JP5051594B2 - Apparatus and method for processing dielectric material - Google Patents

Description

  The present invention relates to an apparatus for curing and / or removing porogen from a dielectric material, and more particularly to curing porogen from a low-k dielectric material using ultraviolet radiation in a controlled environment. And / or an apparatus for removing.

  As semiconductor and other microelectronic devices have become innovatively smaller in size, the demand on device components continues to increase. For example, preventing capacitive crosstalk between crossing lines becomes more critical as devices get smaller. Capacitive crosstalk is basically a function of both the distance between conductors and the dielectric constant (k) of the material placed between the conductors. Much interest has been devoted to electrically insulating the conductors from each other using new insulators with low dielectric constants. This is because, due to the relatively low dielectric constant of about 4, the conventionally used silica (SiO2) in the device met the requirements for faster (ie, larger) applications. This is because silica is not suitable as a smaller device in the future. The low k (ie, dielectric constant less than 4) material is desirable for use as, for example, an inner dielectric layer (ILD).

  In order to achieve a low dielectric constant, it is possible to use a material with a low dielectric constant and / or to introduce porosity into the material. According to the latter, since the dielectric constant of air is nominally 1, the dielectric constant is effectively reduced. Porosity has been introduced into low-k materials by various means. In the case of low-k dielectric spins, a reduction in the value of k can be achieved by using porogens based on using high-boiling solvents, or using templates (templates), or forming pores during continuous processing. It is. However, it has been found difficult to integrate porous and low-k materials in the manufacture of semiconductor devices.

The use of UV radiation for curing low-k dielectric films has recently been found, and the electrical, mechanical and chemical properties of the resulting dielectric materials in comparison with other curing methods Improvement was shown. Furthermore, the UV assisted method can effectively remove the porogen material, the sacrificial organics used to create the porous structure.
Test results based on different low-k materials have shown several different improvements to low-k films due to exposure to different wavelength distributions of UV light combined with a suitable background and sufficiently high wafer temperature. Obtained results were obtained. In particular, some wavelength distributions (A) are very effective for porogen removal and improved low-k matrix (matrix) crosslinking, while other wavelength distributions (B) It has been found that it contributes to the cross-linking of the low-k matrix without removing the porogen. Therefore, many different low-k cure flow aspects are feasible (schemes), which are beneficial for the synthesis and integration of porous, low-k dielectrics.

  There are no existing ultraviolet radiation devices that truly address the special issues and concerns associated with removing and / or curing porogens from various dielectric materials. Therefore, there is a need for equipment technologies suitable for processing dielectric materials such as low-k materials, oxides, nitrides, premetal dielectrics, barrier layers for the manufacture of innovative devices. .

Disclosed herein are apparatus and methods for processing dielectric materials such as low-k dielectrics and pre-metal dielectrics for innovative semiconductor devices.
In one embodiment, the apparatus is an apparatus for processing a dielectric material comprising:
A radiation source module having a reflector, an ultraviolet radiation source, and a plate that transmits wavelengths between 150 nm and 300 nm, forming a sealed interior region, wherein the interior region is in fluid communication with the first fluid source; A closable opening coupled to the radiation source module to operate in communication with the ultraviolet radiation source and receive the substrate, a support for supporting the substrate, and a second fluid A process chamber module having a gas inlet in fluid communication with the source; a load lock chamber module having an air lock chamber in fluid communication with the third fluid source and the chuck and operating in fluid communication with the process chamber module and the wafer handler; Including
The radiation source module further includes a fluid inlet in fluid communication with a fourth fluid source for supplying a cooling medium to the reflector, and a mesh screen disposed between the radiation source and the substrate and having a plurality of openings. And an optical filter .

In another embodiment, an apparatus for processing a dielectric material, comprising a reflector, an ultraviolet radiation source that generates broadband radiation, and a plate that transmits wavelengths between 150 nm and 300 nm to form a sealed interior region. A radiation source module in fluid communication with the first fluid source; an optical filter including a mesh screen disposed between the radiation source and the substrate and having a plurality of openings; and the radiation source. A closable opening coupled to the module to operate in communication with the ultraviolet radiation source and to receive the substrate; a support for supporting the substrate; and a second fluid source; A processing chamber module having a gas inlet in fluid communication,
The radiation source module further includes a fluid inlet in fluid communication with a further fluid source that supplies a cooling medium to the reflector.

A method of processing a dielectric material is disposed between a reflector , an ultraviolet radiation source , a plate that forms a sealed internal region and transmits wavelengths between 150 nm and 300 nm, and the ultraviolet radiation source and the substrate. Transporting the substrate from the load lock chamber to a processing chamber coupled to a radiation source module including an optical filter including a mesh screen having a plurality of openings; and an inert gas, the processing chamber and the sealed A dielectric material comprising: flowing into an internal region; generating ultraviolet broadband radiation at a wavelength of 150 nm to 300 nm; exposing the substrate with the broadband radiation; and flowing a cooling medium around the reflector Includes each stage of processing.

  These and other features are embodied by the drawings and detailed description.

  As shown in FIG. 1, an apparatus 10 that cures and / or removes porogen from dielectric material using ultraviolet radiation in a controlled environment includes a radiation source module 12 and the radiation source module 12 in communication therewith. Using the processing chamber module 14, the load lock chamber module 16 close to the processing chamber module 14 for transferring the substrate into and out of the processing chamber module 14, and the apparatus 10. And a wafer load station module (not shown) close to the load lock chamber module 16 for mounting a substrate for processing. Beneficially, the environment within each module is controllable and adjustable for the particular dielectric material processed therein.

