiment of the present invention. It is a vertical side view which shows the washing | cleaning module provided in the above-mentioned substrate processing apparatus. It is a top view which shows the board | substrate delivery mechanism with which the above-mentioned washing | cleaning module is equipped. It is a perspective view which shows the gas supply part with which the above-mentioned washing | cleaning module is equipped. It is a conceptual sectional view of a substrate part explaining an operation in a washing process. It is a characteristic view which shows the moving speed of the particle by each dynamic action. It is a cross-sectional top view which shows the holding | maintenance inversion mechanism which concerns on 2nd Embodiment. It is a vertical side view which shows the washing | cleaning module which concerns on 3rd Embodiment. It is a vertical side view which shows the holding | maintenance part which concerns on 3rd Embodiment. It is a longitudinal section schematic diagram showing another example of a substrate to be cleaned. It is a longitudinal section schematic diagram showing another example of a substrate to be cleaned.

  An embodiment of a substrate cleaning apparatus of the present invention will be described with reference to FIGS. FIG. 1 shows a substrate processing apparatus 1 constituting a multi-chamber system including a substrate cleaning apparatus of the present invention. In FIG. 1, reference numeral 11 denotes an atmospheric transfer chamber. In the atmospheric transfer chamber 11, a loading / unloading stage 12 for loading / unloading a semiconductor wafer (hereinafter referred to as a wafer) W as a substrate and a positioning of the wafer W are provided. An alignment module 13 is provided adjacent to each other, and a substrate transfer mechanism 14 for transferring the wafer W between the loading / unloading stage 12, the alignment module 13, and a load lock chamber 15 described later is provided. The atmospheric transfer chamber 11 is connected to the vacuum transfer chamber 16 via the load lock chamber 15.

  The vacuum transfer chamber 16 is airtightly connected with a plurality of etching modules 17 and a cleaning module 2 that is a substrate cleaning apparatus according to an embodiment of the present invention. Further, the vacuum transfer chamber 16 is provided with a substrate transfer mechanism 18 that can be rotated and expanded, so that the wafer W can be transferred between the load lock chamber 15 and the modules 17 and 2. It has become. The substrate processing apparatus 1 includes a control unit 10, and the operation of each device including the cleaning module 2 is controlled by the control unit 10.

  Next, the cleaning module 2 will be described. As shown in FIG. 2, the cleaning module 2 includes a processing container 3 that is a vacuum container, and a holding and reversing mechanism 6 for holding and reversing the wafer W is provided in the processing container 3. As shown in FIGS. 2 and 3, the holding and reversing mechanism 6 includes a rotation mechanism 67 provided on the side wall of the processing container 3 on the side opposite to the vacuum transfer chamber 16, and the rotation mechanism 67 to the center of the processing container 3. A rotating shaft 63 extending horizontally (X direction in the figure) toward the horizontal, and extending horizontally (Y direction in FIG. 3) so as to be orthogonal to the rotating shaft 63 at the tip (end opposite to the rotating mechanism 67) of the rotating shaft 63. A guide member 64 is provided.

  At both ends of the guide member 64, there are provided a pair of clamp members 62, 62 that extend in the X direction and move so as to approach each other or move away from each other. The portions of the clamp members 62, 62 facing each other have an arc shape corresponding to the periphery of the wafer W so as to hold (clamp) the periphery of the wafer W with a narrow pressure. As a mechanism for moving the clamp members 62, 62, a ball screw that extends along the guide member 64 and is threaded so that both ends are in a reverse screw relationship with each other is screwed into the clamp members 62, 62. It consists of a mechanism that rotates a ball screw with a motor. In this case, by rotating the ball screw forward and backward, the clamping members 62 and 62 can move toward and away from each other, and the wafer W can be clamped and released. Further, the rotation mechanism 67 rotates the rotation shaft 63 by 180 degrees about the X direction, thereby reversing the direction of the wafer W held by the clamp member 62, that is, the surface of the wafer W between the upward and downward directions. Can be reversed.

