KR20220132438A - Plasma processing apparatus, and method of plasma processing - Google Patents

Abstract

The purpose of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of suppressing contamination due to contaminants. According to an embodiment, the plasma processing apparatus comprises: a first chamber which maintains an atmosphere reduced in pressure from atmospheric pressure and has a substance to be processed therein; a first exhaust unit which can depressurize the inside of the first chamber to a predetermined pressure; a plasma generation unit which can generate the plasma; a first gas supply unit which can supply a process gas to an area in which the plasma is generated as the inside of the first chamber; a second chamber which is connected to the first chamber through a gate valve and can maintain an atmosphere depressurized than atmospheric pressure; a conveying unit which is disposed inside the second chamber and can convey the substance to be processed between the first chamber and the conveying unit; a second exhaust unit which can depressurize the inside of the second chamber to a predetermined pressure; a second gas supply unit which can supply gas to the inside of the second chamber; and a controller which can control the conveying unit, the second exhaust unit, and the second gas supply unit. When the substance to be processed is conveyed by the conveying unit, the controller controls the second exhaust unit so that the pressure inside the second chamber is approximately equal to the pressure inside the first chamber, and controls the second gas supply unit when the conveyance of the substance to be processed by the conveyance unit is completed, so that the gas is supplied to the second chamber.

Description

Plasma processing apparatus and plasma processing method

An embodiment of the present invention relates to a plasma processing apparatus and a plasma processing method.

The dry process using plasma is utilized, for example, when manufacturing a microstructure. For example, in manufacture of a semiconductor device, a flat panel display, a photomask, etc., various plasma processes, such as an etching process, an ashing process, and removal of damage, are performed.

In the plasma processing apparatus for performing such plasma processing, for example, a process chamber for performing plasma processing on a processing object, a transfer chamber connected to the process chamber through a gate valve, and the inside of the transfer chamber, the processing is performed between the process chamber and the process chamber A transport robot that transports water and the like are provided.

Here, in the inside of the transfer chamber, contaminants containing organic matter may be generated. Since the processed object is conveyed inside the transfer chamber, when contaminants are generated, there is a risk that the generated contaminants may adhere to the surface of the processed object. In this case, when the processed object to which the contaminant adheres is carried into a process chamber and plasma processing is performed, there exists a possibility that the quality of a product may be affected. Moreover, when the processed material to which the contaminant adhered is carried out from the transfer chamber to the outside, there exists a possibility that the processing of a post process may be affected.

Therefore, the technique of suppressing that a processed material is contaminated with a contaminant is proposed (refer patent documents 1 and 2, for example).

However, in recent years, diversification and miniaturization of materials of microstructures have progressed, and there is a fear that the influence of contaminants on quality and the like may increase.

Therefore, the development of a technology capable of further suppressing contamination by contaminants has been demanded.

Patent Document 1: Japanese Patent Laid-Open No. Hei 6-196540 Patent Document 2: Japanese Patent Laid-Open No. 2003-17478

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of suppressing contamination by contaminants.

A plasma processing apparatus according to an embodiment includes: a first chamber capable of arranging a processed object therein while maintaining an atmosphere reduced in pressure from atmospheric pressure; a first exhaust unit capable of depressurizing the interior of the first chamber to a predetermined pressure; A plasma generating unit capable of generating plasma; a first gas supply unit capable of supplying a process gas to a region generating the plasma as an interior of the first chamber; and a gate valve connected to the first chamber; A second chamber capable of maintaining a more reduced pressure atmosphere, a transport unit provided inside the second chamber and capable of transporting the processed material between the first chamber, and a predetermined interior of the second chamber A second exhaust unit capable of reducing pressure to a pressure, a second gas supply unit capable of supplying gas to the inside of the second chamber, and a controller capable of controlling the conveying unit, the second exhaust unit, and the second gas supply unit; have. the controller controls the second exhaust unit when conveying the processed object by the conveying unit so that the pressure inside the second chamber is substantially equal to the pressure inside the first chamber; When the transfer of the processed object by the transfer unit is finished, the second gas supply unit is controlled to supply the gas to the inside of the second chamber.

According to an embodiment of the present invention, a plasma processing apparatus and a plasma processing method capable of suppressing contamination by contaminants are provided.

1 is a layout diagram for illustrating a plasma processing apparatus according to the present embodiment.
2 is a schematic cross-sectional view for illustrating an example of a processing unit.
3 is a schematic cross-sectional view for illustrating a processing unit according to another embodiment.
4 is a schematic cross-sectional view for illustrating a transmission unit.
5 is a vapor pressure curve of C ₁₆ H ₃₀ O ₄ .
6 is a timing chart for illustrating the supply of gas.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is illustrated, referring drawings. In addition, in each figure, the same code|symbol is attached|subjected to the same component, and detailed description is abbreviate|omitted suitably.

1 is a layout diagram for illustrating a plasma processing apparatus 1 according to the present embodiment.

As shown in FIG. 1 , the plasma processing apparatus 1 includes, for example, a controller 2 , an accommodating unit 3 , a conveying unit 4 , a load lock unit 5 , a processing unit 6 , and a transmission unit 7 . have

The controller 2 has, for example, an arithmetic unit such as a CPU (Central Processing Unit) and a storage unit such as a memory. The controller 2 is, for example, a computer or the like. The controller 2 controls the operation of each element provided in the plasma processing apparatus 1, for example, based on the control program stored in the storage unit.

The accommodating part 3 accommodates, for example, the processed object 100 in a stacked type (multi-stage type). The accommodating unit 3 is, for example, a so-called pod or a Front-Opening Unified Pod (FOUP), which is a front-opening carrier. However, the accommodating part 3 is not limited to what was illustrated, and what is necessary is just what can accommodate the processed object 100 . At least one accommodating part 3 can be provided.

The transport section 4 is provided between the storage section 3 and the load lock section 5 . The conveyance unit 4 conveys and delivers the processed object 100 between the storage unit 3 and the load lock unit 5 . In this case, the conveying unit 4 conveys and delivers the processed object 100 in an environment of a pressure (eg, atmospheric pressure) higher than the pressure at the time of plasma processing. The transport unit 4 is, for example, a transport robot having an arm that holds the processed object 100 .

