Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/02041—Cleaning
  • H01L21/02057—Cleaning during device manufacture
  • H01L21/0206—Cleaning during device manufacture during, before or after processing of insulating layers
  • H01L21/02063—Cleaning during device manufacture during, before or after processing of insulating layers the processing being the formation of vias or contact holes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
  • H01J37/32—Gas-filled discharge tubes
  • H01J37/32431—Constructional details of the reactor
  • H01J37/32798—Further details of plasma apparatus not provided for in groups H01J37/3244 - H01J37/32788; special provisions for cleaning or maintenance of the apparatus
  • H01J37/32853—Hygiene
  • H01J37/32862—In situ cleaning of vessels and/or internal parts
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/02041—Cleaning
  • H01L21/02057—Cleaning during device manufacture
  • H01L21/02068—Cleaning during device manufacture during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
  • H01L21/02071—Cleaning during device manufacture during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers the processing being a delineation, e.g. RIE, of conductive layers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
  • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
  • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
  • H01L21/76801—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
  • H01L21/76802—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing by forming openings in dielectrics
  • H01L21/76814—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing by forming openings in dielectrics post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
  • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
  • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
  • H01L21/76801—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
  • H01L21/76822—Modification of the material of dielectric layers, e.g. grading, after-treatment to improve the stability of the layers, to increase their density etc.
  • H01L21/76825—Modification of the material of dielectric layers, e.g. grading, after-treatment to improve the stability of the layers, to increase their density etc. by exposing the layer to particle radiation, e.g. ion implantation, irradiation with UV light or electrons etc.
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
  • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
  • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
  • H01L21/76801—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the dielectrics, e.g. smoothing
  • H01L21/76822—Modification of the material of dielectric layers, e.g. grading, after-treatment to improve the stability of the layers, to increase their density etc.
  • H01L21/76828—Modification of the material of dielectric layers, e.g. grading, after-treatment to improve the stability of the layers, to increase their density etc. thermal treatment

Definitions

• the present invention effectively removes a mixture or stack of an inorganic material containing silicon oxide and a fluorine-based organic material, which is generated on the substrate by performing, for example, plasma treatment on the substrate.
• an inorganic material containing silicon oxide and a fluorine-based organic material which is generated on the substrate by performing, for example, plasma treatment on the substrate.
• the etching gas may react with the layer to be etched or the underlayer, producing a composite product on the substrate, which may remain on the substrate surface.
• a contact hole for connecting an electrode to a source or drain region of a MOS transistor is formed in a silicon oxide layer on a silicon substrate by etching using a CF-based etching gas and oxygen gas. .
• FIG. 16 is a diagram schematically showing a state where the composite product 208 a is generated on the bottom surface of the contact hole 208.
• the components of composite product 208a are also shown.
• the silicon oxide film 202 formed on the silicon layer 201 of the substrate 200 is etched using a CF-based etching gas and oxygen gas, the bottom surface of the contact hole 208 is oxidized with a CF polymer 205 containing carbon and fluorine.
• the composite product 208a composed of the silicon layer 204 and the amorphous silicon layer 203 are also generated in this order. This is thought to be formed by the following process.
• the surface layer of the silicon layer 201 is altered by plasma energy, and the amorphous silicon layer 203 and become. Further, the silicon oxide layer 204 is generated by being oxidized by the upper layer oxygen gas plasma of the amorphous silicon layer 203 (FIG. 17C). Thereafter, CF polymer 205 containing carbon and fluorine is deposited on the silicon oxide layer 204 to form a composite product 208a (FIG. 17D). This composite product 208a increases the contact resistance and decreases the yield. Therefore, this composite generation Object 208a needs to be removed.
• the composite product 208a is not a simple laminate as schematically shown in FIG. 17D. That is, the silicon oxide layer 204 is a mixture of silicon oxide 207 and CF compound 206 as shown in FIG. 18A, or silicon, oxygen, carbon, and fluorine as shown in FIG. 18B. It was found that these were chemically bonded compounds and were in a very stable state. Therefore, the composite product 208a cannot be sufficiently removed by a cleaning process using an organic solvent or an acid solution generally performed after etching. In particular, if the design rule of semiconductor devices is reduced and the aspect ratio is increased, the cleaning solution will not spread sufficiently into the holes and trenches.
• the composite product 208a is a composite of an organic substance and an inorganic substance, the organic substance cannot be removed if the inorganic substance is removed, and the inorganic substance cannot be removed if the organic substance is removed. That is, it can be said that the composite product 208a is a very troublesome residue. For this reason, there is an urgent need to develop a method for removing such residues from devices.
• a substrate 200 in which, for example, two layers of silicon oxide films 210 and polysilicon films 211 are alternately stacked on a silicon film 209 is formed.
• the ability to form the recess 220 by etching through the resist film 215 has been studied.
• a halogen-based gas plasma and a gas plasma containing carbon and fluorine are used, respectively.
• halogenated silicon oxide 213 containing halogen, silicon, and oxygen is deposited on the side wall of the recess 220.
• the polymer 212 containing carbon and fluorine is deposited on the sidewall of the recess 220.
• a laminated product 214 in which the rogenated silicon oxide 213 and the polymer 212 are laminated is deposited.
• This stacked product 214 also needs to be removed because it causes a reduction in device yield.
• the force laminated product 214 is a stable substance, so it is difficult to remove it reliably.
