JPH07134413A - Device manufacturing process using resist material containing fullerene - Google Patents

Abstract

PURPOSE: To form a thin resist film by a dry method with a fullerene-contg. resist material in a lithographic process for producing a device. CONSTITUTION: A fullerene-contg. resist material is deposited on a substrate 18 by a dry method to form a thin resist film 10 on the substrate 18. This resist film 10 is selectively exposed to form an image and the film 10 is patterned by development. The pattern of the film 10 is then transferred to the inside of the substrate 18 by reactive ion etching or other applicable technique.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to the use of fullerene-containing resist materials in lithographic processes for device fabrication.

[0002]

BACKGROUND OF THE INVENTION Lithographic processes are often used to fabricate integrated circuits and similar devices.
These processes use radiation-sensitive compounds known as resists to transfer the desired pattern into the material. The pattern so transferred is used to make an integrated circuit. Materials that transfer the pattern include materials that include silicon such as SiO ₂ , metal layers such as aluminum, polysilicon and other materials from which integrated circuits and similar devices are made. The layer that transfers the pattern is often referred to as the substrate when describing the lithographic process.

In order to function as a resist, a compound must have different properties before and after it is exposed to radiation. By illuminating only a portion of the radiation sensitive resist, a hidden image of the desired pattern
It occurs in the resist. This hidden image is a negative or positive tone image of the pattern to be transferred into the substrate.

Depending on the material used, the size of the individual features in the pattern, the dose, the wavelength of the radiation used and other factors,
Lithography processes are subject to various process constraints. Obviously, no single resist is perfectly suitable for a single application. However, as more resist compositions are obtained, the possibility of obtaining a resist composition having a composition suitable for a specific application increases. Therefore, new resist compositions with attractive process characteristics are desired.

[0005]

SUMMARY OF THE INVENTION Fullerenes The deposition and properties of (Fullerene) film, Hebado (Hebard) et al., "Deposition and properties of fullerene thin film", Applied Physics Letters (Appl. Phys. Lett), 59 (17) 2109
Page, (October 21, 1991), but their use as resist films in lithographic films is not recognized. Fullerene-containing thin films are deposited using dry techniques such as sublimation. This makes them attractive from a process perspective. Therefore, the lithographic process for manufacturing a device using a fullerene-containing resist thin film has certain process advantages.

The present invention relates to a lithographic process using a fullerene-containing resist composition. The fullerene-containing resist, preferably a C ₆₀ resist, is deposited as a thin film on the layer of material to which the pattern is to be transferred. This layer is called the substrate. The fullerene-containing resist is deposited on the substrate using well-known techniques for depositing fullerene thin films on surfaces.

Fullerene-containing resist films are deposited as resist on a substrate containing the materials from which deposition circuits and similar devices are made. Such materials include, for example, semiconductors such as silicon on which is deposited a resist that transfers a pattern from the resist. This layer that transfers the pattern is made of a variety of materials well known to those skilled in the art of deposited circuit type devices. Such materials include oxides such as SiO ₂ , other silicon-containing materials such as Si ₃ N ₄ , metals such as aluminum, polysilicon and the like.

The fullerene-containing material deposited on the substrate is about 100 to about 10,000Å thick and about 50
It has a thickness of 0 to about 2000Å.

The fullerene-containing resist film is exposed to radiation from an energy source. Energy source is about 0.0
It emits radiation at wavelengths between 1Å and about 5000Å. Radiation can have a wavelength of about 200Å to about 500Å,
preferable. However, only some of the fullerene-containing resist film is exposed to radiation. This creates exposed thin film regions and unexposed thin film regions in the resist. The thin film can be exposed to radiation using acceptable process techniques to produce an image in the resist. These methods include placing a mask between the energy source and the resist film. The mask has apertures therethrough that describe the pattern. In another method, a beam of energy is directed only at selected portions of the resist film.

The fullerene-containing resist film is exposed to radiation for a time sufficient to provide sufficient contrast between exposed and unexposed areas of resist material. Due to such contrast, the unexposed portions of the resist film are removed during development, while the exposed portions of the resist film remain on the substrate. The exposure time is about 1 minute to about 4 hours, preferably about 5 minutes.