The load lock part 5 is provided between the conveyance part 4 and the delivery part 7 . The load lock unit 5 transfers the processed object 100 between the conveying unit 4 and the transmitting unit 7 having different atmospheric pressures. Therefore, the load lock unit 5 has a chamber 51 , an exhaust unit 52 , and a gas supply unit 53 .

The chamber 51 has an airtight structure capable of maintaining an atmosphere pressure-reduced from atmospheric pressure. An opening for carrying in and carrying out the processed object 100 is provided in the side wall of the chamber 51 . Moreover, the gate valve 51a which opens and closes an opening is provided. The chamber 51 is connected to the chamber 71 (corresponding to an example of a 2nd chamber) of the delivery part 7 via the gate valve 51a.

The exhaust unit 52 exhausts the inside of the chamber 51 so that the pressure inside the chamber 51 is approximately equal to the pressure inside the chamber 71 of the delivery unit 7 . The exhaust unit 52 may include, for example, a turbo molecular pump (TMP) and an auto pressure controller (APC).

The gas supply unit 53 supplies gas to the inside of the chamber 51 so that the pressure inside the chamber 51 is approximately equal to the pressure of the conveyance unit 4 . The supplied gas may be, for example, air or nitrogen gas.

The processing unit 6 performs plasma processing on the processed object 100 in an atmosphere reduced in pressure from atmospheric pressure.

The processing unit 6 may be, for example, a plasma processing apparatus such as a plasma etching apparatus, a plasma ashing apparatus, a sputtering apparatus, or a plasma CVD apparatus.

In this case, the method for generating plasma is not particularly limited, and for example, plasma may be generated using a high frequency wave, microwave, or the like.

However, the type of the plasma processing apparatus and the plasma generation method are not limited to those exemplified. That is, the processing unit 6 may perform plasma processing on the processed object 100 in an atmosphere reduced in pressure from atmospheric pressure.

In addition, there is no limitation in particular also in the number of the processing parts 6 . At least one processing unit 6 may be provided. When providing a plurality of processing units 6 , the same type of plasma processing apparatus may be provided, or different types of plasma processing apparatuses may be provided. In addition, when a plurality of plasma processing apparatuses of the same type are provided, the processing conditions may be different, or the processing conditions may be the same.

2 is a schematic cross-sectional view for illustrating an example of the processing unit 6 .

The processing unit 6 illustrated in FIG. 2 is an inductively coupled plasma processing apparatus. That is, it is an example of a plasma processing apparatus that processes the object 100 by generating a plasma product from the process gas G using the plasma P excited and generated by high-frequency energy.

As shown in FIG. 2 , the processing unit 6 includes, for example, a chamber 61 (corresponding to an example of the first chamber), an arrangement unit 62 , an antenna 63 , high-frequency power sources 64a and 64b , and a gas supply unit. 65 (corresponding to an example of the first gas supply unit), an exhaust unit 66 (corresponding to an example of the first exhaust unit), and the like are provided.

The chamber 61 has, for example, a substantially cylindrical shape having a bottom, and has an airtight structure capable of maintaining an atmosphere pressure-reduced from atmospheric pressure. In the upper part of the chamber 61, the transmission window 61a is provided so that it may become airtight. The transmission window 61a has a plate shape, has a high transmittance to high-frequency energy, and can be formed of a material that is difficult to etch when subjected to plasma processing. The transmission window 61a may be formed of, for example, a dielectric material such as quartz.

An opening 61b for carrying in and taking out the processed object 100 is provided in the side wall of the chamber 61 . Moreover, the gate valve 61c which opens and closes the opening 61b is provided. The chamber 61 is connected to the chamber 71 of the delivery unit 7 via a gate valve 61c.

The arrangement part 62 is provided inside the chamber 61 . The processed object 100 is disposed on the upper surface of the placement unit 62 . In this case, the processed object 100 may be arranged directly on the upper surface of the arranging unit 62 , or may be arranged on the arranging unit 62 through a support member (not shown) or the like. In addition, a holding device such as an electrostatic chuck may be provided in the placement unit 62 .

The antenna 63 supplies high-frequency energy (electron energy) to a region where the plasma P is generated inside the chamber 61 . Plasma P is generated by the high frequency energy supplied to the inside of the chamber 61 . For example, the antenna 63 supplies high-frequency energy to the inside of the chamber 61 through the transmission window 61a.

The high frequency power supply 64a is electrically connected to the antenna 63 via a matching unit 64a1. The matching device 64a1 is provided with a matching circuit or the like for matching between the impedance on the high frequency power supply 64a side and the impedance on the plasma P side. The high frequency power supply 64a is a power supply for generating the plasma P. That is, the high frequency power supply 64a is provided in order to generate the high frequency discharge in the inside of the chamber 61 and generate|occur|produce the plasma P. The high frequency power supply 64a applies high frequency power having a frequency of about 100 kHz to 100 MHz to the antenna 63 .

In the present embodiment, the antenna 63 and the high-frequency power supply 64a serve as a plasma generating unit for generating the plasma P. As shown in FIG.

The high-frequency power supply 64b is electrically connected to the placement unit 62 via a matching unit 64b1. The matching circuit 64b1 is provided with a matching circuit for matching between the impedance on the high frequency power supply 64b side and the impedance on the plasma P side. The high-frequency power supply 64b controls the energy of ions drawn into the processing object 100 arranged in the placement unit 62 . The high-frequency power supply 64b applies high-frequency power having a relatively low frequency (eg, 13.56 MHz or less) suitable for attracting ions to the disposition unit 62 .

The gas supply unit 65 supplies the process gas G to the region where the plasma P is generated inside the chamber 61 through the flow rate control unit 65a. The flow rate controller 65a can be, for example, a mass flow controller (MFC) or the like. The gas supply unit 65 is, for example, a side wall of the chamber 61 and can be connected to the vicinity of the transmission window 61a.

The process gas G is appropriately selected according to the type of processing, the material of the processing surface of the processing object 100, and the like. For example, in the case of an etching process, it can be set as the process gas G containing fluorine atoms, such as _{CF4 and} CF3, so that a highly reactive radical may be produced|generated. In this case, the process gas G may be, for example, only a gas containing a fluorine atom or a mixed gas of a gas containing a fluorine atom and a rare gas.