• JP-A-4-83340 (especially, the second column, right column, lines 23 to 44, the seventh page, left column, lines 10 to 15), the surface of the substrate was cleaned with alcohol vapor. Later, the method of removing particles generated when etching the substrate using HF vapor was described! /, And the power of the inorganic / organic composite product as described above! /, Don't mention that! /.
• An object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of reliably removing a composite product of inorganic and organic substances generated on a substrate by plasma processing.
• the present invention can be applied to a processing container in which a composite product as described above is generated or a method for cleaning a member in the processing container.
• the present invention relates to a substrate processing method performed on a substrate on which a composite product of an inorganic substance containing silicon oxide and an organic substance containing carbon and fluorine is formed, and the surface of the substrate is irradiated with ultraviolet rays. Then, an ultraviolet treatment process for removing a part of the organic substance, and a process performed after the ultraviolet treatment process, wherein vapor of hydrogen fluoride is supplied to the surface of the substrate, so that at least one of the inorganic substances is obtained.
• a substrate processing method characterized by comprising:
• a composite product of an inorganic substance and an organic substance formed on the surface of a substrate by a combination of an ultraviolet treatment process, a hydrogen fluoride treatment process, and a heat treatment process is extremely effective. Can be removed.
• the hydrogen fluoride treatment step is performed at least once before the heat treatment step and at least once after the heat treatment step.
• the substrate is heated to 100 ° C or higher.
• the present invention provides a substrate processing method performed on a substrate on which a composite product of an inorganic substance containing silicon oxide and an organic substance containing carbon and fluorine is formed.
• An ultraviolet treatment process for irradiating and removing a part of the organic substance, and a process performed after the ultraviolet treatment process, by supplying hydrogen fluoride vapor to the surface of the substrate,
• a substrate treatment method comprising: a hydrogen fluoride treatment step for removing a portion, and a process group force comprising the ultraviolet treatment step and the hydrogen fluoride treatment step, which is repeated a plurality of times.
• the process group consisting of the ultraviolet treatment process and the hydrogen fluoride treatment process is repeated a plurality of times, so that the composite product of inorganic and organic substances formed on the surface of the substrate is extremely effective. Can be removed.
• the method further includes a heat treatment step for shrinking a part of the organic material that has not yet been removed by heating the substrate.
• the substrate is heated to 100 ° C. or higher.
• the present invention provides a composite product forming step in which a process of forming a composite product of an inorganic substance containing silicon oxide and an organic substance containing carbon and fluorine is formed on the surface of the substrate, A step performed after the composite product forming step, the step of irradiating the surface of the substrate with ultraviolet rays to remove a part of the organic matter, and the step performed after the ultraviolet ray treatment step.
• Each of the hydrogen treatment steps is a substrate treatment method characterized in that it is performed in a vacuum atmosphere.
• a composite product of an inorganic substance and an organic substance formed on the surface of a substrate is extremely effectively obtained by an ultraviolet treatment process and a hydrogen fluoride treatment process performed in a vacuum atmosphere. Can be removed.
• the composite product forming step, the ultraviolet treatment step, and the hydrogen fluoride treatment step are continuously performed in the same vacuum atmosphere.
• the composite product forming step includes a gas containing carbon and fluorine and an oxygen gas.
• a recess is formed by etching the silicon oxide film formed on the silicon layer on the substrate to a surface portion of the silicon layer with a predetermined pattern by plasma obtained by converting the processing gas to plasma. It is a process.
• the concave portion is formed by performing etching in a predetermined pattern on a laminated body in which a silicon oxide film and a polysilicon film are laminated in this order on the substrate in this order.
• the present invention provides a method in which a substrate is subjected to a process in which a composite product of an inorganic substance containing silicon oxide and an organic substance containing carbon and fluorine is formed on the surface of the substrate in the processing vessel.
• a method of cleaning the inside of the processing container and / or the constituent members in the processing container, and irradiating the inner surface of the processing container and / or the surface of the constituent members in the processing container with ultraviolet rays An ultraviolet treatment process for removing a part of the organic matter formed in the processing container and / or a constituent member in the processing container, and a process performed after the ultraviolet treatment process, the inner surface of the processing container and / Or supplying hydrogen fluoride vapor to the surface of a component in the processing vessel to remove at least a portion of the inorganic material formed in the processing vessel and / or the component in the processing vessel.
• the hydrogen fluoride treatment step is performed at least once before the heat treatment step and at least once after the heat treatment step.
• the substrate is heated to 100 ° C or higher.
• the present invention may be performed after a treatment is performed on a substrate in which a composite product of an inorganic substance containing silicon oxide and an organic substance containing carbon and fluorine is formed on the surface of the substrate in the treatment container.
• a method of cleaning the inside of the processing container and / or the constituent members in the processing container, and irradiating the inner surface of the processing container and / or the surface of the constituent members in the processing container with ultraviolet rays An ultraviolet treatment process for removing a part of the organic matter formed in the processing container and / or a constituent member in the processing container, and a process performed after the ultraviolet treatment process, the inner surface of the processing container and / Or supplying hydrogen fluoride vapor to the surface of a component in the processing vessel to remove at least a portion of the inorganic material formed in the processing vessel and / or the component in the processing vessel.
• the process group consisting of the ultraviolet treatment process and the hydrogen fluoride treatment process is repeated a plurality of times, thereby forming the inner surface of the treatment container and / or the surface of the component in the treatment container.
