JP2008140830A - Excimer vacuum ultra-violet light irradiation treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excimer vacuum ultra-violet light irradiation treatment apparatus for effectively irradiating a wafer with excimer vacuum ultra-violet light emitted from an excimer vacuum ultra-violet light lamp and for successfully changing quality of a thin film of wafer by utilizing the vacuum ultra-violet light. <P>SOLUTION: The excimer vacuum ultra-violet light irradiation treatment apparatus 10 includes a chamber 12 for storing a wafer 16, a vacuum pump 13 for maintaining the inside of the chamber 12 to the vacuum condition, a gas supplier 14 for supplying nitrogen into the chamber 12, a heater 15 for heating the wafer 16 stored in the chamber 12 to the predetermined temperature, and an excimer vacuum ultra-violet light lamp 21 for irradiating the thin film of wafer 16 stored in the chamber 12 with the excimer vacuum ultra-violet light. The apparatus 10 directly applies the vacuum ultra-violet light to the thin film of wafer 16 stored within the chamber 12 that is maintained in the vacuum condition, while the lamp 21 is exposed within the chamber 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an excimer vacuum ultraviolet light irradiation processing apparatus for irradiating a thin film formed on one surface of a wafer with excimer vacuum ultraviolet light to modify the physical properties of the thin film.

A processing chamber for storing a wafer which is an object of dry cleaning, an excimer lamp for irradiating the wafer accommodated in the chamber with ultraviolet light, and a gas exhaust device for exhausting air in the chamber. There is a wafer dry cleaning apparatus that evacuates the chamber (see Patent Document 1). The excimer lamp is attached to a lamp house located above the chamber. A stage for holding the wafer is installed at the bottom of the chamber, and a space is formed between the lamp house and the stage. In the lamp house, a plate-like quartz glass is located directly under the excimer lamp, and a lamp housing portion is formed between the quartz glass and the upper wall of the house. The excimer lamp is fixed to the lamp housing portion and is separated from the space with quartz glass interposed therebetween. In this wafer dry cleaning apparatus, the ultraviolet light emitted from the excimer lamp passes through the quartz glass and is irradiated onto the wafer located on the stage, and the wafer is cleaned by the ultraviolet light.
JP 2001-35826 A

  When ultraviolet light passes through the glass, if the energy gap of the glass is smaller than the photon energy of the ultraviolet light, the glass strongly absorbs the ultraviolet light. Therefore, in the wafer dry cleaning apparatus disclosed in the above publication, quartz glass that hardly absorbs ultraviolet rays is used as glass. However, when the ultraviolet light emitted from the excimer lamp hits the quartz glass, the short wavelength light of the ultraviolet light is absorbed by the quartz glass, and only the ultraviolet light of a specific wavelength can reach the wafer. The irradiation efficiency on the wafer may be reduced. In particular, if silica glass contains impurities such as SiOH, metal impurities, or dissolved oxygen, the ultraviolet light transmittance may be significantly reduced, and the absorption of ultraviolet light by quartz glass cannot be ignored.

  An object of the present invention is to efficiently irradiate a wafer with excimer vacuum ultraviolet light emitted from an excimer vacuum ultraviolet light lamp, and to improve a thin film formed on one surface of the wafer by using excimer vacuum ultraviolet light. An object of the present invention is to provide an excimer vacuum ultraviolet light irradiation treatment apparatus that can be improved in quality.

  An excimer vacuum ultraviolet light irradiation processing apparatus of the present invention for solving the above problems is accommodated in a processing chamber for storing a wafer having a thin film formed on one surface, a vacuum device for holding the processing chamber in a vacuum, and a processing chamber. A heating device that heats the wafer to a predetermined temperature, and an excimer vacuum ultraviolet light lamp that irradiates a thin film of the wafer accommodated in the processing chamber with excimer vacuum ultraviolet light, and the excimer vacuum ultraviolet light lamp is exposed to the processing chamber. However, excimer vacuum ultraviolet light can be directly irradiated onto a thin film of a wafer accommodated in a processing chamber in a vacuum state.

  As an example of the present invention, the excimer vacuum ultraviolet light irradiation processing apparatus includes a gas supply device that supplies an inert gas into the processing chamber. In the excimer vacuum ultraviolet light irradiation processing apparatus, the processing chamber is reduced from a low vacuum via a vacuum device. The excimer vacuum ultraviolet lamp irradiates the thin film of the wafer accommodated in the processing chamber with the excimer vacuum ultraviolet light while the gas supply device supplies an inert gas into the processing chamber when the medium vacuum state is maintained. To do.

  As another example of the present invention, the processing chamber is formed above the vertical direction to fix the excimer vacuum ultraviolet lamp, and the wafer mounting portion is formed below the vertical direction to position the wafer. In the excimer vacuum ultraviolet light irradiation processing apparatus, the excimer vacuum ultraviolet light lamp has a rod shape that is long in one direction, and a plurality of excimers are formed. The vacuum ultraviolet lamps are arranged in parallel at equal intervals in a direction crossing the vertical direction at the lamp fixing portion.

As another example of the present invention, in the excimer vacuum ultraviolet light irradiation processing apparatus, the illuminance of these excimer vacuum ultraviolet light lamps can be individually adjusted in the range of 5 to 50 mw / cm ² .