  A gas supply unit 7 is provided in the processing container 3. As shown in FIG. 4, the gas supply unit 7 has a large number of gas spray holes 71 formed at intervals on the upper surface of the hollow ring-shaped member along the circumferential direction. A gas supply pipe 72 is connected to the lower part of the gas supply unit 7. The gas supply pipe 72 penetrates the bottom surface of the processing container 3 and branches below the processing container 3, and at the end of the branch, a hydrogen fluoride (HF) gas supply system 76 and ozone are respectively connected via an on-off valve. (O3) Connected to the gas supply system 78.

  In addition, a heating mechanism 4 made of a radiant lamp such as an infrared lamp is provided in the upper part of the processing container 3. The heating mechanism 4 can heat the wafer W by irradiating infrared rays toward the wafer W held by the reversing mechanism 6 below. An exhaust port 51 is formed in the ceiling portion of the processing container 3, and the exhaust port 51 is connected to a vacuum pump 5 that is a vacuum exhaust mechanism via an exhaust pipe 52. G is a gate valve, and 31 is a wafer W transfer port.

  Next, the operation of the cleaning module in this embodiment will be described. First, a carrier containing a plurality of wafers W to be processed is placed on the carry-in / out stage 12 of the substrate processing apparatus 1. One wafer W is taken out of the carrier by the transfer mechanism 14 in the atmospheric transfer chamber 11, the holding position of the wafer W is adjusted by the alignment module 13, and then the wafer W is transferred into the load lock chamber 15. The wafer W is received by the transfer mechanism 18 of the vacuum transfer chamber 16 and is carried into the etching module 17 through the vacuum transfer chamber 16. The etching module 17 is provided with an upper electrode forming a parallel plate electrode and a lower electrode also serving as a wafer W mounting table in a vacuum vessel, and is configured to supply high-frequency power between these electrodes to turn the etching gas into plasma. ing. As for the surface structure of the wafer W, a resist mask is formed on the polysilicon layer 83, and trenches or holes are formed on the surface of the wafer W by etching with plasma such as hydrogen bromide (HBr) gas by the etching module 17. (Recess) 85 is formed. Next, the resist mask is removed by ashing the wafer W with oxygen (O 2) plasma, and a silicon oxide (SiO 2) thin film 8 is formed over the entire surface of the wafer W including the inside of the trench 85. ((A) in FIG. 5).

  Then, the wafer W unloaded from the etching module 17 is held and taken out by the transfer mechanism 18 on the back surface side with the processing surface facing upward. The wafer W is carried into the cleaning module 2 through the vacuum transfer chamber 16 and the carry-in port 31 in this state. Then, the wafer W is sandwiched and held by the clamp member 62, and the transfer mechanism 18 is slightly lowered. As a result, the wafer W is transferred from the transfer mechanism 18 to the holding and reversing mechanism 6, and then the transfer mechanism 18 is moved out of the cleaning module 2 and the gate valve G is closed. The holding / reversing mechanism 6 reverses the wafer W held by the clamp member 62 from the front to the back.

  Thereafter, the wafer W is heated to, for example, 150 ° C. to 200 ° C. by infrared rays irradiated from the heating mechanism 4 ((a) in FIG. 5), and in this state, hydrogen fluoride gas is supplied from the gas supply unit 7 to the wafer W. This is supplied to the surface, whereby the silicon oxide film 8 on the surface of the wafer W is etched. For this reason, the particles P, which are foreign substances adhering to the surface of the wafer W, are separated from the surface together with the silicon oxide film 8 and float in the air near the surface of the wafer W ((b) in FIG. 5). . Note that residues on etching or resist wrinkles on ashing adhere to the surface of the wafer W, and these are collectively referred to as foreign substances in the present application. Will be described. The film thickness to which the silicon oxide film 8 is etched is extremely thin, for example, 0.5 mm or less. Although the silicon oxide film 8 is etched, water is generated on the surface of the wafer W. However, since the temperature of the wafer W is 150 ° C. to 200 ° C., a dry environment is maintained.