The exhaust unit 66 depressurizes the inside of the chamber 61 to a predetermined pressure. The exhaust unit 66 may be, for example, a turbo molecular pump (TMP). The exhaust part 66 can be connected to the bottom surface of the chamber 61 through the pressure control part 66a. The pressure control unit 66a controls the inside of the chamber 61 to a predetermined pressure based on the output of a pressure gauge (not shown) that detects the pressure inside the chamber 61 . The pressure control unit 66a may be, for example, an auto pressure controller (APC) or the like.

When plasma processing is performed on the object 100 , the inside of the chamber 61 is decompressed to a predetermined pressure by the exhaust unit 66 , and a predetermined amount of process gas G ( For example, CF ₄ , etc.) is supplied to a region generating plasma P inside the chamber 61 . On the other hand, high-frequency power of a predetermined power is applied to the antenna 63 from the high-frequency power source 64a, and electron energy is radiated into the chamber 61 through the transmission window 61a. In addition, a high frequency power of a predetermined power is applied from the high frequency power source 64b to the arrangement unit 62 for arranging the object 100 to generate an electric field that accelerates ions from the plasma P toward the object 100 . is formed

Plasma P is generated by the electron energy radiated inside the chamber 61 , and the process gas G is excited and activated by the generated plasma P to generate plasma products such as neutral active species and ions do. Then, the generated plasma product is supplied to the processed object 100 , whereby plasma processing is performed on the processed object 100 .

3 is a schematic cross-sectional view for illustrating the processing unit 16 according to another embodiment.

The processing unit 16 is a microwave excitation type plasma processing apparatus generally called a "CDE (Chemical Dry Etching) apparatus" or a "remote plasma apparatus". The processing unit 16 generates a plasma product from the process gas G using the plasma P, and mainly processes the processed object 100 using radicals contained in the plasma product.

As shown in FIG. 3 , the processing unit 16 includes, for example, a plasma generation unit 161 , an exhaust unit 162 (corresponding to an example of the first exhaust unit), a microwave generation unit 163 , and a chamber 164 (first exhaust unit). It has an example of one chamber), an arrangement part 165 , and a gas supply part 166 (corresponding to an example of a first gas supply part).

The plasma generating unit 161 includes, for example, a discharge tube 161a, an introduction waveguide 161b, and a transport tube 161c.

The discharge tube 161a has a region for generating plasma P therein, and is provided at a position spaced apart from the chamber 164 . The discharge tube 161a has a tubular shape and may be formed of a material that is difficult to be etched due to its high transmittance to microwaves (M). For example, the discharge tube 161a may be formed of a dielectric material such as alumina or quartz.

The introduction waveguide 161b is connected to the outside of the discharge tube 161a so as to be substantially orthogonal to the discharge tube 161a. A termination matching device 161b1 is provided at the end of the introduction waveguide 161b. Further, a stub tuner 161b2 is provided on the entry side of the introduction waveguide 161b (the introduction side of the microwave M).

An annular slot 161b3 is provided at the connection portion between the introduction waveguide 161b and the discharge tube 161a. The microwave M propagating inside the introduction waveguide 161b is radiated into the discharge tube 161a through the slot 161b3.

One end of the transport pipe 161c is connected to an end of the discharge tube 161a opposite to the gas supply unit 166 side. The other end of the transport pipe 161c is connected to the chamber 164 . The transport pipe 161c is formed of a material resistant to radicals contained in the plasma product. The transport pipe 161c is made of, for example, quartz, stainless steel, ceramics, fluororesin, or the like.

The exhaust unit 162 depressurizes the inside of the chamber 164 to a predetermined pressure. The exhaust unit 162 may be connected to the bottom surface of the chamber 164, for example, through the pressure control unit 66a. The exhaust unit 162 may be, for example, the same as the above-described exhaust unit 66 .

The microwave generator 163 is provided at an end of the introduction waveguide 161b opposite to the discharge tube 161a side. The microwave generator 163 generates microwaves M of a predetermined frequency (eg, 2.75 GHz) and radiates them toward the introduction waveguide 161b.

The chamber 164 has an airtight structure capable of maintaining an atmosphere lowered than atmospheric pressure. An opening 164a for carrying in and carrying out the processed object 100 is provided in the side wall of the chamber 164 . In addition, a gate valve 164b for opening and closing the opening 164a is provided. The chamber 164 is connected to the chamber 71 of the delivery unit 7 via a gate valve 164b.

In addition, a rectifying plate 164c may be provided inside the chamber 164 . The baffle plate 164c may be provided on the inner wall of the chamber 164 so as to be substantially parallel to the arrangement surface of the arrangement unit 165 . A gas containing radicals is introduced into the space between the rectifying plate 164c and the ceiling of the chamber 164 through the transport pipe 161c. If the baffle plate 164c is provided, it becomes easy to make the amount of radicals in the processed surface of the processed object 100 substantially uniform.

The arrangement part 165 is provided inside the chamber 164 . The processed object 100 is disposed on the upper surface of the arrangement unit 165 . In this case, the processed object 100 may be disposed directly on the upper surface of the placement unit 165 , or may be placed on the placement unit 165 through a support member not shown or the like. In addition, a holding device such as an electrostatic chuck may be provided in the placement unit 165 .

The gas supply unit 166 is connected to an end of the discharge tube 161a opposite to the chamber 164 side. The gas supply unit 166 supplies the process gas G to the inside of the discharge tube 161a. Also, a pressure control unit 166a may be provided between the gas supply unit 166 and the discharge tube 161a. The pressure control unit 166a controls the pressure of the process gas G supplied to the inside of the discharge tube 161a.

When plasma processing is performed on the object 100 , the inside of the chamber 164 is decompressed to a predetermined pressure by the exhaust unit 162 . At this time, the pressure inside the discharge tube 161a communicating with the chamber 164 is also reduced. Next, the process gas G of a predetermined pressure is supplied to the inside of the discharge tube 161a from the gas supply unit 166 through the pressure control unit 166a. In addition, microwaves M of a predetermined power are radiated into the introduction waveguide 161b from the microwave generator 163 . The emitted microwave M propagates inside the introduction waveguide 161b and is radiated into the discharge tube 161a through the slot 161b3.