  Reference is now made to FIG. The radiation source module 12 basically includes a sealed interior region 20 defined by an ultraviolet radiation source 22, a plate 24, and a reflector 26. The portion 27 of the ultraviolet radiation source 22 projects from the sealed inner region 20 and / or is joined at the boundary with the sealed inner region 20 and is essentially transparent to ultraviolet radiation. However, it is basically impermeable to microwaves and functions as a high-pass filter. For example, the end portion 28 of the portion 27 protruding from the sealed inner region 20 and / or joining at the boundary with this inner region can be formed of a tungsten mesh material with a sufficiently small opening, As a result, most microwave radiation is blocked, while UV radiation is essentially transmitted.

  The reflector 26 includes a reflective layer formed by aluminum metal, a dichroic (dichroic) material, or a multilayer coating. The reflective layer may further include a protective layer of a combination including at least one of magnesium, silicon oxide, aluminum oxide, and these materials. Other suitable materials will be apparent to those skilled in the art in view of the present disclosure. The above materials have been found to provide greater reflectivity than UV radiation with shorter wavelengths, eg, less than 200 nm.

  The radiation source module 12 further includes a fluid inlet 33 in fluid communication with the sealed interior region 20 and a fluid source 35. The fluid source 35 is configured to purify the atmosphere contained within the inner region 20 that is sealed during processing. Further, the fluid source 35 can be used to cool an ultraviolet radiation source such as an electrodeless tube (electrodeless tube, electrodeless bulb). Suitable fluids include, for example, an inert gas for purifying ambient gas from the sealed interior region 20. However, it is not intended to be limited to these. Suitable inert gases include nitrogen, argon, helium, combinations containing at least one of these gases, and the like. However, it is not limited to these. Similarly, the sealed inner region 20 can be further evacuated by means of a vacuum pump, an exhaust pipe or the like (not shown), allowing optimal transmission of UV light. That is, oxygen or other species that absorb ultraviolet radiation at wavelengths less than 200 nm are removed. As used herein, the phrase “sealed” used for a radiation source module (as well as a processing chamber) is radiation that can be appropriately purified during processing. It refers to the area inside the source module. The sealed inner region need not be sealed with a vacuum. By purifying, an advantageous atmosphere can be easily provided in the internal region (or the processing chamber). However, in some embodiments, the sealed inner region can be sealed in a vacuum depending on the application.

  The radiation source chamber 12 can also include a fluid inlet 34 in fluid communication with a fluid source 36. In this aspect, a fluid such as water or some other refrigerant (cooling medium) may be used to cool the reflector 26, components, etc. that will be heated during processing. For example, the reflector 26 may further include a water cooling jacket through which fluid flows to provide a desired amount of cooling. The fluid selected for cooling can be the same as or different from the fluid used to clean the sealed interior region 20. Thus, the fluid source 35 or 36 is not intended to be limited to a single fluid, but can provide multiple fluids that may be desired for different applications, where each fluid is a manifold, etc. Can be stored in a pressurized container or the like in fluid communication with the inlets 33, 34.

Purifying the sealed interior region 20 of the source module 12 (as well as the processing chamber 14) provides numerous advantages, especially during processing of low-k dielectric materials. For example, air contains about 21% oxygen, which is known to absorb radiation of wavelengths below about 200 nm, and among other products of oxygen, forms ozone, among others. To react. As ozone begins to absorb at the same height as 250 nm and continues to shorten the wavelength, the generation of ozone slows down the wavelength decay. As a result, the processing efficiency of curing and / or removing the porogen from the low-k material is degraded. Purifying the sealed interior region 20 (and processing chamber 14) of the radiation source module 12 or evacuating it before exposing the substrate to the ultraviolet radiation pattern reduces the absorption of the wavelength, As a result, the processing efficiency is improved. Other cleaning fluids can be used to absorb wavelengths that are selective for the ultraviolet radiation pattern inherent to the particular radiation source used. Suitable absorption gas (absorption gas) is O ₂ (oxygen gas), O ₃ (ozone gas), N ₂ O (nitrogen monoxide gas), CO ₂ (carbon dioxide gas), H ₂ O (water vapor), etc. including. However, it is not intended to be limited to these.

  The radiation source module 12 preferably emits at least one broadband wavelength pattern of less than about 400 nm, more preferably from about 150 nm to about 300 nm, and even more preferably from about 150 nm to about 250 nm.

  The radiation source module 12 as shown illustrates the use of an electrodeless tube 30 that is connected to a heat source, such as a microwave cavity, well known to those skilled in the art. In an embodiment, a desired broadband radiation pattern is generated, thereby generating a desired broadband ultraviolet radiation pattern. As an example, while using a microwave energy source, a magnetron and a waveguide are connected to the microwave cavity 32 to excite the gas filled inside the electrodeless tube and generate ultraviolet radiation. Let Different fills can be used for microwave electrodeless bulbs 28, thus providing different radiation patterns. The amount of the filling may be present, for example, at least about 1 atm, preferably from 2 atmospheres (atm) to 20 atmospheres, at the operating temperature when the filling is excited at a relatively high power density. It is a thing. For example, the power density of microwave energy will be at least 50 watts / cc, preferably greater than 100 watts / cc. The electrodeless tube 28 can emit a desired broadband radiation pattern at a high frequency output.