  Here, the force acting on the particles P released from the wafer W will be described. Since the surface of the wafer W faces downward, the particles P tend to leave the surface of the wafer W due to gravity. In addition, since the wafer W is heated, a temperature gradient is formed between the interface of the wafer W and the lower space. For this reason, thermophoretic force acts on the particles P, and the particles P are subjected to gravity and heat. A downward force due to the migration force, that is, a force to move away from the surface of the wafer W acts. On the other hand, although the particle P performs the Brownian motion, the direction of the Brownian motion is random. Therefore, if the influence of the Brownian motion is relatively large compared to the gravity or thermophoretic force, the particle P reattaches to the wafer W. Is likely to occur.

FIG. 6 is a diagram showing the calculation result of the moving speed of the particle P at the atmospheric pressure of 13.3 × 10 ³ Pa (1 torr) derived from the thermophoresis under the temperature gradient of 5 ° C./cm and the Brownian motion, respectively. is there. For example, in the case of a particle P having a particle size of 0.07 μm or more, the moving speed due to gravity is larger than the moving speed due to the Brownian motion, so that the surface of the wafer W is directed downward to prevent the reattachment of the particles P. It is valid. Further, for example, in a particle P having a particle diameter of 0.01 μm to 10 μm, the moving speed by thermophoresis under a temperature gradient of 5 ° C./cm is larger than the moving speed by Brownian motion, so that the reattachment of the particles P For prevention, it is effective to use thermophoresis under a temperature gradient of 5 ° C./cm. However, even in this case, when the surface of the wafer W is directed upward, the movement speed due to gravity is more dominant than the movement speed due to thermophoresis in the particle P of 1 μm or more. The risk is high.

  In this embodiment, since the surface of the wafer W faces downward, the risk of redeposition of particles P released from the wafer W due to the lift-off described above to the wafer W due to gravity and thermophoretic force is reduced. This also means that large particles P are reattached to the wafer W due to gravity, and minute particles P are reattached to the wafer W by thermophoresis. The free particles P are carried by the airflow flowing on the surface of the wafer W while being prevented from reattaching to the wafer W, and are discharged from the exhaust port 51. Thus, the surface of the wafer W is cleaned. In this embodiment, after the first lift-off, the silicon oxide film 8 is formed again on the surface of the wafer W and lift-off is performed. Specifically, ozone gas is supplied from the ozone gas supply system 78 to the surface of the wafer W through the gas supply unit 7 after the first lift-off. As silicon is oxidized by ozone, a silicon oxide film 8 is formed on the surface of the wafer W ((c) in FIG. 5). Then, hydrogen fluoride gas is supplied from the hydrogen fluoride gas supply system 76 to the surface of the wafer W through the gas supply unit 7 and lifted off ((d) in FIG. 5).

  In summary, the wafer W is oxidized by ashing with a gas containing oxygen to remove the resist mask by the etching module 17, then etched by the cleaning module 2, and further oxidized and etched. . That is, in this embodiment, the cleaning module 2 performs a continuous process of oxidation and etching. However, this continuous process may be performed only once or may be performed a plurality of times. The number of times may be set to an appropriate value, for example, by a preliminary test according to the amount of particles P based on the performance of the etching module 17 and the line width of the pattern formed by etching.

  The advantages of etching the surface of the wafer W oxidized by ashing by the cleaning module 2 and further oxidizing and etching are as follows. As shown in FIG. 5, the free movement of the particles P caused by Brownian motion occurs. Even if the free particle P moves within the recess 85 such as a fine trench in a direction in which the particle P is slightly discharged due to gravity or thermophoretic force, there is a possibility that it will reattach due to this Brownian motion. Therefore, by repeating oxidation and etching, the particle P can be finally removed at a high removal rate by moving the reattachment position of the particle P to the surface layer side of the wafer W.

  According to the above-described embodiment, since the silicon oxide film 8 whose surface has been oxidized by ashing is etched with hydrogen fluoride gas, the particles P adhering during the etching performed using the resist mask in the etching module 17 are removed. The entire silicon oxide film 8 is removed. Then, when etching with hydrogen fluoride, the orientation of the wafer W is set so that the surface faces downward, and the wafer W is further heated to apply a thermophoretic force to the particles P in addition to gravity. The reattachment of the particles P released from W is suppressed, and a good particle P removal process (cleaning process) can be performed. Since the surface of the wafer W is cleaned in a dry environment to remove the particles P, the problems taken up by wet cleaning such as generation of a watermark and pattern collapse are solved. Further, after etching the silicon oxide film 8 at the time of ashing, a continuous process of oxidizing the surface of the wafer W with, for example, ozone gas and then etching with hydrogen fluoride gas is performed once or twice, so that As described above, the particles P can be removed more reliably.

