JP5246474B2 - Milling apparatus and milling method - Google Patents

Description

  The present invention relates to a milling processing apparatus and a milling processing method.

  There is known a milling apparatus that performs an etching process by irradiating the surface of a workpiece such as a substrate with an ion beam or a neutral particle beam.

For example, in the surface treatment apparatus disclosed in Patent Document 1, a means for irradiating a neutral particle beam and a means for causing a chemical reaction in a sample are included in the same vacuum vessel, and the ion beam and the neutral particle beam are used. In addition, by supplying radicals, chemical reactivity in the vicinity of the surface of the sample is improved, and etching processing using an ion beam and a neutral particle beam is promoted.
JP-A-4-180621

  However, the above-described surface treatment apparatus irradiates an ion beam or a neutral particle beam from a direction orthogonal to the surface of the sample. Since physical etching using an ion beam and a neutral particle beam is strong, there is a problem that the sample is excessively shaved. Also, when processing a workpiece made of multiple different materials, the resistance to physical etching and chemical reactivity differ depending on the material, so the surface of the workpiece is leveled with an ion beam and neutral particle beam. There was a problem that I could not.

  Therefore, an object of the present invention is to provide a milling apparatus and a milling method for leveling the surface of a workpiece made of different materials.

In order to solve the above-described problems, the present invention provides a processing chamber, a workpiece holder that is disposed in the processing chamber and holds the workpiece, and a processing surface of the workpiece has an angle of 80 to 90 °. the incident angle, and a supply capable radical source to the processing surface of the workpiece radical, the incidence angle of 0 ° with respect to the machined surface of the workpiece, a neutral particle beam neon as a raw material And a neutral particle beam source capable of irradiating the workpiece.

According to such a milling apparatus, radicals are supplied from the radical source to the processed surface of the workpiece at an incident angle of 80 to 90 ° with respect to the processed surface of the workpiece. Therefore, when processing a workpiece composed of a plurality of materials, a portion where a material having low resistance to physical etching (soft) is used in the workpiece is substantially orthogonal to the processing surface. A material (hard) having high resistance to physical etching can be cut without being cut too much in the direction. In addition, the neutral particle beam source irradiates the neutral particle beam at an incident angle of 0 to 10 ° with respect to the processed surface of the work piece, so that a portion where a chemically stable material is used is physically etched. Can be supplementarily processed. Therefore, it is possible to make up the processing surface of the workpiece by flattening the unevenness of the processing amount due to radicals with the neutral particle beam. In addition, since the neutral particle beam is used as the beam irradiated to the workpiece, it is possible to prevent the workpiece from being electrically influenced as compared with the case of using the ion beam as the beam. Further, since the neutral particle beam uses neon having an atomic weight smaller than that of argon as a raw material, the workpiece is not excessively shaved by the neutral particle beam.

  Further, it is preferable that the neutral particle beam source irradiates the workpiece with a neutral particle beam along a direction parallel to a processing surface of the workpiece.

  According to such a configuration, since the neutral particle beam is irradiated along a direction parallel to the processing surface of the workpiece, the workpiece is not excessively cut in a direction perpendicular to the processing surface. It is possible to cut a material (hard) having high resistance to physical etching.

  The neutral particle beam is preferably a beam obtained by mixing ionic particles and neutral particles.

  According to such a configuration, the neutral particle beam is a beam in which ion particles and neutral particles are mixed. Therefore, by adjusting the ratio of ion particles to neutral particles, the workpiece can be processed. The amount and processing speed can be adjusted.

  The radical source preferably includes an ion source that generates plasma, and a grid that is disposed between the processing chamber and the ion source and emits ion particles from the plasma generated in the ion source. .

  According to such a configuration, the radical source includes an ion source that generates plasma, and a grid that is disposed between the processing chamber and the ion source and emits ion particles from the plasma generated in the ion source. Compared with the case where only radicals are supplied from a radical source, etching with radicals can be performed in a state where the reactivity of the processed surface of the workpiece is increased. It should be noted that the energy provided by the ion particles from the grid is smaller than the energy required to extract the neutral particle beam in the neutral particle beam source.

Further, the present invention provides the above-described milling apparatus, wherein the workpiece is placed in the processing chamber from the radical source at an incident angle of 80 to 90 ° with respect to the processing surface of the workpiece. While supplying radicals to the processed surface of the workpiece, and simultaneously using neon as a raw material from the neutral beam source to the workpiece at an incident angle of 0 to 10 ° with respect to the processed surface of the workpiece And a processing step of irradiating the active particle beam.