  An electrodeless tube that generates UV having a different spectral distribution is selected depending on its application. For example, the application is the use of electrodeless bulbs for different microwaves, for example for Type I and Type II microwaves available from Axelis Technology, Inc. (Beverly, Massachusetts). It is an electrodeless tube. Spectra obtained from the above type I and type II tubes suitable for use in curing and / or porogen removal processes are shown in FIGS. 3 and 4, respectively. Another suitable microwave driven electrodeless bulb is disclosed in Wood et al., US Pat. No. 5,541,475, which is hereby incorporated by reference in its entirety. Has been. Further, instead of the electrodeless tube, an arc discharge, a dielectric barrier discharge, or an electron impact generator can be used to generate the desired ultraviolet radiation pattern.

  For example, a light source for dielectric barrier discharge basically includes two parallel electrodes having a dielectric insulating layer disposed between one of the electrodes or between the electrodes, and basically operates at substantially atmospheric pressure. The substrate to be processed is often used as one of the planar electrodes, or generally disposed between two planar electrodes. The dielectric barrier discharge light source is preferably capable of being refilled with a number of gas mixtures to produce the desired radiation pattern. Computer control is used to change the gas mixture during operation, changing the wavelength generated in the radiation pattern.

  In one embodiment, the substrate is heated from below by a high intensity lamp while being illuminated from above by a light source. This configuration will provide a programmable substrate temperature. In this embodiment, the pins will be used to support the existing substrate over the heating window. Below this window, the heating lamp will be arranged. In this embodiment, if desired, one or more pins are further implemented to monitor the substrate temperature to control the temperature and feed back this temperature information to the lamp controller to control the temperature. Temperature sensors such as springs to be embedded, or embedded thermocouples. Instead, a proximity thermal chuck (proximity thermal chuck) controls the substrate temperature by controlling the embedded closed loop thermocouple.

  The plate 24 inside the radiation source module 12 functions effectively to isolate the ultraviolet radiation source 22 from the underlying processing chamber 14 (as shown in FIG. 1). Beneficially, the plate 24 removes particulate contaminants from the substrate to the ultraviolet radiation source 22, insulates the ultraviolet radiation source 22 from the processing chamber 14 to allow individual access, and if present. If so, the use of gas to cool the ultraviolet radiation source 22 and / or the microwave cavity is allowed. Plate 24 also allows the use of a specifically selected process gas in process chamber 14 without interfering with the operation of ultraviolet radiation source 22.

  In one embodiment, the plate 24 is fabricated from a quartz material that has optical transmission substantially transparent to the desired radiation pattern for curing and / or removing porogen from the low-k dielectric material. The An example of such a quartz material is commercially available under the trade name Dynasil 1000 from Dynasil Corporation in West Berlin, New Jersey. As long as it has the above-mentioned characteristics, it is possible to use materials other than quartz. For example, it may be desirable to expose the substrate to ultraviolet radiation having a wavelength of less than 220 nm that is unique for progen removal. The plate 24 is mounted in the radiation source module 12 by conventional mounting means. This mounting means further includes a suitable spacer. Further, the plate 24 is formed by plates arranged to be stacked one or more. In some embodiments, the plate is coated with a non-reflective material, thus minimizing the reflection of UV radiation back to the radiation source module 12. For example, the plate 24 is coated with magnesium fluoride, or silicon, fluorine, etc. are deposited on the plate 24.

  In one embodiment, a light filter 40, such as a screen, is placed on the plate 24. In the case of a screen, the screen 40 is preferably constructed with a plurality of apertures that provide improved radiation uniformity to the substrate. The aperture can be resized according to the intensity characteristics of the ultraviolet radiation source so as to promote uniform radiation to the underlying substrate. The screen 40 can be manufactured from metal and has the form of a mesh. The screen 40 can include one or more zones to provide greater radiation exposure uniformity. FIG. 5 shows an example screen 40 having three zones 42, 44 and 46. The zone 42 has a finer mesh pattern than the zone 44, and the zone 44 has a finer mesh pattern than the zone 46. It has been found that without using a screen, the central portion of the substrate exhibits the maximum intensity of radiation incident on the surface. In the illustrated embodiment, better radiation uniformity is obtained by changing the aperture density of the screen 40. An annular ring 48 holds the mesh screen defined by zones 42, 44 and 46.

  In other embodiments, the screen 40 is disposed between the processing chamber module 14 and the radiation source module 12. In yet another embodiment, the screen 40 is embedded inside the plate 24.

  As clearly shown by FIG. 6, the processing chamber 14 basically includes a base unit 52 that includes a bottom wall 54 and a side wall 56 extending therefrom to form a cavity 58. The chuck assembly 60 is, for example, a gravity chuck (gravity chuck) assembly or the like, and is disposed in the cavity 58. As is generally known to those skilled in the art, a gravity chuck assembly supports and secures the substrate so that the substrate does not contact and apply force to the support surface by any means other than the gravity of the substrate. Use gravity as a means to do this. The chuck includes a vacuum holding mechanism as may be desired for several applications and applications and chuck assemblies.

  A structure 62 connected to and extending from the base unit 52, which is further connected to the radiation source module 12 to form a sealed chamber 68 in which the substrate can be processed. The processing chamber 14 is suitably manufactured from materials that are inert to the operating environment including, but not limited to, processing gases and reaction byproducts. Side wall 64 of structure 62 includes at least one opening 66. The opening 66 is dimensioned to transport the substrate from and to the processing chamber 14 from and to the adjacent load lock chamber 16 (as also shown in FIG. 1).