• the ability S to remove and wash inorganic and organic complex products very effectively is reduced.
• the heat treatment step of shrinking a part of the organic matter that has not yet been removed by heating the inner surface of the processing container and / or the surface of the constituent member in the processing container. are further provided.
• the inner surface of the processing container and / or the surface of a component in the processing container is heated to 100 ° C. or more.
• the present invention provides a substrate processing apparatus for processing a substrate on which a composite product of an inorganic material including silicon oxide and an organic material including carbon and fluorine is formed.
• An ultraviolet treatment module that removes a part of the organic substance by irradiating the substrate with ultraviolet rays
• a hydrogen fluoride treatment module that removes at least a part of the inorganic substance by supplying hydrogen fluoride vapor to the surface of the substrate
• the substrate is still removed by heating the substrate, and a heat treatment module that shrinks a part of the organic matter, an ultraviolet treatment module, a hydrogen fluoride treatment module, and a heat treatment module.
• Connected And a control unit capable of controlling them.
• the control unit performs processing by the hydrogen fluoride processing module and processing by the heat processing module after processing by the ultraviolet processing module is executed.
• the substrate processing apparatus is characterized in that each module is controlled to be executed in an arbitrary order! /.
• a composite product of an inorganic substance and an organic substance formed on the surface of a substrate by a combination of an ultraviolet treatment module, a hydrogen fluoride treatment module, and a heat treatment module is obtained. It can be removed very effectively.
• control unit is performed at least once before the processing by the hydrogen fluoride processing module and the processing by the heating processing module, and at least once after the processing by the heating processing module.
• Each module is controlled as follows.
• the heat treatment module is configured to heat the substrate to 100 ° C or higher.
• the heat treatment module is formed so as to overlap the ultraviolet treatment module by providing a heating means in the ultraviolet treatment module.
• the present invention provides a substrate processing apparatus for processing a substrate on which a composite product of an inorganic substance containing silicon oxide and an organic substance containing carbon and fluorine is formed.
• An ultraviolet treatment module that removes a part of the organic substance by irradiating the substrate with ultraviolet rays
• a hydrogen fluoride treatment module that removes at least a part of the inorganic substance by supplying hydrogen fluoride vapor to the surface of the substrate
• a UV processing module and a control unit connected to the hydrogen fluoride processing module and capable of controlling them.
• the control unit is connected to the processing by the UV processing module and the hydrogen fluoride processing module.
• the substrate processing apparatus is characterized in that each module is controlled so as to repeat a processing group consisting of processing by a plurality of times!
• the treatment group consisting of the treatment by the ultraviolet treatment module and the treatment by the hydrogen fluoride treatment module is repeated a plurality of times, thereby forming a composite formation of inorganic and organic substances formed on the surface of the substrate. Can be removed very effectively [0040] Also in this case, it is preferable to further include a heat treatment module that shrinks a part of the organic matter that has not yet been removed by heating the substrate, and the control unit is also connected to the heat treatment module. Therefore, the heat treatment module can also be controlled. In this case, preferably, the heat treatment module heats the substrate to 100 ° C. or higher.
• the heat treatment module is formed to overlap the ultraviolet treatment module by providing a heating means in the ultraviolet treatment module.
• a process module is further provided that performs a process on the substrate such that a composite product of an inorganic substance containing silicon oxide and an organic substance containing carbon and fluorine is formed on the surface of the substrate. It has been.
• a substrate transfer module including a chamber into which the substrate is loaded, and a substrate transfer means provided in the chamber.
• the inside of the chamber of the substrate transfer module is in a vacuum atmosphere.
• the substrate transport module, the ultraviolet processing module, and the hydrogen fluoride processing module are connected to each other in an airtight manner.
• the present invention is a storage medium used in a substrate processing apparatus for processing a substrate and storing a computer program that operates on a computer, wherein the computer program has any one of the above-described features.
• the storage medium is characterized in that steps are assembled so as to implement the substrate processing method.
• the present invention is a storage medium used for a substrate processing apparatus for processing a substrate and storing a computer program that operates on a computer, wherein the computer program has any one of the characteristics described above.
• the storage medium is characterized in that steps are taken to implement a cleaning method comprising:!
• FIG. 1 is an explanatory diagram showing a process flow of the first embodiment of the present invention.
• FIG. 2A is a cross-sectional view of the substrate before etching according to the first embodiment.
• FIG. 2B is a cross-sectional view of the substrate after etching in the first embodiment.
• FIGS. 3A to 3E are views of a substrate when each step is performed in the first embodiment. It is the schematic of the cross section in the bottom face of a contact hole.
• FIG. 4A to FIG. 4C are schematic views of the cross section of the substrate when each step is performed in the first embodiment.
• FIG. 5 is an explanatory diagram showing a process flow of the second embodiment of the present invention.
• FIG. 6 is a schematic cross-sectional view of the bottom surface of the contact hole of the substrate when each step is performed in the second embodiment.
• FIG. 7 is an explanatory diagram showing a process flow of the third embodiment of the present invention.
• FIGS. 8A to 8F are schematic cross-sectional views of the bottom surface of the contact hole of the substrate when each step is performed in the third embodiment.
• FIG. 9 is a horizontal sectional view showing an embodiment of a substrate processing apparatus of the present invention.
• FIG. 10 is a longitudinal sectional view showing an example of a plasma processing apparatus used for the plasma processing of the present invention.
