This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-017490, filed Feb. 4, 2020, the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a processing apparatus and a processing method.
As a lithography process for the manufacturing of a semiconductor device, nanoimprint lithography has been proposed as a pattern transfer method which takes the place of photolithography. In nanoimprint lithography, a patterned template is directly pressed against a substrate coated with a liquid organic material to transfer the pattern of the template to the substrate.
In general, according to one embodiment, a processing apparatus includes a chamber, a first gas introduction port that introduces a first gas into the chamber, a first gas discharge port that discharges the first gas from the chamber, and a stage that supports a processing object in the chamber. The processing apparatus has a plasma generating section with an electrode. The plasma generating section is configured to generate a plasma in the chamber. The processing apparatus includes a shield at a first position that is between the plasma generating section and the stage. The shield is light transmissive.
Certain example embodiments of the present disclosure will now be described with reference to the drawings. In the drawings and in the following description, the same reference symbols are used for the same or substantially similar components or elements. The drawings are schematic; thus, the size ratio between components or elements, etc. are not necessarily to scale.
A processing apparatus and a processing method according to a first embodiment will be described with reference to
The processing apparatus of the first embodiment will be described first. The processing apparatus of this embodiment is, for example, an apparatus for smoothing a pattern already formed on a substrate (or processing object). While the following description illustrates the use of an imprinting template as a processing object, it is also possible to use a patterned semiconductor substrate (such as a semiconductor wafer or the like).
As shown in
As shown in
A shield 40 is provided in the chamber 10 in the space between the stage 11 and the electrode 13. The chamber 10 is thus divided by the shield 40 into a processing division 6, which contains the stage 11, and a light source division 7, which contains the plasma generating section 5. The shield 40 comprises, for example, glass, sapphire, calcium fluoride, magnesium fluoride, polycarbonate, or an acrylic resin. The shield 40 shields the processing division 6 from ions, radicals, etc. generated along with the plasma in the light source division 7.
Gas introduction ports 21 (21a, 21b) and gas discharge portions 22 (22a, 22b) are provided in the chamber 10. The gas introduction port 21a and the gas discharge portion 22a are provided in the processing division 6, while the gas introduction port 21b and the gas discharge portion 22b are provided in the light source division 7. The gas discharge portions 22 are provided with pressure regulators 23 (23a, 23b) for regulating the amount of exhaust gas. The gas introduction ports 21 may be provided with flow regulators for regulating the flow rate of an incoming gas. The gas introduction port 21a, provided in the processing division 6, introduces a processing gas 61 into the processing division 6. The gas introduction port 21b, provided in the light source division 7, introduces a light source gas 62 into the light source division 7.
An opening is provided in the side wall of the processing division 6 of the chamber 10, and a gate valve 16 is provided such that it closes the opening.
The template 50 as a processing object is carried through the opening into the processing division 6, and carried through the opening out of the processing division 6. The processing apparatus 1 also includes a conveyance section or the like that places the template 50 on the stage 11.