  Another opening (not shown) is further disposed in the sidewall 64. This is for purposes generally known to those skilled in the art, e.g. during the processing of inlets and exhaust and / or pump manifolds, optical ports for monitoring the process, e.g. porogens, For an inlet of a weight spectrometer for analyzing released gas species, an oxygen analyzer for monitoring the concentration of oxygen, and the like. For example, inlet and exhaust manifolds are used to provide a cross flow of gas near the permeation plate during permeation and / or processing. Furthermore, the processing chamber includes an outlet connected to an exhaust or vacuum pump (exhaust section, vacuum section). As a result, the fluid flow provides a curtain of gas near the transmission plate, thereby minimizing the deposition of porogen or degassed material from the substrate being processed, or of reactive gases within the processing chamber 14. Clean the coated plate by utilizing UV activation. In one embodiment, the flow of fluid to the processing chamber to form the curtain includes opposing outlet slots and inlet slots near the permeation plate, and a crossed flow of fluid across the plate. And provide curtains.

  The processing chamber 14 further includes a gas inlet 69 and a sealed interior region 68 in fluid communication with the gas source. The fluid flow into the sealed chamber 68 can be axial, crossed (crossflowed), or other depending on the desired application. For example, the processing chamber 14 can be tuned for the downstream flow of gas during the cleaning and / or cleaning process. Thus, depending on the gas piped to the system, the purification system can provide chamber preparation, ie, and / or chamber cleaning due to inert conditions. For example, an in situ chamber cleaning function is desirable. The reason for this is that during the curing and / or porogen removal process, some dielectric materials emit organic volatiles, which result in these organic volatiles on the chamber walls and the radiating plate 24. It is because it will deposit. The in-situ cleaning function includes an operating mode in which the substrate-free chamber 14 is cleaned using oxygen (and / or active gas) and exposed to ultraviolet radiation to deposit organic matter. A sufficient amount of ozone and other excited oxygen species can be generated that can react with and remove the deposits. For example, periodic cleaning of the processing chamber includes detecting changes in the transmission of ultraviolet broadband radiation to the processing chamber. Here, the cleaning process is started when the change exceeds a predetermined threshold value. The cleaning process is discontinuous when the rate of change of transmission is less than a predetermined rate of change or about 100% transmission for a given wavelength width.

For the purification operation, the purification system is designed to make multiple gases such as helium, nitrogen or argon optional as well as the absorbing gas as described above. For some dielectric cure applications, it is desirable to add a small amount of reactive gas to improve the cure results. As such, the apparatus can include one or more quantities of flow control gas channels (channels) that contain oxygen (O ₂ ), carbon monoxide (CO), and carbon dioxide. Carbon (CO ₂ ), and a compound of carbon and hydrogen (CxHy), a compound of carbon and fluorine (CxFy), a compound of nitrogen and hydrogen (NxHy), etc. (where x and y are each greater than 1) It is possible to provide one or more mass flow control gas channels that can be introduced in a controlled manner.

  The processing chamber 14 further includes an oxygen sensor that detects the amount of oxygen contained in the chamber. A feedback loop can be provided to prevent the device from operating until the oxygen level is below a predetermined amount. As is known in innovative semiconductor manufacturing techniques, the presence of oxygen not only affects the processing of dielectric materials at high temperatures, but can also cause unwanted oxidation reactions in metal interconnects.

  As shown in FIG. 7, the chuck assembly 60 basically includes a support 70, an annular insulating ring 72, and a lift pin assembly mechanism 74. An annular insulating ring 72 is disposed while sealing between the lower surface of the support 70 and the base unit 52 of the processing chamber 14. The flat surface of the support 70 includes a plurality of peripheral pins 76. Two of them are shown in FIG. In one embodiment, the support 70 is stationary, i.e. does not rotate. In other embodiments, the support 70 is made from aluminum or an aluminum alloy.

  A lift pin assembly mechanism 74 is disposed below the support 70 and includes an air cylinder or the like for driving a lift pin (lifting pin) 76 by a lift pin sleeve 96 (see FIG. 8) during processing. As with any other piping required for the apparatus 10, the gas lines required to operate the lift pin mechanism 74 are suitably arranged on one of the side walls in the base unit 52. Yes. In other embodiments, while the chuck is supported by the pins, the chuck moves vertically and contacts the substrate.

  As further shown in FIGS. 8-10, the support 70 includes a flat surface on which a substrate is placed during processing. Further, the support 70 includes a gas transfer hole 78 and a passage 80 extending therefrom. As a result, the heat transfer gas, such as helium, can pass through the holes 78 and / or the passages 80 to improve the transfer rate between the substrate and the surface of the support 70. The holes 78 and / or passages 80 may also apply a vacuum to the back side of the substrate 38 to increase the number of contact points between the bottom surface of the substrate and the surface of the support 70, such as by elastic deformation of the substrate. Used to apply. When vacuum holddown is used, many contact points obtained from the vacuum and increased between the substrate and the surface of the support 70 increase the rate at which the substrate reaches the processing temperature. Let In this case, the holes 78 and / or the passages 80 are preferably connected to the vacuum line 82. The vacuum line 82 is connected downstream of a processing chamber insulation valve, a flow control valve and the like (not shown). Beneficially, reducing the time to process temperature reduces the overall process time.