The fullerene-containing resist film is preferably exposed to radiation in the presence of gas. The gas associates with the exposed portions of the resist film and provides a greater contrast between the exposed and unexposed portions of the resist film. The gas preferably comprises oxygen, although other gases are possible. Gas is about 380 Torr to about 1
520 Torr, about room temperature to about 27 ° C. The gas is preferably at atmospheric pressure and ambient temperature.

The fullerene-containing resist film is optionally placed in an atmosphere containing a gas prior to exposure to radiation. Place in advance in such an atmosphere,
The time is about 10 minutes to about 60 minutes. This gas is the same as or different from the gas in exposing the resist to radiation. Chlorine is the preferred gas to be treated prior to exposing the fullerene-containing resist to radiation.

The image described by the exposed and unexposed areas of the resist film is developed using many different techniques. The image is developed by placing the substrate coated with the fullerene-containing resist material in an organic solvent that selectively dissolves the fullerene-containing resist.
Such solvents include aldehydes, ketones, alcohols and halogenated hydrocarbons, specific examples of which include acetone, toluene and ethane trichloride. The solvent for developing the fullerene-containing resist thin film therein is preferably ethane trichloride.

The image in the fullerene-containing resist film is also air-free, preferably in vacuum or an inert gas,
Develop with heat. The substrate coated with the fullerene-containing resist thin film is placed in a container. The air in the container is
Evacuate until the pressure drops to about 10 ^-6 Torr. The temperature of the atmosphere is raised to about 250 ° C to about 400 ° C.
The coated substrate is held at reduced pressure and elevated temperature for about 1 hour to about 48 hours or until the unexposed portions of the C ₆₀ resist film have been removed.

Alternatively, the hidden image in the resist film is
Develop using a rapid thermal annealer. The coated substrate is placed in a thermal annealer. An inert atmosphere is provided in the annealer. The temperature in the annealer is raised to about 360 to about 500 ° C. and held there until the unexposed portions of the C ₆₀ resist film have been removed.

Hidden images in the resist film are also developed by exposing the coated substrate to photons. A mercury arc lamp with a dominant wavelength in the range of about 365 nm to 405 nm is preferred as the energy source for this photon irradiation. The substrate coated with the fullerene-containing resist material is placed in a suitable container and then selected in the absence of oxygen for about 1 hour to about 4 hours or until the unexposed portion of the C ₆₀ resist film is removed. Are exposed to photons from the generated energy source. Expose the resist film using the same photon energy source,
A developing process is also conceivable. However, if the resist film is exposed to an oxygen atmosphere, the oxygen atmosphere must be evacuated before the resist film is developed.

After the image in the fullerene-containing resist has been developed using these techniques, the developed image is transferred into the substrate. Reactive ion etching is preferably used to transfer the developed pattern into the substrate.

[0018]

DETAILED DESCRIPTION The present invention relates to a lithographic process in which fullerene-containing resist compositions are used. Examples of fullerenes include C ₆₀ and C ₇₀ . The fullerene containing resist, preferably a C ₆₀ resist, is deposited as a thin film on a substrate using well known techniques for depositing a fullerene thin film on a surface. The thin film is preferably sublimed onto the substrate. The process of sublimation, also known as thermal evaporation, is described in the above cited paper by Hebard et al. The deposition techniques discussed in that article are included herein by reference.

The substrate is, as also mentioned in this description, a layer of material on which the fullerene-containing resist is deposited ("patterning layer") and a layer or layers of material underlying this layer ("lower layer"). ")including. These layers are made of various materials well known to those skilled in the art of integrated circuit devices. By way of example, and not limitation, the bottom layer is a semiconductor material such as silicon. The patterned layer may be an oxide such as SiO ₂ , Si ₃ N
It is made of various materials including silicon-containing materials such as ₄ , metal such as aluminum, and polysilicon. For convenience, the term substrate shall refer to the combination of single or multiple layers of these materials. The fullerene-containing resist material deposited on the substrate is about 100 to 10,000.
With a thickness of 0Å, a thickness of about 500 to 2000Å is preferred.

FIG. 1 schematically illustrates various steps taken to transfer a pattern into a substrate using a fullerene-containing resist film according to the present invention. As shown in FIG. 1, the fullerene-containing resist thin film 10 is
Exposed to radiation 12 from an energy source (not shown). Energy source is about 0.1Å to about 500
Provides radiation at a wavelength of 0Å. This includes radiation in the ultraviolet (UV) and X-ray range of the spectrum. Radiation is about 20
It is preferred to have a wavelength of 0Å to about 500Å.