As shown in
The elevated portion 53 has a patterned surface 54 having a three-dimensional pattern formed therein or thereon as a topographic relief structure or the like. For example, the three-dimensional pattern may comprise grooves, trenches, recesses, holes, or the like etched into the patterning surface and/or protrusions, tiers, pillars, or the like formed on the patterning surface. While
The template 50a shown in
The template 50b of
As shown in
A method for processing the template 50 using the processing apparatus 1 will now be described with reference to
First, the gate valve 16 of the processing apparatus 1, shown in
Subsequently, a processing gas 61 is introduced into the processing division 6 of the chamber 10. A light source gas 62 is introduced into the light source division 7. Examples of the processing gas 61 include reactive gases such as oxygen (O2), ozone (O3), nitrous oxide (N2O), carbon monoxide (CO), carbon dioxide (CO2), fluorine (F2), nitrogen trifluoride (NF3), nitrogen tetrafluoride (NF4), hexafluoro-1,3-butadiene (C4F6), octafluorocyclobutane (C4F8), fluoroform (CHF3), difluoromethane (CH2F2), sulfur hexafluoride (SF6), chlorine (Cl2), boron trichloride (BCl3), hydrogen chloride (HCl), and hydrogen bromide (HBr). A mixed gas comprising such a reactive gas and an inert gas, such as nitrogen (N2), argon (Ar) or helium (He) may also be used. The reactive gas may be appropriately selected depending on the material and thickness of the patterned surface 54 of the template 50, etc. The use of the reactive gas enables etching of raised portions of the fine structures 56 of the template 50. A gas such as N2, O2, Ar or He, for example, can be used as the light source gas 62. The light source gas 62 may be appropriately selected depending on the dissociation energy of the reactive gas used for the processing gas 61, etc., as will be described below. The pressure in the processing division 6 and the pressure in the light source division 7 are regulated by the pressure regulators 23. The pressure in the processing division 6 is regulated, for example, to about 1 Pa to about atmospheric pressure. The pressure in the light source division 7 is regulated, for example, to about 0.1 Pa to about 100 Pa.
Thereafter, the plasma generating section 5 generates a plasma P in the light source division 7. The plasma P may be generated, for example, by an inductively-coupled plasma method or an electron cyclotron resonance discharge method. As shown in
A combination of the light source gas 62 with the reactive gas contained in the processing gas 61 will now be described.
When N2 gas is used as the light source gas 62 and O2 gas is used as the reactive gas for the processing gas 61, the O2 gas dissociates into ions or radicals when it is irradiated with light having a wavelength of 242 nm or less, which corresponds to the absorption edge wavelength of O2 gas. However, as described above, no appreciable emission occurs at a wavelength of less than 290 nm in the plasma emission of N2 gas; therefore, dissociation of the O2 gas does not occur. Accordingly, dissociation of the reactive gas, and thus etching of the template 50, will not occur by merely applying the plasma light 31 to the processing division 6. As described above, the type of the light source gas 62 can be appropriately selected depending on the absorption edge wavelength of the reactive gas used for the processing gas 61. Thus, the emission wavelength of the light source gas 62 is preferably set to be longer than the absorption edge wavelength of the reactive gas contained in the processing gas 61.
Instead of selecting a particular light source gas 62 in view of the reactive gas to be used, another method for adjusting the wavelength of the plasma light 31 applied to the processing division 6 is to impart to the shield 40 a function as a filter that blocks light at wavelengths shorter than the absorption edge wavelength of the processing gas 61. This alternative method enables the use, as the light source gas 62, of a gas which has a plasma emission spectrum containing light whose wavelength is shorter than the absorption edge wavelength of the processing gas 61. The impartment of the filter function can be achieved by using, as the shield 40 a colored glass filter having a long-pass filter function, for example.
In this first embodiment, leveling is performed on the fine structures 56 shown in
Leveling according to this first embodiment, performed by using near-field light, will now be described. As shown in
In this first embodiment, as shown in
After the completion of leveling, the gate valve 16 of the processing apparatus 1 is opened, and the template 50 is detached from the stage 11 and then carried out of the chamber 10. Thereafter, the gate valve 16 is closed. The template 50 can now be used, for example, in imprinting.
According to the processing apparatus 1 and the above-described processing method of this embodiment, it is possible to perform leveling of a processing object while preventing etching of the processing object that would be caused by ions or radicals generated along with a plasma. In the case of a leveling technique which utilizes near-field light and uses laser as a light source, it is necessary to provide a laser light source having a desired wavelength appropriate to the reactive gas used. However, according to the leveling technique of this embodiment, which utilizes near-field light and uses plasma light as a light source, leveling processes using different reactive gases can be performed within the same apparatus simply by changing the light source gas 62.