  As another example of the present invention, the vertical separation distance between the lower end of the excimer vacuum ultraviolet lamp and one surface of the wafer located on the wafer mounting portion is in the range of 20 to 100 mm.

As another example of the present invention, in the excimer vacuum ultraviolet light irradiation processing apparatus, the vacuum pressure in the processing chamber can be adjusted in the range of 10 ⁴ to 10 ⁻⁵ Pa.

  According to the excimer vacuum ultraviolet light irradiation processing apparatus of the present invention, there is no inclusion between the excimer vacuum ultraviolet light lamp and the wafer accommodated in the processing chamber, and the excimer vacuum ultraviolet light emitted from the lamp is applied to one surface of the wafer. Since the thin film formed directly is directly irradiated, part of the vacuum ultraviolet light is not absorbed by the quartz glass unlike the conventional cleaning apparatus, and the vacuum ultraviolet light is efficiently applied to the thin film on the wafer. Can do. This excimer vacuum ultraviolet light irradiation processing apparatus can efficiently irradiate a thin film formed on one surface of a wafer with excimer vacuum ultraviolet light, and can reliably and well improve the physical properties of the thin film.

  A wafer in which an excimer vacuum ultraviolet lamp is accommodated in the processing chamber while the gas supply device supplies an inert gas into the processing chamber when the processing chamber is maintained from a low vacuum to an intermediate vacuum state via a vacuum device. Excimer vacuum ultraviolet light irradiation processing equipment that irradiates thin film of excimer with vacuum ultraviolet light increases the thermal conductivity in the processing chamber by supplying an inert gas into the processing chamber in a vacuum state, so that the wafer is set in a short time. It can be heated to a temperature, and the physical property modification of the thin film formed on one surface of the wafer can be shortened. This excimer vacuum ultraviolet light irradiation processing apparatus exhausts oxygen existing in the processing chamber outside the processing chamber by supplying an inert gas into the processing chamber in a low vacuum to medium vacuum state, and the excimer vacuum ultraviolet light is absorbed by oxygen. It is possible to prevent the irradiation efficiency of vacuum ultraviolet light from being reduced. This excimer vacuum ultraviolet light irradiation processing apparatus can efficiently irradiate a thin film formed on one surface of a wafer with excimer vacuum ultraviolet light, and can reliably and well improve the physical properties of the thin film.

  The excimer vacuum ultraviolet light lamp has a rod shape that is long in one direction, and the excimer vacuum ultraviolet light irradiation processing apparatus in which a plurality of vacuum ultraviolet light lamps are arranged in parallel at equal intervals in the direction intersecting the vertical direction in the lamp fixing part, These multiple excimer vacuum ultraviolet light lamps simultaneously emit excimer vacuum ultraviolet light toward one surface of the wafer, so that the entire surface of the wafer can be uniformly irradiated with vacuum ultraviolet light. Irradiation unevenness can be prevented. This excimer vacuum ultraviolet light irradiation processing apparatus can efficiently irradiate a thin film formed on one surface of the wafer via these excimer vacuum ultraviolet light lamps with excimer vacuum ultraviolet light, thereby improving the properties of the thin film reliably and satisfactorily. Can be quality.

The excimer vacuum ultraviolet light irradiation processing apparatus capable of individually adjusting the illuminance in a range of 5 to 50 mw / cm ^{2 with} a plurality of excimer vacuum ultraviolet light lamps can uniformly irradiate the entire surface of the wafer with excimer vacuum ultraviolet light. The illuminance of these vacuum ultraviolet lamps can be individually adjusted, so that even a large-area wafer can be uniformly irradiated with excimer vacuum ultraviolet light over the entire surface. This excimer vacuum ultraviolet light irradiation processing equipment can control the intensity of the excimer vacuum ultraviolet light irradiated on one surface of the wafer by individually adjusting the illuminance of these vacuum ultraviolet light lamps, and a strong vacuum on a part of the wafer Irradiation with ultraviolet light or weak vacuum ultraviolet light can be applied to a part of the wafer. This excimer vacuum ultraviolet light irradiation processing equipment can greatly modify the physical properties of a thin film formed on one surface of a wafer, and can modify the physical properties of the thin film partially if necessary. Can be modified.

  The excimer vacuum ultraviolet light irradiation processing apparatus in which the vertical distance between the lower end of the excimer vacuum ultraviolet light lamp and one surface of the wafer located on the wafer mounting portion is in the range of 20 to 100 mm, the excimer vacuum ultraviolet light lamp is applied to the wafer. It is possible to prevent a rapid and local change in physical properties of the thin film due to being too close, and it is possible to prevent prolonged thinning of the physical properties of the thin film due to the vacuum ultraviolet lamp being too far away from the wafer. This excimer vacuum ultraviolet light irradiation processing apparatus can satisfactorily modify the physical properties of the thin film formed on one surface of the wafer at an appropriate speed by separating the excimer vacuum ultraviolet light lamp and the wafer within the above range. .

The excimer vacuum ultraviolet light irradiation treatment device that can adjust the vacuum pressure in the processing chamber in the range of 10 ⁴ to 10 ⁻⁵ Pa uses a wide range of vacuum conditions from low vacuum to high vacuum, which is slightly lower than atmospheric pressure. In addition, the thin film formed on one surface of the wafer can be modified. This excimer vacuum ultraviolet light irradiation treatment apparatus can select an appropriate vacuum state according to the type of thin film and the degree of modification, and can perform the best modification of the thin film under the selected vacuum state.