Further, the present invention provides the above-described milling apparatus, wherein the workpiece is placed in the processing chamber from the radical source at an incident angle of 80 to 90 ° with respect to the processing surface of the workpiece. A radical supply step for supplying radicals to the work surface of the workpiece; and after the radical supply step , the neutral particle beam source from the neutral beam source at an incident angle of 0 to 10 ° with respect to the work surface of the workpiece. And a beam irradiation step of irradiating a workpiece with a neutral particle beam using neon as a raw material .

Further, the present invention provides the above-described milling apparatus , wherein the neutral particle beam source is arranged at an incident angle of 0 to 10 ° with respect to a processing surface of the workpiece and an arrangement step of arranging the workpiece in a processing chamber. A beam irradiation step of irradiating the workpiece with a neutral particle beam using neon as a raw material, and after the beam irradiation step, at an incident angle of 80 to 90 ° with respect to a processing surface of the workpiece. And a radical supply step of supplying radicals from a radical source to the processed surface of the workpiece.

According to such a milling method, when processing a workpiece composed of a plurality of materials, a portion where a material with low resistance to physical etching (soft) is used in the workpiece is processed. A material that is highly resistant to physical etching (hard) can be cut without being cut too much in a direction substantially perpendicular to the surface. In addition, the neutral particle beam source irradiates the neutral particle beam at an incident angle of 0 to 10 ° with respect to the processed surface of the work piece, so that a portion where a chemically stable material is used is physically etched. Can be supplementarily processed. Therefore, it is possible to make up the processing surface of the workpiece by flattening the unevenness of the processing amount due to radicals with the neutral particle beam. Further, since the neutral particle beam uses neon having an atomic weight smaller than that of argon as a raw material, the workpiece is not excessively shaved by the neutral particle beam.

  According to the present invention, it is possible to provide a milling apparatus and a milling method for leveling the surface of a workpiece made of different materials.

  A milling apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4B. A milling apparatus 1 shown in FIG. 1 is an apparatus that etches a substrate S with a radical R and a neutral particle beam NB, which will be described later. As the substrate S, for example, a substrate such as a thin film magnetic head as described in JP 2007-149308 A and JP 2007-287863 A can be cited.

  The milling apparatus 1 irradiates a processing chamber 2 that accommodates a substrate S, a radical source 3 that can supply a radical R (FIG. 4A) to the substrate S, and a neutral particle beam NB (FIG. 4B). Possible neutral particle beam source 4. The processing chamber 2, the radical source 3, and the neutral particle beam source 4 communicate with each other via a plurality of grids described later.

A vacuum pump 21 is connected to the processing chamber 2 for evacuating the processing chamber 2 and maintaining the predetermined pressure. The vacuum pump 21 communicates with the inside of the processing chamber 2 through the exhaust valve 21A. By driving the vacuum pump 21, the inside of the processing chamber 2 can be brought to a vacuum state of about 1 × 10 ⁻⁴ Pa.

  A substrate holder 22 for holding the substrate S is installed in the processing chamber 2. The substrate holder 22 includes a main body portion 22A having a substantially cylindrical shape, a holder shaft 22B that pivotally supports the main body portion 22A, and a substrate holding portion 22C that is provided rotatably about the axis of the main body portion 22A. It consists of. The main body 22A can swing around the holder shaft 22B by a holder motor 22D (FIG. 2). The holder shaft 22B extends in a direction orthogonal to the axial direction of the main body portion 22A (paper surface direction in FIG. 1). The substrate holding portion 22C has a substantially cylindrical shape, has one end face that comes into close contact with the substrate S, and includes a shield cover (not shown) that covers the outer periphery of the substrate holding portion 22C and an illustration for flowing cooling water inside the substrate holding portion 22C. A cooling water flow path is formed. Further, a high frequency power source 22E (FIG. 2) for applying a negative voltage to the substrate S is connected to the substrate holding part 22C via a matching unit 22F (FIG. 2). For example, the high frequency power supply 22E (FIG. 2) applies a negative voltage of several tens V to several kV to the substrate S.

The radical source 3 includes a vacuum vessel (not shown), a discharge vessel 31 having an opening 31a, a coil 32 provided outside the discharge vessel 31, and a high frequency power source 32A for supplying high frequency power to the coil 32 (FIG. 2). When, and a supply grid 33 the radicals R in the generated plasma P _R of the discharge vessel 31 from the opening 31a into the processing chamber 2. A vacuum container (not shown) is formed in a cylindrical shape from stainless steel or the like.