FIG. 1 shows schematically the exposure of the resist film to radiation. A mask material 14 is inserted between the radiation source and the surface of the substrate 18 on which the fullerene-containing resist film 10 is to be deposited. Although the substrate 18 is depicted in FIG. 1 as a single layer, it is contemplated that the resist film may be deposited on multiple layers of material, as described above. Mask material 1
4 there is an aperture 16 that allows the radiation 12 to pass from the radiation source to the resist material 10. Openings 16 in mask material
Defines the pattern. The size of the aperture defines the size of the features created in the substrate by this process. Typically, the shape produced by this process has dimensions of about 1
To about 4 microns. However, it is also conceivable that features with dimensions less than 1 micron will also be produced.

As the radiation 12 is transmitted from a radiation source (not shown) through the mask apertures 16 to the resist film 10, the hidden image of the pattern defined by the mask apertures is a fullerene-containing resist film. Specified in.
This hidden image is depicted by the exposed and unexposed areas in the fullerene-containing resist film 10.

Although FIG. 1 illustrates exposing a thin resist film using a mask material to write a pattern in the resist material, those skilled in the art will use it during an exposure process such as an electron beam exposure technique. You will recognize that there are many technologies that can be done. The process is not limited to techniques for exposing fullerene-containing resist films.

The fullerene-containing resist film 10 is exposed to radiation for a time sufficient to provide sufficient contrast between the exposed and unexposed areas of the resist film. Due to such contrast, the unexposed parts of the resist film are removed during development, while the exposed parts of the resist film 10 remain on the substrate 18. The exposure time is about 1 minute to about 4 hours, with an exposure time of about 5 minutes being preferred.

The fullerene-containing resist film is preferably exposed to radiation in the presence of a contrast-introducing gas between the unexposed areas of the resist film. The gas preferably comprises oxygen, but other gases that introduce the desired contrast are also contemplated. Other possible gases are those containing an element with an electronegativity similar to oxygen.

Although the applicant does not wish to adhere to a particular theory, it is believed that the gas "dopes" the fullerene-containing thin film during the exposure process. This doping effect is
Although it may or may not be the result of the reaction of the gas with the exposed fullerene-containing resist film, it significantly increases the contrast between the exposed and unexposed areas of the fullerene-containing resist.

The gas pressure is about 380 Torr to about 1520.
At Torr, the gas temperature is about room temperature to about 27 ° C. The gas is preferably at atmospheric pressure and at ambient temperature.

The fullerene-containing resist film is optionally placed in a gas containing atmosphere prior to exposure to radiation. Such pre-exposure in such an atmosphere is for a period of about 10 minutes to about 60 minutes. When the resist film is placed in a gas atmosphere before it is exposed to radiation, it has increased sensitivity during exposure, thereby exposing the resist film to energy in order to transfer the hidden image into the resist film. Is reduced.
Chlorine gas is the preferred gas to process before exposing the resist to radiation.

As represented by the developing process shown schematically in FIG. 1, the image drawn in the exposed and unexposed areas of the resist film is developed using many different techniques. The image is developed by dropping the substrate 18 coated with the fullerene-containing resist film 10 into an organic solvent (not shown) that selectively dissolves the unexposed fullerene-containing resist 10. These solvents are aldehydes, ketones, alcohols and halogenated hydrocarbons, specific examples of which include acetone, toluene, methanol and trichloroethane. The specifically listed developing solvents are not intended to exclude the list of suitable solvents. It will be within the ability of one of ordinary skill in the art to find other suitable developing solvents based on the guidance provided herein. The solvent for developing the fullerene-containing resist thin film is preferably trichloroethane.

After development, the coated substrate is washed to remove the residual amount of undeveloped fullerene-containing resist film that remains. An organic solvent that does not dissolve the exposed fullerene-containing resist is preferable as the cleaning agent. Suitable solvents include methanol, ethanol, propanol and isopropanol. Isopropanol is preferred because it has little effect on the exposed fullerene-containing resist. However, the class of detergents is not excluded and it is within the ability of one of ordinary skill in the art to find other suitable detergents based on the guidelines provided herein.

