TWI445074B - Method of treating a mask layer prior to rerforming an etching process - Google Patents

Description

Mask layer processing method performed before etching process

The present invention relates to a method of etching a film on a substrate in a plasma processing system, and more particularly to treating a mask layer on a film prior to etching the film with a ballistic electron beam assisted plasma.

In semiconductor processing, a (dry) plasma etch process can be used to remove or etch materials along the edges patterned on the substrate, or in the vias, or in contact. The plasma etch process generally involves placing a semiconductor substrate having a protective layer (eg, a photoresist layer) patterned with a bottom surface in a processing chamber. Once the substrate is in the processing chamber, the ionizable and dissociable gas mixture is introduced into the processing chamber at a predetermined flow rate while the vacuum pump is adjusted to achieve the processing pressure of the surrounding environment.

Thereafter, when a portion of the existing gas species is heated and ionized, a plasma is formed. Heating electrons is heated by inductively or capacitively transferring the power of a radio frequency (RF) power source, or for example, using microwave power transferred by an electron cyclotron oscillator (ECR). In addition, the heated electrons are used to dissociate some species of the surrounding gas species and produce reactive species suitable for the etch chemical that exposes the surface. Once the plasma is formed, the surface of the selected substrate is etched by the plasma. Adjusting the treatment to appropriate conditions includes etching the appropriate desired reactant concentration and ion concentration for different features (eg, trenches, vias, contacts, etc.) in selected regions of the substrate. Exemplary substrate materials that require etching include cerium oxide (SiO ₂ ), low-k dielectric materials, polymeric germanium, and tantalum nitride.

It is an object of the present invention to provide an improved method and system for etching dielectrics.

Another object of the present invention is to provide an improved method and system for processing patterned mask layers to facilitate etching processes.

These and/or other objects of the present invention are provided by a method of etching a film formed on a substrate and having a patterned mask layer thereon. The method includes treating the mask layer by exposing the mask layer to an oxygen-containing plasma, or a halogen-containing plasma, or an inert gas, or a combination of two or more thereof, and then processing the mask The layer is etched in order to transfer the pattern of the mask layer to the film. Etching includes forming a plasma from a process gas in a plasma processing system; coupling a direct current (DC) power source to an electrode in the plasma processing system to form an electron beam that assists the plasma during etching in the plasma processing system; and exposing the substrate In plasma and electron beam.

Another embodiment of the invention includes a method of etching a thin film formed on a substrate and having a patterned mask layer thereon. The method includes disposing a substrate on a substrate support in a plasma processing system for forming a plasma and a ballistic electron beam, and in the plasma processing system, by exposing the mask layer to an oxygen-containing plasma, or Halogen plasma, or inert gas plasma, or a combination of two or more, to treat the mask layer without forming a ballistic electron beam. Still further, after processing the mask layer, in order to etch the film and transfer the patterned pattern of the mask to the film, a plasma and ballistic electron beam is formed in the plasma processing system.

In still another embodiment, a plasma processing system for etching a substrate includes a processing chamber, a gas supply system that supplies gas to the processing chamber, a substrate holder coupled to the processing chamber and used to support the substrate, and is disposed in the processing chamber. The electrode of the part. In order to form a plasma in the processing chamber, an AC power system is coupled to the processing chamber and couples at least one AC signal to the substrate holder, or the electrodes, or both, in order to form a ballistic electron beam through the plasma, A DC power system is coupled to the processing chamber and couples a DC voltage to the electrodes. The controller is used to control the gas supply system, the AC power system, and the DC power system to perform the following steps: in the plasma processing system, by exposing the mask layer to an oxygen-containing plasma, or a halogen-containing plasma, or Is an inert gas plasma, or a combination of two or more, to treat the mask layer without forming a ballistic electron beam; and after processing the mask layer, in order to etch the film and transfer the patterned mask The pattern to the film forms a plasma and ballistic electron beam in the plasma processing system.

In the following description, specific details are set for illustrative purposes and not for purposes of limitation, such as the geometry of the plasma processing system and the different processes. However, it is to be understood that the invention may be embodied in other embodiments without departing from the specific details.

In the material processing methodology, in order to transfer a pattern to a film on a substrate underneath during etching, the pattern etch comprises applying a thin layer of a photosensitive material (eg, photoresist) to the upper surface of the substrate to be patterned. Patterning of the photoresist material generally involves exposure of the photoresist material through the refracting reticle (and associated optical instrument) by the emission source, using, for example, a lithography etching system, followed by removal of the illumination region using a developing solution ( Photosensitive material in the case of a positive photoresist or in the case of an unilluminated area (in the case of a negative photoresist). Additionally, the mask layer can comprise multiple secondary layers. For example, the mask layer can include a layer of photo-sensitive material, such as a photoresist, and an underlying anti-reflective coating (ARC) layer.

In pattern etching, a dry etching process is often used in which atoms and/or molecules of ions and/or molecules of the subsequent process gas are heated and dissociated by coupling electromagnetic (EM) energy [eg, radio frequency (RF) power] to The gas is treated to form a plasma from the process gas. Further, in order to generate a high energy (ballistic) electron beam that strikes the surface of the substrate during a portion of the RF cycle, such as the positive half cycle of the coupled RF power source, a negative high voltage direct current (DC) power source can be coupled to the plasma processing system. It is known that ballistic electron beams can enhance the characteristics of dry plasma etching processes, reduce impact damage, such as electronic shadow damage, etc., by, for example, increasing the selectivity between the film (which will be etched) and the mask layer. It is believed that the dry plasma etching process is enhanced by the ballistic electronically modified mask layer, for example, the mask layer is more resistant to etching processes resulting in enhanced etching selectivity. </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; The entire contents thereof are hereby incorporated by reference.

Referring now to Figure 1, an overview of a plasma processing system incorporating a ballistic electron beam is provided. The plasma processing system includes a first electrode 120 and a second electrode 172 that are opposite each other in the processing chamber, wherein the first electrode 120 is used to support the substrate 125. The first electrode 120 is coupled to the first RF generator 140 to provide RF power at a first RF frequency, and the second electrode is coupled to the second RF generator 170 to provide RF power at a second RF frequency, the second RF frequency being The first RF frequencies are the same or different. For example, the second RF frequency can be a higher frequency relative to the first RF frequency. Coupling the RF power to the first and second electrodes can facilitate the formation of the plasma 130.

Additionally, the plasma processing system includes a DC power supply 150 for supplying a DC voltage to the second electrode 172. The coupling of the negative DC voltage to the second electrode 172, for example, may facilitate the formation of the ballistic electron beam 135. The power of the electron beam is obtained by overlapping the negative DC voltage to the second electrode 172. The application of a negative DC power source to the plasma processing system affects the formation of a ballistic (or collision free) electron beam that impacts the surface of the substrate 125, as disclosed in U.S. Patent Application Serial No. 2006/0037701 A1.

In general, ballistic electron beams can be used with any type of plasma processing system, as described below. In this example, the negative DC voltage overlaps the RF-driven capacitively coupled plasma (CCP) processing system. Therefore, the invention is not limited by this example. This example is for descriptive purposes only.

Ballistic electron beams are important for enhancing the etch characteristics, and the inventors have also found that in many cases where ballistic electron beams are used, streaks or pattern anomalies formed in the mask layer are caused (often referred to as "line margins". Degree (LER)). Specifically, the inventors have discovered that LER most often occurs in relatively low polymerization formations (eg, relatively low CF ₂ radical content) etching chemistries (eg, CF ₄ chemistries), and less frequently occurs in relatively high polymerizations. An etch chemistry (eg, C ₄ F ₈ or C ₅ F ₈ chemistry) is formed (eg, a relatively high CF ₂ group content). In the ongoing etching process and/or the subsequent etching process, pattern anomalies and sidewall thicknesses are transferred to the underlying layers. For example, in the case where the initial substrate is exposed to a plasma having an excitation breaking bond, such as ballistic electron beam assist, the mask layer may be modified such that the pattern formed in the mask layer appears to be performed while the etching process is in progress. Transfer to the sidewall thickness of the etched film (or pattern anomaly). This can reduce manufacturing throughput and/or poor device performance and reliability.