The plasma P is generated by the energy of the microwave M radiated into the discharge tube 161a. The generated plasma P excites and activates the process gas G to generate a plasma product containing radicals, ions, and the like.

The gas containing the plasma product is supplied into the chamber 164 through the transport pipe 161c. At this time, ions with a short lifetime cannot reach the inside of the chamber 164 , and radicals with a long lifetime reach the inside of the chamber 164 . The gas containing radicals supplied into the chamber 164 is rectified by the rectifying plate 164c to reach the processing surface of the object 100 to be subjected to plasma processing such as etching. In this case, chemical treatment with radicals is mainly performed. In addition, since ions used for physical processing are not supplied to the inside of the chamber 164 , the processing surface of the processing object 100 is not damaged by the ions. Therefore, the processing unit 16 is suitable for removing damage caused by, for example, etching using ions.

In the above, an Inductively Coupled Plasma (ICP) processing apparatus and a CDE apparatus (remote plasma apparatus) have been described as examples of the processing unit, but the processing unit is not limited to these plasma processing apparatuses. For example, the processing unit may include a capacitively coupled plasma (CCP) processing apparatus (eg, a parallel plate type reactive ion etching (RIE) apparatus), another microwave excitation type plasma processing apparatus (eg, SWP (Surface Wave Plasma): surface wave plasma) device) may be used. In addition, since a known technique can be applied to the basic structure of another plasma processing apparatus, detailed description is abbreviate|omitted.

Next, returning to FIG. 1, the delivery part 7 is demonstrated.

As shown in FIG. 1 , the transmission unit 7 is provided between the processing unit 6 ( 16 ) and the load lock unit 5 . The transfer unit 7 transfers the processed object 100 between the processing unit 6 ( 16 ) and the load lock unit 5 .

4 is a schematic cross-sectional view for illustrating the transmission unit 7 .

4 is a cross-sectional view taken along line A-A of the transmission unit 7 in FIG. 1 .

As shown in FIG. 4 , the delivery unit 7 includes a chamber 71 , a conveying unit 72 , an exhaust unit 73 (corresponding to an example of the second exhaust unit), and a gas supply unit 74 (second gas). Corresponding to an example of the supply unit).

The chamber 71 has an airtight structure capable of maintaining an atmosphere lowered than atmospheric pressure. The chamber 71 is connected to the chamber 61 (164) via a gate valve 61c (164b).

The transfer unit 72 is provided inside the chamber 71 . The transfer unit 72 transfers the processed object 100 between the processing unit 6 ( 16 ) and the load lock unit 5 . For example, the conveying unit 72 conveys (carrying in and out) the processed object 100 between the chamber 61 ( 164 ) of the processing unit 6 ( 16 ). The transfer unit 72 may be, for example, a transfer robot (eg, an articulated robot) having an arm for holding the processed object 100 .

The exhaust unit 73 depressurizes the inside of the chamber 71 to a predetermined pressure. The exhaust part 73 can be connected to the bottom surface of the chamber 71, for example via the pressure control part 66a.

The exhaust part 73 can be said to be the same as the exhaust part 66 mentioned above, for example.

The pressure control unit 66a controls the pressure inside the chamber 71 to become a predetermined pressure based on the output of a pressure gauge (not shown) that detects the pressure inside the chamber 71 .

Here, as described above, some of the process gas G used in the plasma treatment have high reactivity, for example, a gas containing a fluorine atom. When the highly reactive gas flows from the inside of the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) to the inside of the chamber 71 of the delivery unit 7 , the highly reactive gas flows into the chamber 71 . There is a possibility that contamination may occur by reacting with the elements exposed inside.

In addition, by-products generated during plasma processing may adhere to the inner wall of the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) or an element exposed inside the chamber 61 ( 164 ). . Therefore, when an airflow flowing from the inside of the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) toward the inside of the chamber 71 of the delivery unit 7 is formed, the There is a risk that by-products peeled off from the inner wall of the chamber 61 (164) or the like are carried by the airflow and enter the chamber 71 of the delivery unit 7 . By-products entering the chamber 71 of the delivery unit 7 become contaminants for the treated object 100 .

Therefore, the processed object 100 is loaded into the chamber 61 ( 164 ) of the processing unit 6 ( 16 ), or the processed object 100 is removed from the chamber 61 ( 164 ) of the processing unit 6 ( 16 ). When carrying out, the exhaust unit 73 and the pressure control unit 66a attached to the chamber 71 cooperate to increase the pressure inside the chamber 71 to the chamber 61(164) of the processing unit 6(16). )) to be approximately equal to the internal pressure (eg, the pressure when plasma processing is performed). For example, the pressure inside the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) can be about 1×10 ⁻³ Pa to about 1×10 ⁻² Pa.

In this case, the internal pressure of the chamber 71 of the delivery unit 7 is approximately equal to the internal pressure of the chamber 61 (164) of the processing unit 6 (16). It means that the pressure ranges from a pressure equal to the pressure inside the chamber 61 to a pressure equal to the pressure inside the chamber 61 by 5×10 ⁻² Pa higher than the pressure equal to the pressure inside the chamber 61 . In this way, it is possible to effectively suppress the intrusion of highly reactive gases or by-products into the chamber 71 of the delivery unit 7 .

The inventors have determined that the pressure in the chamber 71 of the delivery unit 7 is applied to the pressure in the chamber 61(164) of the processing unit 6(16) in order to suppress the inflow of particles into the processing unit 6(16). An attempt was also made to make it approximately equal to . Specifically, by evacuating the inside of the chamber 71 of the delivery unit 7 by the exhaust unit 73 , the pressure in the chamber 71 is maintained at 1×10 ^-3 Pa to 5×10 ^-3 Pa did.

In this way, even if contaminants move from the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) to the chamber 71 of the delivery unit 7 , the capacity of the chamber 71 is proportional to the capacity of the exhaust unit. If the exhaust amount of 73 is sufficiently large, since it is considered that the pollutants are exhausted from the inside of the chamber 71 by the exhaust unit 73 before adhering to the treated object 100, it is also considered that contamination by the pollutants can be eliminated. .