  The details of the excimer vacuum ultraviolet light irradiation treatment apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a partially broken perspective view of an excimer vacuum ultraviolet light irradiation processing apparatus 10 shown as an example, and FIG. 2 is a perspective view of the excimer vacuum ultraviolet light irradiation processing apparatus 10 shown in a state where the lamp house 11 is turned upward. It is. 3 is a partial enlarged cross-sectional view taken along line 3-3 of FIG. 2, and FIG. 4 is an excimer vacuum ultraviolet light showing a separation dimension L1 between the lower end 39 of the excimer vacuum ultraviolet light lamp 21 and the surface 17 of the wafer 16. 1 is a partially enlarged view of an irradiation processing apparatus 10. FIG. 1 and 2, the vertical direction is indicated by an arrow A, the front-rear direction is indicated by an arrow B, and the horizontal direction is indicated by an arrow C. In FIG. 2, the vacuum pump 13 and the gas supply device 14 are not shown.

  The excimer vacuum ultraviolet light irradiation processing apparatus 10 includes a lamp house 11 (lamp fixing portion) positioned above the vertical direction, a processing chamber 12 (processing chamber) positioned below the vertical direction and capable of accommodating the wafer 16, A vacuum pump 13 (vacuum device) that holds the inside of the chamber 12 in a vacuum, a gas supply device 14 that supplies an inert gas such as nitrogen, helium, and argon into the chamber 12, and a wafer 16 that is accommodated in the chamber 12 are predetermined. The heater 15 is heated to a temperature (heating device).

  The wafer 16 has a circular planar shape and has a front surface 17 (one surface) and a back surface 18 (one surface). A thin film 19 is formed on the surface 17 of the wafer 16. The wafer 16 includes a glass substrate in addition to a silicon wafer. The planar shape of the wafer 16 is circular. However, the planar shape of the wafer 16 is not limited to the circular shape shown in the figure, and includes any other shape such as an ellipse, a rectangle, and a polygon. The thin film 19 includes an Si oxide insulating film, a Si nitride insulating film, a low dielectric constant interlayer insulating film, a high dielectric constant interlayer insulating film, an insulating film such as a ferroelectric insulating film, an aluminum / aluminum alloy film, a refractory metal film, There are semiconductor films such as silicide films, conductive nitride films, metal / conductive films such as Cu thin films, epitaxial films, polysilicon films, and amorphous films. These thin films can be produced by a CVD method or a PVD method.

  The lamp house 11 has a quadrangular prism shape whose outer shape is long in the front-rear direction, and a plurality of excimer vacuum ultraviolet lamps 21 are attached to the bottom portion 20 thereof. The lamp house 11 is made of aluminum. The lamp house 11 can also be made from aluminum light alloys such as duralumin, super duralumin, Y alloy, and laural. The lamp house 11 accommodates a high frequency (RF) power source (not shown). A radio frequency (RF) power source is connected to a controller (not shown). A predetermined power is supplied to a high frequency (RF) power source via a line (not shown). The frequency and voltage of the radio frequency (RF) power source are held at set values by the control device.

  The lamp house 11 can turn in the vertical direction about the rear end portion 22. When the lamp house 11 is swung upward, as shown in FIG. 2, the lamp house 11 is separated upward from the processing chamber 12, and the upper opening 23 of the chamber 12 can be opened. When the lamp house 11 is swung downward from the state of FIG. 2, the bottom peripheral edge 24 of the lamp house 11 and the top peripheral edge 25 of the chamber 12 are brought into close contact with each other, and the upper opening 23 of the chamber 12 is closed as shown in FIG. Can do.

  The control device is a computer having a CPU and a memory. Predetermined power is supplied to the control device via a line (not shown). An input device such as an ON / OFF switch and a key unit, and an output device such as a display and a printer are connected to the control device via an interface. The CPU activates an application program from the memory based on the control by the operating system stored in the memory, and executes various feedback control means and a transfer means for the wafer 16 according to the activated application program. Each numerical value necessary for feedback control is input to the control device via the input device.

  The excimer vacuum ultraviolet lamp 21 has a bar shape that is long in the horizontal direction, and is formed of a cylindrical inner tube 26 that is long in the horizontal direction and a cylindrical outer tube 27 that is long in the horizontal direction, as shown in FIG. Yes. The outer tube 27 covers the outer peripheral surface 28 of the inner tube 26. The lamp 21 has both lateral ends (not shown) fixed to the bottom peripheral edge 24 of the lamp house 11. Seven lamps 21 are arranged in parallel in the front-rear direction at the bottom 20 of the lamp house 11. The seven lamps 21 are spaced apart at equal intervals in the front-rear direction. The entire lamp 21 is exposed downward from the bottom 20 of the lamp house 11 except for both lateral ends thereof. When the upper opening 23 of the processing chamber 12 is closed by the lamp house 11, as shown in FIG. 1, the entire lamp 21 excluding both lateral ends is exposed to a space 37 of the chamber 12 described later. Note that the number of the lamps 21 is not limited to seven, and the number can be freely selected according to the volume of the chamber 12, the area of the wafer 16, and the like.