  The discharge vessel 31 is disposed in a vacuum vessel (not shown). The discharge vessel 31 is made of a dielectric material such as quartz or aluminum oxide, and is formed in a cylindrical shape having an opening 31a on the lower side of FIG. On the upper surface of the discharge vessel 31 in FIG. 1, a raw material gas supply port 31 b for supplying a raw material gas into the discharge vessel 31 from a rare gas supply device 61 and a molecular gas supply device 62 described later is provided.

  The coil 32 is provided inside the vacuum vessel (not shown) and outside the discharge vessel 31. The coil 32 is provided so that the axis is located in the discharge vessel 31. As shown in FIG. 2, the coil 32 is connected to a high-frequency power source 32A via a matching unit 32B. The high frequency power supply 32A is, for example, a high frequency power supply or a high frequency amplifier. The frequency of the high frequency power supply 32A is several MHz to several tens of MHz (for example, 2 to 13.5 MHz), and is about 4 MHz in the present embodiment. The high frequency power supply 32 </ b> A applies, for example, 200 to 2000 W of power to the coil 32 according to the capacity and shape of the discharge vessel 31 (FIG. 1).

The grid 33 shown in FIG. 1 is a metal plate in which a plurality of holes are formed. The grid 33 is provided in the opening 31 a of the discharge vessel 31 and partitions the radical source 3 and the processing chamber 2. Grid 33 is the radical R of plasma P _R that is generated is supplied to the substrate S in the discharge vessel 31, an electrode withdrawing the ion particles IP (Figure 4 (a)). The grid 33 is connected to a DC power source 33A (FIG. 2) for continuously applying a positive voltage. For example, a voltage of about 1500 V at the maximum can be applied practically. When a positive potential is applied to the grid 33, positive ions can be extracted, and when a negative potential is applied, negative ions can be extracted. The ion energy of the ion particles IP is determined by the voltage applied to the grid 33.

The neutral particle beam source 4 includes a vacuum vessel (not shown), a discharge vessel 41 in which an opening 41a is formed, a coil 42 provided inside the vacuum vessel (not shown) and outside the discharge vessel 41, and a coil 42 and supplying high frequency power high frequency power source 42A (FIG. 2), and the extraction electrode 43 to draw the ions in the generated plasma P _N of the discharge vessel 41 from the opening 41a, a neutralization vessel 47, neutralized container 47 And a retarding electrode 48 for preventing ions from being discharged from the substrate. A vacuum container (not shown) is formed in a cylindrical shape from stainless steel or the like. The ions will be described later.

  The discharge vessel 41 is disposed in a vacuum vessel (not shown). The discharge vessel 41 is formed of a dielectric material such as quartz or aluminum oxide into a cylindrical shape having an opening 41a on the right side of FIG. In the left surface of the discharge vessel 41 in FIG. 1, a source gas supply port 41 b for supplying a source gas into the discharge vessel 41 from a rare gas supply device 61 and a molecular gas supply device 62 described later is formed.

  The coil 42 is provided outside the discharge vessel 41 in a vacuum vessel (not shown). The coil 42 is provided in the discharge vessel 41 so that its axis is located. As shown in FIG. 2, a high frequency power source 42A is connected to the coil 42 via a high frequency matching unit 42B. The high frequency power supply 42A is, for example, a high frequency power supply or a high frequency amplifier. The frequency of the high-frequency power source is several MHz to several tens of MHz (for example, 2 to 13.5 MHz), and is about 4 MHz in the present embodiment. The high frequency power source 42 </ b> A applies, for example, 200 to 2000 W of power to the coil 42 according to the capacity and shape of the discharge vessel 41 (FIG. 1). With the above configuration, the high-frequency power source 42A can supply predetermined high-frequency power to the coil 42 by the high-frequency matching unit 42B.

  As shown in FIG. 1, the extraction electrode 43 has a screen grid 44, an acceleration grid 45, and a deceleration grid 46. The screen grid 44, the acceleration grid 45, and the deceleration grid 46 are arranged in order from the inside to the outside of the discharge vessel 41. The screen grid 44, the acceleration grid 45, and the deceleration grid 46 are each made of a metal plate in which a plurality of holes are formed.