The coated substrate is then placed in a cleaning agent for a time sufficient to remove residual undeveloped fullerene-containing resist. The time required for this step is preferably at least 10 seconds or less. The detergent is preferably agitated during this step.

As shown schematically in FIG. 1, the hidden image in fullerene containing resist 10 is also developed using heat. The substrate 18 coated with the fullerene-containing resist 10 is placed in an atmosphere such as a glass pressure vessel, the atmosphere surrounding the coated substrate is removed, and the substrate is heated. The pressure in the vessel decreases below atmospheric pressure as the atmosphere surrounding the coated substrate is withdrawn. Pressure is about 10 ^-6 T
decrease to orr. The temperature in the vessel is raised to about 250 ° C to about 400 ° C. The coated substrate is under reduced pressure and high temperature
Hold for about 1 hour to about 48 hours, or until the desired amount of unexposed C ₆₀ is removed from the substrate.

Alternatively, the hidden image in the resist material is
It is also developed using a thermal annealer. Annealer is 6
An inch silicon wafer is included on which the coated substrate is placed. The silicon wafer is surrounded by infrared lamps.
The coated substrate is placed in a thermal annealer. An inert atmosphere such as argon gas is supplied into the annealer.
The temperature in the annealer is raised to about 360 to about 500 ° C., at which temperature about 2 to about 10 minutes, or C _60.
Hold until the undeveloped portion of the resist film is removed.

As shown schematically in FIG. 1, the image in the resist material is also developed by exposing the exposed resist material to photons. Coated substrate 18
Are placed in a container and then the atmosphere is evacuated. The atmosphere is evacuated and the atmospheric pressure is reduced to about 5 × 10 ⁻⁷ Torr. The container must withstand the internal vacuum without collapsing and must pass through its walls so that photons from the energy source illuminate the interior of the coated substrate. The energy source is preferably a mercury lamp having a dominant wavelength in the range of about 365 to 405 nm. The coated resist material is then exposed to radiation from the mercury arc lamp for about 1 hour to about 4 hours, or until the unexposed portions of the C ₆₀ film have been removed.

After the hidden image is developed using one of these techniques, the developed image is transferred into the substrate.
This transfer process is also shown schematically in FIG. Such pattern transfer would be achieved by reactive ion etching. Reactive ion etching is well known to those skilled in the art of performing lithographic processes for device fabrication.

For example, good pattern transfer from the resist into the substrate can be performed by reactive ion etching in plasma such as carbon tetrafluoride (CF ₄ ). The CF ₄ plasma etches silicon material at a rate of about 150Å / min. By way of example, such etching conditions include a CF ₄ flow rate of 10 sccm and a pressure of 10 mTorr. The power supplied to the plasma generated reactive ion etcher is about 60 watts and the supplied current is about 200 volts. Under these conditions, 1500Å
Deep trenches are etched into the silicon in about 10 minutes. Reactive ion etching in other suitable plasmas is also envisioned.

The following examples are specific examples of the general process conditions described above. They are intended to clarify the general description of the invention.

Example 1 Development of C ₆₀ Containing Resist Material A C ₆₀ 1735Å thin film was deposited on a silicon wafer using the well-known technique of thermal sublimation. The silicon wafer used is Si (100), and "100" indicates the direction of the crystal lattice. The C ₆₀ coated wafer was placed in a photo exposure unit equipped with an ultraviolet (UV) radiation source. C ₆₀ coated wafer and U
A mask was inserted between the V radiation sources. The mask had a pattern of 4 μm and a gap of 6 μm between the patterns. These patterns were defined by the openings in the mask material. Radiation could only be transmitted through the mask aperture. Only the portion of the C ₆₀ resist film that was aligned with the mask aperture was exposed to radiation.

The radiation source was UV light having a dominant wavelength in the range of about 365 nm to 405 nm. Exposure power is 17mW
It was / cm ² . The C ₆₀ resist film was exposed to the atmosphere for 1 hour at ambient temperature.

After being exposed, the C ₆₀ coated wafer was placed in pure trichloroethane developer for 35 seconds. Trichloroethane were dissolved most of the C ₆₀ resist film not exposed but, C ₆₀ resist film is exposed,
Almost no erosion.