  A second embodiment of the present invention will be described. In this embodiment, electrostatic repulsion is used together with gravity, and the device configuration is substantially the same as that of the above-described embodiment, but the structure of the holding and reversing mechanism 6 is different. As shown in FIG. 7, the clamp member 62 of the holding / reversing mechanism 6 is provided with an electrode 44 so as to contact the wafer W held by the holding / reversing mechanism 6. The electrode 44 is connected to the negative electrode of the DC power supply 100 also provided outside the processing container 3 through a switch SW provided outside the processing container 3 by a power supply line 45. The power supply line 45 is wired along the clamp member 62 and the guide member 64 from the electrode 44 side, and is drawn out of the processing container 3 through the rotation shaft 63 and the rotation mechanism 67.

  In this case, when the wafer W is held by the holding / reversing mechanism 6, the peripheral end of the wafer W comes into contact with the electrode 44. Therefore, by closing the switch SW in this state, the wafer W is negatively charged via the electrode 44. . As a result, the particles P adhering to the wafer W are also negatively charged, and a repulsive force is generated between the wafer W and the particles P. This repulsive force works together with gravity as an action for preventing reattachment of the released particles P. Also in this embodiment, the wafer W may be heated by the heating mechanism 4 so that the thermophoretic force acts on the particles P in addition to gravity and electrostatic repulsion. In this example, the power supply line 45, the DC power supply 100, and the electrode 44 constitute a charging mechanism.

  A third embodiment of the present invention will be described with reference to FIGS. In this embodiment, a holding portion 9 that is an electrostatic chuck for horizontally holding the wafer W is provided on the lower surface side of the processing container 3. In the holding portion 9, an adsorption electrode 41 connected to the positive electrode side of the DC power source 100 whose negative electrode side is grounded is embedded. The surface of the holding unit 9 is covered with a dielectric layer 43, and the wafer W is held by suction through the dielectric layer 43. An electrode 44 is provided on a part of the dielectric layer 43 so as to come into contact with the attracted wafer W. The electrode 44 is grounded via a power supply line 45, and the electrode 44 and the power supply line 45 are insulated from the adsorption electrode 41. In this embodiment, the Z guide 61 is provided on the side wall of the processing container 3, and the holding and reversing mechanism 6 is provided on the Z guide 61 so as to be movable up and down via an elevator body (not shown).

  The wafer W carried into the processing container 3 through the carry-in port 31 is received by the holding / reversing mechanism 6 and then reversed so that the surface faces downward. Then, the holding and reversing mechanism 6 is raised along the Z guide 61, and in this state, the back surface that is the upper surface of the wafer W is brought into contact with the holding portion 9. Next, the switch SW is closed and the wafer W is attracted to the holding unit 9. Next, the clamp member 62 is opened, the holding and reversing mechanism 6 is lowered along the Z guide 61, and waits at the lower part in the cleaning module 2, and then the cleaning process is performed as in the above embodiment.

  In this case, when the switch SW is closed and the wafer W is attracted to the holding unit 9, the wafer W is negatively charged, and the particles P adhering on the wafer W are the same as in the second embodiment. Is negatively charged, a repulsive force is generated between the wafer W and the particles P. This repulsive force works together with gravity as an action for preventing reattachment of the released particles P. Also in this embodiment, for example, a heater may be provided in the holding unit 9 as a heating mechanism so that thermophoretic force acts on the particles P in addition to gravity and electrostatic repulsion. In this example, the adsorption electrode 41, the DC power source 100, and the electrode 44 constitute a charging mechanism.