The screen grid 44 separates the plasma _PN and the acceleration grid 45. The screen grid 44, for example, a DC power source 44A for continuously applying a voltage to the plasma P _N (FIG. 2) is connected. The voltage applied to the screen grid 44 is, for example, 200 to 1500V. The voltage applied to the screen grid 44 determines the energy of the ion beam that is extracted into the neutralization vessel 47.

The acceleration grid 45 is connected to a DC power supply 45A (FIG. 2) for continuously applying a negative voltage. The voltage applied to the acceleration grid 45 is, for example, −200 to −1000V. The deceleration grid 46 is grounded. Ion particles drawn from the plasma P _N in the discharge vessel 41, a screen grid 44, the accelerator grid 45, is emitted to the neutralizing vessel 47 through a hole formed respectively on the reduction grid 46 become ion beam. The extraction electrode 43 can control the beam diameter of the ion beam within a predetermined numerical range using the lens effect by adjusting the potential difference between the acceleration grid 45 and the deceleration grid 46.

  The neutralization container 47 is made of a conductive material such as stainless steel, and is formed in a cylindrical shape having an inlet side opening 47a on the left side and an outlet side opening 47b on the right side in FIG. In the neutralization vessel 47, atoms and molecules filled in the neutralization vessel 47 before plasma generation, and atoms and molecules of the source gas that has not been converted into plasma in the discharge vessel 41 (hereinafter referred to as atoms, etc.) And radicals are supplied through the extraction electrode 43 and the inlet opening 47a. The inlet side opening 47 a of the neutralization vessel 47 is connected to the opening 41 a of the discharge vessel 41 through the extraction electrode 43. In the neutralization vessel 47, a charge exchange reaction occurs between the ion beam extracted by the extraction electrode 43 and neutral atoms that are not ionized. Specifically, when a high-speed ion beam passes near a low-speed atom or the like, electrons possessed by the atom or the like move from the atom or the like to the ion beam. By this movement of electrons, a high-speed ion beam and low-speed atoms are converted into a high-speed neutral particle beam NB and low-speed ions (including polyatomic ions, hereinafter referred to as ions).

  A retarding electrode 48 that partitions the neutral particle beam source 4 and the processing chamber 2 is provided in the outlet side opening 47 b of the neutralization vessel 47. The retarding electrode 48 is an electrode that prevents ions in the neutralization vessel 47 from being discharged into the processing chamber 2 and draws only the neutral particle beam NB to the processing chamber 2.

  The retarding electrode 48 includes a deceleration prevention grid 49, a repulsion grid 50, and an adjustment grid 51. The deceleration prevention grid 49, the repulsion grid 50, and the adjustment grid 51 are sequentially arranged from the inlet side opening 47a side of the neutralization container 47 toward the outlet side opening 47b side. The deceleration prevention grid 49, the repulsion grid 50, and the adjustment grid 51 are each made of a metal plate in which a plurality of holes are formed.

  A DC power supply 49A (FIG. 2) for continuously applying a negative voltage is connected to the deceleration prevention grid 49. The voltage applied to the deceleration prevention grid 49 is, for example, −10 to −20V. By applying a negative voltage to the deceleration prevention grid 49, the speed reduction and diffusion of the ion beam extracted by the extraction electrode 43 are prevented. Specifically, since the deceleration grid 46 is grounded and at 0 V, by applying a negative voltage to the deceleration prevention grid 49, the ion beam is accelerated slightly from the entrance side opening 47a to the exit side. It can lead to the opening 47b.

Connected to the repulsion grid 50 is a DC power supply 50A (FIG. 2) for continuously applying a positive voltage. When the voltage applied to the repulsion grid 50 completely blocks the passage of ions, the voltage applied to the screen grid 44, the value obtained by inverting the sign of the voltage applied to the deceleration prevention grid 49, and the discharge vessel 41 voltage obtained by summing the potential of the plasma P _N of the inner is required. For example, the applied voltage = 400V in screen grid 44, the applied voltage = -20 V to the speed reduction prevention grid 49, when the potential = 20V plasma _{P N} is completely to repel the grid 50 to prevent the passage of ions The voltage that needs to be applied = 400 + (− 20) × (−1) + 20 = 440V. When a positive voltage is applied to the repulsion grid 50, the ion beam and ions in the neutralization vessel 47 are repelled to prevent ion atoms and the like from passing into the processing chamber 2. Here, the ions and the like include not only low-speed ions converted in the neutralization vessel 47 but also high-speed ion beams in which charges are not exchanged in the neutralization vessel 47. That is, in the present embodiment, only the neutral particle beam NB can pass through the repulsion grid 50.