After removing the C ₆₀ coated wafer from the developer, to remove the unexposed residual amount of C ₆₀ from it,
It was placed in a solution of pure isopropanol. Isopropanol removed the unexposed C ₆₀ balance in about 10 seconds, but the unexposed portions of the C ₆₀ resist had no visible effect. But one coated wafer
Exposed C ₆₀ after placing in isopropanol for more than a minute
The film began to show signs of erosion from isopropanol.

The obtained 4 μm line is carbon tetrafluoride (CF ₄ ).
Using reactive ion etching (RIE) in plasma,
Transferred into the substrate. The plasma was generated at 200 volts with a power of 50 watts. The flow rate of CF ₄ was 10 cc / min at a pressure of 10 mTorr.
The coated substrate was etched for 10 minutes. After 10 minutes, trenches about 1500 Å deep were etched into the portion of the substrate not covered by the exposed C ₆₀ resist film. This corresponds to an etching rate of silica of 150Å / min in this plasma. The 4 μm lines transferred into the C ₆₀ imaging layer during exposure were well reproduced in the etched substrate.

[0043]

Example 2 Effect of Exposure Pressure on Sensitivity of C ₆₀ Resist Thin Film A 1000 Å thick C ₆₀ resist thin film was formed by sublimation on a silicon wafer using a known technique. The wafer was divided into four equal pieces. Each of the four debris was separately exposed to radiation in a mask aligner with a mask sandwiched between the radiation source and the resist material. Each exposure was done in a different gas atmosphere. The Mask Aligner was a Model 84-3 light source obtained from the Hybrid Tech Group in San Jose, CA. The mask aligner was modified by adding a gas input. If the wafer was exposed to radiation in an atmosphere other than air, the atmosphere was supplied through a gas input.

Air between the coated wafer and the mask is eliminated,
The coated wafer was replaced with several different gas atmospheres before it was exposed to radiation. The gaseous atmosphere with three of the four coated portions of the wafer exposed separately was argon, nitrogen and oxygen. The two pieces of the coated wafer were exposed to radiation separately in an oxygen atmosphere.

Each piece was exposed to UV radiation having a dominant wavelength in the range of about 365 nm to 405 nm for 1 hour in each atmosphere. The exposed wafer was then placed in a solution of trichloroethane and observed. C ₆₀ resist films exposed to radiation in nitrogen and argon atmosphere showed pattern development in trichloroethane solution, but substantially all of the exposed C ₆₀ resist films on both wafers were 6%.
It dissolved within 0 seconds. Therefore, neither argon nor nitrogen was added to the contrast between the exposed areas of the C ₆₀ resist film and the exposed areas.

However, a C ₆₀ resist thin film exposed to radiation in an oxygen atmosphere, when placed in a developing solution of trichloroethane, than a resist thin film exposed in another gas,
The contrast between the unexposed and exposed areas of the resist film was greater. After 60 seconds in trichloroethane, the pattern was developed and the exposed portions of the C ₆₀ resist film remained on the wafer.

The other two C ₆₀ thin films were formed by sublimation on a silicon wafer using a well-known technique. These thin films were also 1000Å thick. These C ₆₀ resist films were exposed to the same type of radiation as previously described in this example, one in a nitrogen oxygen atmosphere and the other in a helium atmosphere. Both wafers were placed in a solution of trichloroethane after exposing them to radiation for 1 hour.

After 60 seconds in trichloroethane, both the unexposed and exposed areas of the C ₆₀ resist film on both samples were almost completely dissolved. Therefore, by exposing a C ₆₀ thin film to radiation in an atmosphere of nitrogen, oxygen or helium, exposed and unexposed parts of the thin film as observed when the C ₆₀ thin film is exposed to radiation in an oxygen atmosphere. No contrast between can be obtained.

[0049]

Example 3 Effect of Chlorine Gas Atmosphere on the Sensitivity of Radiation-Exposed C ₆₀ Resist Films C ₆₀ resist films were formed by sublimation on several different silicon wafers using known techniques. The thin film deposited was 1000Å thick. The thin film was exposed to chlorine gas for 1 hour. Each C ₆₀ resist film was then exposed to UV radiation having a dominant wavelength in the range of about 365 nm to 405 nm. The mask was between the energy source and the C ₆₀ resist film. The mask had apertures through which the radiation passed. Therefore, only the portion of the C ₆₀ thin film aligned with the mask aperture was exposed to UV radiation. All of the thin film was in an air atmosphere when exposed to radiation.