Other examples of the wafer W to be cleaned in the present invention are listed below.
(1) FIG. 10 shows a structure in which a single crystal silicon layer 81, a silicon oxide film 82, and a polysilicon layer 83 are laminated in this order, using a silicon nitride film (abbreviated as SiN film) 84 as a hard mask. The surface structure of the wafer W in which the recess 85 is formed in the laminated structure by etching is shown. As a gas for etching the polysilicon layer 83 and the single crystal silicon layer 81, for example, a mixed gas of hydrogen bromide and oxygen is used as a processing gas. Further, as a gas for etching the silicon oxide film 82, for example, a CF-based gas such as CF4 or C2F4 is used. At the time before the cleaning process, the silicon oxide residue 86 and the fluorocarbon compound 87 are stacked and attached to the side walls of the recess 85 as by-products during etching as shown in FIG. In the cleaning module 2, as described above, the wafer W is held by the holding / reversing mechanism 6 so that the surface (surface to be processed) faces downward, and hydrogen fluoride gas is supplied to the surface of the wafer W, so The product silicon oxide 86 is removed, and at this time, the particles P adhering to the sidewalls of the recess 85 and the fluorocarbon compound 87 laminated on the silicon oxide 86 are also removed.

  Also in this case, after removing silicon oxide residue 86 by etching with hydrogen fluoride gas, polysilicon layer 83 and single crystal silicon layer 81 are oxidized with ozone gas, and then etched with hydrogen fluoride gas. Further, this continuous process of oxidation and etching may be repeated twice or more.

  (2) FIG. 11 shows the surface structure of the wafer W after the etching module 17 has etched the silicon oxide film 82 using the SiN film 84 as a hard mask. As described above, for example, a CF-based gas is used as the gas for etching the silicon oxide film 82. On the side wall of the silicon oxide film 82 in the recess 85 at the time before the cleaning process, a gas is generated as a by-product during etching. A residue 87, which is a carbonized carbon compound, adheres as shown in FIG. In the cleaning module 2, by supplying ozone gas, the fluorocarbon compound 87 as the by-product is removed, and at this time, the particles P adhering to the side wall of the recess 85 are also removed.

  Then, the silicon oxide film 82 exposed by removing the residue 87 may be etched with hydrogen fluoride gas. By performing further etching in this way, it is possible to remove the particles P reattached in the recess 85 when the residue 87 is removed. Note that, when the silicon oxide film 82 is etched with hydrogen fluoride gas, it is necessary to etch the silicon oxide film 82 so as to be within an error range of the design dimension of the recess 85.

(3) As an example of the substrate W in the above (1), any of metal oxide films such as Al 2 O 3, HfO, and ZnO may be used instead of the silicon oxide film 82.
Even in the case where the cleaning process is performed on each wafer W described in (1) to (3), it is needless to say that thermophoresis or electrostatic repulsion may be used as in the previous embodiment.

  A film for etching the surface of the wafer W to be cleaned is not limited to silicon. Further, when removing the particles P by etching the surface of the wafer W, it is not essential to perform an oxidation treatment before the etching. If a combination of a film on the surface of the wafer W and a gas capable of etching this film is established. For example (for example, (2) in the other embodiment), the wafer W carried into the cleaning module 2 may be etched as it is. Etching for removing the particles P may be performed by converting the etching gas into plasma. In this case, for example, an induction coil for supplying power to the processing space is provided inside or outside the processing container 3. You can do it.

  In the example described above, the surface of the wafer W is oxidized in the cleaning module 2 and then etched. However, the oxidation treatment of the surface of the wafer W is performed outside the processing vessel 3, that is, in the example of FIG. In other words, even if the etching is performed by the etching module 17 and then the etching is performed by the cleaning module 2, it is within the scope of the present invention. Furthermore, the cleaning module 2 is not limited to being incorporated into a multi-chamber system, and may be configured as a stand-alone device.

G Gate valve W Semiconductor wafer P Particle 1 Substrate processing apparatus 10 Control unit 11 Atmospheric transfer chamber 12 Loading / unloading stage 13 Alignment module 14 Transfer mechanism of atmospheric transfer chamber 15 Load lock chamber 16 Vacuum transfer chamber 17 Etching module 18 Transfer of vacuum transfer chamber Mechanism 2 Cleaning module 3 Processing container 31 Carrying-in port 4 Heating mechanism 44 Electrode 45 Feed line 5 Vacuum pump 51 Exhaust port 52 Exhaust pipe 6 Holding reversing mechanism 62 Clamp member 63 Rotating shaft 64 Guide member 67 Rotating mechanism 7 Gas supply part 71 Gas blowing Hole 72 Gas supply pipe 76 Hydrogen fluoride gas supply system 78 Ozone gas supply system 8 Oxide film formed on semiconductor wafer