  The adjustment grid 51 is connected to a DC power source 51A (FIG. 2) that can select whether to ground or apply a negative voltage. The adjustment grid 51 is a grid that adjusts the energy of the ion beam that has passed through the repulsion grid 50 in order to mix and emit the neutral particle beam NB in the neutralization vessel 47. When the energy of the ion beam extracted by the extraction electrode 43 is larger than the potential wall of the repulsion grid 50 (plus voltage applied to the repulsion grid 50), a part of the ion beam passes through the repulsion grid 50, but passes through it. The velocity of the ion beam is attenuated. When the ion beam that has passed through the repulsion grid 50 is accelerated again to irradiate the substrate S that is a workpiece, a negative voltage is applied to the adjustment grid 51. At this time, since the neutral particle beam NB is not charged, nothing is affected. In this way, the neutral particle beam NB and the mixed ion beam pass through the holes formed in the deceleration prevention grid 49, the repulsion grid 50, and the adjustment grid 51, respectively, and are irradiated into the processing chamber 2.

  The rare gas supply device 61 stores a rare gas among the source gases. Examples of the rare gas (inert gas) include neon, argon, xenon, and krypton. The molecular gas supply device 62 stores a molecular gas among the source gases. Examples of the molecular gas (active gas) include CHF3 (trifluorinated methane), CF4 (tetrafluoromethane), C2F6 (hexafluoroethane), and C4F8 (perfluorobutane). In the present embodiment, neon having a smaller atomic weight than argon is used as a rare gas, and CHF3 is used as a molecular gas. The rare gas supply device 61 is connected to the source gas supply port 31b of the radical source 3 through a valve 63A and a supply pipe, and is connected to the source gas supply port 41b of the neutral particle beam source 4 through a valve 63B and a supply pipe. Has been. Similarly, the molecular gas supply device 62 is connected to the raw material gas supply port 31b of the radical source 3 through the valve 64A, and is connected to the raw material gas supply port 41b of the neutral particle beam source 4 through the valve 64B. Yes.

  The control device 7 shown in FIG. 2 causes the milling device 1 to execute a milling process and the like. Specifically, the control device 7 controls the above-described high-frequency power sources 22E, 32A, 42A, matching units 22F, 32B, 42B, DC power sources 33A, 44A, 45A, 49A, 50A, 51A, and the like. Furthermore, the control device 7 can control the valves 63A, 63B, 64A, 64B and the like, and can select the source gas supplied to the radical source 3 and the neutral particle beam source 4. The control device 7 also controls the operations of the vacuum pump 21 and the substrate holder 22.

  The milling process performed in the milling apparatus 1 mentioned above is demonstrated with reference to Fig.3 (a) thru | or FIG.4 (b). The milling process is a process of etching the substrate S with the radical R and the neutral particle beam NB. In order to simplify the description, the case where the substrate S is made of three kinds of materials will be described. As shown in FIG. 3A, the substrate S is composed of three kinds of materials, that is, tantalum Ta, cobalt iron CoFe, and copper Cu. Tantalum Ta and cobalt iron CoFe are materials (hard) that are more resistant to physical etching than copper Cu.

  First, as shown in FIG. 1, the substrate S is placed in the processing chamber 2. Specifically, the substrate S is held by the substrate holding part 22 </ b> C of the substrate holder 22. When the substrate S is held by the substrate holder 22C of the substrate holder 22, the angle of the substrate S is adjusted by the control device 7 (FIG. 2). Specifically, the main body portion 22A of the substrate holder 22 is rotated and fixed clockwise in FIG. 1 from the initial position to a predetermined angle about the holder shaft 22B by the control device 7. The initial position is a position where the holding surface of the substrate holder 22C is orthogonal to the axial direction of the discharge vessel 31 of the radical source 3 and parallel to the axial direction of the neutral particle beam source 4. The predetermined angle is an angle (0 to 10 °) parallel or substantially parallel to the neutral particle beam source 4. In other words, the incident angle of the neutral particle beam NB with respect to the substrate S is 80 to 90 °.

Next, the inside of the processing chamber 2 is evacuated to about 1 × 10 ⁻⁴ Pa by the vacuum pump 21. At this time, the inside of the discharge vessel 31 of the radical source 3 is evacuated by the vacuum pump 21 through the processing chamber 2 and the grid 33. Similarly, the inside of the discharge vessel 41 and the neutralization vessel 47 of the neutral particle beam source 4 is also evacuated by the vacuum pump 21 through the processing chamber 2, the extraction electrode 43, and the retarding electrode 48.