However, in reality, it has been found that contaminants may adhere to the processed object 100 inside the chamber 71 . When the treated material 100 to which the contaminants adhere is carried into the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) and subjected to plasma treatment, the quality of the product may be affected. In addition, when the treated object 100 to which the contaminants have adhered is carried out from the plasma processing apparatus 1 , there is a fear that the processing of the post-process may be affected.

As a result of examination, the inventors of the present inventors have found that, when the processed object 100 is brought in or out of the chamber 61 ( 164 ) of the processing unit 6 ( 16 ), the pressure inside the chamber 71 is applied to the processing unit 6 ( 16 ). ))), it was found that contaminants were generated inside the chamber 71 when it was made to be substantially equal to the pressure inside the chamber 61 ( 164 ). That is, when the pressure inside the chamber 71 was reduced, it was found that the inside of the chamber 71 was exposed, and contaminants were generated from the elements containing organic matter.

As mentioned above, the chamber 71 has the airtight structure which can maintain the atmosphere pressure-reduced rather than atmospheric pressure. Therefore, seal members, such as an O-ring, are used for the chamber 71 in order to comprise an airtight structure. When the present inventors earnestly investigated, the following knowledge was acquired.

It turned out that the above-mentioned sealing member contains organic substances, such as C ₁₆ H ₃₀ O ₄ , for example. And when the sealing member containing an organic substance was exposed to the atmosphere pressure-reduced rather than atmospheric pressure, it became clear that the organic component of the sealing member evaporated and may be discharged|emitted to the inside of the chamber 71. Moreover, the heat|fever at the time of plasma processing is transmitted to the chamber 71, and the temperature of the chamber 71 may become about 50 degreeC. In such a case, the temperature of the sealing member becomes high, and the component of the sealing member is more likely to be discharged. The components of the seal member discharged to the inside of the chamber 71 become contaminants.

As a result of further investigation, the inventors of the present inventors have found that if the pressure inside the chamber 71 is controlled, the release of the components of the sealing member can be suppressed, and further, the processed object 100 is contaminated in the inside of the chamber 71 . I have gained the knowledge that it can be suppressed.

5 is a vapor pressure curve of C ₁₆ H ₃₀ O ₄ .

C ₁₆ H ₃₀ O ₄ is a component frequently contained in sealing members such as O-rings.

In addition, the points B1 and B2 in FIG. 5 are measured values, and the dotted line in FIG. 5 is an approximate curve based on the points B1 and B2.

In the region below the vapor pressure curve, the component of C ₁₆ H ₃₀ O ₄ tends to evaporate, and in the region above the vapor pressure curve, the component of C ₁₆ H ₃₀ O ₄ becomes difficult to evaporate. For example, after the transfer of the processed object 100 to the chamber 61 (164) of the processing unit 6 (16) is performed, if the pressure inside the chamber 71 becomes the region above the vapor pressure curve, Release of the components of the sealing member can be suppressed.

By the way, since the chamber 61 of the processing part 6 is exposed to plasma, it may be heated to about 80 degreeC - 100 degreeC. In addition, the processed object 100 may be plasma-processed in the state heated to about 150 degreeC - 300 degreeC in the chamber 164 of the processing part 16 in some cases. For this reason, the chamber 164 of the processing part 16 may also be heated to about 80 degreeC - 100 degreeC.

In the above case, since the chamber 71 is connected to the chamber 61 (164) via the gate valve 61c (164b), the temperature of the chamber 71 also rises to about 50°C to 70°C. .

For example, after conveying the processed object 100 to the chamber 61 (164) of the processing unit 6 (16), if the pressure inside the chamber 71 is 5 × 10 ^-3 Pa or more, Even if the temperature of the chamber 71 becomes about 50 degreeC, it can suppress that the component of C ₁₆ H ₃₀ O ₄ evaporates.

However, depending on the type of plasma processing, processing conditions, etc., the temperature of the chamber 71 may become higher.

As a result of examination, the inventors of the present inventors determined that after the transfer of the processed object 100 to the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) is performed, the pressure inside the chamber 71 is 1×10 ^{−1 .} When it was set to Pa or more, even if the type of plasma treatment, treatment conditions, etc. were changed, the knowledge that evaporation of the component of C ₁₆ H ₃₀ O ₄ could be almost eliminated was obtained.

In addition, when the pressure inside the chamber 71 is too high, the inner wall of the chamber 61 ( 164 ) is caused by an airflow from the chamber 71 to the chamber 61 ( 164 ) of the processing unit 6 ( 16 ). There is a risk that the by-products adhering to the surface may be peeled off or the by-products may float in the chamber 61 ( 164 ). Therefore, when carrying in and taking out the processed object 100 from the processing part 6, it is preferable to make the pressure inside the chamber 71 into about 8x10 ^-3 Pa - 5x10 ^-2 Pa. Further, the pressure inside the chamber 71 of the delivery unit 7 is determined to be slightly higher than the pressure inside the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) in the above pressure range.

Although the pressure control of the chamber 71 can be performed by the exhaust part 73 and the pressure control part 66a, it is difficult to quickly increase the lowered pressure.

Then, as shown in FIG. 4, the gas supply part 74 is provided in the delivery part 7 which concerns on this embodiment.

The gas supply unit 74 supplies the gas G1 to the inside of the chamber 71 through the flow rate control unit 74a. The flow control unit 74a can be, for example, a mass flow controller (MFC) or the like.

The gas G1 may be, for example, a gas that is difficult to react with the processing object 100 or an element exposed inside the chamber 71 . For example, the gas G1 may be a noble gas such as nitrogen gas or argon gas, or a mixed gas thereof.

In addition, since the gas G1 is supplied for the control of the pressure inside the chamber 71, and the control amount of a pressure is also small, the quantity of the gas G1 supplied to the inside of the chamber 71 is small. For example, the flow rate of the gas G1 is 10 sccm or more and 1000 sccm or less.

Therefore, the gas reacting with the contaminant containing the organic substance may be supplied as the gas G1, or the gas reacting with the contaminant containing the organic substance may be supplied by adding the aforementioned nitrogen gas or the like. The gas that reacts with the contaminant containing organic matter may be, for example, ozone gas or the like. If the gas G1 is ozone gas or contains ozone gas, even if pollutants containing organic matter are generated, at least a part of the generated pollutants can be decomposed.