The passages 84 (FIG. 9) are also machined or cast in the support 70 so that fluid from the cooling system circulates to further control the temperature of the substrate. In this embodiment, fluid is circulated through cooling conduit 86, which is in fluid communication with passageway 84. Resistive heating element 88 (FIG. 9) is also loaded into support 70 while making available an elevated processing temperature that is utilized for increasing tool throughput. The support 70 preferably has a shape corresponding to the shape of the substrate and is operable in an operating range of about 20 ° C. to about 450 ° C. In a preferred embodiment, the operating temperature of the support 70 is preferably variable by a feedback or closed loop control system, while using a proportional integral derivative (PID) controller with heating and cooling capabilities. This controller will alternately supply current to the heating element 88 and cool the fluid (air or water) as needed. Feedback to the PID controller measures the temperature of the substrate during processing using a temperature measuring device such as a spring-driven thermocouple 90 mounted inside the surface of the support 70 as shown in FIG. Will be provided. Thermocouple 90 includes a spring 92 which communicates acts with the contact portion 94, as a result, the contact portion 94, in the support, is maintained in contact with the back surface of the substrate. On the other hand, the temperature of the support 70 is controlled in an open loop process (ie without a feedback device). This is accomplished by adjusting the current supplied to the heating element 88 and by introducing a fluid flow (air or water) through the passage 84 into the support 70 at the appropriate point during the process. Is called. Furthermore, thermocouples, are embedded within the chuck support member, and capable of measuring the temperature of the substrate.

  The support 70 includes an irradiance probe for measuring the intensity and spectral characteristics of ultraviolet radiation. The probe functions in the absence of an overlying substrate and provides a means of characterizing the ultraviolet radiation pattern in front of the substrate being exposed. This means depends on various parameters as described above. For example, by gas filling, valve cooling, gas in the processing chamber, transport of plates, and the like.

  Beneficially, the processing chamber 14 described above provides a substantially sealed environment for processing substrates. The quality of the cure (and / or porogen removal) and the quality of the low-k material have proven to be due to a higher inert environment. The cleaned and sealed structure serves to provide an inert environment with a concentration of oxygen of less than 100 ppm, preferably less than 50 ppm, and more preferably less than 20 ppm. A minimal purge gas flow is used (even in standby mode) to maintain the process chamber with a gas fill that is substantially free of oxygen.

Further, description will be made with reference to FIG. The load lock chamber 16 includes an air lock chamber (air lock chamber) 102 and a wafer holding device (not shown) that operate and communicate with the processing chamber 14. The opening 104 is located on the side wall of the air lock chamber 102 that is in communication with the processing chamber opening 66 (see FIG. 6). The air lock chamber 102 includes an additional opening 106 for introducing or removing a substrate from the air lock chamber 102. Such a load lock chamber module 16 can be adjusted to match the operating pressure in the processing chamber 14 so that the substrate can be transported into or out of the processing chamber 14, while Furthermore, it is possible to maintain the processing chamber 14 at a relatively constant pressure, for example at atmospheric pressure. Further, the load lock chamber 16 includes at least one gas inlet (not shown) for introducing an inert gas into the air lock chamber 102. By maintaining an inert atmosphere in the air lock chamber, oxidation of the material on the substrate, such as oxidation of metal interconnects or low k dielectrics, can be substantially prevented. is there. As the processing substrate is removed from the processing chamber, the processing substrate is substantially heated (typically after exposure to ultraviolet radiation in a high temperature processing chamber between about 20 ° C. and about 450 ° C.). In temperature. Oxidation gases such as monoxide gas (CO), dioxide gas (CO ₂ ), oxygen (O ₂ ), ozone (O ₃ ), etc., not only connect the metal internally, but also oxidize low-k dielectric materials. Can help. By maintaining an inert atmosphere until the substrate is substantially cooled, little or no oxidation, if any, occurs. Maintaining an inert environment in the load lock also helps to minimize transport to undesirable types of processing chambers.

  The load lock chamber module 16 transports the substrate to and / or from the processing chamber, and the substrate to and / or from the air lock chamber and further to and / or from the wafer handler. , Including at least one robot arm (not shown) for transport. The robot arm may be a single arm (arm), and when it moves, the wafer is moved in a substantially linear manner. The air lock chamber preferably includes a chuck that cools the substrate after processing.

  In other embodiments, the apparatus 10 can be used in addition to the UV processing chamber disclosed above, since the plasma can additionally be used to change the dielectric material and / or remove the porogen. Or it can be modified to include more plasma reactors. The plasma chamber may use high frequency or microwave frequencies for excitation of oxidation, reduction, or neutralization plasma chemicals. Substrates processed in these chambers will be heated by either a hot chuck or a lamp.

  In other embodiments, a preheat station (not shown) is added prior to UV exposure to volatile to degas the substrate before the volatile material is introduced into the processing chamber. Remove most of the material.

  In operation, a substrate is loaded from the wafer handler module into the air lock chamber 102 of the load lock chamber module 16 at atmospheric pressure. The atmosphere is preferably purged with an inert gas to remove oxidizing gas, such as air, from the air lock chamber 102. The substrate is then transferred to the processing chamber 14. The processing chamber 14 is preferably cleaned in the same manner as desired for the intended application, and the radiation source module 12 further comprising an adsorbed or reactive gas is also sealed within the sealed inner region 20. Is purified to remove any gas from and further comprises an adsorbed gas as desired. At this time, the substrate is exposed to a broad UV radiation pattern generated from radiation source 22 at an elevated temperature, as desired.

  Preferably, the processing chamber 14 is configured to automatically handle the substrate, for example, so as to eliminate handling the wafer by hand.

  In one embodiment, the process uses one or more inert gases to clean the process chamber 14, load lock chamber 16, and interior region 20 of the radiation source module 12 and expose the substrate 40 to an ultraviolet radiation pattern. Air is removed prior to the removal and / or air is removed prior to transporting the substrate from the processing chamber to the load lock chamber.