  The tube pressure of the inner tube 26 is maintained at substantially atmospheric pressure. An electrode 29 is installed inside the inner tube 26. In the inner pipe 26, an inert gas such as nitrogen, helium, or argon is supplied from one end in the horizontal direction, and the inert gas is discharged from the other end in the horizontal direction. In the lamp 21, an inert gas circulates inside the inner tube 26 and cools the electrode 29. A high frequency (RF) power source is individually connected to the electrode of each excimer vacuum ultraviolet lamp 21. The tube pressure of the outer tube 27 is maintained at a pressure slightly lower than the atmospheric pressure. Inside the outer tube 27 (between the outer peripheral surface 28 of the inner tube 26 and the inner peripheral surface 30 of the outer tube 27), a discharge gas such as xenon or argon is enclosed.

In the excimer vacuum ultraviolet lamp 21, by applying a high frequency / high voltage to the electrode 29 by a high frequency (RF) power source, the discharge gas is excited to be in an excimer state, and the discharge gas in the excimer state is brought into a ground state. Excimer vacuum ultraviolet light (VUV) is emitted when returning. The wavelength of the excimer vacuum ultraviolet light varies depending on the type of discharge gas sealed in the outer tube 27, but is approximately 150 nm or more and 200 nm or less. The illuminance of the lamp 21 is independently adjusted by a radio frequency (RF) power source. When a high frequency / high voltage is applied to the electrode from a high frequency (RF) power source to turn on the excimer vacuum ultraviolet light lamp 21, the excimer vacuum ultraviolet light is emitted from the lamp 21, and the vacuum ultraviolet light is irradiated into the processing chamber 12. . In addition, the illumination intensity of the lamp | ramp 21 can be adjusted in the range of 5-50 mw / cm < ² > by changing the frequency and voltage of a high frequency (RF) power supply via a control apparatus.

  The processing chamber 12 includes front and rear walls 31 and 32 and both side walls 33 having a rectangular planar shape, and a bottom wall 34 having a rectangular planar shape. The chamber 12 is formed with an internal accommodation area 35 surrounded by the walls 31, 32, 33, and 34. Similar to the lamp house 11, the chamber 12 is made of aluminum or an aluminum light alloy. The internal accommodation area 35 is formed by a circular stage 36 (wafer mounting portion) on which the wafer 16 is placed, and a space 37 between the lamp house 11 and the stage 36. When the wafer 16 is placed on the stage 36, the upper surface of the stage 36 and the back surface 18 of the wafer 16 come into contact with each other, and the surface 17 of the wafer 16 faces the excimer vacuum ultraviolet lamp 21.

  As shown in FIG. 4, the lower end 39 of the outer tube 27 of the excimer vacuum ultraviolet lamp 21 (the lower end 39 of the outer peripheral surface 38 of the outer tube 27) and the surface 17 of the wafer 16 positioned on the stage 36 (opposite the lamp 21). The vertical distance L1 from the surface 17) (the length in the vertical direction of the space 37 between the lamp 21 and the wafer 16) is in the range of 20 to 100 mm. When the separation dimension L1 is less than 20 mm, although depending on the illuminance of the lamp 21, there may be a sudden and local change in physical properties of the thin film 19 due to the lamp 21 being too close to the wafer 16. If the separation dimension L1 exceeds 100 mm, it may take a long time to improve the physical properties of the thin film 19. In addition, in order to shorten the physical property modification, the illuminance of the lamp 21 must be increased more than necessary, leading to unnecessary power consumption. The stage 36 can be moved up and down via an elevating mechanism (not shown), and the separation dimension L1 between the lamp 21 and the wafer 16 can be changed within the above range. The planar shape of the stage 36 is not limited to the circular shape shown in the figure, and any other shape such as an ellipse, a quadrangle, or a polygon can be adopted.

  On the front wall 31 of the processing chamber 12, an entrance 40 for introducing the wafer 16 into the stage 36 and delivering the wafer 16 to the outside of the chamber 12 is formed. A wafer transfer device (not shown) is connected to the entrance / exit 40. The entrance / exit 40 is provided with an automatic shutter mechanism (not shown) that closes the entrance / exit 40 after the wafer 16 is introduced into the stage 36 or after the wafer 16 is sent out of the chamber 12. Two openings 41 and 42 are formed in the bottom wall 34 of the chamber 12. An air supply pipe 43 is connected to the opening 41, and an exhaust pipe 44 is connected to the opening 42. The supply pipe 43 is connected to the gas supply device 14. The exhaust pipe 44 is connected to the vacuum pump 13. The gas supply device 14 is formed of a cylinder 45, a flow meter (not shown), and a flow rate adjusting valve (not shown). The cylinder 45 is filled with nitrogen in an inert gas under a predetermined pressure. A predetermined power is supplied to the vacuum pump 13 via a line (not shown).

When the vacuum pump 13 is operated, the air in the chamber 12 is exhausted to the outside of the chamber 12 through the exhaust pipe 44, and the inside of the chamber 12 is maintained in a vacuum. The vacuum pressure in the chamber 12 can be adjusted in the range of 10 ⁴ to 10 ⁻⁵ Pa. Although not shown, the exhaust pipe 44 is provided with a pressure gauge and a pressure control valve. The pump 13, the pressure gauge, and the pressure control valve are connected to a control device and form a control element for feedback control. The internal pressure of the exhaust pipe 44 is input to the control device via a pressure gauge. When the internal pressure of the exhaust pipe 44 is out of the target value range, the control device controls the output of the pump 13 and the valve mechanism of the pressure control valve to return the internal pressure of the exhaust pipe 44 to the target value.