In order to determine the cause of the above LER problem, the inventors have made an effort to study the characteristics of ballistic electron beam-assisted plasma. The inventors believe that even if the extended mask layer (e.g., photoresist layer) is exposed to the upgradeable mask layer to enhance the high energy electron beam (e.g., electron energy exceeds about 100 eV) of the etching process as described above, when halogen atoms are present Initial exposure to the electron beam can cause damage to the formation of fringes (referred to as LER) in the mask layer, such as defects caused by electrons. For example, when the mask layer is exposed to the fluorine-containing etch chemistry described above, the disintegration of the chemical bonds on the surface layer of the mask layer causes oxidation of fluorine (by fluorine atoms) and removal of carbon from the surface of the mask layer. , hydrogen, and oxygen (to the depth determined by the energy of the impact electron). In general, the inventors believe that in conventional ballistic electron beam etching processes, even if exposed to a ballistic electron beam having a halogen atom species beneficial to the etching process, the initial exposure of the mask layer to the presence of a halogen atom species Ballistic electron beams can cause LER.

Therefore, the inventors expect that processing the mask layer before performing the etching process can reduce the LER induced at the etching process. The mask layer comprises a layer containing germanium or a layer containing no germanium. Furthermore, this mask layer contains a light-sensitive material such as a photoresist. For example, the mask layer may comprise 248 nm (nm) photoresist, 193 nm photoresist, 157 nm photoresist, or EUV (ultraviolet) photoresist, or two or more of them. combination.

According to an embodiment, the patterned mask layer is exposed to an oxygen-containing plasma, or a halogen-containing plasma, or an inert gas, prior to performing an etching process of transferring the pattern formed in the mask layer to the underlying film. Plasma, or a combination of two or more. The mask layer is treated with an oxygen-containing plasma that lacks a destructive bond, or a halogen-containing plasma, or an inert gas plasma, or a combination of two or more thereof, such as high energy electrons or high energy photons. Preferably, the treatment of the plasma is a plasma that causes little or no ions to impinge on the patterned mask (i.e., the low energy ions of the substrate). Therefore, the radio frequency (RF) or microwave power source disposed in the plasma source is preferably set at a power level sufficient to dissociate and ionize oxygen or a halogen gas, and to ionize the inert gas. In one embodiment, the power of the plasma source is about 2000 W or less, and the power of the desired plasma source is about 500 W or less. In addition, the substrate electrode has a bias power of less than about 500 W and the desired bias power is less than about 100 W. More preferably, the bias power includes power that is not actually applied to the substrate electrode. Still further, the plasma treatment is carried out for about 1 to 30 seconds, and the desired treatment is about 2 to 20 seconds, for example about 10 seconds, for the plasma treatment.

The exposure of the mask layer can be performed in a plasma processing system for etching processes, such as the plasma processing system shown in Figure 1, or exposing another substrate that can be in a plasma processing system other than performing an etching process. Implemented in the processing system. The plasma can be generated in situ using a plasma generating system that promotes plasma formation during the etching process. Alternatively, the plasma may be generated using a remote plasma source coupled to the plasma processing system performing the etching process or a separate substrate processing system where it is not in situ.

The oxygen-containing plasma may be formed from O ₂ , CO, CO ₂ , NO, N ₂ O, or NO ₂ , or a combination of two or more thereof. The flow rate of the oxygen-containing gas is about 10 sccm (standard cubic centimeters per minute) to about 1000 sccm, for example, about 100 to 300 sccm. The chamber pressure can be from about 1 mTorr to about 1000 mTorr, and the desired chamber pressure is from about 50 mTorr to about 500 mTorr. The oxygen-containing plasma may further comprise an inert gas, an inert gas, N ₂ , H ₂ , or CN. The inventors believe that the use of oxygenated plasma promotes secondary layer formation in a mask layer having an increased oxygen concentration. The inventors expect that the treated mask layer can help reduce the LER in the mask layer in successive etching processes. For example, in the case of a germanium-containing mask layer, a "glass-like" (i.e., SiO _x ) secondary layer that is particularly resistant to the formation of LER can be formed.

In one example, a masking layer treatment by an oxygen-containing plasma is performed in a plasma processing system. The conditions of the treatment include: the flow rate of the oxygen-containing gas ranges from about 100 sccm to about 500 sccm; the chamber pressure is greater than or equal to about 100 mTorr; and the small or no RF bias power is applied to the lower electrode (on which the substrate is placed) Applying approximately 500 W of RF power to the upper electrode (or induction coil); and the processing time is approximately 10 seconds. In another example, the masking process performed by the oxygenated plasma is to use a displaced (or remote) plasma source, such as a microwave powered plasma source. Processing conditions include: a flow rate of the oxygen-containing electric gas ranging from about 100 sccm to about 500 sccm; a chamber pressure greater than or equal to about 100 mTorr; applying a small or no RF bias power to the lower electrode (on which the substrate is placed) The microwave power is approximately 1000 W; and the processing time is approximately 10 seconds.

The halogen-containing plasma may be from Cl ₂ , Br ₂ , F ₂ , HBr, HCl, HF, C ₂ H ₄ Br ₂ , ClF ₃ , NF ₃ , SiCl ₄ , SF ₆ , or both or more The combination is formed. The flow rate of the halogen-containing gas is about 10 sccm to about 1000 sccm, for example, about 100 to 300 sccm. The chamber pressure ranges from about 1 mTorr to about 1000 mTorr, with room pressures ranging from about 20 mTorr to about 500 mTorr, and more for chamber pressures from 20 mTorr to about 100 mTorr. The halogen-containing plasma further contains an inert gas, an inert gas, N ₂ , H ₂ , or CN. In addition, the halogen-containing plasma further contains an oxygen-containing gas. The inventors expect that exposure of the mask layer to a halogen-containing plasma lacking a high energy electron beam can passivate the surface layer of the mask layer, thereby helping to reduce LER formation in the mask layer in the subsequent etching process.

In one example, a masking layer treatment by a halogen-containing plasma is performed in a plasma processing system that performs an etching process. Processing conditions include: a flow rate of the halogen-containing gas of from about 100 sccm to about 500 sccm; a chamber pressure ranging from about 25 mTorr to about 50 mTorr; applying a small or no RF bias power to the lower electrode (on which the substrate is placed) Applying about 100 W to about 500 W of RF power at the upper electrode (or induction coil); and the processing time is about 10 seconds. In another example, the masking process by the halogen-containing plasma is performed using a displaced (or remote) plasma source, such as a microwave powered plasma source. Processing conditions include: a flow rate of the halogen-containing gas ranging from about 100 sccm to about 500 sccm; a chamber pressure greater than or equal to about 100 mTorr; applying a small or no RF bias power to the lower electrode (on which the substrate is placed); The microwave power is approximately 1000 W; and the processing time is approximately 10 seconds.

The inert gas plasma may be formed of an inert gas such as He, Ne, Ar, Xe, Kr or a combination of two or more thereof. The flow rate of the inert gas is about 10 sccm to about 1000 sccm, for example, about 100 to 300 sccm. The chamber pressure ranges from about 1 mTorr to about 1000 mTorr, and the desired chamber pressure is from about 50 mTorr to about 500 mTorr, more preferably for chamber pressures from about 50 mTorr to about 200 mTorr. The inventors believe that the use of an inert gas can promote the formation of a surface layer on a carbon-rich or "carbonized" mask layer (i.e., for example, depleting O and H). The "carbonized" surface layer can extend a few nanometers (nm) into the mask layer (eg, 1 to 10 nm) depending on the ion energy of the ions striking the mask layer. For example, ions with energies ranging from about 25 to about 50 eV should be able to penetrate from about 1 nm to about 2 nm. The inventors expect that this treated mask layer can help reduce the LER in the mask layer in successive etching processes.