The substrate temperature is further controlled in the range from about room temperature to about 450 ° C. by an infrared light source, an optical light source, or the light source itself. The treatment pressure can be less than atmospheric pressure, greater than atmospheric pressure, or equal to atmospheric pressure. In one embodiment, the processing pressure is atmospheric pressure. In general, a UV cured dielectric material is processed in about 300 seconds or less, particularly between about 60 seconds and about 180 seconds. Further, the temperature is between about room temperature and about 450 ° C., the processing pressure is less than, greater than, or approximately equal to the atmospheric pressure, and the UV power is about 0.1 mW / cm ² to about 2000 mW / UV treatment is possible with a UV wavelength spectrum between about 100 nm and about 400 nm between cm ² . Furthermore, the UV-cured dielectric material includes nitrogen (N ₂ ), oxygen (O 2), argon (Ar), helium (He), hydrogen (H ₂ ) water vapor (H ₂ O vapor), carbon dioxide gas (CO ₂ ). ), Carbon-hydrogen gas (CxHy), carbon-fluorine gas (CxFy), carbon-hydrogen-fluorine gas (CxHzFy), air, and any combination of these can be used for UV treatment by purification. (X is an integer from 1 to 6, y is an integer from 4 to 14, and z is an integer from 1 to 3).

  Suitable low-k dielectric materials that can be processed using the apparatus described above include commonly used spin-on low-k dielectric materials and CVD-deposited low-k dielectric materials. However, there is no intention limited to these. The low-k material can be an organic material, an inorganic material, or a combination thereof. For example, the dielectric material may be a low-k dielectric material, a pre-metal dielectric material, an oxide, a nitride, an oxynitride, a barrier layer, an etch stop material, a cap layer, a high-k material, a shallow groove shape (a shallow trench) A shallow trench isolation (STI) dielectric material, or a combination comprising at least one of the above dielectric materials. More particularly, suitable low-k dielectric materials include hydrogensilsesquioxane (HSQ), alkyl silsesquioxane dielectric materials such as MSQ, and carbon-doped oxide. (CDO) dielectric materials (CDO) dielectric materials, fluorine-silicate glass, diamond-like carbon, parylene (B) Silicon oxycarbide (SiCOH) dielectric material (Hydrogenated silicon oxy-carbide), allylcyclobutene-based dielectric materials, polyphenylene-based dielectric materials, polyphenylene-based dielectric materials, polyphenylene-based dielectric materials, and polyphenylene-based dielectric materials. B-staged polymers such as polyimides, porous silicas, silica zeolites, porous derivatives of the above dielectric materials, combinations of any of these It may include rs). Porous derivatives, ie mesoporous or nanoporous derivatives, can have pores due to porogen generation, pores formed by a solvent, or molecular engineering pores. These holes are like interconnected or filled, as well as dispersed, messy or vertically oriented holes.

  Other suitable dielectrics are silicates, hydrogensilsesquioxanes, organic silsesquioxanes, organic siloxanes, organic hybrid siloxanes, organic siloxanes. Includes silsesquioxane-silicate copolymers, silazane-based materials, polycarbosilanes, and acetoxylines. However, it is not intended to be limited to these.

  Suitable substrates include silicon, silicon on insulator, silicon germanium, silicon dioxide, glass, silicon nitride, ceramics, aluminum, copper, gallium arsenide, plastics, polycarbonate, circuit boards, FR-4 and polyimide. A hybrid circuit board, aluminum nitride alumina and the like. However, it is not intended to be limited to these. Such a substrate further includes a thin film deposited thereon. Such thin films include metal carbide, metal silicide, metal oxide, and any mixture thereof. However, it is not intended to be limited to these. In multilayer integrated circuit (IC) devices, the lower layer of insulated and planarized circuit lines can also function as a substrate.

  In this example, multiple substrates containing the same dielectric material were processed in an apparatus as described above. FIG. 12 shows the effect of the period on the graph in the in-situ cleaning function. The in situ cleaning process involved flowing an oxidizing fluid through the processing chamber and exposing the oxidizing fluid to ultraviolet broadband radiation. A radiation probe measured the broadband radiation intensity of the ultraviolet light into the processing chamber. As a result of degassing and deposition of contaminants on the transmission plate during processing of multiple substrates containing dielectric materials, broadband broadband radiative transfer of UV as a function of the processing substrate is slowed. Periodic cleaning of the processing chamber substantially cleans the plate so as to restore ultraviolet broadband radiation transmission. Beneficially, the walls and other surfaces of the processing chamber may be considered cleaned in addition to the transmission plate.

  FIG. 13 is a graph showing the reconditioning (reconditioning state setting) of the processing chamber after the in-situ cleaning process is completed. On the left side of the graph, the transmissivity of ultraviolet broadband radiation is measured while the in situ cleaning process described immediately above is being performed. After about 5 minutes exposure to the in-situ cleaning process, the plate was substantially cleaned as indicated by the transmission rate of ultraviolet broadband radiation to the processing chamber. In order to remove the oxidizing fluid, the processing chamber was cleaned with an inert gas. An oxygen probe measured the oxygen concentration remaining in the processing chamber as a function of time.

  While the present disclosure will be described with reference to illustrative embodiments, various changes may be made and equivalents may be substituted for the disclosed elements without departing from the scope of the disclosure. Will be understood by those skilled in the art. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the essential scope thereof. Therefore, the present disclosure is not limited to the specific embodiments disclosed as the best mode contemplated for carrying out the disclosure, and the disclosure is within the scope of the claims. Including all embodiments.