  When the gas supply device 14 is operated, nitrogen flowing out from the cylinder 45 flows into the chamber 12 through the intake pipe 43. During the operation of the gas supply device 14, the vacuum pump 13 is also in operation. Nitrogen that has flowed into the chamber 12 flows into the exhaust pipe 44 by the suction force of the vacuum pump 13, and is exhausted to the outside of the apparatus 10 through the exhaust pipe 44. A flow meter and a flow control valve forming the gas supply device 14 are connected to the control device and form a control element for feedback control. A flow rate of nitrogen flowing through the supply pipe 43 is input to the control device via a flow meter. When the flow rate of nitrogen flowing through the supply pipe 43 deviates from the target value range, the control device controls the valve mechanism of the flow control valve to return the flow rate to the target value.

  The heater 15 is built in the stage 36. A predetermined power is supplied to the heater 15 via a line (not shown). When the heater 15 is operated, the stage 36 is heated, and the wafer 16 positioned on the stage 36 is heated to 250 to 400 ° C. The stage 36 is provided with a thermometer (not shown). The heater 15 and the thermometer are connected to a control device and form a control element for feedback control. The temperature of the stage 36 is input to the control device via a thermometer. When the temperature of the stage 36 is out of the target value range, the control device controls the output of the heater 15 to return the temperature of the stage 36 to the target value.

FIG. 5 is a cross-sectional view of the excimer vacuum ultraviolet light irradiation processing apparatus 10 schematically showing an example of excimer vacuum ultraviolet light irradiation. In FIG. 5, the vertical direction is indicated by an arrow A, the front-rear direction is indicated by an arrow B, and the irradiation processing apparatus 10 is shown from the side. In the embodiment of FIG. 5, the vacuum pressure in the chamber 12 is maintained from low vacuum to medium vacuum by the vacuum pump 13, and nitrogen is supplied into the chamber 12 by the gas supply device 14. It is assumed that a low dielectric constant interlayer insulating film 19 is formed on the surface 17 of the wafer 16. The distance L1 between the excimer vacuum ultraviolet light lamp 21 and the wafer 16 is adjusted using the lifting mechanism, the power is turned on, and the excimer vacuum ultraviolet light irradiation processing apparatus 10 is activated. After starting the irradiation processing apparatus 10, the internal pressure of the exhaust pipe 44 is set via the input device so that the vacuum pressure in the chamber 12 is maintained from low to medium vacuum, and is supplied into the chamber 12. The flow rate of nitrogen flowing through the supply pipe 43 is set so that the flow rate of nitrogen is kept constant. Furthermore, the temperature of the stage 36 is set via the input device, the illuminance of the excimer vacuum ultraviolet lamp 21 is individually set, and the lighting time of the lamp 21 (excimer vacuum ultraviolet light irradiation time) is set. Here, when the vacuum pressure is low, the atmospheric pressure in the chamber 12 is maintained at 10 ⁴ to 10 ² Pa, and when the vacuum pressure is medium vacuum, the atmospheric pressure in the chamber 12 is 10 ² to 10 ⁻¹ Pa. Retained.

  When these numerical values are set and the irradiation processing apparatus 10 is operated, the control apparatus operates the vacuum pump 13 and the pressure control valve, and exhausts air from the chamber 12 as indicated by an arrow L2, and the chamber 12 The pressure inside the chamber 12 is maintained from low to medium vacuum, the gas supply port of the cylinder 45 is opened and the flow rate control valve is operated, and a set amount of nitrogen is introduced into the chamber 12 as indicated by an arrow L3. Let it flow. Further, the heater 15 is operated to heat the temperature of the stage 36 to a set temperature. When air is exhausted from the chamber 12 by the vacuum pump 13 and nitrogen flows into the chamber 12 by the gas supply device 14, oxygen in the air remaining in the chamber 12 is exhausted and the interior of the chamber 12 becomes a nitrogen atmosphere. By making the inside of the chamber 12 a nitrogen atmosphere, it is possible to prevent the excimer vacuum ultraviolet light emitted from the excimer vacuum ultraviolet light lamp 21 from being absorbed by oxygen, and the vacuum ultraviolet light can be prevented from interposing the low dielectric constant interlayer insulation of the wafer 16. The film 19 can be efficiently irradiated.