• FIG. 11 is a longitudinal sectional view showing an example of a UV irradiation apparatus used in the UV irradiation process of the present invention.
• FIG. 12 is a longitudinal sectional view showing an example of an HF cleaning apparatus used in the HF vapor cleaning process of the present invention.
• FIG. 13 is a horizontal sectional view showing another embodiment of the substrate processing apparatus of the present invention.
• FIG. 14 is a horizontal view showing still another embodiment of the substrate processing apparatus of the present invention.
• FIG. 15A to FIG. 15C are schematic views showing TEM photographs of a cross section of a substrate in an example of the present invention.
• FIG. 16 is an explanatory view of a composite product generated by etching.
• FIGS. 17A to 17D are explanatory diagrams for explaining how the composite product of FIG. 16 is generated.
• FIG. 18A and FIG. 18B are conceptual diagrams showing composition examples in the composite product of FIG.
• FIG. 19A and FIG. 19B are explanatory views of a stacked product generated by etching.
• a first embodiment which is a process for removing a composite product after forming a contact hole by etching, will be described.
• FIG. 1 shows a flow until a complex product is generated and removed in the first embodiment.
• step S 11 etching is performed on wafer W having the structure of FIG. 2A on the surface.
• 100 is a silicon substrate
• 101 is a silicon oxide film which is an insulating film, for example
• 102 is a resist mask.
• Reference numeral 103 denotes a gate electrode
• 104 denotes a gate oxide film
• 105 denotes an impurity diffusion layer
• 106 denotes an element isolation film.
• the plasma processing apparatus 51 described later for example, from CF gas and O gas.
• the processing gas is converted into plasma, and the silicon oxide film 101 is etched by this plasma.
• a contact hole 107 that is a recess is formed.
• the composite product 111 is generated on the bottom surface of the contact hole 107 (surface portion of the silicon substrate 100) as described above.
• the surface layer of the silicon substrate 100 exposed on the bottom surface of the contact hole 107 is transformed into the amorphous silicon layer 108 by the plasma energy as described above.
• the surface layer of the amorphous silicon layer 108 is oxidized by oxygen gas plasma, and the silicon oxide layer 109 is generated.
• the state force of the bottom surface of the contact hole 107 is schematically shown in FIGS. 3A to 3E.
• a polymer 110 containing carbon and fluorine is generated on the surface of the silicon oxide layer 109.
• the polymer 110 actually enters the silicon oxide layer 109 as a particulate or molecular polymer as shown in FIG. 18 described above, and is intricately mixed with the silicon oxide 112. .
• the polymer 110 and the silicon oxide layer 109 form a composite product 111.
• the polymer 110 is laminated on the silicon oxide layer 109.
• the silicon oxide layer 109 is composed of the silicon oxide 112 and the polymer 110a, and the reference numerals are used.
• Step S 12 UV irradiation process
• the wafer W is irradiated with a heating means such as a halogen lamp (not shown) so that the wafer W is irradiated with, for example, UV having a wavelength of 172 nm for a predetermined time and the wafer W is set to 200 ° C., for example. Heated.
• a heating means such as a halogen lamp (not shown) so that the wafer W is irradiated with, for example, UV having a wavelength of 172 nm for a predetermined time and the wafer W is set to 200 ° C., for example. Heated.
• the bond between carbon and fluorine or the bond between carbons is broken, and as shown in FIG. 4A, the polymer 110 is removed by gasification, for example. Then, UV is also applied to the silicon oxide layer 109 exposed on the surface by removing the polymer 110, and the polymer 110a on the surface of the silicon oxide layer 109 is removed. In addition, the heating of the wafer W facilitates the removal of the polymer 110 and the polymer 110a in this step.
• the silicon oxide 112 in the silicon oxide layer 109 is exposed, and the ratio of the silicon oxide 112 on the surface of the silicon oxide layer 109 increases as shown in FIG. 3B.
• the polymer 110 on the upper layer of the silicon oxide layer 109 is thicker than the polymer 110a in the silicon oxide layer 109 as shown in FIG. 3A described above. However, as described above, the polymer 110 is quickly removed by heating the wafer W together with UV irradiation.
• Step S 13 HF steam cleaning process
• HF hydrogen fluoride
• vapor power S is supplied to the wafer W, for example, for 600 seconds.
• silicon oxide 112 on the surface of wafer W is dissolved in HF vapor and removed together with HF vapor as shown in FIG. 4B.
• the polymer 110a in the silicon oxide layer 109 is exposed, and the ratio of the polymer 110a on the surface of the silicon oxide layer 109 increases as shown in FIG. 3C.
• the wafer W is heated to 300 ° C., for example.
• the polymer 110a dispersed in the silicon oxide layer 109 or the polymer 1 10a bonded to the silicon oxide 112 in the silicon oxide layer 109 is bonded by this caloric heat.
• the weak part of the bond breaks and frees up to gasify. This gas diffuses to the surface of the wafer W through the gap between the polymer 110a and the silicon oxide 112, for example, and is removed from the wafer W.
• Step S 15 HF steam cleaning process
• HF vapor is supplied to the wafer W again for 600 seconds, for example. Since the gap between the polymer 110a and the silicon oxide 112 is widened by the heating process in step S14, HF vapor can diffuse from the gap to the inside of the silicon oxide layer 109. Thereby, the silicon oxide 112 in the silicon oxide layer 109 is almost removed. At this time, even if a small amount of the polymer 110a remains in the silicon oxide layer 109, the silicon oxide 112 around the polymer 110a is almost eliminated, so that the force for physically holding the polymer 110a is weakened. For this reason, the polymer 110a falls off or is released from the silicon oxide layer 109. Along with this, the polymer 110a slightly adheres!