FIG. 1 shows a cross-sectional view of an apparatus for processing dielectric material during the manufacture of an integrated circuit (IC) including a radiation source module, a processing chamber module, and a load lock chamber module. FIG. 2 shows a cross-sectional view of the radiation source module of FIG. FIG. 3 shows the broadband spectral output of an Axcelis Type I microwave-powered electrodeless tube that can be used as an ultraviolet radiation source as appropriate. FIG. 4 graphically illustrates the broadband spectral output of an Axcelis Type II microwave-driven electrodeless tube that can be used as an ultraviolet radiation source as appropriate. FIG. 5 shows a top view of the screen intermediate the processing chamber module and radiation source module of FIG. 6 shows an exploded perspective view of the processing chamber module of FIG. FIG. 7 shows a partially exploded perspective view of a proximity thermal chuck assembly used in a processing chamber. FIG. 8 is a top view of a support member used in the proximity thermal chuck assembly of FIG. 7. FIG. 9 shows a cross-sectional view of the support member of FIG. FIG. 10 shows a cross-sectional view of the support member of FIG. FIG. 11 shows a cross-sectional view of the load lock chamber module of FIG. FIG. 12 graphically illustrates the transmission of ultraviolet broadband radiation as a function of the substrate being processed and the periodic cleaning of the processing chamber. FIG. 13 graphically illustrates the transmittance of broadband radiation of ultraviolet light as a function of time during the in-situ cleaning process, and further shows the concentration of oxygen as a function during cleaning of the processing chamber following the in-situ cleaning process.

Claims (52)