In one example, the masking process by inert gas plasma is performed in a plasma processing system that performs an etching process. Processing conditions include: a flow rate of the inert gas ranging from about 100 sccm to about 300 sccm; a chamber pressure ranging from about 25 mTorr to about 50 mTorr; applying a small or no RF bias power to the lower electrode (on which the substrate is placed) Applying about 500 W to about 1000 W of RF power to the upper electrode (or induction coil); and the processing time is about 10 seconds.

According to another example, a protective layer is formed on the mask layer prior to performing the transfer of the pattern formed in the mask layer to the underlying film. The protective layer formed on the mask layer contains a layer of material that is consumed or partially consumed during the etching process, and thereby the mask layer can be protected early in the etching process. Alternatively, the protective layer formed on the mask layer can provide increased etch resistance during the etch process, particularly providing increased etch resistance during the early stages of the etch process.

The formation of the protective layer on the mask layer can be performed in a plasma processing system that performs an etching process, such as the plasma processing system shown in Figure 1, or the exposure can be performed in another different from the implementation of the plasma processing system. Executed in the substrate processing system. The plasma generation system that promotes plasma formation during etching can be used to form plasma in situ, or can be generated by a plasma processing system coupled to an etching process or a remote plasma processing of a separate substrate processing system. The system displaces the plasma.

When a protective layer is formed over the mask layer, a deposition gas plasma is used in which exposure of the mask layer to the deposition gas plasma results in a net deposition of material on the surface of the substrate. The formation of the protective layer on the mask layer may include exposing the mask layer to a deposition gas plasma, such as a hydrocarbon-containing plasma (ie, containing a C _x H _y plasma, where x and y are greater than or equal to An integer of 1), or a fluorocarbon plasma (containing C _x F _z plasma, where x and z are integers greater than or equal to 1), or a hydrofluorocarbon containing slurry (containing C _x H _y F _z plasma, where x, y, and z are integers greater than or equal to 1, or a combination of two or more thereof. The mask layer is treated with a deposition gas plasma in the absence of a destructive bond (eg, high energy electrons or high energy photons). C ₂ H ₄ , CH ₄ , C ₂ H ₂ , C ₂ H ₆ , C ₃ H ₄ , C ₃ H ₆ , C ₃ H ₈ , C ₄ H ₆ , C ₄ H may be used for the C _x H _y- containing plasma. _8. C ₄ H ₁₀ , C ₅ H ₈ , C ₅ H ₁₀ , C ₆ H ₆ , C ₆ H ₁₀ , C ₆ H ₁₂ , or a combination of two or more thereof. The C _x F _z- containing plasma may be formed by a combination of C ₂ F ₆ , CF ₄ , C ₃ F ₈ , C ₄ F ₈ , C ₅ F ₈ , C ₄ F ₆ , or a combination of two or more thereof. . The C _x H _y F _z containing plasma may be formed using CH ₃ F, C ₂ HF ₅ , CH ₂ F ₂ , or CHF ₃ or a combination of two or more thereof.

The conditions of the treatment are selected to form a hydrocarbon protective layer, or a fluorocarbon protective layer, or a combination thereof on the mask layer using the one or more deposition gases described above. The processing conditions should be chosen such that the pattern formed in the mask layer is not covered or "clamped". The protective layer can cover a flat plate. In addition, the protective layer may include some protrusions on the pattern, and may further include some coverage of the sidewalls of the mask layer pattern. For example, processing conditions should be selected to form ion-driven deposition plasmas with little or no sputtering (ie, low ion energy on the surface of the substrate) (ie, deposition of ionized species). ). The flow rate of the deposition gas is from about 10 sccm to about 1000 sccm, and the flow rate is desirably in the range of from about 100 sccm to about 300 sccm, for example about 200 sccm. The chamber pressure can range from about 1 mTorr to about 1000 mTorr, with a chamber pressure of from about 50 mTorr to about 500 mTorr, and a chamber pressure of from about 50 mTorr to about 200 mTorr. In addition, the deposition gas plasma further contains a diluent gas such as an inert gas. For example, the flow rate of the deposition gas ranges from about 1% to about 20% of the flow rate of the gas mixture, and the remainder includes the flow rate of the diluent gas. Further, for example, the flow rate of the deposition gas ranges from about 5% to about 10% of the gas mixture, and the remainder includes the flow rate of the diluent gas. Further, the deposition gas may also include H ₂ , O ₂ , CO, CO ₂ , NO, N ₂ O, NO ₂ , N ₂ , CN, or blunt gas, or a combination of two or more thereof. .

In one example, a deposition gas such as C ₄ F ₈ or C ₄ F ₆ with or without CF ₄ may be used in the deposition of CF (ie, C _X F _Z ) polymer. The processing conditions include: the flow rate of the diluent gas ranges from about 100 sccm to about 500 sccm; the flow rate of the deposition gas ranges from about 1% to about 20% of the flow rate of the dilution gas; and the chamber pressure ranges from about 50 mTorr to about 200 mTorr; apply small or no RF bias power to the lower electrode (on which the substrate is placed); apply approximately 500 W to approximately 1500 W of RF power to the upper electrode (or induction coil); and processing time is sufficient to form a thickness Films ranging from about a few nm to about 200 nm.

In another example, when the CH (ie, C _x H _y ) polymer is deposited, the processing conditions include: the flow rate of the diluent gas ranges from about 100 sccm to about 500 sccm; and the flow rate of the deposition gas is the range of the dilution gas flow rate. From about 1% to about 20%; chamber pressure in the range of about 50 mTorr to about 200 mTorr; applying little or no RF bias power to the lower electrode (on which the substrate is placed); applying about 500 W to about 1500 W The RF power is applied to the upper electrode (or induction coil); and the processing time is sufficient to form a film having a thickness ranging from about several nm to about 200 nm.

Since the inventors believe that the CF film provides relatively higher etching resistance in the etching process, the thickness of the CH thin film protective layer is required to be larger than that of the CF film. The minimum thickness of the protective layer should be selected according to the penetration thickness of the charged species in the etching process. For example, a film having a thickness of about 50 nm would require an electron beam of 1 keV, and a film having a thickness of about 100 nm would require an electron beam of 1.5 keV.

In yet another example, the formation of the protective layer on the mask layer includes immersing the mask layer in an alcohol, such as methanol or ethanol.

The inventors expect that the formation of a protective layer on the mask layer using a hydrocarbon-based chemical or a hydrofluoro-based compound increases the hydrogen content of the surface of the mask layer, thereby modulating high-energy electrons at the beginning of the etching process. By mitigating damage caused by high energy electrons at the beginning of the etching process, the protective layer can help reduce the LER in the mask layer in the subsequent etching process. Furthermore, the inventors expect that the formation of a protective layer on the mask layer using a hydrocarbon-based chemical or a hydrofluoro-based compound can promote the formation of a polymer film that provides additional etch resistance during the etching process. Increasing the etch selectivity of the modified mask layer can help reduce the LER in the mask layer during the subsequent etching process.

According to still another embodiment, the mask layer is treated by an electron beam in the absence of an atomic state of the halogen species (i.e., F, Cl, Br, etc.) prior to performing the etching process. The inventors desire to expose the mask layer to "cure" or harden the surface layer of the mask layer in the electron beam of the halogen species lacking atomic state, thus making the mask layer less prone to form LER during the etching process.

Exposing the mask layer to the electron beam can be performed in a plasma processing system that performs an etching process, such as the plasma processing system shown in FIG. 1, or the exposing step can also be performed in another plasma processing system different from the etching process. Implemented in a substrate processing system. For example, the electron beam source can be coupled to a plasma processing system (for etching processing purposes) or other substrate processing system, and can be used to generate an electron beam that processes the mask layer.