• the composite product 111 composed of the polymer 110 and the silicon oxide layer 109 is first irradiated with UV and then washed with HF vapor.
• the polymer 110 and the silicon oxide layer 109 are removed to some extent, and then the wafer W is heated to gasify and shrink the remaining polymer 110a. Since cleaning with HF vapor is performed again in this state, the HF vapor penetrates into the silicon oxide layer 109, and as a result, the silicon oxide 112 and the polymer 110a are removed as described above, resulting in the silicon oxide. Layer 109 is easily removed. Therefore, after that, contact hole 107 When the electrodes are embedded, an increase in contact resistance can be suppressed and yield can be improved.
• HF cleaning may be performed.
• step S12 UV irradiation process
• step S13 HF vapor cleaning process
• the heating step may be performed without performing the HF vapor cleaning step of Step 13. Even in this case, since the polymer 110a contracts by heating, there is an advantage that the subsequent HF vapor cleaning step (step S15) can be performed effectively.
• the thick polymer 110 has already been removed in the first UV irradiation process.
• FIG. 5 shows a flow chart of steps in the present embodiment
• FIG. 6 shows a schematic cross-sectional view of the bottom surface of the contact hole 107 of wafer W in each step.
• Etching is performed as in step S11 described above. This allows contact holes
• a double product 111 is generated on the bottom surface of 107.
• Step S 52 UV irradiation process
• step S12 the wafer W is irradiated with UV and the wafer W is heated.
• step S12 the wafer W is irradiated with UV and the wafer W is heated.
• FIG. 6B polymer 110 and polymer 110a exposed on the surface layer of silicon oxide layer 109 are removed, and the ratio of silicon oxide 112 on the surface of silicon oxide layer 109 increases.
• Step S 53 HF steam cleaning process
• step S13 Similar to step S13 above, by supplying HF vapor to the wafer W, The silicon oxide 112 exposed on the surface of the silicon oxide layer 109 is removed. As a result, as shown in FIG. 6C, the ratio of the polymer 110a on the surface of the silicon oxide layer 109 increases.
• Step S52 and step S53 described above are repeated for a preset number of times.
• the heating process corresponding to step S14 described above is not performed.
• the silicon oxide 112 and the polymer 110a are sequentially removed, and the composite product 111 is removed. It can be easily removed and can suppress the increase in contact resistance. Also in this embodiment, the wafer W does not have to be heated in the UV irradiation process after the second time.
• FIG. 7 is a diagram showing a process flow in the present embodiment.
• Figure 8A shows a silicon substrate
• a wafer W is shown in which a silicon oxide film 121, a polysilicon film 122, a silicon oxide film 123, and a polysilicon film 124 are stacked on the substrate 120 in this order. The following processes are performed on this wafer W.
• the following steps are all performed in a vacuum atmosphere. Also, during each step (while the wafer W is being transferred), the wafer W is placed in a vacuum atmosphere and is not exposed to the atmosphere!
• Step S71 Etching Process of Polysilicon Film 124)
• a gas containing a halogen-based gas such as HBr (hydrogen bromide) gas
• HBr hydrogen bromide
• FIG. 8B the polysilicon film 124 is etched to form a recess 125.
• halogenated silicon oxide 126 which is an inorganic product in which bromine diffuses into silicon oxide, is generated on the sidewall of the recess 125.
• a gas containing carbon and fluorine such as CF
• the gas is turned into plasma and the silicon oxide film 123 is etched as shown in FIG. 8C. .
• a polymer 127 that is an organic product containing carbon and fluorine is generated on the side wall of the recess 125 outside the above-described halogenated silicon oxide 126.
• the polysilicon film 122 is etched as shown in FIG. 8D. By this etching, the side wall of the recess 125 is again formed on the halogenated silicon oxide.
• the silicon oxide film 121 is etched. By this etching, polymer 127 is generated again on the side wall of the recess 125.
• a laminated product 128 that is a laminated body of the non-oxysilicate silicon 126 and the polymer 127 is generated on the concave J-wall.
• Step S 75 UV irradiation process
• the wafer W is subjected to the same process as the UV irradiation process in step S52 of the second embodiment, and the polymer 127 on the surface of the recess 125 is removed. In this step, it is not necessary to heat the wafer W.
• Step S 76 HF steam cleaning process
• step S53 in the second embodiment by supplying HF vapor to the wafer W, the halogenated silicon oxide 126 on the surface of the recess 125 is removed.
• step S75 and step S76 are repeated for the number of times set in advance.
• the number of repetitions of step S75 and step S76 is two. After that, through a process such as cleaning of the wafer W, an electrode or metal wiring is embedded in the recess 125.
• the removal of the stacked product 128, which is a composite product in which the halogenated silicon oxide 126 and the polymer 127 are alternately multilayered, is performed.
• the wafer W is transferred and processed in a vacuum atmosphere so that the wafer w is not exposed to the air atmosphere. Therefore, the removal treatment can be performed before the halogenated silicon oxide 126 is oxidized and becomes a stable substance.
• oxidation of the metal film embedded in the recess 125 due to moisture absorption can be prevented.
