JP2009176788A - Manufacturing process and washing method of apparatus for fabricating semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing process and a washing method of an apparatus for fabricating a semiconductor device which can enhance the yield by controlling generation of dust particles. <P>SOLUTION: A manufacturing process of an apparatus for fabricating a semiconductor device which processes a substrate to be processed mounted on a sample stand in a container comprises a step for forming a dielectric film on the upper surface of the sample stand by spraying and cleaning the dielectric film with fluid, and a step for mounting a wafer on the upper surface of the dielectric film and attracting the wafer electrostatically a plurality of times. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a manufacturing method or a cleaning method of a semiconductor device manufacturing apparatus, and more particularly to a manufacturing method or a cleaning method of a semiconductor device manufacturing apparatus that reduces foreign matter adhering to the back surface of a substrate to be processed.

  In manufacturing a processed semiconductor device having a process of forming a thin film on the surface of a sample, which is a substrate to be processed such as a semiconductor wafer, or etching the thin film, a submicron level foreign substance affects each manufacturing process. For example, in the above etching process, foreign substances adhering to the substrate to be processed serve as a mask and an accurate electric circuit is not formed, which may lead to a decrease in manufacturing yield. Such foreign matter is generated due to various factors, but the foreign matter adhering to the back surface of the substrate to be processed is transferred to another substrate in the processing apparatus when the substrate to be processed is moved or cleaned. This is thought to be a factor causing deterioration. Moreover, since the mixing of heavy metal components into semiconductor devices also deteriorates device characteristics, it is required to eliminate them as much as possible.

  Conventionally, it has been studied to solve such a problem. For example, Japanese Patent Application Laid-Open No. 8-32447 (Patent Document 1) discloses an electrostatic chuck that electrostatically chucks a wafer during processing. It is disclosed that foreign substances adhering to the upper surface of the electrostatic adsorption device are transferred to and captured by the dummy wafer by placing the dummy wafer on the wafer and electrostatically adsorbed to reduce the foreign substances adhering to the wafer for manufacturing the product. . Japanese Patent Laid-Open No. 10-32488 (Patent Document 2) describes a foreign substance that has a substrate having adhesiveness on the back surface and is attached to the contact member surface by an adhesive component on the back surface of the substrate. Is disclosed in which the substrate is transferred and captured on the back surface of the substrate.

JP-A-8-32447 Japanese Patent Laid-Open No. 10-32488

  However, in recent years, semiconductor devices have been further miniaturized, and even finer foreign matter has become a problem, and the materials of members that come into contact with the substrate inside the processing apparatus in which the substrate to be processed is processed are diverse. As for the surface state, a sintered material or a thermal spray material is used, and the surface state exhibits a considerably uneven surface when viewed from a fine surface. For this reason, there are cases where foreign matters cannot be removed efficiently only by using the conventional foreign matter removing method.

  A member that contacts and holds the substrate to be processed, for example, a film made of a dielectric material such as a ceramic on the upper surface of the sample table on which the substrate is placed and held, has a considerable amount on the surface. Concavities and convexities are formed, and after such a portion is formed, there are portions where pieces and fragments are attached to the surface of the concavity and convexity, or are separated by a slight external force. Since such a portion has a high possibility of adhering as a foreign substance to the substrate to be processed placed during the process, a process for reducing the foreign substance such as performing an ultrasonic cleaning process is performed.

  However, it has been difficult to sufficiently remove foreign matter even if such conventional processing is performed. For example, even if particles that become foreign substances are reduced from the surface of the part on which the substrate is placed in the processing apparatus by ultrasonic processing, foreign substances may be further generated from the part covered with the particles, or members in the processing apparatus Since the size of particles on the surface of a wide range can be removed, it is difficult to remove smaller particles even if large particles can be removed, and vice versa However, the above-described prior art has not taken into consideration that the problem that the problem cannot be made has occurred.