Alternatively, for example, the electron beam can be generated in a plasma processing system by coupling a direct current (DC) power source to an electrode in a plasma processing system (as shown in Figures 1 and 2 and Figures 7 through 7 below). And produce plasma. Referring to FIG. 1, a pre-etched plasma can be formed by coupling an alternating current (AC) power source, such as a radio frequency (RF) power source, to the first electrode 120, or the second electrode 172, or both. A DC power source is coupled to the second electrode 172 to form an electron beam.

Using a pre-etched electron beam, the surface layer of the mask layer can be treated prior to the etching process. The processing depth ranges from about 1 nm to about 100 nm, and the desired depth ranges from about 5 nm to about 50 nm, such as 10 nm. This penetration depth can be achieved with an electron beam having an energy ranging from about 500 eV to about 1.5 keV. The energy of the pre-etched electron beam can be as high as 1.5 keV, and the desired range is from about 200 eV to about 1.5 keV, such as 500 eV. The pre-etched electron beam exposure can be selected to produce a dose ranging from about 10 ¹⁴ electrons per square centimeter (cm ^-2 ) to about 10 ¹⁶ electron cm ^-2 .

In one example, the pre-etched electron beam is formed in the plasma processing system of FIG. Processing conditions include: a flow rate of the inert gas ranging from about 100 sccm to about 300 sccm; a chamber pressure ranging from about 20 mTorr to about 100 mTorr; applying a small or no RF bias power to the lower electrode (on which the substrate is placed) Applying RF power ranging from approximately 500 W to approximately 1000 W to the upper electrode (or induction coil); applying a DC voltage ranging from approximately -500 V to approximately -1000 V to the upper electrode; and processing time is approximately 10 seconds .

The pre-etched plasma may be formed with an inert gas such as an inert gas (i.e., He, Ne, Ar, Xe, Kr). In addition, the pre-etched plasma further contains CHF ₃ . Appears in the plasma, CHF ₃ from the solution has a tendency to produce CF ₂ (e.g., to form a polymer radical) and (ionization connection) of the HF. The free radicals forming the polymer are beneficial for the treatment of the mask layer by providing a sacrificial layer as described above. However, it is important to process the mask layer in order to reduce the LER problem described above. Additional gases (other than the inert gas forming the plasma) should be selected to minimize the absence of atomic halogen species in the plasma.

The mask layer can be treated by pre-etching the electron beam and pre-etching the plasma for a predetermined period of time, such as 10 seconds. Further, the electron beam is pre-etched for about 1 to 30 seconds, and the desired one is to perform pre-etching of the electron beam for about 2 to 20 seconds, for example, about 10 seconds. After this treatment, an etching plasma is used to form an etching plasma, an electron beam is etched, and an etching process is performed by exposing the substrate and the processed mask layer to etch the electron beam and etching the plasma. The energy of the pre-etched electron beam can be selected to be approximately equal to the energy of the etched electron beam, or the energy of the pre-etched electron beam can be selected to be less than the energy of the etched electron beam. For example, the energy of the pre-etched electron beam can be about 500 eV, and the energy of the etched electron beam can be about 1500 eV. The energy of the electron beam (or the voltage applied to the second electrode 172 in Fig. 1) may be increased in a stepwise manner at the time of the pre-etching treatment, or may be ramped up at the time of the pre-etching treatment. Further, the energy of the electron beam (or the voltage applied to the second electrode 172 in FIG. 1) may be pulsed. For example, the voltage applied to the second electrode 172 can be pulsed between about 0 V and about -1500 V, and the voltage can be pulsed between about -100 V and about -1500 V, or more preferably The voltage can be pulsed between approximately -500 V and approximately -1500 V.

The pre-etched electron beam treatment of the mask layer may also be treated with an oxygen-containing plasma, or a halogen-containing plasma, or an inert gas plasma as a mask layer. Furthermore, a pre-etched electron beam treatment of the mask layer can also be achieved prior to the formation of the protective layer on the mask layer. For example, the pre-processed electron beam can prepare the surface of the mask layer for the growth of the polymer when the protective layer is formed.

These embodiments can be used in any plasma processing system of the type shown below.

Referring to Figure 2, in accordance with an embodiment of the present invention, a plasma processing system for treating a mask layer prior to etching a bottom layer with a ballistic electron beam reinforced plasma is shown. The plasma processing system 1 comprises a plasma processing chamber 8 for promoting plasma formation, a substrate holder 2, is coupled to the plasma processing chamber 8 and is used to support the substrate 3, the electrode 9, is coupled to the plasma processing chamber 8 and is used for contacting electricity. Pulp. In addition, the plasma processing system 1 includes an AC power system 4 coupled to the plasma processing chamber 8 and coupled to at least one AC signal to the substrate holder 2, or the electrode 9, or both for forming a plasma. The DC power system 5 is coupled to the plasma processing chamber 8 and couples a DC voltage to the electrode 9 in order to form a ballistic electron beam through the plasma.

Still further, the plasma processing system 1 includes a process gas distribution system 6, coupled to the plasma processing chamber 8, and used to introduce the gases of any of the above embodiments to the plasma processing chamber 8. Still further, the plasma processing system 1 includes a vacuum pumping system (not shown) coupled to the plasma processing chamber 8 and used to remove gas from the processing chamber.

Optionally, the plasma processing system 1 further comprises a controller 7 coupled to the plasma processing chamber 8, the substrate holder 2, the AC power system 4, the DC power system 5, and the process gas distribution system 6, and for the purpose of plasma Processing of the processing substrate 3 is performed in the processing chamber 8, and data is exchanged with these components. The plasma processing system 1 can facilitate the processing of the mask layer on the substrate 3, or the etching process of the substrate 3, or both.

Figure 3 shows a plasma processing system in accordance with another embodiment. The plasma processing system 1a includes a plasma processing chamber 10, a substrate holder 20 on which the substrate 25 to be processed is fixed, and a vacuum pumping system 30. The substrate 25 may be a semiconductor substrate, a wafer, or a liquid crystal display. The plasma processing chamber 10 can promote plasma generation of the processing region 15 adjacent the surface of the substrate 25. An ionizable gas or gas mixture is introduced through a gas injection system (not shown) and the process pressure is adjusted. For example, a control mechanism (not shown) can be used to adjust the vacuum pump system 30. The plasma can be used to make materials that are particularly useful in the processing of predetermined materials, and/or to assist in removing material from the exposed surfaces of the substrate 25. The plasma processing system 1a can be used to process substrates of any size, such as a 200 mm substrate, a 300 mm substrate, or a larger substrate.

The substrate 25 is fixed to the substrate holder 20 by an electronic steady state clamping system. Further, the substrate holder 20 further includes a cooling system containing a circulating liquid stream that receives heat from the substrate holder 20 upon cooling and converts heat to a heat exchange system (not shown), or converts from a heat exchange system upon heating. Heat to liquid heating system. Further, gas can be transported to the rear side of the substrate 25 through the rear side gas system to improve air gap heat conduction between the substrate 25 and the substrate holder 20. Such a system can be used when the substrate requires temperature control at elevated or reduced temperatures. For example, the backside gas system can include a dual zone gas distribution system in which the backside gas (eg, helium) pressure can be independently varied between the center and the edge of the substrate 25. In other embodiments, a heating/cooling element, such as a resistive heating element or an electrothermal heater/cooler, may be included in the substrate support 20 while the chamber walls of the plasma processing chamber 10 and any other plasma treatments Elements in system 1a can also be included in the plasma processing system 1a.