A processing apparatus and a processing method according to a second embodiment will now be described with reference to
The processing apparatus 2 according to the second embodiment differs from the first embodiment in that the shield 40 is connected to a moving section 17 so that the shield 40 can be moved between the position shown in
A method for processing the template 50 using the processing apparatus 2 will now be described with reference to
First, the template 50 is placed on the stage 11 in the chamber 10. The shield 40 is in the position shown in
After the gate valve 16 is closed, the mixed gas 63 is introduced from the gas introduction port 21 into the chamber 10. When a mixed gas of N2 (light source gas) and O2 (reactive gas), for example, is used, the ratio of the O2 gas to the N2 gas may be 20% to 80%, preferably about 50%. The pressure in the chamber 10 may be adjusted to about 0.1 Pa to about 100 Pa.
Thereafter, the shield 40 is moved to the position shown in
After the completion of leveling, the shield 40 is moved to the position shown in
The processing apparatus 2 and the above-described processing method of this second embodiment can achieve the same effects as the first embodiment. Additionally, plasma etching processes may be performed simply by moving the shield 40 of the processing apparatus 2 to a position where it does not interfere.
A processing apparatus and a processing method according to a third embodiment will now be described with reference to
A method for processing the template 50 using the processing apparatus 3 will now be described. First, the template 50 is carried upside down to the stage 11 in the chamber 10 by the conveyance arm 44, as shown in
The carry-in process will be described with reference to
After lowering the template 50, leveling of the template 50 is performed. After the completion of leveling, the template 50 is carried out of the chamber 10. The carrying-out of the template 50 is performed by reversing the carry-in process (excepting for the introduction of the mixed gas 63, which is not carried out in the carrying-out process).
According to the processing apparatus 3 and the above-described processing method of this third embodiment, the substrate 51 itself of a reverse facing template 50 performs the same function as the shield 40. Therefore, the same effects as the first embodiment can be achieved. Furthermore, by just reversing the facing direction of the template 50 placed on the stage 11, the processing apparatus 3 can also be used to perform plasma etching, as in the second embodiment.
A processing method according to a fourth embodiment will now be described with reference to
In the processing method of this fourth embodiment, the template 50 is irradiated with plasma light 31, as shown in
According to the processing apparatus 1 and above-described processing method of this fourth embodiment, it is possible to perform leveling of a processing object while preventing etching of the processing object that would otherwise be caused by ions or radicals generated along with a plasma. In the case of a leveling technique which utilizes near-field light and uses laser as a light source, it is necessary to provide a laser light source having a desired wavelength appropriate to the deposition gas used. However, according to the leveling technique of this fourth embodiment, which utilizes near-field light and uses plasma light as a light source, leveling processes using different deposition gases can be performed within the same apparatus simply by changing the light source gas 62.
A processing method according to a fifth embodiment will now be described. The processing method according to the fifth embodiment is performed using the processing apparatus 2 as in the second embodiment. This fifth embodiment differs from the second embodiment in that instead of the reactive gas, a deposition gas is used for the processing gas 61 in the processing. This embodiment is otherwise the same as the second embodiment.
The processing apparatus 2 and processing method of this fifth embodiment can achieve the same effect as the fourth embodiment. Plasma etching can also be performed by moving the shield 40 of the processing apparatus 2 to a position where it does not interfere between the electrode 13 and the template 50.
A processing method according to a sixth embodiment will now be described. The processing method according to the sixth embodiment is performed using the processing apparatus 3 as in the third embodiment. This sixth embodiment differs from the third embodiment in that instead of the reactive gas, a deposition gas is used for the processing gas 61 in the processing. This sixth embodiment is otherwise the same as the third embodiment.
The processing method of this sixth embodiment can achieve the same effects as the fourth embodiment. Furthermore, by reversing the direction of the template 50 placed on the stage 11, the processing apparatus 3 can also perform plasma etching, as in the second embodiment.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the present disclosure. Indeed, the novel embodiments described herein maybe embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the present disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the present disclosure.
Number | Date | Country | Kind |
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2020-017490 | Feb 2020 | JP | national |