  An object of the present invention is to provide a manufacturing method of a semiconductor device manufacturing apparatus or a cleaning method of a semiconductor device manufacturing apparatus that can improve the yield by suppressing the generation of foreign matters.

  An object of the present invention is a manufacturing method of a semiconductor device manufacturing apparatus or a cleaning method thereof for processing a substrate to be processed placed on a sample stage inside a container, and spraying a dielectric film on the upper surface of the sample stage The dielectric film is formed by the step of cleaning with a fluid and the process of placing the wafer on the upper surface of the dielectric film and electrostatically attracting the dielectric film is performed a plurality of times. Is done.

  Furthermore, the adhesive film is attached to and peeled off from the upper surface of the dielectric film before the step of performing a process of placing the wafer on the dielectric film and electrostatically adsorbing it multiple times. This is achieved by providing a process for performing.

  Furthermore, it is achieved by performing ultrasonic cleaning or steam cleaning as cleaning using the fluid. Furthermore, it is achieved by performing cleaning using two kinds of fluids as cleaning using the fluid.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing an outline of a configuration of a semiconductor device manufacturing apparatus according to the present invention. In this figure, 100 is a processing chamber which is a space disposed in a vacuum vessel, 101 is an upper antenna disposed above the processing chamber 100, 102 is a high frequency power source for supplying high frequency power to the upper antenna 101, and 103 is a matching Filter circuit 104, solenoid coil for supplying a magnetic field into the processing chamber 100, 105 plasma, 106 side wall sleeve, 107 substrate to be processed, 108 substrate to be processed, 109 matching filter circuit, 110 RF Bias power supply, 111 is susceptor ring, 112 is an electrode cover, 113 is a rotary valve, and 114 is a turbo molecular pump.

In the plasma etching apparatus shown in FIG. 1, an etching gas such as argon (Ar), CF ₄ , CHF ₃ , nitrogen (N ₂ ) or the like is selectively configured in the evacuated processing chamber 100 and is not shown. However, it is supplied in a shower form from a plurality of through holes arranged in a disc-shaped shower plate arranged on the processing chamber 100 side of the upper antenna 101 from a cylinder via a gas pipe and a mass flow controller. . The pressure in the processing chamber 100 is adjusted to a desired value by the balance between the supply of such gas and the exhaust and decompression in the processing chamber 100 by the exhaust device including the rotary valve 113 and the turbo molecular pump 114.

  In addition, a high frequency generated from the high frequency power source 102 (for example, a UHF power source having a frequency of 450 MHz and an RF power source having a frequency of 13.56 MHz) is introduced into the processing chamber 100 via the matching filter circuit 103 and the upper antenna 101. As a result, an ECR discharge is generated in the processing chamber 100 due to the interaction between the magnetic field formed by the solenoid coil 104 disposed around the processing chamber 100 and the UHF wave, the etching gas is dissociated, and the plasma 105 is covered. It is formed in a space inside the processing chamber 100 above the processing substrate mounting electrode 107.

  Here, on the processing substrate mounting electrode 107 provided below the processing chamber 100, here, for example, the processing substrate 108 having a diameter of 200 mm has a shape that can be regarded as a substantially circular shape in accordance with the processing substrate 108 that can be mounted. The placed placement surface is arranged, and the substrate to be processed 108 placed on the placement surface is held. Here, for example, an RF bias power source 110 of 800 KHz is connected to the substrate mounting electrode 107 via a matching filter circuit 109. As a result, ions in the plasma are attracted onto the substrate to be processed 108, and anisotropic etching is advanced by an ion-assisted reaction by interaction with radicals adsorbed on the surface. Reaction products generated during the etching are exhausted from the processing chamber 100 by the operation of the turbo molecular pump 114.