By the way, the sealing member used by the processing part 6 is the same as the sealing member used by the delivery part 7 . Further, the pressure inside the chamber 61 ( 164 ) is maintained at a pressure at which the components of the sealing member may evaporate during periods other than the plasma treatment. Accordingly, there is a fear that the components of the sealing member are evaporated, discharged to the inside of the chamber 61 (164), and adhered to the processed object (100). However, as the inventor intensively investigated, the probability of contaminants adhering to the inside of the chamber 71 was higher than the probability of contaminants adhering to the inside of the chamber 61 ( 164 ).

Presumably, since a process gas is introduced into the chamber 61 ( 164 ) in order to perform plasma processing, contaminants (components of the vaporized seal member) are transferred to the interior of the chamber 61 ( 164 ) together with the process gas. It is considered to be due to the emission from That is, it is considered that by increasing the pressure in the chamber by introducing the gas, it is possible to suppress the contaminants from adhering to the treated object 100 .

6 is a timing chart for illustrating the supply of gas G1.

T1 in FIG. 6 is the timing of starting loading of the processed object 100 from the chamber 71 of the delivery part 7 to the chamber 61 (164) of the processing part 6 (16).

T2 in FIG. 6 is the timing of starting the unloading of the processed object 100 from the chamber 61 ( 164 ) of the processing unit 6 ( 16 ) to the chamber 71 of the delivery unit 7 .

When there is no processing object 100 to be processed, the plasma processing apparatus 1 is in a standby state. When the plasma processing apparatus 1 is in the standby state, the inside of the chamber 51 of the load lock unit 5 is exhausted by the exhaust unit 52 , and approximately 1×10 ^-2 Pa to 1×10 ^-1 Pa maintained at a pressure of In this embodiment, for example, it is 5x10 ^-2 Pa.

The pressure inside the chamber 71 of the delivery unit 7 is maintained at a pressure of 5×10 ^-3 Pa or more that can suppress evaporation of the C ₁₆ H ₃₀ O ₄ component. Specifically, the controller 2 controls the pressure control unit 66a attached to the chamber 71 based on the output of a pressure gauge (not shown) that detects the pressure inside the chamber 71 , 71) is set to be 5×10 ^-3 Pa or more.

The interior of the chamber 61 of the processing unit 6 is exhausted by the exhaust unit 66 and maintained at a pressure of 1×10 ^-3 Pa to 1×10 ^-2 Pa. In this embodiment, it is 1x10 ^-3 Pa, for example.

When processing the object 100 , the pressure inside the chamber 51 is set to the same pressure as the atmospheric pressure by venting the inside of the chamber 51 of the load lock unit 5 . The conveyance part 4 takes out the processed object 100 in the inside of the storage part 3, and carries it into the inside of the chamber 51 of the load-lock part 5 ((1) of FIG. 6).

If the treated material 100 is loaded into the chamber 51 , the pressure inside the chamber 51 is decompressed. When the inside of the chamber 51 is reduced to a predetermined pressure, the gas G1 is supplied from the gas supply unit 74 to the inside of the chamber 71 to increase the pressure inside the chamber 71 to 1×10 ⁻¹ Pa do more than In addition, the predetermined pressure is 1x10 ^-2 Pa or more and a pressure smaller than 1x10 ^-1 Pa. In this embodiment, for example, it is 5x10 ^-2 Pa.

When the pressure inside the chamber 51 and the pressure inside the chamber 71 become the above pressures, the gate valve 51a is opened. And the processed object 100 is carried into the inside of the chamber 71 by the conveyance part 72 ((2) of FIG. 6).

The chamber 51 communicates with a space outside of the plasma processing apparatus 1 . For this reason, when the processed object 100 is conveyed, air from the external space is drawn into the chamber 51 . The air in the external space may contain water vapor or particles. By setting the pressure inside the chamber 71 to a pressure higher than the pressure inside the chamber 51 , it is possible to suppress the inflow of water vapor or particles from the chamber 51 into the chamber 71 .

When the processed material 100 is conveyed into the chamber 71, the gate valve 51a is closed. If the gate valve 51a is closed, the supply of the gas G1 to the inside of the chamber 71 is stopped. In addition, the pressure reduction inside the chamber 51 is maintained.

When the pressure inside the chamber 71 becomes 5×10 ⁻² Pa, for example, the gate valve 61c is opened. And the processed object 100 is carried into the inside of the chamber 61 (164) by the conveyance part 72 (T1 in FIG. 6).

Inside the chamber 61 ( 164 ) of the processing unit 6 ( 16 ), a plasma product is generated from a highly reactive gas using plasma, and the processing object 100 is processed. For this reason, when a highly reactive gas remains inside the chamber 61 ( 164 ), or by-products generated during plasma processing are generated on the inner wall of the chamber 61 ( 164 ) of the processing unit 6 ( 16 ), etc. It may be attached. When the pressure inside the chamber 71 is approximately equal to the pressure inside the chamber 61 ( 164 ) of the processing unit 6 ( 16 ), a highly reactive gas or by-product is transferred to the delivery unit 7 . Intrusion into the interior of the chamber 71 of the can be suppressed.

When the processed material 100 is loaded into the chamber 61 ( 164 ), the gate valve 61c is closed. Let the period from opening the gate valve 61c to closing the process object 100 carry-in period T1a. When the gate valve 61c is closed, the gas G1 is supplied to the inside of the chamber 71 from the gas supply unit 74 . Thereby, the pressure inside the chamber 71 is maintained at 1x10 ^-1 Pa or more.

If the pressure inside the chamber 61 (164) is reduced to a predetermined pressure, the pressure inside the chamber 61 (164) by controlling the gas supply unit 65 (166) is the pressure to perform plasma processing. Until the process gas (G) is supplied. The pressure for plasma processing is about 1×10 ⁻¹ Pa to about 10 Pa. In this embodiment, it is 1 Pa, for example. In addition, the predetermined pressure is 1x10 ^-3 Pa - 1x10 ^-2 Pa.