Claims (9)

Holding the substrate in the holding portion so that the surface faces downward;
Supplying an oxidizing gas to the surface of the substrate to oxidize the surface of the substrate;
Removing the foreign matter attached to the surface of the substrate together with the oxide film by supplying an etching gas to the downward surface of the substrate held by the holding unit and etching the oxide film oxidized by the process Including a process,
This removal step is performed by using at least one of the step of heating the substrate and the step of charging the substrate in order to cause at least one of thermophoretic force and electrostatic repulsive force to act on the foreign matter in addition to the action of gravity. And a substrate cleaning method.   The substrate cleaning method according to claim 1, wherein the step of oxidizing the surface of the substrate is performed in a state where the substrate is held by the holding portion so that the surface faces downward. In the method of removing foreign matter adhering to the surface of the substrate after etching with an etching gas in a vacuum atmosphere using an etching mask,
Holding the substrate in a holding portion so that the surface faces downward without breaking the vacuum after the etching;
An etching process is performed by supplying an etching gas to the downward surface of the substrate held by the holding unit, and etching the surface layer portion of the substrate to remove foreign matter adhering to the surface of the substrate together with the surface layer portion; Including
This removal step is performed by using at least one of the step of heating the substrate and the step of charging the substrate in order to cause at least one of thermophoretic force and electrostatic repulsive force to act on the foreign matter in addition to the action of gravity. And a substrate cleaning method.   The substrate cleaning method according to claim 3, wherein the substrate held by the holding portion is etched using an etching mask and then ashed with an ashing gas containing oxygen.   Before the step of supplying an etching gas to the surface of the substrate and etching the surface layer portion of the substrate, performing a step of supplying an oxidizing gas to the surface of the substrate and forming an oxide film on the surface layer portion of the substrate 5. The substrate cleaning method according to claim 3, wherein the substrate is cleaned. After the step of removing the foreign matter adhering to the surface of the substrate together with the oxide film by etching the oxide film,
Supplying the oxidizing gas again to the surface of the substrate to oxidize the surface of the substrate, and then supplying an etching gas to the surface of the substrate facing downward to etch the oxide film oxidized by the above-described steps, 6. The method for cleaning a substrate according to claim 1, wherein the step of removing the foreign matter adhering to the surface of the substrate together with the oxide film is performed. A processing container having a holding part for holding the substrate so that the surface faces downward;
An oxidizing gas supply unit that supplies an oxidizing gas to oxidize the surface of the substrate held by the holding unit;
An etching gas supply unit that etches the surface of the substrate oxidized by the oxidizing gas while facing downward, and supplies an etching gas to the surface of the substrate in order to remove foreign matter adhering to the surface of the substrate together with the oxide film When,
And at least one of a heating mechanism for heating the substrate to apply a thermophoretic force to the foreign matter on the substrate and a charging mechanism for charging the substrate to cause an electrostatic repulsive force to the foreign matter on the substrate. A substrate processing apparatus. An etching module having a processing container for etching, and etching the surface of the substrate with an etching gas using an etching mask;
A vacuum transfer chamber that is airtightly connected to the processing container for etching and has a substrate transfer mechanism for transferring a substrate;
A processing container for cleaning, which is hermetically connected to the vacuum transfer chamber and has a holding unit for holding the substrate so that the surface faces downward,
An etching gas supply unit for supplying an etching gas to the surface of the substrate in order to remove the entire surface layer of the foreign matter adhering to the surface of the substrate held by the holding unit;
And at least one of a heating mechanism for heating the substrate to apply a thermophoretic force to the foreign matter on the substrate and a charging mechanism for charging the substrate to cause an electrostatic repulsive force to the foreign matter on the substrate. A substrate processing apparatus.   The substrate processing apparatus according to claim 8, wherein the holding unit includes a mechanism for inverting the substrate received from the substrate transfer mechanism in the vacuum transfer chamber.

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