  In order to control the temperature of the substrate to be processed 108, although not shown in the drawings, generally on the mounting surface upper surface of the processing substrate mounting electrode 107, which is a sample stage on which the substrate to be processed 108 is mounted, A gas having heat transfer properties such as helium gas is introduced between the processing substrate mounting electrode 107 and the processing substrate 108 to improve the thermal conductivity. Further, in order to stabilize the thermal conductivity, the substrate to be processed 108 is attracted and held on the substrate mounting electrode 107 by electrostatic force from a power supply device (not shown). At this time, the foreign matter remaining on the surface of the substrate mounting electrode 107 is transferred to the back surface of the substrate 108 by electrostatic force. For this reason, it is important to form a state in which there is little residual foreign matter on the surface of the substrate mounting electrode 107.

  Examples of the present invention are shown together with comparative examples in FIGS. FIG. 4 shows the foreign matter reduction effect of the embodiment of the present invention and the comparative example with respect to the substrate mounting member. Regarding the reduction of foreign matter by electrostatic attraction in FIG. 4, the surface roughness is the same as or higher than that of a semiconductor wafer used for manufacturing a product for the substrate mounting electrode 107 of the semiconductor device manufacturing apparatus shown in FIG. A non-manufacturing wafer (mirror wafer) formed with a small size was used, and the non-processed substrate mounting electrode configuration shown in FIG. 2 was used.

  FIG. 2 is a longitudinal sectional view schematically showing the configuration of the substrate mounting electrode 107 according to the embodiment shown in FIG. In this figure, the substrate mounting electrode 107 to be processed is composed of a mounting table 1, a dielectric 2 and an electrode 3. The dielectric 2 constituting the mounting surface of the upper surface of the processing substrate mounting electrode 107 is a ceramic film that covers the upper surface of the mounting table 1, and the processing target substrate 108 is placed on the dielectric 2 film inside. An electrode 3 to which power for adsorbing and holding is supplied is disposed.

The dielectric 2 as a film is formed so as to cover the upper surface after forming appropriate irregularities on the upper surface of the mounting table 1 made of a conductor to have a predetermined roughness. This formation is performed by, for example, a thermal spraying method. In a state where fine particles of a ceramic material such as alumina (Al ₂ O ₃ ) or yttria (Y ₂ O ₃ ) are sprayed on the upper surface of the mounting table 1 by the thermal spraying, and the dissolved surfaces of the particles are bonded to each other. Upon cooling, a porous chamber film of the same material is formed.

  Further, the surface of the dielectric 2 which is this film is cut or polished into a shape suitable for adsorption and holding of the wafer 7 which is the substrate to be processed 108 or heat transfer by helium gas, or between particles bonded by thermal spraying. A process for closing the hole is performed. In the present embodiment, electrostatic attraction of the substrate to be processed 108 is applied to the electrode 3 by the DC power source 5 in which the voltage variable mechanism is provided via the electric circuit 4 and the switch 6 between the electrode 3, the dielectric 2 and the wafer 7. It was carried out by the adsorption force due to static electricity generated by the applied voltage.

  The number of foreign matters is placed on the electrode 3 by using a laser type foreign matter inspection apparatus so that the mirror surface of a silicon wafer for measuring foreign matter having a diameter of 200 mm is brought into contact with the upper surface of the dielectric 2 of the substrate placement electrode 107. The wafer was electrostatically adsorbed and then released, and the number of foreign matters of 1 μm or more on the mirror surface was measured. The removal of foreign matter by electrostatic chucking of the wafer was performed by performing electrostatic chucking and separation successively on a plurality of wafers for foreign matter suction for each combination of processes for reducing each foreign matter. In particular, in the present example, five new wafers were used. The evaluation of the foreign matter reduction effect is based on the relative foreign matter remaining when the number of foreign matters on the first suction sheet is 100% under the processing conditions (Comparative Example 1) in which the ultrasonic cleaning process and the removal of the foreign matter by the adhesive sheet are not performed. Evaluated as a percentage.