When the pressure inside the chamber 61 ( 164 ) becomes a pressure for performing plasma processing, a high-frequency voltage is applied to the antenna 63 from the high-frequency power supply 64a to generate plasma P. Then, a plasma product is generated from the process gas G using the plasma P, and the treated object 100 is treated using radicals contained in the plasma product.

When the plasma processing is completed, the application of the high frequency voltage from the high frequency power supply 64a and the supply of the process gas G are stopped. The inside of the chamber 61 (164) is pressure-reduced until it becomes a pressure of 1x10 ^-3 Pa - 1x10 ^-2 Pa. In the present embodiment, the pressure inside the chamber 61 ( 164 ) is reduced until, for example, 1×10 ⁻³ Pa.

When the pressure inside the chamber 61 (164) becomes 1×10 ^-3 Pa, the supply of the gas G1 from the gas supply unit 74 is stopped. And when the pressure inside the chamber 71 becomes 5x10 ^-2 Pa, for example, the gate valve 61c is opened. The processed object 100 is carried out from the inside of the chamber 61 (164) by the conveyance part 72 (T2 in FIG. 6).

When the processed object 100 is transferred into the chamber 71 by the transfer unit 72 , the gate valve 61c is closed. Let the period from opening the gate valve 61c until closing the gate valve 61c be the carrying-out period T2a of the processed object 100. After the carrying out period T2a , the gas G1 is supplied into the chamber 71 from the gas supply unit 74 .

When the pressure inside the chamber 71 becomes 1x10 ^-1 Pa or more, the gate valve 51a is opened, and the processed object 100 is conveyed to the chamber 51 by the conveyance part 72 (FIG. 6 of (4)).

If the processed material 100 has been transferred into the chamber 51 , the gate valve 51a is closed. In the delivery unit 7 , the supply amount of the gas G1 to the inside of the chamber 71 is reduced. The supply amount of the gas G1 is such that the pressure inside the chamber 71 is 1×10 ⁻² Pa or more. For example, the supply amount of the gas G1 is multiplied by 0.5. By doing in this way, it can suppress that the component of a sealing member evaporates and is discharged|emitted to the inside of the chamber 71. In addition, even if contaminants (components of the vaporized sealing member) are generated when the processed material 100 is taken out from the chamber 61 ( 164 ), the contaminants are removed together with the gas G1 by supplying the gas G1 . It can be discharged to the outside of the chamber (71).

In addition, not only reducing the supply amount of the gas G1 into the chamber 71 but also reducing the exhaust amount of the exhaust portion 73 by the pressure control unit 66a attached to the chamber 71 is performed. it may be good to do That is, the gas supply unit 74 and the pressure control unit 66a may cooperatively maintain the pressure inside the chamber 71 to be 1×10 ⁻² Pa or more. By doing in this way, the usage-amount of the gas G1 can be reduced.

As the load lock part 5, the inside of the chamber 51 is vented, and the pressure inside the chamber 51 is made into atmospheric pressure. When the pressure inside the chamber 51 becomes about the same as atmospheric pressure, the processed object 100 is taken out from the inside of the chamber 51 by the conveyance part 4, and is accommodated in the accommodating part 3 (Fig. 6 of (5)). Then, the next processed object 100 is conveyed to the load lock unit 5 ((6) in Fig. 6).

The carrying-in period T1a of the treated object 100 after T1 and the unloading period T2a of the treated object 100 after T2 include the pressure of the delivery unit 7 temporarily in the region below the vapor pressure curve of FIG. 5 . pressure to be Specifically, when the gate valve 61c is opened, the gas inside the chamber 71 flows into the processing unit 6 . For this reason, the pressure inside the chamber 71 is the pressure inside the chamber 61 (164) of the processing unit 6 (16) (eg, 1×10 ⁻ which is a predetermined pressure just before plasma processing is performed). ³ Pa) and is reduced in pressure so as to be approximately equal to 3 Pa). Therefore, in the carrying-in period T1a and carrying-out period T2a, the component of a sealing member evaporates and it will be discharged|emitted inside the chamber 71.

However, after the lapse of the carry-in period T1a and the carry-out period T2a, between the chamber 71 of the delivery unit 7 and the chamber 61 (164) of the processing unit 6 (16) is a gate valve ( 61c (164b)). Then, the gas supply unit 74 supplies the gas G1 to the inside of the chamber 71 of the delivery unit 7 , so that the pressure inside the chamber 71 is 5×10 ^-3 Pa or more, preferably It becomes 1×10 ^-1 Pa or more. Therefore, it can suppress that the component of a sealing member evaporates.

In addition, even if the pressure inside the chamber 71 of the delivery part 7 and the chamber 61 of the processing part 6 is set below the pressure at which the components of the sealing member can evaporate, the inside of the delivery part 7 is By introducing the gas, it is possible to suppress adhesion of the contaminants (components of the vaporized sealing member) to the treated object 100 . The chamber 71 and the interior of the chamber 61 are evacuated so as to maintain a predetermined reduced pressure atmosphere. The exhaust speed (L/min) of the exhaust part 73 and the exhaust part 66 is determined. In addition, when the gas G1 is supplied to the chamber 71 and the chamber 61 , the pressure in the chamber 71 increases, and the amount of the gas G1 discharged per unit volume increases. As a result, as much as the gas G1 is supplied, it appears that the exhaust inside the chamber has been performed. That is, by this exhaust, pollutants can be discharged together with the gas G1.

6, the pressure inside the chamber 71 is below the pressure at which the components of the sealing member can evaporate, that is, the chamber 61 (164) of the processing part 6 (16). The period during which the pressure is reduced can be shortened to be approximately equal to the internal pressure of the . Therefore, it can suppress that the component of a sealing member evaporates.

In addition, even if the component of the sealing member evaporates inside the chamber 71, by supplying the gas G1, similarly to the chamber 61 (164), contaminants (components of the vaporized sealing member) are removed from the gas ( It may be discharged to the outside of the chamber 71 together with G1).

When the state in which the processed object 100 is not present in the chamber 71 continues for a long time, the pressure control unit 66a attached to the chamber 71 may be controlled to reduce the exhaust amount of the exhaust unit 73 . By making the exhaust amount of the exhaust part 73 small, the amount of the gas G1 required to set the pressure inside the chamber 71 to 1x10 ^-2 Pa or more can be reduced. In addition, the time for which the state in which there is no processed object 100 in the chamber 71 continues, for example, after the supply of the gas G1 is stopped, the pressure inside the chamber 71 is 1×10 ^-2 Pa It's time to become

The above procedure can be performed, for example, when the controller 2 controls the conveyance unit 72 , the exhaust unit 73 , and the gas supply unit 74 .