  When the atmospheric pressure in the chamber 12 changes from the set low vacuum to the medium vacuum state and the temperature of the stage 36 reaches the set temperature, the control device outputs a carry-in command to the irradiation processing apparatus 10 for the wafer 16 to the transfer device. The transfer device carries the wafer 16 into the irradiation processing device 10 in accordance with a carry-in command from the control device. In addition, the inside of the conveying apparatus is also maintained from a set low vacuum to a medium vacuum state. The wafer 16 is loaded into the entrance / exit 40 of the chamber 12 by the transport mechanism of the transport device. When the wafer 16 reaches the entrance / exit 40, the control device operates the shutter mechanism to open the entrance / exit 40, and introduces the wafer 16 into the chamber 12 from the entrance / exit 40. When the wafer 16 enters the chamber 12, the controller closes the entrance / exit 40 in an airtight manner by the shutter mechanism. The wafer 16 that has entered the chamber 12 is placed on the center of the stage 36, and its surface 17 faces the excimer vacuum ultraviolet lamp 21. The wafer 16 on the stage 36 is heated to a set temperature (250 to 400 ° C.) by the heater 15. In addition, by supplying nitrogen into the chamber 12 from the gas supply device 14, the thermal conductivity in the chamber 12 is increased, and the wafer 16 can be heated in a short time. When the wafer 16 is heated to a set temperature, the control device applies a high frequency / high voltage to the electrode of the excimer vacuum ultraviolet lamp 21 from a high frequency (RF) power source, and turns on the lamp 21. The excimer vacuum ultraviolet light emitted from the lamp 21 irradiates the low dielectric constant interlayer insulating film 19 formed on the surface 17 of the wafer 16 as indicated by an arrow L4 in FIG. Is done.

  When the low dielectric constant interlayer insulating film 19 of the wafer 16 is irradiated with excimer vacuum ultraviolet light, the Si—O—Si bond that is the skeleton of the insulating film 19 is strengthened, while the Si that forms the holes of the insulating film 19 is strengthened. Only the weak part of the —CH 3 bond is cleaved, leaving a stable part. The unstable Si—CH 3 bonds in the insulating film 19 disappear, the insulating film 19 itself is densified and contracted, and the hole diameter slightly increases. By irradiating the low dielectric constant interlayer insulating film 19 with vacuum ultraviolet light, the dielectric constant (k value) of the insulating film 19 is lowered, and the vacancy system keeps the initial state or slightly increases. Thus, the Si—O skeleton is densified, and the mechanical strength of the entire insulating film 19 is improved.

  When a preset lighting time of the excimer vacuum ultraviolet light lamp 21 elapses, the control device turns off the radio frequency (RF) power source to turn off the lamp 21, and sends a command to carry out the wafer 16 from the irradiation processing device 10 to the transfer device. Output. The control device operates the shutter mechanism to open the entrance / exit 40 and delivers the wafer 16 to the outside of the chamber 12 from the entrance / exit 40. The transfer device takes out the wafer 16 sent to the outside of the entrance / exit 40 in accordance with an unload command from the control device. The wafer 16 on which the physical properties of the low dielectric constant interlayer insulating film 19 have been modified by the irradiation processing apparatus 10 moves to the transport apparatus and is transported to a predetermined location by the transport mechanism of the transport apparatus. In the embodiment of FIG. 5, when the chamber 12 is in a medium vacuum state, the excimer vacuum ultraviolet light is irradiated to the insulating film 19 of the wafer 16 without supplying nitrogen into the chamber 12 while maintaining the medium vacuum state. There is also.

FIG. 6 is a cross-sectional view of the excimer vacuum ultraviolet light irradiation processing apparatus 10 schematically showing another example of excimer vacuum ultraviolet light irradiation. In FIG. 6, the vertical direction is indicated by an arrow A, the front-rear direction is indicated by an arrow B, and the irradiation processing apparatus 10 is shown from the side. In the embodiment of FIG. 6, the degree of vacuum in the chamber 12 is maintained in a high vacuum state via the vacuum pump 13. In this aspect, the gas supply device 14 is stopped, and nitrogen is not supplied into the chamber 12. It is assumed that a low dielectric constant interlayer insulating film 19 is formed on the surface 17 of the wafer 16 as in FIG. After turning on the power and starting the excimer vacuum ultraviolet light irradiation processing apparatus 10, the internal pressure of the exhaust pipe 44 is set via the input device so that the vacuum pressure in the chamber 12 is maintained at a high vacuum, and the stage 36. Set the temperature. Further, the illuminance of the excimer vacuum ultraviolet light lamp 21 is individually set via the input device, and the lighting time of the lamp 21 (excimer vacuum ultraviolet light irradiation time) is set. Here, when the vacuum pressure is high, the atmospheric pressure in the chamber 12 is maintained at 10 ⁻¹ to 10 ⁻⁵ Pa.

  When these numerical values are set and the irradiation processing apparatus 10 is operated, the control apparatus operates the vacuum pump 13 and the pressure control valve, and exhausts air from the chamber 12 as indicated by an arrow L2, and the chamber 12 The pressure in the chamber 12 is reduced and the inside of the chamber 12 is maintained in a high vacuum state, and the heater 15 is operated to heat the temperature of the stage 36 to a set temperature. When air is discharged from the chamber 12 by the vacuum pump 13 and the inside of the chamber 12 is in a high vacuum state, oxygen does not exist in the chamber 12. The absence of oxygen in the chamber 12 can prevent the excimer vacuum ultraviolet light emitted from the excimer vacuum ultraviolet light lamp 21 from being absorbed into the oxygen, and the vacuum ultraviolet light can be prevented from interfering with the low dielectric constant interlayer of the wafer 16. The film 19 can be efficiently irradiated.