Next, as shown in FIG. 4A, the radical R is supplied from the radical source 3 to process the processed surface of the substrate S. Specifically, the valve 63A is opened, and, for example, CHF 3 gas is supplied from the molecular gas supply device 62 into the discharge vessel 31. In a state in which CHF3 gas in the discharge vessel 31 is filled, the voltage from the high frequency power source 32A (FIG. 2) is applied to the coil 32 to generate plasma _{P R} in the discharge vessel 31. In a state in which plasma is generated P _R, a voltage is applied to the grid 33. Thus, at the same time the radical R from the plasma _{P R} CHF3 is supplied, ion particles IP of CHF3 by the grid 33 is withdrawn from the plasma _{P R.} The radical R of CHF3 specifically refers to CF2, CF, F, and the like. At this time, the substrate S is chemically etched by the radicals R as shown in FIG. Further, the CHF3 ion particles IP extracted by the grid 33 are attracted to the substrate S to which a negative voltage is applied, and physical etching and reactive etching are performed to process the processed surface of the substrate S. As a result, the substrate S changes from the shape shown in FIG. 3B to the shape shown in FIG. Specifically, since tantalum Ta has higher chemical reactivity with respect to the radical R of CHF3 and the ion particles IP than copper Cu and cobalt iron CoFe, the tantalum Ta is etched more than copper Cu and cobalt iron CoFe with the radical R.

Next, as shown in FIG. 4B, the processing surface of the substrate S is irradiated with the neutral particle beam NB extracted by the neutral particle beam source 4. Specifically, first, the control device 7 opens the valve 64B and supplies neon gas from the rare gas supply device 61 into the discharge vessel 41 and the neutralization vessel 47. In a state in which the discharge vessel 41 is filled with neon gas, a voltage is applied to the coil 32 from the high frequency power supply 32A (FIG. 2), and plasma _PN is generated in the discharge vessel 41. A voltage is applied to the extraction electrode 43 and the retarding electrode 48 while the plasma _PN is generated. More specifically, as described above, a positive voltage is applied to the screen grid 44, a negative voltage is applied to the acceleration grid 45, and the deceleration grid 46 is grounded. Further, a negative voltage is applied to the deceleration prevention grid 49, a positive voltage is applied to the repulsion grid 50, and 0V is applied to the adjustment grid 51. Thereby, a neon ion beam is extracted from the discharge vessel 41 to the neutralization vessel 47 by the extraction electrode 43. Further, the extracted neon ion beam is attracted in the direction from the extraction electrode 43 toward the retarding electrode 48 due to the potential difference between the deceleration prevention grid 49 and the deceleration grid 46, and the neon gas filled in the neutralization vessel 47. The charge exchange reaction occurs, and a high-speed neutral neon beam NB is emitted from the retarding electrode 48. In this way, as shown in FIG. 3C, the neutral particle beam source 4 emits the neutral neon beam NB in a direction parallel or substantially parallel to the processing surface of the substrate S, S is processed. Specifically, the substrate S has a flat surface as shown in FIG. 3D from the shape shown in FIG. This is because copper Cu is softer than tantalum Ta and cobalt iron CoFe, and is thus etched more by a neutral neon beam.

  According to the milling apparatus 1 described above, the radical R of CHF 3 is supplied from the radical source 3 to the processed surface of the substrate S along a direction substantially orthogonal to the processed surface of the substrate S. Therefore, when processing the substrate S composed of a plurality of materials, a portion of the substrate S where copper Cu having low resistance to physical etching (soft) is used is substantially orthogonal to the processing surface of the substrate S. The tantalum Ta having high resistance to physical etching (hard) can be shaved without being shaved too much in the direction. Further, since the neutral particle beam source 4 irradiates the neutral neon beam NB along a direction substantially parallel to the processed surface of the substrate S, the copper Cu and cobalt iron CoFe protruding from the tantalum Ta are neutralized. Auxiliary processing can be performed by physical etching using the neon beam NB. Therefore, the processing amount bias due to the radical R of CHF3 can be complemented by the neutral neon beam NB, and the processing surface of the substrate S can be flattened. Further, since the neutral particle beam is used as the beam for irradiating the substrate S, it is possible to prevent the substrate S from being electrically affected as compared with the case where the ion beam is used as the beam.