  As for the contents of the processing in FIG. 4, a detailed foreign matter reduction processing flow is shown in FIG. 5 together with the embodiment and the comparative example. Of the foreign matter removal processing shown in Example 1, Example 2 and Comparative Example 3 shown in FIG. 5, ultrasonic cleaning processing was performed as fluid cleaning processing. Further, the removal of foreign matter by the adhesive sheet having the adhesive component shown in Example 1, Example 2 and Comparative Example 2 is performed on the upper surface of the dielectric 2 of the substrate-mounted electrode 107 as shown in FIG. Then, the operation of attaching the adhesive sheet 8 that is an adhesive film disposed on the back surface of the wafer for removing foreign substances, separating the wafer and peeling the adhesive sheet 8 was repeated four times.

  In the above-described embodiment, in the cleaning process with the fluid, the foreign particles existing near the surface of the processing chamber member are removed by the kinetic energy of the fluid, and the foreign particles near the surface portion are used with the adhesive force by using the adhesive member. Then, the foreign matter on the upper surface of the dielectric 2 is removed. Thereafter, the back surface of the wafer for removing foreign matter is brought close to the surface, and the foreign matter can be removed more efficiently by transferring the fine foreign matter to the mirror surface wafer by electrostatic attraction force. By adding the step of removing the foreign particles near the surface portion by the adhesive force using the adhesive member to the preceding stage of the fluid cleaning treatment step, the foreign matters can be further efficiently reduced.

  Further, in this embodiment, at least one of ultrasonic cleaning, steam cleaning, and two-fluid cleaning using a plurality of types, for example, two types of fluid, is performed as a process. By selecting the permutation sequence of cleaning treatment with fluid, removal of foreign matter by adhesive force using an adhesive sheet, and removal of foreign matter by electrostatic attraction force, foreign matters remaining on the surface of the substrate mounting electrode 107 are efficiently removed. Is done. Such a foreign substance removal process is performed after a film of the dielectric 2 is formed on the upper surface of the substrate mounting electrode 107 by thermal spraying in a process of manufacturing a semiconductor device manufacturing apparatus, thereby manufacturing a semiconductor device. The yield of the semiconductor device is improved, and the operation rate is increased and the manufacturing cost of the semiconductor device is reduced by reducing the occurrence of an initial failure or abnormality in the manufacturing of the semiconductor device.

  Further, such a foreign matter removing step may be performed after processing a predetermined number of product manufacturing wafers or when the detected amount of deposits on the wall surface in the processing chamber 100 reaches a predetermined value. good. In this case, it is necessary to open the inside of the processing chamber 100, which is a vacuum vessel, to the atmosphere side, remove the substrate mounting electrode 107, and perform a process of removing foreign matter outside the semiconductor device manufacturing apparatus. On the other hand, this reduces the generation of foreign substances due to the deposits adhering to the dielectric 2 and the ceramic particles easily peeled off from the upper surface of the dielectric 2 by repeating the operation of manufacturing the product. can do.

  Embodiment 1 of the present invention will be described below with reference to the drawings. In addition, as described above, the effect of reducing foreign matter is expressed as a relative foreign matter residual ratio when the number of foreign matters on the first suction sheet in Comparative Example 1 is 100%.

  FIG. 4 shows the state of foreign matter on the surface of the substrate mounting electrode 107, in particular, the members inside the semiconductor device manufacturing apparatus in contact with the substrate to be processed 108 according to the present embodiment. FIG. The flow of the process of the foreign material removal of a comparative example is shown. As shown in FIG. 5, the processing for reducing foreign matter on the substrate-mounted electrode 107 of Example 1 is configured appropriately for foreign matter removal by fluid cleaning, foreign matter removal by an adhesive sheet, and foreign matter removal by electrostatic adsorption force. It is. After the fluid cleaning process (ultrasonic cleaning process) is performed on the substrate-to-be-processed electrode 107, foreign matter removal by the adhesive sheet is performed four times on the dielectric surface of the substrate-to-be-processed electrode 107 as shown in FIG. The sticking and peeling of the adhesive sheet were repeated. Thereafter, the electrostatic adsorption treatment according to FIG. 2 was performed using five wafers. When the number of foreign matter on the first wafer suction in Comparative Example 1 is 100%, the remaining ratio of foreign matter on the first to fifth wafers is 58.5%, 7.4%, and 4.1%, respectively. , 3.1%, 2.6%.