In the embodiment shown in FIG. 3, substrate support 20 includes an electrode through which RF power is coupled to the processing plasma within processing region 15. For example, RF power of RF generator 40 can be transferred to substrate holder 20 via an optional impedance matching network 42 coupled to substrate holder 20, while substrate holder 20 is electrically biased to the RF voltage. The RF bias can be used to heat electrons to form and maintain plasma, or to affect the ion energy distribution function therein, or both. In this composition, the system can operate as a reactive ion etching (RIE) reactor where the processing chamber can act as a ground plane. The RF bias frequency range of the electrical type is approximately from 0.1 MHz to 100 MHz. RF systems used in plasma processing are well known to those skilled in the art.

Further, in order to influence the spatial distribution of the electron beam flux of the substrate 25, the amplitude of the RF power source coupled to the substrate holder 20 can be modulated. Additional details can be found in U.S. Patent Application Serial No. 11/XXXXXX, filed on Jul. 31, 2006, entitled,,,,,,,,,,,,,,, The entire contents of this are hereby incorporated by reference.

Still further, the impedance matching network 42 can improve the conversion of RF energy into the plasma in the plasma processing chamber 10 by reducing the reflected energy. Matching network topologies (e.g., L-type, π-type, T-type, etc.) and automated control methods are well known to those skilled in the art.

Still referring to FIG. 3, the plasma processing system 1a further includes a direct current (DC) power supply 50 coupled to the upper electrode 52 facing the substrate 25. The upper electrode 52 may include an electrode plate. The electrode plate may comprise a ruthenium containing electrode plate. Furthermore, the electrode plates may comprise doped yttrium electrode plates. The DC power supply can include a variable DC power supply. Additionally, the DC power supply can include a bipolar DC power supply. The DC power supply 50 can further include a system for performing at least one of monitoring, adjusting, or controlling the polarity, current, voltage, and on/off state of the DC power supply 50. Once the plasma is formed, the DC power supply 50 promotes the formation of a ballistic electron beam. An electrical filter can be used to decouple the RF power from the DC power supply 50.

For example, the DC voltage applied to electrode 52 by DC power supply 50 ranges from approximately -2000 volts (V) to approximately 1000 V. The desired value is that the absolute value of the DC voltage is equal to or greater than about 100 V, and more preferably, the absolute value of the DC voltage is equal to or greater than about 500 V. In addition, the desired voltage is negative for the DC voltage. Further, the DC voltage of the negative voltage has an absolute value larger than the self-bias generated from the surface of the upper electrode 52. The surface facing the electrode 52 above the substrate holder 20 may be included in the ruthenium containing material.

The vacuum pump system 30 can include a turbo molecular vacuum pump (TMP) with a pump speed of up to 5000 liters per second (and greater), and a gate valve that regulates chamber pressure. In a conventional plasma processing apparatus for dry plasma etching, TMP of 1000 to 3000 liters per second can be used. TMP can be used at lower pressures, typically less than 50 mTorr. At high pressures (ie greater than 100 mTorr), mechanical thrusters and dry rough pumps can be used. Still further, means (not shown) for monitoring chamber pressure may be coupled to the plasma processing chamber 10. The pressure measuring device can be, for example, a Type 628B Baratron absolute capacitance manometer commercially available from MKS Instruments, Inc. (Andover, MA).

Still referring to FIG. 3, the plasma processing system 1a further includes a controller 90 including a microprocessor, a memory, and a digital I/O port. The controller 90 is capable of generating an input sufficient to communicate and activate the plasma processing system 1a. The control voltage of the output of the slurry processing system 1a. Additionally, controller 90 can be coupled to RF generator 40, impedance matching network 42, DC power supply 50, gas injection system (not shown), vacuum pump system 30, rear side gas delivery system (not shown), substrate / Substrate support temperature measurement system (not shown), and / or electronic steady state clamp system (not shown), and exchange information with it. In order to implement the method of etching the film, the program stored in the memory can activate the components of the plasma processing system described above in accordance with the teachings of the process. One case the controller 90 from Dell Corporation, Austin, Texas obtainable DELL PRECISION WOPKSTATION 610 ^TM.

The controller 90 can be located at the relatively proximal end of the plasma processing system 1a or can be located at the opposite distal end of the plasma processing system 1a via a network or internal network. Thus, controller 90 can exchange data with plasma processing system 1a using at least one of a direct link, an internal network, or a network. Controller 90 can be coupled to the internal network of the client (i.e., device manufacturer, etc.) or to the vendor (and device manufacturer). Further, another computer (also a controller, a server, etc.) can access the controller 90 to exchange data through at least one of a direct connection, an internal network, or a network.

In the embodiment illustrated in Figure 4, the plasma processing system 1b is similar to the embodiment illustrated in Figures 2 or 3, and in order to potentially increase the plasma density and/or improve the uniformity of the plasma treatment, except In addition to the components described in FIG. 2, a stationary portion, or a mechanical or electrical rotating magnetic field system 60 is included. Additionally, controller 90 may be coupled to magnetic field system 60 in order to adjust rotational speed and field strength. The design and application of rotating magnetic fields are well known to those skilled in the art.

In the embodiment illustrated in FIG. 5, the plasma processing system 1c is similar to the embodiment illustrated in FIGS. 2 and 3, and further includes an RF generator that couples RF power to the upper electrode 52 via an optional impedance matching network 72. 70. Typical RF power supply frequencies for the upper electrode 52 range from about 0.1 MHz to about 200 MHz. In addition, typical application power supply frequencies for the substrate support 2O range from about 0.1 MHz to about 100 MHz. For example, the RF frequency coupled to the upper electrode 52 can be relatively higher than the RF frequency coupled to the substrate support 20. Further, the RF power generated by the RF generator 70 to the upper electrode 52 may be amplitude-modulated, or the RF power generated by the RF generator 40 to the substrate holder 20 may be amplitude-modulated or both RF power supplies. However, the amplitude is modulated. As desired, the RF power supply at a higher RF frequency is amplitude modulated. Additionally, in order to control the application of RF power to the upper electrode 70, the controller 90 is coupled to the RF generator 70 and the impedance matching network 72. The design and application of the upper electrode are well known to those skilled in the art.

Still referring to FIG. 5, the DC power supply 50 can be coupled directly to the upper electrode 52, or can also be coupled to an RF transmission line extending from the output of the impedance matching network 72 to connect to the upper electrode 52. An electrical filter can be used to decouple the RF power from the DC power supply.

In the embodiment shown in FIG. 6, the plasma processing system 1d can be similar to the embodiment shown in FIGS. 2, 3, and 4, and can further include coupling RF power through the selected impedance matcher 84 via the RF generator 82. Induction coil 80. The RF power source is inductively coupled to the processing region 15 from the induction coil 80 through a dielectric window (not shown). The RF frequency typically applied to the induction coil 80 ranges from about 10 MHz to about 100 MHz. Similarly, power supply frequencies typically applied to substrate support 20 range from about 0.1 MHz to about 100 MHz. Additionally, a slotted Faraday shield (not shown) can be used to reduce capacitive coupling between the induction coil 80 and the plasma. Additionally, controller 90 is coupled to RF generator 82 and impedance matching network 84 in order to control the power applied to induction coil 80. In an alternative embodiment, the induction coil 80 can be a "spigot-shaped" coil or a "pancake-like" coil that is connected to the processing region 15 from above, such as in a transformer coupled plasma (TCP) reactor. The design and application of inductively coupled plasma (ICP) sources, or plasma coupled transformer (TCP) sources are well known to those skilled in the art.

Alternatively, the plasma can be formed using an electron cyclotron oscillating oscillator (ECR). In yet another embodiment, the plasma is formed by emitting a Helicon wave. In yet another embodiment, the plasma is formed from a propagating surface wave. Each of the above plasma sources is well known to those skilled in the art.