• by repeatedly performing the UV irradiation process and the HF vapor cleaning process it is possible to easily and reliably remove the laminated product 128.
• the number of repetitions of the UV irradiation process and the HF vapor cleaning process may be determined according to the number of stacked layers of the silicon oxide film 121 (123) and the polysilicon film 122 (124) that are to be etched. . In the case of the above-mentioned laminated power layer, the steps need not be repeated.
• a common advantage is that the use of UV and HF vapors rather than liquids such as organic solvents and acid solutions to remove the composite product 111 and the laminated product 128 results in contact holes 10 7 (125 Even when the opening diameter of () is small, the vapor of UV and HF can enter the contact hole 107 (125), so that the composite product 111 and the laminated product 128 can be quickly removed.
• no oxygen gas plasma is used, oxidation of the silicon substrate 100 (120) can be suppressed, and SiOCH containing silicon, carbon, fluorine and hydrogen, which has recently attracted attention as a low dielectric constant film. Even when a film is included, there is no problem that this SiOCH film is ashed by oxygen.
• the substrate processing apparatus 11 shown in FIG. 9 is a multi-chamber system for performing the above-described substrate processing, including carrier chambers 12a to 12c, a first transfer chamber 13 that is a loader module, and a load lock. Chambers 14 and 15 and a second transfer chamber 16 which is a substrate transfer module.
• the second transfer chamber 16 includes a plasma processing apparatus 5 as a process module;! To 54, a UV irradiation module 55 as a UV processing module and a heating module, and a hydrogen fluoride module.
• the Yule HF cleaning device 56 is connected in an airtight manner.
• An alignment chamber 19 is provided on the side surface of the first transfer chamber 13.
• the load lock chambers 14 and 15 are provided with a vacuum pump and a leak valve (not shown) so as to be switched between an air atmosphere and a vacuum atmosphere. That is, the atmospheres of the first transfer chamber 13 and the second transfer chamber 16 can be maintained in an air atmosphere and a vacuum atmosphere, respectively. Therefore, the load port chambers 14 and 15 can adjust the atmosphere to which the wafer W is exposed when the wafer W is transferred between the transfer chambers.
• the first transfer chamber 13 and the second transfer chamber 16 are provided with a first transfer means 17 and a second transfer means 18, respectively.
• the first transfer means 17 transfers the wafer W between the carrier chambers 12a to 12c and the load lock chambers 14 and 15 and between the first transfer chamber 13 and the alignment chamber 19. It is an arm.
• the second transfer means 18 is a transfer arm for transferring the wafer W between the load lock chambers 14 and 15 and the plasma processing apparatus 5;! -54, the UV irradiation apparatus 55 and the HF cleaning apparatus 56. .
• the plasma processing apparatus 51 for example, a known parallel plate type plasma processing apparatus can be used.
• An example of the configuration is shown in FIG.
• the plasma processing apparatus 51 includes a processing container 21 capable of maintaining the inside in a vacuum.
• a mounting table 3 that forms a lower electrode disposed in the center of the bottom surface of the processing vessel 21, and an upper electrode 4 that forms a gas shower head provided on the upper surface of the processing vessel 21.
• the processing gas is introduced into the processing container 21 from the processing gas introduction pipe 41 through the upper electrode 4, and a high-frequency voltage from the high-frequency power source 31 is placed between the mounting table 3 and the upper electrode 4. As a result, the processing gas is turned into plasma.
• etching is performed on the wafer W electrostatically attracted to the mounting table 3 by applying a high-frequency voltage from the bias power source 32 and drawing ions in the plasma to the wafer W.
• 24 is an exhaust pipe
• 23 is a vacuum pump
• 25 is a wafer transfer port
• G is a gate.
• the vacuum pump 23 passes the exhaust pipe 24 through the exhaust pipe 24.
• the inside of the processing container 21 is evacuated.
• the processing gas plasma described above Plasma processing (etching) is performed.
• the process gas may be mixed with Ar gas as a dilution gas!
• the UV irradiation device 55 includes a mounting table 61 made of a transparent material such as quartz and capable of adsorbing the wafer W in a processing container 62 that can be held in a vacuum, and a heating means for the wafer W provided below the mounting table 61.
• the mounting table 61 is supported on the bottom surface of the processing container 62 by a support table 61a, and is configured to be rotatable by a motor 60 connected to the support table 6la, for example.
• the halogen lamp 63 is a concentric ring-shaped lamp provided, for example, five times, and is connected to a power source (not shown) and fixed in a substantially cylindrical reflector 63a having an upper opening. Further, a measuring device (not shown) for measuring the temperature of the wafer W on the mounting table 61 is provided in the processing container 62. Based on the measurement result of this measuring instrument, the output of the halogen lamp 63 can be controlled.
• the UV lamp unit 64 is connected to a power source (not shown), and a large number of UV irradiation tubes (not shown) are accommodated therein.
• a gas supply port 66 is provided on the side surface of the processing container 62, and, for example, nitrogen gas is supplied into the processing container 62 from the gas supply source 67 through the gas supply port 66.
• An exhaust port 68 is formed on the bottom surface of the processing container 62, and the atmosphere in the processing container 62 can be exhausted by a vacuum pump 69.
• a transfer port 65 for the wafer W is formed on the side surface of the processing container 62 and can be opened and closed by a gate G.
• a plurality of ring-shaped radiation tubes having different diameters may be provided.