  As described above, in this embodiment, in the cleaning process step with the fluid, the foreign particles existing near the surface of the processing chamber member are removed by the kinetic energy of the fluid, and the foreign particles near the surface portion are removed using the adhesive member. Further removal by adhesive force. Thereafter, the foreign matter can be more efficiently removed by transferring the fine foreign matter to the mirror surface wafer by electrostatic attraction force.

  In Example 2, a foreign substance removing step using an adhesive sheet is added to the previous stage of the processing flow of Example 1, and the foreign substance evaluation status and the foreign substance reduction processing flow are shown in Example 2 of FIGS. As shown in Example 2 in FIG. 4, the residual ratios of the first to fifth foreign wafers are 35.4%, 3.1%, 2.2%, 1.6%, and 1.4, respectively. % And the effect of further reducing foreign matters than Example 1.

  As described above, in this embodiment, by adding the foreign substance removing step by the adhesive force of the adhesive member to the previous stage of the first embodiment, an effect of further improving the foreign substance removing efficiency can be obtained.

[Comparative Example 1]
As shown in the processing flow of FIG. 5, Comparative Example 1 is obtained by removing the fluid cleaning (ultrasonic cleaning) processing and the foreign matter removal processing step using the adhesive sheet from the foreign matter reduction processing flow of Example 1 of the present application. This is an evaluation of the effect of reducing foreign matter by repeating the above. As shown in Comparative Example 1 in FIG. 4, the residual ratios of the first to fifth wafers are 100%, 65.6%, 50.9%, 39.7%, and 33.1%, respectively. However, the residual ratio of foreign matter is larger than that of the first embodiment.

[Comparative Example 2]
As shown in the processing flow of FIG. 5, the comparative example 2 is the foreign matter reduction processing flow of the first embodiment of the present application except for the foreign matter removal processing step by the fluid cleaning (ultrasonic cleaning) processing. This is an evaluation of the effect of reducing foreign matter by repeating the above. As shown in Comparative Example 2 in FIG. 4, the residual ratios of foreign matters in the first to fifth wafers are 72.7%, 33.4%, 28.4%, 28.3%, and 22.7%, respectively. The residual ratio of foreign matter is steadily reduced, and the foreign matter reducing effect is obtained, but the residual ratio of foreign matter is larger than that in the first embodiment.

[Comparative Example 3]
As shown in the processing flow of FIG. 5, the comparative example 3 is obtained by removing the foreign matter removal processing step by the adhesive sheet from the foreign matter reduction processing flow of the embodiment of the present application. The fluid cleaning (ultrasonic cleaning) processing and the electrostatic adsorption processing are performed. It evaluates the foreign matter reduction effect by repetition. As shown in Comparative Example 3 in FIG. 4, the residual ratios of foreign matters on the first to fifth wafers are 89.3%, 58.1%, 47.9%, 31.6%, and 25.8%, respectively. The residual ratio of foreign matter is steadily reduced, and the foreign matter reducing effect is obtained, but the residual ratio of foreign matter is larger than that in the first embodiment.

[Comparative Example 4]
In Comparative Example 4, as shown in the processing flow of FIG. 5, the order of fluid cleaning (ultrasonic cleaning) in the foreign matter reduction processing flow of Example 1 of the present application and cleaning processing using an adhesive sheet are interchanged. In other words, the substrate mounting member is first treated with an adhesive sheet and then subjected to a fluid cleaning process (ultrasonic cleaning process), and the evaluation of the foreign matter reduction effect by repeated electrostatic adsorption processes is performed. is there.