In the embodiment shown in FIG. 7, the plasma processing system 1e can, for example, be similar to the embodiment shown in Figures 3, 4, and 5, and can further include a second RF generator 44, through another optional The impedance matching network 46 couples the RF power to the substrate holder 20. Whether it is the first RF generator 40 or the second RF generator 44 or both, the RF power supply typically applied to the substrate holding 20 ranges from about 0.1 MHz to about 200 MHz. The RF frequency of the second RF generator 44 may be relatively greater than the frequency of the first RF generator 40. Further, the RF power source applied from the RF generator 40 to the substrate holder 20 may be amplitude-modulated, or the RF power source applied from the RF generator 44 to the substrate holder 20 may be amplitude-modulated or two The RF power supply is amplitude modulated. As desired, the RF power supply at a higher RF frequency is amplitude modulated. Further, to control the RF power applied to the substrate holder 20, the controller 90 is coupled to the second RF generator 44 and the impedance matching circuit 46. The design and application of RF systems for substrate holders are well known to those skilled in the art.

In the following discussion, a method of etching a film using a plasma processing system having a ballistic electron beam is presented. For example, the plasma processing system can include various components, such as the components of Figures 1 through 7, and combinations thereof.

Figure 8 shows a flow chart of a method of etching a thin film in accordance with an embodiment of the present invention. Step 500 begins with processing 510 of the mask layer, the mask layer having a pattern formed therein and positioned over a film on the substrate.

The mask layer can be treated with any of the foregoing embodiments. For example, the treatment of the mask layer includes exposing the mask layer to an oxygen-containing plasma, or a halogen-containing plasma, or an inert gas plasma, or a combination of two or more thereof. Alternatively, the processing of the mask layer can include forming a protective layer over the mask layer. Alternatively or additionally, the processing of the mask layer can include exposing the mask layer to an electron beam of a halogen species lacking an atomic state. Alternatively or additionally, the processing of the mask layer comprises a combination of any of the above.

In 520, in order to transfer the pattern formed in the mask layer to the underlying film, the substrate having the treated mask layer is exposed to a dry etching plasma assisted by a high energy (ballistic) electron beam, and simultaneously Reduce pattern anomalies, such as LER. In a plasma processing system, (process) plasma is formed from a process gas by coupling a power source to a process gas (to cause ionization and dissociation of process gas molecules). By coupling a DC power source to the electrodes in the plasma processing system and by forming a plasma, a high energy (ballistic) electron beam having an energy level dependent on the magnitude of the DC voltage applied to the electrodes can be fabricated.

The DC power source is coupled to the plasma processing system. For example, the DC voltage applied to the plasma processing system by the DC power supply ranges from about one 2,000 volts (V) to about 1000 volts. The desired value is that the absolute value of the DC voltage is equal to or greater than approximately 100 V. More preferably, the absolute value of the DC voltage is equal to or greater than approximately 500 V. Further, as desired, the DC voltage has a negative polarity. Further, the desired DC voltage is a negative voltage having an absolute value greater than the self-bias voltage generated by the electrode surface of the plasma processing system.

Even though some specific embodiments have been described in detail above, it will be apparent to those skilled in the art that many modifications can be made without departing from the novel teachings and advantages of the invention. Accordingly, all modifications are intended to be included within the scope of the present invention.

1. . . Plasma processing system

1a. . . Plasma processing system

1b. . . Plasma processing system

1c. . . Plasma processing system

1d. . . Plasma processing system

1e. . . Plasma processing system

2. . . Substrate support

3. . . Substrate

4. . . AC power system

5. . . DC power system

6. . . Gas distribution system

7. . . Controller

8. . . Plasma processing room

9. . . electrode

10. . . Plasma processing room

15. . . Plasma processing area

20. . . Substrate support

25. . . Substrate

30. . . Vacuum pump system

40. . . RF generator

42. . . Impedance matching network

44. . . Second RF generator

46. . . Impedance matching network

50. . . DC power supply

52. . . Upper electrode

60. . . Magnetic field system

70. . . RF generator

72. . . Impedance matching network

80. . . Induction coil

82. . . RF generator

84. . . Impedance matching network

90. . . Controller

120. . . First electrode

125. . . Substrate

130. . . Plasma

135. . . Ballistic electron beam

140. . . First RF generator

150. . . DC power supply

170. . . Second RF generator

172. . . Second electrode

500. . . step

510. . . Processing a mask layer on the substrate

520. . . After processing the mask layer, the substrate is etched using electron beam-assisted electricity in the future.

In the drawings: Figure 1 is a schematic representation of a plasma processing system in accordance with an embodiment of the present invention; Figure 2 is a schematic illustration of a plasma processing system in accordance with another embodiment of the present invention; A schematic view of a plasma processing system of another embodiment; FIG. 4 shows a schematic view of a plasma processing system according to another embodiment of the present invention; and FIG. 5 shows a plasma processing system according to another embodiment of the present invention. FIG. 6 is a schematic view showing a plasma processing system according to another embodiment of the present invention; FIG. 7 is a schematic view showing a plasma processing system according to another embodiment of the present invention; and FIG. A substrate processing method for a plasma according to an embodiment of the present invention.

1. . . Plasma processing system

2. . . Substrate support

3. . . Substrate

4. . . AC power system

5. . . DC power system

6. . . Gas distribution system

7. . . Controller

8. . . Plasma processing room

9. . . electrode

Claims (67)