  When the atmospheric pressure in the chamber 12 becomes a set high vacuum state and the temperature of the stage 36 reaches the set temperature, the control device outputs a carry-in command to the irradiation processing device 10 for the wafer 16 to the transfer device. The process of loading the wafer 16 into the apparatus 10 is the same as that shown in FIG. When the wafer 16 enters the chamber 12, the controller closes the entrance / exit 40 in an airtight manner by the shutter mechanism. The wafer 16 that has entered the chamber 12 is placed on the center of the stage 36. When the wafer 16 on the stage 36 is heated to the set temperature (250 to 400 ° C.) by the heater 15, the control device applies a high frequency and a high voltage from the high frequency (RF) power source to the electrode of the excimer vacuum ultraviolet lamp 21. The lamp 21 is turned on.

  The excimer vacuum ultraviolet light emitted from the excimer vacuum ultraviolet light lamp 21 maintains the set illuminance, and the low dielectric constant interlayer insulation formed on the surface 17 of the wafer 16 as shown by an arrow L4 in FIG. The film 19 is irradiated. By irradiating the low dielectric constant interlayer insulating film 19 of the wafer 16 with excimer vacuum ultraviolet light, the dielectric constant (k value) of the insulating film 19 is lowered and the insulating film is reduced as in the insulating film 19 of FIG. 19 The overall mechanical strength is improved. The process of unloading the wafer 16 from the apparatus 10 in which the physical properties of the low dielectric constant interlayer insulating film 19 have been modified from the apparatus 10 is the same as that shown in FIG. In this embodiment, the low dielectric constant interlayer insulating film 19 has been described as an example of the thin film 19. However, the irradiation processing apparatus 10 uses other insulating films, metal / conductive films, and semiconductor films of the low dielectric constant interlayer insulating film 19. It can also be used for physical property modification.

  In the excimer vacuum ultraviolet light irradiation processing apparatus 10, the excimer vacuum ultraviolet light lamp 21 is exposed in the space 37 in the chamber 12, and there are no inclusions between the lamp 21 and the wafer 16 accommodated in the chamber 12. Since the excimer vacuum ultraviolet light emitted from the lamp 21 is directly applied to the low dielectric constant interlayer insulating film 19 (thin film 19) formed on the surface 17 of the wafer 16, the low dielectric constant interlayer insulating film 19 of the wafer 16 is vacuumed. Irradiation with ultraviolet light can be performed efficiently. The irradiation processing apparatus 10 can reduce the relative dielectric constant (k value) of the insulating film 19 by efficiently irradiating the low dielectric constant interlayer insulating film 19 on the surface 17 of the wafer 16 with excimer vacuum ultraviolet light. The mechanical strength of the insulating film 19 can be improved, and the physical properties of the insulating film 19 can be reliably and satisfactorily modified.

In the excimer vacuum ultraviolet light irradiation processing apparatus 10, the excimer vacuum ultraviolet light lamp 21 is a rod shape long in one direction, and these seven lamps 21 are arranged in parallel at equal intervals in the front-rear direction at the bottom 20 of the lamp house 11. Since the lamp 21 simultaneously emits excimer vacuum ultraviolet light toward the surface 17 of the wafer 16, the vacuum ultraviolet light is uniformly applied to the entire area of the low dielectric constant interlayer insulating film 19 (thin film 19) formed on the surface 17 of the wafer 16. Irradiation unevenness of the vacuum ultraviolet light onto the wafer 16 can be prevented. The irradiation processing apparatus 10 can individually adjust the illuminance of the vacuum ultraviolet lamps 21 so that the entire surface 17 of the wafer 16 can be uniformly irradiated with excimer vacuum ultraviolet light, whereby a wafer having a large surface area can be adjusted. Even so, excimer vacuum ultraviolet light can be uniformly irradiated over the entire surface. Further, by individually adjusting the illuminance of the excimer vacuum ultraviolet lamp 21 in the range of 5 to 50 mw / cm ² , the intensity of the excimer vacuum ultraviolet light irradiated on the surface 17 of the wafer 16 can be increased and decreased. A part of the wafer 16 can be irradiated with strong vacuum ultraviolet light, or a part of the wafer 16 can be irradiated with weak vacuum ultraviolet light. In this irradiation processing apparatus 10, the physical properties of the low dielectric constant interlayer insulating film 19 formed on the surface 17 of the wafer 16 can be greatly modified at a certain portion, and can be modified small at a certain portion. The physical properties of the film 19 can be partially modified.

The excimer vacuum ultraviolet light irradiation processing apparatus 10 can adjust the vertical distance L1 between the lower end 39 of the excimer vacuum ultraviolet light lamp 21 and the surface 17 of the wafer 16 located on the stage 36 within a range of 20 to 100 mm. Therefore, the rapid and local physical property change of the low dielectric constant interlayer insulating film 19 due to the excimer vacuum ultraviolet lamp 21 being too close to the wafer 16 can be prevented, and the vacuum ultraviolet lamp 21 is too far away from the wafer 16. Accordingly, it is possible to prevent the property of the insulating film 19 from being modified for a long time, and the properties of the insulating film 19 formed on the wafer 16 can be favorably modified at an appropriate speed. Since this irradiation processing apparatus 10 can adjust the vacuum pressure in the chamber 12 in a range of 10 ⁴ to 10 ⁻⁵ Pa, it uses a wide range of vacuum conditions from a low vacuum to a high vacuum slightly lower than the atmospheric pressure. Therefore, an appropriate vacuum state can be selected according to the type of thin film 19 and the degree of modification, and the best modification of the thin film 19 can be performed under the selected vacuum state.