Chlorine treated C ₆₀ resist films were exposed to radiation for two different times: 5 minutes and 1 hour. The exposed thin films were then placed in toluene to evaluate their respective sensitivity and contrast. 5
One resist film that was exposed for a minute was underdeveloped, but showed a pattern after 1 minute in toluene. 15 more
After being placed in toluene for a minute, the exposed C ₆₀ resist film looked rough, although there was still a pattern on the substrate.

The second resist film exposed to radiation for 5 minutes showed a better developed pattern after 5 minutes in toluene than the sample before 1 minute development in toluene. Most of the unexposed C ₆₀ resist was removed after 5 minutes, but the remaining exposed portion of the resist film was swollen and rough.

The C ₆₀ resist film exposed to radiation for 1 hour showed a pattern after 10 minutes in toluene. Most of the unexposed resist film was removed after 10 minutes, but the exposed portion of the resist film remained.

The pattern was transferred into the C ₆₀ resist film using a shorter time and less energy than the C ₆₀ resist film exposed to chlorine gas prior to radiation. Therefore, C ₆₀
The sensitivity of the resist film is increased by exposing it to chlorine gas before exposing it to radiation.

[0054]

Example 4 Development of C ₆₀ Resist Thin Film Using Thermal Development Process A C ₆₀ resist thin film was formed by sublimation on a silicon wafer by using a well-known technique. The resist thin film was 1735 Å thick. The C ₆₀ thin film was exposed to radiation as described in Example 1. The coated wafer was then placed in a glass tube and the atmosphere in the tube was evacuated to a pressure of 6 × 10 ⁻⁷ Torr. The glass tube was then placed in an oven and gradually heated to 350 ° C. for about 5 hours with heat. The oven was kept at 350 ° C for 1 hour. After 1 hour, the exposed wafer was removed from the oven. A pattern corresponding to the exposed areas of the resist film was observed in the C ₆₀ resist.

Another C ₆₀ resist thin film was formed by sublimation on a silicon wafer using well known techniques. The thin film was 1200Å thick. The thin film was exposed to radiation as described in Example 1, except that the exposure was done in an oxygen atmosphere instead of an air atmosphere. The exposed wafer was then placed in a glass tube. The atmosphere was evacuated from the gas tube and the pressure in the tube was reduced to about 6 × 10 ⁻⁷ Torr. The glass tube was placed in an oven heated to about 250 ° C. The glass tube was placed in the oven for several days. When the coated wafer was removed from the oven, a developed pattern was observed in the C ₆₀ resist film.

A rapid thermal annealer was also used to thermally develop the C ₆₀ resist film. Several silicon wafers coated with a C ₆₀ resist film and exposed as described in Example 1 were developed by rapid thermal annealing under various conditions. The resist thin film was 1000Å thick. The coated wafers were placed in one go in an annealer on a quartz surface surrounded by infrared lamps.

The temperature of the coated wafers developed using this technique was varied from about 360 ° C to about 500 ° C. The annealing time was changed to 2 to 10 minutes. The best pattern was developed at a temperature of 450 ° C. for about 10 minutes.

[0058]

EXAMPLE 5 Using the C ₆₀ resist film development known techniques using photon development techniques, on a silicon wafer, was formed by sublimation C ₆₀ resist film. The thickness of the deposited C ₆₀ thin film was 930Å. The coated wafer was then placed in a UV exposer and the film was exposed to UV light for 1 hour.
Only a portion of the C ₆₀ thin film is to be exposed to the radiation as described in Example 1, was exposed to the radiation. In this example, C ₆₀
The exposure of the thin film is not the air atmosphere in the case of Example 1,
It was performed in an oxygen atmosphere.

After the coated wafer was exposed, it was divided into three parts. One part was placed in a quartz tube. The atmosphere was evacuated from the quartz tube to a pressure of about 10 ^-6 Torr, removing essentially all of the air. The quartz tube was placed in a mercury arc lamp. Mercury arc lamp is 155mW / cm ²
, And has a spectral distribution with a dominant wavelength in the range of about 365 nm to 405 nm. The coated substrate was photon developed for 4 hours, but some pattern development was observed after 1 hour. Essentially all of the unexposed C ₆₀ film was removed after 4 hours, but the exposed portion of C ₆₀ remained.