  Further, since neon, which is an inert element having an atomic weight smaller than that of argon, is used as a raw material for the neutral particle beam, the neutral particle beam is lighter than the case where an argon beam is used, so that the substrate S is excessive. There is no shaving.

Furthermore, the radical source 3, the discharge vessel 31 to generate plasma P _R, coil 32, and the high-frequency power source 32A and the matching box 32B, is disposed between the processing chamber 2 and the discharge vessel 31, it is generated in the discharge vessel 31 since comprises a a grid 33 which emits CHF3 ion particles IP from the plasma P _R, as compared with the case of supplying only the radicals R to be generated from the radical source 3 CHF3, improving the reactivity of the processed surface of the substrate S In this state, etching with the radical R of CHF3 can be performed. Note that the energy that the ion particles IP of the CHF 3 are given from the grid 33 is smaller than the energy required to extract the neutral neon beam NB in the neutral particle beam source 4.

  Moreover, according to the above-described milling method, the neutral particle beam source 4 irradiates the substrate S with the neutral neon beam NB along a direction parallel or substantially parallel to the processing surface of the substrate S. When processing the substrate S made of a material, a portion of the substrate S where copper Cu having low resistance to physical etching (soft) is used is cut too much in a direction substantially perpendicular to the processing surface of the substrate S. Can be processed without any problems. Further, since the radical R of CHF3 is supplied from the radical source 3 to the processed surface of the substrate S along the direction substantially orthogonal to the processed surface of the substrate S, the processing amount bias due to the neutral neon beam NB is reduced. Complemented by the radical R, the processed surface of the substrate S can be flattened.

  The milling device and milling method according to the present invention are not limited to the above-described embodiments, and various modifications and improvements can be made. For example, in the embodiment described above, the substrate S is irradiated with the neutral neon beam NB after the CHF3 radical R is supplied from the radical source 3, but the CHF3 radical R is irradiated after the neutral neon beam NB is irradiated. May be supplied.

  Further, as shown in FIGS. 5A and 5B, the radical R of CHF 3 may be supplied to the substrate S at the same time as the irradiation with the neutral neon beam NB. According to such a milling method, the radical R of CHF 3 is supplied from the radical source 3 along a direction substantially orthogonal to the processed surface of the substrate S, and is parallel to or approximately parallel to the processed surface of the substrate S. A neutral neon beam NB is irradiated from the neutral particle beam source 4 along the parallel direction to cut the processed surface of the substrate S. Therefore, when processing the substrate S composed of a plurality of materials, a portion of the substrate S where a material having low resistance to physical etching (soft) is used is cut too much in a direction substantially orthogonal to the processing surface. Without cutting, a material having high resistance to physical etching (hard) can be cut. At this time, since the neutral particle beam source 4 irradiates the neutral neon beam NB along a direction substantially parallel to the processed surface of the substrate S, there is a place where a chemically stable material is used. Even so, the substrate S can be processed by physical etching. Therefore, the processing time of the substrate S can be shortened in addition to the effect that the unevenness of the processing amount due to the physical etching and the reactive etching can be complemented to flatten the processing surface of the substrate S.

  In the embodiment described above, a positive voltage is applied to the grid 33 and the ion particles IP are extracted together with the radicals R. However, the grid 33 may be grounded. According to such a configuration, the neutral radical R is mainly supplied to the surface of the substrate S, so that etching can be performed without affecting the substrate S electrically.

  Further, in the above-described embodiment, in the neutral particle beam source 4, the ion beam extracted by the extraction electrode 43 is subjected to a charge exchange reaction in the neutralization vessel 47, and only the neutral particles are neutralized by the retarding electrode 48. Although it was set as the structure extracted as particle beam NB, it is not limited to this. For example, the voltage applied to the extraction electrode 43 and the retarding electrode 48 may be adjusted, and the extracted particle beam may be a beam in which ion particles and neutral particles are mixed at a predetermined ratio. According to such a configuration, the processing amount and processing speed of the extracted particle beam with respect to the substrate S can be adjusted by adjusting the ratio between the ion particles and the neutral particles.

  Moreover, although the neutral particle beam source 4 was set as the structure provided with the neutralization container 47 and the retarding electrode 48, it is not limited to this. As a configuration in which the neutralization container 47 and the retarding electrode 48 are not provided in the neutral particle beam source, an ion beam may be extracted instead of the neutral particle beam.