An apparatus for processing a dielectric material, comprising:
A source module having a reflector, an ultraviolet radiation source, and a plate that transmits wavelengths between 150 nm and 300 nm, forming a sealed interior region, wherein the interior region is in fluid communication with the first fluid source;
A closable opening coupled to the radiation source module to operate in communication with the ultraviolet radiation source and receive the substrate; a support for supporting the substrate; and a second A processing chamber module having a gas inlet in fluid communication with a fluid source;
An air lock chamber in fluid communication with the third fluid source and the chuck, the process chamber module and a load lock chamber module operating in fluid communication with the wafer handler;
The radiation source module further includes a fluid inlet in fluid communication with a fourth fluid source for supplying a cooling medium to the reflector, and a mesh screen disposed between the radiation source and the substrate and having a plurality of openings. An apparatus comprising an optical filter . The mesh screen, an inner zone having a first mesh size, having a second mesh size, according to claim 1 comprising an outer zone disposed around the inner zone. The apparatus of claim 2 wherein the inner zone is coaxially aligned with the ultraviolet radiation source. The apparatus of claim 1 , wherein the optical filter comprises a coating, an absorbing gas, an absorbing solid material, or any combination thereof.   The apparatus of claim 1, wherein the ultraviolet radiation source comprises an electrodeless tube connected to an energy source.   The ultraviolet radiation source is a broadband radiation source having a spectrum of a selected wavelength and is responsive to distinguish a first set of chemical bonds and functional groups of the dielectric material; and The apparatus of claim 1, wherein the apparatus is permeable to a second set of selected chemical bonds and functional groups of the dielectric material.   The apparatus of claim 1, wherein the ultraviolet radiation source comprises a dielectric barrier discharge device, an arc discharge device, or an electron impact generator. The first fluid source is an inert gas, an ultraviolet absorbing gas, or a combination gas including at least one of these gases;
It said second fluid source is a said inert gas, a reactive gas, wherein the ultraviolet absorbing gas, or a combination of gas containing at least one of these gases, and,
The apparatus of claim 1, wherein the third fluid source comprises the inert gas.   The apparatus of claim 1, further comprising a cooling jacket disposed about the reflector in fluid communication with the cooling medium.   The dielectric material is a low-k dielectric material, a pre-metal dielectric material, an oxide, a nitride, an oxynitride, a barrier layer material, an etch stop material, a cap layer, a high-k material, a dielectric that is insulated by a shallow groove The device of claim 1, wherein the device is a material, or a combination of materials comprising at least one of these.   The apparatus of claim 1, wherein the processing chamber includes a heat source for heating the substrate. The heat source includes a proximity thermal chuck assembly that is spring mounted or embedded to measure a temperature of the substrate and a plurality of pins for supporting the substrate. 12. The apparatus of claim 11 including a thermocouple.   The apparatus of claim 1, wherein the load lock chamber provides an inert state for a substrate transported from the processing chamber.   The apparatus of claim 1, wherein the reflector includes a reflective layer formed of aluminum metal, dichroic material, or multilayer coating. The apparatus of claim 14 , wherein the reflective layer comprises a combination comprising at least one of magnesium fluoride, silicon dioxide, aluminum oxide, and the material.   The apparatus of claim 1, wherein the ultraviolet radiation source emits a broadband radiation pattern comprising wavelengths between 150 nm and 300 nm.   The apparatus of claim 1, wherein the processing chamber further comprises an in situ radiation probe positioned to measure the intensity of the broadband radiation of the ultraviolet light.   The apparatus of claim 1, wherein the sealed interior region of the radiation source module is in fluid communication with an exhaust or vacuum.   The apparatus of claim 1, further comprising a preheating station connected to the processing chamber.   The apparatus of claim 1, wherein the plate includes a screen embedded in the plate and uniformly distributes the broadband ultraviolet radiation.   The apparatus of claim 1, further comprising a screen between the plate and the processing chamber.   The apparatus of claim 1, wherein the processing chamber further comprises an oxygen sensor.   The apparatus of claim 1, wherein the ultraviolet radiation source includes a portion protruding into the sealed inner region or a portion joining at a boundary with the inner region. 24. The apparatus of claim 23 , wherein the portion includes an end formed by a wire mesh. An apparatus for processing a dielectric material,
Radiation having a reflector, an ultraviolet radiation source that generates broadband radiation, and a plate that transmits wavelengths between 150 nm and 300 nm, forming a sealed interior region, the interior region being in fluid communication with the first fluid source A source module;
An optical filter including a mesh screen disposed between the radiation source and the substrate and having a plurality of openings ;
A closable opening coupled to the radiation source module to operate in communication with the ultraviolet radiation source and receive a substrate; a support for supporting the substrate; and a second A processing chamber module having a gas inlet in fluid communication with a fluid source;
The radiation source module further includes a fluid inlet in fluid communication with a further fluid source that supplies a cooling medium to the reflector. 26. The optical filter of claim 25 , wherein the optical filter is a screen, the screen comprising an inner zone having a first mesh size and an outer zone having a second mesh size and disposed about the inner zone. apparatus. 26. The apparatus of claim 25 , wherein the optical filter comprises a coating, an absorbing gas, an absorbing solid material, or any combination thereof. The inner side zone, apparatus according to claim 26 which is aligned with the ultraviolet radiation source and coaxially.   27. The apparatus of claim 26, further comprising at least one zone around the outer zone, the zone having a mesh size different from the second mesh size.   27. The apparatus of claim 26, wherein the broadband radiation pattern comprises a wavelength between 150 nm and 300 nm. A reflector , an ultraviolet radiation source , a plate that forms a sealed internal region and transmits a wavelength of 150 nm to 300 nm, and a mesh screen disposed between the ultraviolet radiation source and the substrate and having a plurality of openings. Transporting the substrate from a load lock chamber to a processing chamber coupled to a radiation source module comprising an optical filter comprising:
Flowing an inert gas through the process chamber and the sealed interior region;
Generating ultraviolet broadband radiation at a wavelength of 150 nm to 300 nm and exposing the substrate with the broadband radiation;
Flowing a cooling medium around the reflector, and treating the dielectric material. Exposing the substrate with the ultraviolet broadband radiation includes flowing an ultraviolet absorbing gas into the sealed interior region to remove a portion of the ultraviolet broadband radiation transmitted to the substrate. Item 31. The method according to Item 31 . The method of claim 31 , wherein exposing the substrate with the broadband radiation comprises simultaneously flowing a reactive gas into the processing chamber. 32. The method of claim 31 , further comprising heating the substrate to a temperature between 20C and 450C. 35. The method of claim 34 , further comprising transporting the heated substrate to the load lock chamber and cooling the heated substrate while maintaining an inert gas atmosphere within the load lock chamber. . 32. The method of claim 31 , further comprising periodically cleaning the processing chamber. Periodically cleaning the process chamber includes introducing an oxidizing fluid into the processing chamber, activating the oxidizing fluid using the broadband radiation of the ultraviolet light, and further volatilizing contaminants from the plate and the processing chamber. 40. The method of claim 36 , comprising: Periodically cleaning the process chamber includes detecting a change in transmission of the ultraviolet broadband radiation to the process chamber and initiating the cleaning process when the change exceeds a predetermined threshold value. 37. The method of claim 36 . 39. The method of claim 38 , wherein the cleaning method is discontinuous when the rate of change of transmission falls below a predetermined rate of change or when 100% is transmitted in a predetermined wavelength band. 32. The method of claim 31 , further comprising filtering a portion of the ultraviolet broadband radiation prior to exposing the substrate. Filtering the portion of the ultraviolet broadband radiation includes disposing a coating, an absorbing gas, an absorbing solid material, or any combination thereof in the passage of the ultraviolet broadband radiation. 41. The method of claim 40 . 32. The method of claim 31 , wherein exposing the substrate with the ultraviolet broadband radiation includes changing operating conditions of the ultraviolet radiation source. Exposing the substrate with the ultraviolet broadband radiation includes disposing a filter between the ultraviolet radiation source and the processing chamber, and of the ultraviolet broadband radiation transmitted to the substrate. 32. The method of claim 31 , wherein a portion is removed by the filter. 32. The method of claim 31 , wherein the dielectric material comprises one or more of a pre-metal dielectric material, a low-k dielectric material, a barrier layer, and the dielectric material. 32. The method of claim 31 , wherein flowing the inert gas into the processing chamber includes a downward flow direction. 32. The method of claim 31 , wherein flowing the inert gas into the processing chamber includes intersecting flow directions. 32. The method of claim 31 , wherein generating the ultraviolet broadband radiation comprises exciting a gas filled in an electrodeless tube connected to an energy source. 48. The method of claim 47 , wherein the energy source is microwave energy, radio frequency energy, or any combination of the energy sources. 32. The method of claim 31 , further comprising flowing a gas close to the plate into the processing chamber at a constant volume and flow rate effective to minimize deposition of degassed material or porogen from the substrate to the plate. . The method further comprises flowing a gas near the plate in the processing chamber in an amount and flow rate effective to clean the plate, and the gas is activated by the broadband radiation of the ultraviolet light. 31 methods. 32. The method of claim 31 , further comprising monitoring the oxygen concentration in the processing chamber continuously or periodically. 52. The method of claim 51 , comprising maintaining an oxygen concentration in the processing chamber below 100 ppm.

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