An etching method for etching a film formed on a substrate and having a patterned mask layer thereon, the etching method comprising: a mask layer processing step by exposing the mask layer to an oxygen-containing electricity Treating the mask layer with a slurry, a halogen-containing plasma, or an inert gas plasma, or a combination of two or more thereof, the mask layer processing step is performed without exposing the mask layer a state in which a direct current (DC) power source accelerates an electron beam; and an etching step, after the mask layer processing step, etching the film in order to transfer a pattern of the mask layer to the film, the etching step comprising: a slurry forming step of forming a plasma from a processing gas in a plasma processing system; a DC power coupling step coupling a direct current (DC) power source to an electrode in the plasma processing system to form in the plasma processing system An electron beam assists the plasma in the etching; and a substrate exposure step exposing the substrate to the plasma and the electron beam. The etching method of claim 1, wherein the mask layer processing step comprises exposing the mask layer to O ₂ , CO, CO ₂ , NO, N ₂ O, NO ₂ , or both or Among the plasma formed by more. The etching method of claim 2, wherein the mask layer processing step further comprises exposing the mask layer to N ₂ , H ₂ , CN, blunt gas, or a combination of two or more thereof. in. The etching method of claim 2, wherein the mask layer processing step further comprises exposing the mask layer to a halogen-containing gas. The etching method of claim 1, wherein the mask layer processing step comprises exposing the mask layer to using Cl ₂ , Br ₂ , F ₂ , HBr, HCl, HF, C ₂ H ₄ Br ₂ , SiCl ₄ , NF ₃ , SF ₆ , or a combination of two or more of the plasma formed. The etching method of claim 5, wherein the mask layer processing step further comprises exposing the mask layer to N ₂ , H ₂ , CN, blunt gas, or a combination of two or more thereof. in. The etching method of claim 5, wherein the mask layer processing step further comprises exposing the mask layer to an oxygen-containing gas. The etching method of claim 1, wherein the mask layer processing step comprises exposing the mask layer to a plasma formed in the plasma processing system, the plasma being coupled to the AC power source The electrode is formed either by coupling to another electrode other than the electrode, or to a substrate holder, or to a combination of two or more of the foregoing. The etching method of claim 8, wherein the mask layer processing step comprises exposing the mask layer to a low power plasma formed using a power level lower than or equal to 500 W. The etching method of claim 1, wherein the masking layer processing step comprises exposing the mask layer to a plasma formed in a remote plasma source coupled to the plasma processing system. The etching method of claim 1, wherein the DC power coupling step comprises coupling of a DC power source having a voltage ranging from about -2000V to about 1000V. The etching method of claim 1, wherein the DC power coupling step A DC power source having a negative polarity is coupled, wherein the absolute value of the DC power source is greater than or equal to about 500V. The etching method of claim 1, wherein the DC power coupling step comprises coupling a DC power source to an upper electrode facing the substrate disposed on a substrate holder. The etching method of claim 13, wherein the plasma forming step comprises a radio frequency (RF) power coupling step of coupling an RF power source to the electrode or to another electrode other than the electrode, or It is coupled to the substrate holder or to a combination of two or more of the above. The etching method of claim 14, wherein the radio frequency (RF) power coupling step comprises coupling the first RF power to the upper electrode at a first RF frequency, and a second lower than the first RF frequency. The RF frequency couples a second RF power source to the substrate holder. The etching method of claim 14, further comprising: modulating the amplitude of the RF power source to adjust a spatial distribution of the electron beam flux of the electron beam. The etching method of claim 1, wherein the mask layer is exposed to the oxygen-containing plasma or the halogen-containing plasma before the etching step to form the mask during the etching step. The thickness of the line edge in the layer is reduced. The etching method of claim 1, wherein the mask layer processing step is performed for a predetermined time to prevent the patterned mask from forming a line edge roughness in the mask layer during the etching. The etching method of claim 1, wherein the mask layer processing step comprises exposing the mask layer to a combination of He, Ne, Ar, Xe, Kr, or a combination of two or more thereof. In the plasma. The etching method of claim 1, further comprising: pre-processing the mask with a pre-etched electron beam of a halogen species lacking an atomic state in order to modify the mask layer before the mask layer processing step Cover layer. The etching method of claim 1, wherein the mask layer processing step comprises coupling a first RF power source to the upper electrode at a first RF frequency, and a second RF lower than the first RF frequency. A second RF power source is coupled to the substrate support, and wherein the second RF power source is less than or equal to about 100W. The etching method of claim 21, wherein the second RF power source is substantially zero. An etching method for etching a film formed on a substrate and having a patterned mask layer thereon, the etching method comprising: a substrate setting step of disposing a substrate for forming a plasma and a ballistic electron a substrate support in a plasma processing system; a mask layer processing step by exposing the mask layer in the plasma processing system to an oxygen-containing plasma, a halogen-containing plasma, or Treating the mask layer with an inert gas plasma, or a combination of two or more thereof, and not forming a ballistic electron beam, the mask layer processing step is performed when the mask layer is not exposed to The DC power source accelerates the state of the electron beam; and the plasma and ballistic electron beam forming step, after the mask layer processing step, in order to etch the film and transfer a pattern of the patterned mask to the film, A plasma and a ballistic electron beam are formed in the slurry processing system. A plasma processing system for etching a substrate, comprising: a processing chamber; a gas supply system for supplying a gas into the processing chamber; a substrate holder coupled to the processing chamber and supporting the substrate An electrode disposed inside the processing chamber; an AC power system coupled to the processing chamber, and coupling at least one AC signal to the substrate holder for forming a plasma in the processing chamber, or To the electrode or both; a DC power system coupled to the processing chamber and coupling a DC voltage to the electrode for forming a ballistic electron beam through the plasma; and a controller, Used to control the gas supply system, the AC power system, and the DC power system to perform the following steps: a mask layer processing step by exposing the mask layer in the plasma processing system to an oxygen-containing plasma Treating the mask layer with a halogen-containing plasma, or an inert gas plasma, or a combination of two or more thereof, and not forming a ballistic electron beam, the mask layer processing step is performed The mask layer is not exposed to The flow source accelerates the state of the electron beam; and the plasma and ballistic electron beam forming step, after the mask layer processing step, in order to etch the film and transfer a pattern of the patterned mask to the film, A plasma and a ballistic electron beam are formed in the slurry processing system. An etching method for etching a film formed on a substrate and having a patterned mask layer thereon, the etching method comprising: a protective layer forming step of forming a protective layer on the mask layer to protect the mask a cover layer, the protective layer forming step is performed in a state in which the protective layer is not exposed to a DC power source to accelerate an electron beam; and a thin film etching step, after the protective layer forming step, etching the thin film to one of the mask layers Transferring the pattern to the film; the film etching step includes: a plasma forming step of forming a process gas in a plasma processing system a plasma; direct current (DC) power coupling step of coupling a direct current source to one of the electrodes of the plasma processing system to form an electron beam in the plasma processing system to assist the plasma during the etching; And a substrate exposure step of exposing the substrate to the plasma and the electron beam. The etching method of claim 25, wherein the protective layer forming step comprises exposing the substrate to a deposition gas plasma. The etching method of claim 26, wherein the protective layer forming step comprises exposing the mask layer to a hydrocarbon-containing plasma, a fluorocarbon plasma, a fluorocarbon-containing plasma, Or a combination of two or more. The etching method of claim 26, wherein the protective layer forming step comprises exposing the mask layer to C ₂ H ₄ , CH ₄ , C ₂ H ₂ , C ₂ H ₆ , C ₃ H ₄ , C ₃ H ₆ , C ₃ H ₈ , C ₄ H ₆ , C ₄ H ₈ , C ₄ H ₁₀ , C ₅ H ₈ , C ₅ H ₁₀ , C ₆ H ₆ , C ₆ H ₁₀ , C ₆ H ₁₂ , C ₂ F ₆ , CF ₄ , C ₃ F ₈ , C ₄ F ₈ , C ₅ F ₈ , C ₄ F ₆ , CH ₂ F ₂ , CHF ₃ , CH ₃ F, C ₂ HF ₅ , or both Among the plasma formed by more. The etching method of claim 28, wherein the protective layer forming step further comprises exposing the mask layer to H ₂ , O ₂ , CO, CO ₂ , NO, N ₂ O, NO ₂ , N ₂ , CN , blunt gas or a composition of two or more of them. The etching method of claim 26, wherein the protective layer forming step comprises immersing the mask layer in an alcohol. The etching method of claim 26, wherein the protective layer forming step comprises immersing the mask layer in ethanol, or methanol, or both. The etching method of claim 26, wherein the protective layer forming step comprises exposing the mask layer to a plasma formed in the plasma processing system, the plasma being coupled to the AC power source The electrode is formed either by coupling to another electrode other than the electrode, or to a substrate holder, or to a combination of two or more of the foregoing. The etching method of claim 32, wherein exposing the mask layer to the plasma comprises exposing the mask layer to a low voltage formed by using a power source having a power level greater than or equal to about 500 W. Power plasma. The etching method of claim 26, wherein exposing the mask layer to the plasma comprises exposing the mask layer to electricity formed in a remote plasma source coupled to the plasma processing system. In the pulp. The etching method of claim 25, wherein the direct current (DC) power coupling step comprises coupling of a DC power source having a voltage ranging from about -2000V to about 1000V. The etching method of claim 25, wherein the direct current (DC) power coupling step comprises coupling of a DC power source having a negative polarity, wherein the absolute value of the DC power source is greater than or equal to about 500V. The etching method of claim 25, wherein the step of coupling the direct current (DC) power source to the electrode comprises coupling a DC power source to an upper electrode of the substrate facing a substrate holder. The etching method of claim 37, wherein the plasma forming step comprises a radio frequency (RF) power coupling step of coupling a radio frequency (RF) power source to the electrode or to another electrode other than the electrode, Or to the substrate support, Or to a combination of two or more of the above. The etching method of claim 38, wherein the radio frequency (RF) power coupling step comprises coupling a first RF power source to the upper electrode at a first RF frequency, and lowering the first RF frequency The second RF frequency couples a second RF power source to the substrate holder. The etching method of claim 38, further comprising: modulating the amplitude of the RF power source to adjust a spatial distribution of the electron beam flux of the electron beam. The etching method of claim 25, wherein the step of forming the protective layer on the mask layer before the etching reduces the thickness of the line edge in the mask layer during etching. The etching method of claim 25, wherein the protective layer forming step comprises: coupling a first RF power source to the upper electrode at a first RF frequency, and second to a second one lower than the first RF frequency The RF frequency couples a second RF power source to the substrate holder to form a deposition plasma, and wherein the first RF power source is greater than or equal to about 500 W, and the second RF power source is less than or equal to 100 W. The etching method of claim 42, wherein the second RF power source is substantially zero. An etching method for etching a film formed on a substrate and having a patterned mask layer thereon, the etching method comprising: forming a protective layer on the patterned mask layer, the protective layer having a ballistic electron beam assisted plasma etching process for protecting a predetermined thickness of the mask layer, the forming step being performed by the protective layer not being exposed to a DC power source for accelerating electrons a state of the beam; and after the forming of the protective layer, the ballistic electron beam-assisted plasma etching process is performed on the substrate in order to etch the film and transfer a pattern of the mask to the film, wherein the predetermined The thickness ranges from about 1 nm to about 200 nm. The etching method of claim 44, wherein the predetermined thickness ranges from about 50 nm to about 100 nm. A plasma processing system for etching a substrate, the plasma processing system comprising: a processing chamber; a gas supply system for supplying a gas into the processing chamber; and a substrate holder coupled to the processing chamber And for supporting the substrate; an electrode disposed inside the processing chamber; an AC power system coupled to the processing chamber and configured to couple at least one AC signal to the substrate holder, or the electrode, or Both to form a plasma in the processing chamber; a DC power system coupled to the processing chamber and configured to couple a DC voltage to the electrode to form a ballistic electron beam through the plasma; and a controller for controlling the gas supply system, the AC power system, and the DC power system to perform the steps of: forming a protective layer over the mask layer to protect the mask layer, the forming step is performed After the protective layer is not exposed to the DC power source to accelerate the electron beam; and after the forming the protective layer, a plasma and a ballistic electron beam are formed in the plasma processing system to etch the film and transfer the pattern cover One pattern to the film. An etching method for etching on a substrate and having a pattern thereon Forming a film of one of the mask layers, the etching method comprising: forming a pattern on the mask layer; a mask layer processing step, in order to modify the patterned mask layer, to remove a halogen species in an atomic state Pre-etching the first electron beam to process the patterned mask layer, the pre-etched first electron beam is formed by coupling a negative DC power source to an electrode in a plasma processing system; and an etching step in the mask After the cap layer processing step, in order to transfer a pattern of the mask to the film, the film is etched in the plasma processing system, the etching step comprising: forming an etch plasma from an etching gas; The plasma processing system couples a direct current (DC) power source to an electrode to form a second ballistic electron beam to assist the etching plasma during the etching; and expose the substrate to the etching plasma and the second ballistic electron In the bundle. The etching method of claim 47, wherein the mask layer processing step comprises: disposing the substrate in the plasma processing system, and processing the mask by using an electron beam source coupled to the plasma processing system Floor. The etching method of claim 47, wherein the mask layer processing step comprises: disposing the substrate in another substrate processing system other than the plasma processing system, and using an electron coupled to the substrate processing system The beam source processes the mask layer. The etching method of claim 47, wherein the mask layer processing step comprises: a substrate arranging step of disposing the substrate on one of the substrate holders of the plasma processing system; and etching the plasma forming step in advance, In the plasma processing system, a pre-etched plasma is formed from a pre-etched gas; Pre-etching an electron beam forming step of coupling a DC power source to the electrode in the plasma processing system to form the pre-etched electron beam; and a substrate exposing step of exposing the substrate to the pre-etched plasma and the pre-etched electron beam in. The etching method of claim 50, wherein the pre-etching plasma forming step comprises forming the pre-etched plasma from one or more inert gases. The patentable scope of application of the etching method of 51, wherein the forming step comprises plasma etching in advance of the pre-formed from a plasma etch or more of an inert gas and a mixture of CHF _3. The etching method of claim 50, wherein the pre-etching electron beam forming step comprises coupling a DC power source to an upper electrode of the substrate facing the substrate holder. The etching method of claim 50, wherein the pre-etched electron beam forming step comprises coupling of a DC power source having a negative polarity, wherein the absolute value of the DC power source is greater than or equal to about 500V. The etching method of claim 50, wherein the pre-etching plasma forming step comprises coupling a radio frequency (RF) power source to the electrode, or coupling to another electrode other than the electrode, or coupling to the substrate branch. The RF power supply has a total power level of less than or equal to 500 W, either coupled to a combination of two or more of the above. The etching method of claim 47, wherein the pre-etched electron beam forming step comprises coupling of a DC power source having a voltage ranging from about -2000V to about 1000V. The etching method of claim 47, wherein the pre-etched electron beam forming step comprises coupling of a DC power source having a negative polarity, wherein an absolute value of the voltage of the DC power source is greater than or equal to 500V. The etching method of claim 47, wherein the pre-etching electron beam forming step comprises coupling a DC power source to an upper electrode facing the substrate disposed on a substrate holder. The etching method of claim 58, wherein the pre-etching plasma forming step comprises coupling a radio frequency (RF) power source to the electrode, or coupling to another electrode other than the electrode, or coupling to the substrate branch Block, or a combination of two or more of the above. The etching method of claim 59, wherein the coupling step of the RF power source comprises coupling a first RF power source to the upper electrode at a first RF frequency, and a second RF lower than the first RF frequency. A second RF power source is coupled to the substrate support. The etching method of claim 59, further comprising: modulating the amplitude of the RF power source to adjust a spatial distribution of the electron beam flux of the electron beam. The etching method of claim 47, wherein the mask layer processing step performed by the pre-etched electron beam before the etching step reduces the thickness of the line edge formed in the mask layer during etching . The etching method of claim 47, wherein the mask layer processing step is performed for a predetermined period of time to prevent the patterned mask from forming a line edge roughness in the mask layer during the etching. The etching method of claim 47, wherein the electron beam energy of the pre-etched electron beam is smaller than the electron beam energy of the etched electron beam. The etching method of claim 47, wherein the electron beam energy of the pre-etched electron beam is increased by one or more steps or ramped when the mask layer is processed using the pre-etched electron beam Big. An etching method for etching a film on a substrate by using a plasma processing system having a ballistic electron beam and a plasma, the etching method comprising: forming a mask layer including a pattern on the film; Coupling a negative DC power source to one of the electrodes to form a first ballistic electron beam of one of the halogen species lacking an atomic state; exposing the substrate having the mask layer to the first ballistic electron beam for processing The mask layer; in the plasma processing system, forming an etching plasma from an etching gas; forming a first in the plasma processing system by coupling a negative DC power source to one of the electrodes a second ballistic electron beam; and exposing the substrate to the etched plasma and the second ballistic electron beam to transfer the pattern to the film. A plasma processing system for etching a film having a mask layer on a substrate, the plasma processing system comprising: a processing chamber; a gas supply system for supplying a gas to the processing chamber; a substrate holder coupled to the processing chamber and configured to support the substrate; an electrode disposed within the processing chamber; an AC power system coupled to the processing chamber for coupling at least one AC signal to the substrate a seat, or the electrode, or both, to form a plasma in the processing chamber; a DC power system coupled to the processing chamber and configured to couple a DC voltage to the electrode to form a ballistic electron beam through the plasma; and a controller for controlling the gas supply system, the AC a power supply system, and the DC power supply system to perform the steps of: forming a pattern in the mask layer; a mask layer processing step of processing the patterned mask layer with a pre-etched first electron beam of a halogen species lacking an atomic state To modify the patterned mask layer, the pre-etched first electron beam is coupled to the electrode in the plasma processing system by coupling a negative DC power source; and after the mask layer processing step, the electricity A plasma and a second ballistic electron beam are formed in the slurry processing system to etch the film and transfer a pattern of the patterned mask to the film.