  As shown in Comparative Example 4 in FIG. 4, the remaining ratios of the foreign matters in the first to fifth wafers are 88.0%, 56.7%, 42.5%, 31.3%, and 25.5%, respectively. The residual ratio of foreign matters steadily decreases, and the residual ratio of foreign matters is larger than in Example 1, but the foreign matter reducing effect can be obtained.

  In the above embodiment, in the cleaning process using the fluid, the foreign particles existing on the surface of the member inside the processing chamber 100 are removed by the kinetic energy of the fluid, and the foreign particles near the surface portion are removed using the adhesive member. Further removal by adhesive force. Thereafter, the foreign matter can be more efficiently removed by transferring the fine foreign matter to the mirror surface wafer by electrostatic attraction force.

  It is possible to efficiently remove foreign substances existing on the surface of the member on which the substrate to be processed 108 is placed, and to reduce foreign matter such as a decrease in processing yield due to transfer of foreign matters on the back surface of the substrate 108 to the processing symmetrical surface. Occurrence of such problems can be suppressed, and a semiconductor device manufacturing apparatus with high reliability and improved production efficiency can be provided.

It is a longitudinal cross-sectional view which shows the outline of a structure of the semiconductor device manufacturing apparatus which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows typically the structure of the to-be-processed substrate mounting electrode which concerns on embodiment shown in FIG. It is a figure which shows the foreign material removal condition by an adhesive sheet. It is a table | surface which shows the change of the quantity of the foreign material adhering to the mirror surface wafer using the Example which concerns on embodiment shown in FIG. 1, and a comparative example. It is a table | surface which shows the flow of the process of washing | cleaning or removing a foreign material of the to-be-processed substrate mounting electrode of the Example shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mounting stand 2 Dielectric material 3 Electrode 4 Electric circuit 5 DC power supply 6 Switch 7 Wafer 8 Adhesive sheet 100 Processing chamber 101 Antenna 102 High frequency power supply 103, 109 Matching filter circuit 104 Solenoid coil 105 Plasma 106 Side wall sleeve 107 Substrate mounting Electrode 108 Substrate 110 RF bias power supply 111 Susceptor ring 112 Electrode cover 113 Rotary valve 114 Turbo molecular pump

Claims (5)

  A manufacturing method of a semiconductor device manufacturing apparatus for processing a substrate to be processed placed on a sample table inside a container, wherein a dielectric film is formed on the upper surface of the sample table by thermal spraying, and then the dielectric product is manufactured. A method of manufacturing a semiconductor device manufacturing apparatus, comprising: a step of cleaning the film using a fluid; and a step of performing a process of placing a wafer on the upper surface of the dielectric film and electrostatically attracting the film a plurality of times.   2. The method of manufacturing a semiconductor device manufacturing apparatus according to claim 1, wherein a film having adhesiveness is formed before said step of performing a process of placing a wafer on said dielectric film and electrostatically adsorbing it multiple times. A manufacturing method of a semiconductor device manufacturing apparatus comprising a step of attaching and peeling a film made on the upper surface.   3. The method of manufacturing a semiconductor device manufacturing apparatus according to claim 1, wherein ultrasonic cleaning or steam cleaning is performed as cleaning using the fluid. Method.   3. The method of manufacturing a semiconductor device manufacturing apparatus according to claim 1, wherein cleaning using two types of fluid is performed as cleaning using the fluid. Manufacturing method.   A cleaning method of a semiconductor device manufacturing apparatus for processing a substrate to be processed placed on a sample stage inside a container, wherein after processing the substrate to be processed, a dielectric film is formed on an upper surface of the sample stage A cleaning method for a semiconductor device manufacturing apparatus, which performs a cleaning process including a process of cleaning using a fluid and a process of performing a process of placing a wafer on an upper surface of the dielectric film and electrostatically adsorbing it multiple times.

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