  In the excimer vacuum ultraviolet light irradiation processing apparatus 10 in the embodiment of FIG. 5, nitrogen (inert gas) is supplied into the chamber 12 while maintaining the inside of the chamber 12 from a low vacuum to an intermediate vacuum state. Since the remaining oxygen is exhausted out of the chamber 12 and excimer vacuum ultraviolet light is absorbed by the oxygen, it is possible to prevent a reduction in irradiation efficiency of the vacuum ultraviolet light, so that the relative dielectric constant ( k value) can be reliably reduced, and the mechanical strength of the insulating film 19 can be reliably improved. In the excimer vacuum ultraviolet light irradiation processing apparatus 10 in the embodiment of FIG. 6, the chamber 12 is maintained in a high vacuum state so that no oxygen exists in the chamber 12 and the excimer vacuum ultraviolet light is absorbed by oxygen. Since the reduction of the irradiation efficiency of vacuum ultraviolet light can be prevented, the relative dielectric constant (k value) of the low dielectric constant interlayer insulating film 19 can be reliably reduced, and the mechanical strength of the insulating film 19 can be reliably ensured. Can be improved.

The partially broken perspective view of the excimer vacuum ultraviolet light irradiation processing apparatus shown as an example. The perspective view of the excimer vacuum ultraviolet light irradiation processing apparatus shown in the state which rotated the lamp house upwards. FIG. 3 is a partial enlarged cross-sectional view taken along line 3-3 in FIG. 2. The partial enlarged view of the excimer vacuum ultraviolet light irradiation processing apparatus which shows the separation dimension between the lower end of a lamp | ramp and the surface of a wafer. Sectional drawing of the excimer vacuum ultraviolet light irradiation processing apparatus which shows typically an example of irradiation of an excimer vacuum ultraviolet light. Sectional drawing of the excimer vacuum ultraviolet light irradiation processing apparatus which shows typically another example of irradiation of excimer vacuum ultraviolet light.

Explanation of symbols

10 Excimer vacuum ultraviolet light irradiation treatment 11 Lamp house (lamp fixing part)
12 Processing chamber (processing room)
13 Vacuum pump (vacuum equipment)
14 Gas supply device 15 Heater (heating device)
16 Wafer 17 Surface 19 Thin film (low dielectric constant interlayer insulating film)
21 Excimer vacuum ultraviolet lamp 26 Inner tube 27 Outer tube 29 Electrode 36 Stage (wafer mounting part)
37 Space 39 Lower end 43 Air supply pipe 44 Exhaust pipe 45 Cylinder

Claims (6)

A processing chamber for storing a wafer having a thin film formed on one surface, a vacuum device for holding the processing chamber in a vacuum, a heating device for heating the wafer stored in the processing chamber to a predetermined temperature, and a processing chamber. And an excimer vacuum ultraviolet light lamp for irradiating the excimer vacuum ultraviolet light to the thin film of the wafer, and the excimer vacuum ultraviolet light lamp is exposed in the processing chamber and accommodated in the processing chamber in a vacuum state. Excimer vacuum ultraviolet light irradiation treatment apparatus characterized in that it can directly irradiate excimer vacuum ultraviolet light onto a thin film .   The excimer vacuum ultraviolet light irradiation processing apparatus includes a gas supply device that supplies an inert gas into the processing chamber. In the excimer vacuum ultraviolet light irradiation processing apparatus, the processing chamber is turned from a low vacuum through the vacuum device. The excimer vacuum ultraviolet light lamp applies excimer vacuum ultraviolet light to the thin film of the wafer accommodated in the processing chamber while the gas supply device supplies an inert gas into the processing chamber when the vacuum chamber is maintained. The excimer vacuum ultraviolet light irradiation processing apparatus of Claim 1 irradiated.   The processing chamber is formed above the vertical direction to fix the excimer vacuum ultraviolet lamp, a wafer mounting portion formed below the vertical direction to position the wafer, and the lamp fixing portion. In the excimer vacuum ultraviolet light irradiation processing apparatus, the excimer vacuum ultraviolet light lamp has a rod shape that is long in one direction, and a plurality of the excimer vacuums are formed. The excimer vacuum ultraviolet light irradiation processing apparatus according to claim 1 or 2, wherein the ultraviolet lamps are arranged in parallel at equal intervals in a direction intersecting the vertical direction in the lamp fixing portion. The excimer vacuum ultraviolet light irradiation processing apparatus according to claim 3, wherein the excimer vacuum ultraviolet light irradiation processing apparatus can individually adjust the illuminance of the excimer vacuum ultraviolet light lamp within a range of 5 to 50 mw / cm ² .   The excimer vacuum ultraviolet light according to claim 3 or 4, wherein a vertical separation distance between a lower end of the excimer vacuum ultraviolet light lamp and one surface of the wafer located on the wafer mounting portion is in a range of 20 to 100 mm. Irradiation processing device. The excimer vacuum ultraviolet light irradiation processing apparatus according to any one of claims 1 to 5, wherein in the excimer vacuum ultraviolet light irradiation processing apparatus, a vacuum pressure in the processing chamber can be adjusted in a range of 10 ⁴ to 10 ^-5 Pa. .

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