For example, the controller 2 controls the exhaust unit 73 to increase the pressure inside the chamber 71 when conveying (in/out) the processed object 100 by the conveying unit 72 . (61 (164)) to be approximately equal to the internal pressure. For example, when the transfer of the processed object 100 by the transfer unit 72 is finished, the controller 2 controls the gas supply unit 74 to supply the gas G1 into the chamber 71 . .

For example, the controller 2 makes the pressure inside the chamber 71 higher than the pressure inside the chamber 61 ( 164 ) by supplying the gas G1 .

For example, the controller 2 sets the pressure inside the chamber 71 to 5×10 ⁻³ Pa or more, preferably 1×10 ⁻¹ Pa or more, by supplying the gas G1 .

In addition, as described above, the plasma processing method according to the present embodiment may include the following steps.

A process of plasma-treating the treated object 100 in a first region having an atmosphere reduced in pressure than atmospheric pressure. The first region is, for example, inside the chamber 61 ( 164 ).

The process of conveying the processed object 100 between the 2nd area|region spaced apart from a 1st area|region, and a 1st area|region. The second region is, for example, the interior of the chamber 71 .

And when conveying the processed object 100, the pressure of the atmosphere of the 2nd area|region is made to be substantially equal to the pressure of the atmosphere of a 1st area|region.

When the conveyance of the processed object 100 is completed, the gas G1 is supplied to the second region.

For example, by supplying the gas G1 after conveying the processed object 100 , the pressure of the atmosphere in the second region is higher than the pressure of the atmosphere in the first region when the processed object 100 is transported. make it high

For example, by supplying the gas G1, the pressure of the atmosphere in the second region is set to 5×10 ⁻³ Pa or more, preferably 1×10 ⁻¹ Pa or more.

In addition, since it can be said that the content in each process is the same as that mentioned above, detailed description is abbreviate|omitted.

As mentioned above, the example was given about this embodiment. However, the present invention is not limited to these techniques.

Regarding the above-described embodiments, those skilled in the art to which design changes were appropriately made are also included in the scope of the present invention as long as the features of the present invention are provided.

For example, the shape, dimension, material, arrangement, number, etc. of each element included in the plasma processing apparatus 1 are not limited to what was exemplified, and may be appropriately changed.

In addition, each element with which each embodiment mentioned above is equipped can be combined as much as possible, and a combination of these is also included in the scope of the present invention as long as the characteristics of the present invention are included.

In this embodiment, the pressure control part 66a attached to the chamber 71 controls so that the pressure inside the chamber 71 may be maintained at 5x10 ^-3 Pa or more. However, the present invention is not limited thereto. For example, the exhaust portion 73 may be a combination of a turbo molecular pump and a dry pump, and an exhaust port connected to the dry pump may be provided at the bottom of the chamber 71 . When the processed object 100 is not inside the chamber 71 for a long time, the inside of the chamber 71 may be evacuated by a dry pump. Alternatively, if 5×10 ^-3 Pa is reached, the exhaust unit 73 may be stopped.

1: plasma processing device 2: controller
3: accommodating part 4: conveyance part
5: load lock unit 6: processing unit
7: transfer unit 71: chamber
72: transport unit 73: exhaust unit
74: gas supply unit 100: processed material
G : process gas G1 : gas
P: Plasma

Claims (7)

A first chamber that maintains an atmosphere lowered than atmospheric pressure and can place a processed object therein;
a first exhaust unit capable of depressurizing the interior of the first chamber to a predetermined pressure;
a plasma generating unit capable of generating the plasma;
a first gas supply unit capable of supplying a process gas to a region in which the plasma is generated within the first chamber;
a second chamber connected to the first chamber through a gate valve and capable of maintaining an atmosphere reduced in pressure than atmospheric pressure;
a conveying unit provided inside the second chamber and capable of conveying the processed object between the first chamber and the second chamber;
a second exhaust unit capable of decompressing the interior of the second chamber to a predetermined pressure;
a second gas supply unit capable of supplying gas to the inside of the second chamber;
A controller capable of controlling the conveying unit, the second exhaust unit, and the second gas supply unit
including,
The controller is
When conveying the processed object by the conveying unit, the second exhaust unit is controlled so that the pressure inside the second chamber is substantially equal to the pressure inside the first chamber,
The plasma processing apparatus of claim 1, wherein the second gas supply unit controls the second gas supply unit to supply the gas to the inside of the second chamber when the conveyance unit completes conveyance of the processed object. The pressure inside the second chamber according to claim 1, wherein the controller controls the pressure inside the second chamber by supplying the gas after the processed object is transferred between the first chamber and the second chamber by the transfer unit. , to be higher than the pressure inside the first chamber when the processed object is conveyed. The plasma processing apparatus according to claim 1 or 2, wherein the controller adjusts the pressure inside the second chamber to 5×10 ^-3 Pa or more by supplying the gas. The method according to claim 3, wherein the controller controls the second exhaust unit to increase the pressure inside the second chamber to 5×10 ^-3 Pa or more when the processed object does not exist in the second chamber. Plasma processing apparatus that does. A plasma processing method for plasma-treating a treated object, comprising:
Plasma treatment of the treated object in a first region having an atmosphere pressure-reduced from atmospheric pressure;
The process of conveying the processed object between the 2nd area|region spaced apart from the said 1st area|region, and the said 1st area|region
including,
When conveying the processed object, the pressure of the atmosphere in the second region is approximately equal to the pressure in the atmosphere in the first region,
and supplying a gas to the second region when the transfer of the processed object is completed. 6. The method according to claim 5, wherein the pressure of the atmosphere in the second region is higher than the pressure in the atmosphere in the first region when the processed object is transported by supplying the gas after transporting the processed object. Plasma treatment method. The plasma processing method according to claim 5 or 6, wherein the pressure of the atmosphere in the second region is set to 5×10 ^-3 Pa or more by supplying the gas.

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