[0060]

With Example 6 C ₇₀ resist film exposed and developed well-known techniques, the C ₇₀ resist film on a silicon wafer, it was formed by sublimation. The thin film was exposed using a UV light exposer as described in Example 1. The thickness of the thin film was about 1000Å. The exposure time was 1 hour. C ₇₀ is in an air atmosphere, was exposed to the radiation.

After exposing the coated substrate, it was placed in trichloroethane. The pattern appeared faster than the C ₆₀ resist film, but disappeared faster. The best patterns were observed after 3-4 minutes in developer, but the contrast of these patterns was not as good as that observed with the C ₆₀ resist film.

[0062]

Using Example 7 development known techniques C ₆₀ resist film exposed to X-ray radiation, on a silicon wafer, was formed by sublimation C ₆₀ resist film. Resist thickness is about 1
It was 000Å. A beam of X-ray radiation having a dominant wavelength of 1.5Å was aimed at a point on the resist for about 4 hours.
The C ₆₀ resist thin film was irradiated in an air atmosphere. The X-ray resist was generated using a 50 volt, 250 mA power source.

The exposed resist was then placed in a solution of trichloroethane. After about 10 seconds, points appeared, corresponding to the point at which the beam of X-ray radiation was directed at the resist. C ₆₀
The resist film showed sensitivity to X-ray radiation.

[Brief description of drawings]

FIG. 1 is a schematic illustration of a lithographic process using a fullerene-containing resist material.

[Explanation of symbols]

 10 Resist Thin Film, Resist Material 12 Radiation 14 Mask Material, Material 16 Opening 18 Substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H01L 21/027 (72) Inventor Arthur Foster Heberd United States 07924 New Jersey, Bernersville, Ballantyne Roh De 104 (72) Inventor Gregory Peter Kochanski United States 08812 New Jersey, Dunneren, Third Street 324

Claims (20)

[Claims] 1. Depositing an imaging layer comprising a fullerene-containing resist material on a substrate; in the presence of a first gas,
Exposing a portion of the imaging layer to radiation, thereby forming exposed and unexposed areas defining a pattern on the imaging layer; and developing the pattern in the imaging layer. Device fabrication process including. 2. The process of claim 1 further comprising the step of transferring the developed pattern in the imaging layer into the substrate. 3. The process of claim 1 wherein the fullerene is C ₆₀ . 4. The process of claim 1, wherein the fullerene-containing imaging layer is deposited by sublimation. 5. The process of claim 1 wherein the imaging layer thickness is from about 100Å to about 5000Å. 6. The process of claim 1, wherein the first gas comprises an electronegative element. 7. The process of claim 6, wherein the first gas is oxygen. 8. The imaging layer is provided with a second layer prior to exposure to radiation.
The process of claim 1, wherein the process is exposed to the gas. 9. The process of claim 8, wherein the first gas is the same as or different from the first gas. 10. The process according to claim 9, wherein the second gas is chlorine. 11. The process of claim 10 wherein the imaging layer is exposed to chlorine gas for 1 hour or less. 12. The process according to claim 1, wherein the pattern is developed in an organic solvent. 13. The process according to claim 12, wherein the organic solvent is selected from the group consisting of aldehydes, ketones, alcohols and halogenated hydrocarbons. 14. The process of claim 12 wherein the organic solvent comprises trichloroethane. 15. A pattern having a substrate having a fullerene-containing resist exposed thereon from about 200.degree. C. to about 50.
The process of claim 1 developed by exposing to a temperature of 0 ° C for a time sufficient to remove essentially all of the fullerene-containing resist film not exposed from the substrate. 16. The process according to claim 15, wherein the pattern is developed under reduced pressure in the presence of air. 17. The pattern generates photons from a photon generation source, the substrate having a fullerene-containing resist thereon in the absence of oxygen essentially, and a sufficient amount of fullerene-containing resist thin film not exposed from the substrate. The process of claim 1 developed by exposure to photons for a time sufficient to remove. 18. The process of claim 17, wherein the photon source is a mercury arc lamp having a dominant wavelength in the range of about 365 nm to about 405 nm. 19. The process of claim 1, wherein the pattern is transferred from the imaging layer to the substrate by etching. 20. The process of claim 19, wherein the pattern is transferred from the imaging layer to the substrate by reactive ion etching in a carbon tetrafluoride plasma.