• UV irradiation apparatus 55 when the wafer W is loaded from the transfer port 65 and placed on the stage 61, the stage 61 is rotated by the motor 60, and the processing vessel 62 is rotated by the vacuum pump 69. While the inside is evacuated, the above-described UV irradiation process or heating process is performed in a state where, for example, nitrogen gas is supplied from the gas supply source 67. That is, in the UV irradiation process, UV is irradiated from the UV lamp unit 64 to the wafer W, and in the heating process, The wafer W is heated by the halogen lamp 63.
• the HF cleaning device 56 includes a processing container 72 and a mounting table 71 fixed to the bottom surface of the processing container 72 by a support table 71a.
• a supply port 76 for HF vapor is formed on the upper surface of the processing container 72 so as to face the mounting table 71.
• the supply port 76 is connected to an HF supply source 77 for supplying HF vapor via a valve 80a.
• the HF supply source 77 includes, for example, a storage tank 73 in which an HF solution is stored.
• a heater 74 for evaporating the HF solution is provided in the storage tank 73.
• the storage tank 73 is connected to a gas supply port 80 for supplying a carrier gas.
• a carrier gas such as nitrogen gas is supplied into the storage tank 73 and evaporated by the heater 74. It is configured so that HF vapor can be supplied into the processing vessel 72.
• An exhaust port 78 is formed on the bottom surface of the processing container 72, and the atmosphere inside the processing container 72 can be exhausted by a vacuum pump 79. Further, a transfer port 75 for the wafer W is formed on the side surface of the processing container 72 and can be opened and closed by the gate G.
• the HF cleaning device 56 when the wafer W is loaded from the transfer port 75 and mounted on the mounting table 71, the inside of the processing container 72 is evacuated by the vacuum pump 79. Next, the HF solution in the storage tank 73 is converted into HF vapor by the heating of the heater 74, and is supplied from the HF supply source 77 into the processing container 72 for a predetermined time with the supply of nitrogen gas as the carrier gas. As a result, the HF steam cleaning process described above is performed.
• a control unit 2A composed of a computer, for example.
• the control unit 2A includes a data processing unit including a program, a memory, and a CPU.
• the control unit 2A sends a control signal to each unit of the substrate processing apparatus 11 from the control unit 2A, so that each step described above is performed. Instructions (each step) are incorporated so that
• the memory is provided with an area in which processing parameter values such as processing pressure, processing temperature, processing time, gas flow rate or power value are written, and the CPU executes each instruction of the program. These processing parameters are read out, and a control signal corresponding to the parameter value is sent to each part of the substrate processing apparatus 11.
• this program (program related to input and display of processing parameters) are also stored in a storage unit 2B such as a flexible disk, compact disk, hard disk, or MO (magneto-optical disk), which is a computer storage medium, and installed in the control unit 2A.
• a storage unit 2B such as a flexible disk, compact disk, hard disk, or MO (magneto-optical disk), which is a computer storage medium, and installed in the control unit 2A.
• the wafer W is loaded into one of the carrier chambers 12a to 12c from the atmosphere side through the carrier force gate door GT which is a transfer container of the wafer W.
• the wafer W force S is transferred (loaded) from the carrier into the first transfer chamber 13 by the first transfer means 17.
• the wafer W is transferred to the alignment chamber 19, and after adjusting the orientation and eccentricity of the wafer W, it is transferred to the load lock chamber 14 or 15). After the pressure in the load lock chamber 14 is adjusted, the wafer W is transferred from the load lock chamber 14 to the plasma processing apparatus 51 through the second transfer chamber 16 by the second transfer means 18.
• the above-described plasma processing is performed. Thereafter, the wafer W is taken out from the plasma processing apparatus 51 by the second transfer means 18 and transferred to the UV irradiation apparatus 55 and the HF cleaning apparatus 56 according to each step in each of the above-described embodiments. Each process is performed. Thereafter, the wafer W is returned to the carrier through a path opposite to the loaded path (unloading).
• the UV irradiation step and the HF vapor cleaning step described above are performed by transferring the wafer W in a vacuum atmosphere after the plasma processing, and evacuating the processing container 62 and the processing container 72 as well.
• the wafer W may be exposed to the air atmosphere after the plasma processing. A configuration example of such an apparatus will be described with reference to FIG.
• FIG. 13 shows a substrate processing apparatus 300 that is an example of an apparatus that can be used in the first embodiment and the second embodiment described above.
• the HF cleaning apparatus 56 described above is connected to the first transfer chamber 13, and a plasma processing apparatus 57 is newly connected to the second transfer chamber 16, for example.
• the configuration is the same as the substrate processing apparatus 11 shown in FIG.
• the same components as those of the substrate processing apparatus 11 are denoted by the same reference numerals.
• the HF cleaning device 56 is connected to the first transfer chamber 13 via the gate G.
• the HF cleaning device 56 is provided with a leak valve (not shown).
• the leakage valve and the above-described vacuum pump 79 are configured so that the processing vessel 72 can be switched between an atmospheric atmosphere and a vacuum atmosphere with a force S! /.
• the wafer W is returned from the second transfer chamber 16 in the substrate processing apparatus 300 to the first transfer chamber 13 which is an atmospheric atmosphere in a path opposite to the path when being transferred into the substrate processing apparatus 11 described above. It is.
• the wafer W is mounted on the mounting table 71 in the HF cleaning device 56 by the first transfer means 17.
• the same processing as the HF vapor cleaning step described above is performed.
• the valve 80a is closed, the supply of the HF vapor is stopped, and the gas in the processing container 72 is exhausted by the vacuum pump 79.
• the wafer W is taken out by the first transfer means 17, and the next process is subsequently performed.
• the HF vapor cleaning process is performed in an air atmosphere, but the UV irradiation process is performed by connecting the UV irradiation apparatus 55 to the first transfer chamber 13. It may be performed in an atmosphere. Furthermore, both of these processes may be performed in an air atmosphere.
• the halogen lamp 63 as a heating unit is provided in the UV irradiation apparatus 55, and the heating process is performed in the UV irradiation apparatus 55 in which the UV irradiation process is performed. ing. For this reason, it is possible to reduce the installation area of the substrate processing apparatuses 11 and 300 that do not require separate apparatuses for performing the respective processes. However, each device may be provided separately.
• one UV irradiation device 55 and one HF cleaning device 56 are provided, but two or more of each may be provided.
• the UV irradiation device 55 and the HF cleaning device 56 are provided separately. A configuration in which both processes are performed in the apparatus may be employed. At this time, each component in the equipment is preferably composed of materials that do not deteriorate or corrode due to UV and HF vapor.
• the silicon oxide 112 and the halogenated silicon oxide 126) and the polymer 110 are formed on the members in the processing container 21 of the plasma processing apparatus 51 by etching, like the surface of the wafer W. Adheres to polymer 127).
• those members may be removed and carried into the UV irradiation device 55 and the HF cleaning device 56, and cleaning may be performed by performing the same steps as those in the above-described embodiments.
• the substrate processing apparatus of the present invention is not limited to the embodiment incorporated in the multi-chamber system described above.
• it may be configured as a stand-alone type apparatus that is separated from the plasma processing apparatus 51 and performs processing in a vacuum atmosphere.
• An example of such a substrate processing apparatus 400 is shown in FIG.
• 91 is a carrier stage
• 92 is a housing that forms the main body of the apparatus.
• a UV processing module 93 and an HF processing module 94 that also serve as a heating module are provided, and a transfer arm 95 is further provided. It has been.
• the wafer W force S in the hoop (sealed carrier) 96 carried into the carrier stage 91 is taken out by the transfer arm 95, and the above-described steps are executed based on the control signal of the control unit 97. As described above, each processing is performed by sequentially transporting the modules 93 and 94. After processing, wafer W is returned to hoop 96.
• the atmosphere in the substrate processing apparatus 400 may be an atmospheric atmosphere corresponding to the first embodiment and the second embodiment described above.
• the contact angle of water on the surface of the silicon oxide layer 109 was measured using a contact angle meter. Since silicon oxide 112 shows hydrophilicity, while polymer 110a containing carbon and fluorine shows hydrophobicity, the ratio of both on the surface of silicon oxide layer 109 should be evaluated by measuring the contact angle of water. It is thought that you can. Further, since the amorphous silicon layer 108 under the silicon oxide layer 109 exhibits hydrophobicity, it is considered that the contact angle of water shows the largest value when the silicon oxide layer 109 is removed.
• the contact angle of water is considered to be an intermediate value between the two values. Force to be removed If the silicon oxide layer 109 is removed, it becomes a single layer of a water-repellent substance (amorphous silicon layer 108), and the contact angle of water is considered to be the largest. Table 1 shows each treatment performed in the experiment and the measurement results of the water contact angle at that time.
• the contact angle of water on the surface of the silicon oxide layer 109 was greatly changed by the UV irradiation process and the HF vapor cleaning process.
• the ratio of the silicon oxide 112 increases to show hydrophilicity (the contact angle of water decreases)
• the proportion of polymer 110a increases and becomes hydrophobic (the contact angle of water is large It is thought that it represents.
• the silicon oxide layer 109 is gradually removed because the contact angle of water increases with each HF vapor cleaning step.
• the contact angle of water is increased to 70 degrees in the fourth HF steam cleaning process. This is considered that the silicon oxide layer 109 is almost removed.
• Example 1 2 Example 1 3 and Comparative Example, as shown in Table 1, the contact angle of water is smaller than the result of Example 11. These are considered to be able to further remove the silicon oxide layer 109 (the contact angle of water is increased to about 70 degrees) by repeating the UV irradiation process and the HF vapor cleaning process several times thereafter.
• the contact angle of water decreased to 50 degrees and 46 degrees after 2 days and 13 days. This is thought to be due to the effects of moisture in the atmosphere.
• Etching of the silicon oxide film 101 was performed on the wafer W having the same configuration as in Experimental Example 1.
• a schematic of a TEM photograph (X million times) of the bottom surface of the contact hole 107 at this time is simply shown in FIG. 15A.
• the upper polymer 110 of the silicon oxide layer 109 entered as a polymer 110a, and it was confirmed that a composite product 111 composed of the polymer 110 and the silicon oxide layer 109 was generated.
• FIGS. 15B and 15C schematically show TEM photographs of the bottom surface of the contact hole 107 of the wafer W of Example 2 and Comparative Example 2 after the above processing is performed.
• the composite product 111 was almost removed, and the silicon oxide layer 109 was only slightly confirmed on the wafer W.
• the silicon oxide layer 109 was almost completely removed from Example 1-1, which had been processed to the same degree as Example 2. It is thought that.
• Comparative Example 2 it was confirmed that the thickness of the silicon oxide layer 109 remained about half of the initial thickness.

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