  The radical source 3 is an inductively coupled plasma (ICP) radical source, but may be an electron cyclone resonance (ECR) type radical source.

  In the above-described embodiment, the CHF 3 gas is supplied to the radical source 3 and the neon gas is supplied to the neutral particle beam source 4. However, the present invention is not limited to this. For example, neon gas may be supplied to the radical source 3 and CHF 3 gas may be supplied to the neutral particle beam source 4. That is, a neon radical may be supplied to the substrate S and irradiated with a neutral beam of CHF3. Moreover, only the neon gas may be supplied to both the radical source 3 and the neutral particle beam source 4 as the source gas, or only the CHF 3 gas may be supplied. Further, instead of the CHF 3 gas, a gas suitable for the material of the substrate S that is a workpiece to be etched, for example, a halogen-containing gas such as HBr, ClF 3, HI, or SF 6 may be used.

  In the above-described embodiment, copper (Cu) is used as the material having low resistance to physical etching (soft) in the substrate S, but gold (Au) can also be used as a similar material.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for a milling apparatus that targets workpieces made of different materials.

Explanatory drawing which shows the milling apparatus which concerns on embodiment of this invention. The control circuit diagram which shows the milling apparatus which concerns on embodiment of this invention. It is a figure which shows the workpiece processed with the milling apparatus which concerns on embodiment of this invention, Comprising: (a) is a perspective view, (b) is explanatory drawing at the time of a radical supply process, (c) is a beam irradiation process. Explanatory drawing of time, (d) is explanatory drawing after a process process. Explanatory drawing which shows the radical supply process time of the milling apparatus which concerns on embodiment of this invention. Explanatory drawing which shows the time of the beam irradiation process of the milling apparatus which concerns on embodiment of this invention. Explanatory drawing which shows the milling apparatus at the time of the manufacturing process in the milling processing method which concerns on the modification of embodiment of this invention. Explanatory drawing which shows the to-be-processed object at the time of the manufacturing process in the milling processing method which concerns on the modification of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Milling apparatus 2 Processing chamber 3 Radical source 4 Neutral particle beam source 7 Control apparatus 21 Vacuum pump 21A Exhaust valve 22 Substrate holder 22A Main part 22B Holder shaft 22C Substrate holding part 22D Holder motors 22E, 32A, 42A High frequency power supplies 22F, 32B , 42B Matching device 31, 41 Discharge vessel 31a, 41a Opening 31b, 41b Source gas supply port 32, 42 Coil 33 Grid 33A, 44A, 45A, 49A, 50A, 51A DC power supply 41 Discharge vessel 43 Extraction electrode 44 Screen grid 45 Acceleration Grid 46 Deceleration grid 47 Neutralization vessel 47a Inlet side opening 47b Outlet side opening 48 Retarding electrode 49 Deceleration prevention grid 50 Repulsion grid 51 Adjustment grid 61 Noble gas supply device 62 Molecular gas supply device 63A, 63B, 64A, 64B IP ion particles NB neutral beam _P N, _{P R} Plasma R radical S substrate

Claims (6)

A processing chamber;
A workpiece holder disposed in the processing chamber for holding the workpiece;
A radical source capable of supplying radicals to the processed surface of the workpiece at an incident angle of 80 to 90 ° with respect to the processed surface of the workpiece;
A neutral particle beam source capable of irradiating the workpiece with a neutral particle beam using neon as a raw material at an incident angle of 0 to 10 ° with respect to the processing surface of the workpiece. Milling device to do. The milling apparatus according to claim 1, wherein the neutral particle beam is a beam obtained by mixing ion particles and neutral particles. The radical source is
An ion source for generating plasma;
The milling device according to claim 1 , further comprising a grid that is disposed between the processing chamber and the ion source and emits ion particles from plasma generated in the ion source. The milling device according to claim 1, wherein
An arrangement step of arranging the workpiece in the processing chamber;
A radical is supplied from the radical source to the processed surface of the workpiece at an incident angle of 80 to 90 ° with respect to the processed surface of the workpiece, and at the same time, 0 to And a processing step of irradiating the workpiece with a neutral particle beam using neon as a raw material at an incident angle of 10 ° . The milling device according to claim 1, wherein
An arrangement step of arranging the workpiece in the processing chamber;
A radical supply step of supplying radicals from the radical source to the processed surface of the workpiece at an incident angle of 80 to 90 ° with respect to the processed surface of the workpiece;
After the radical supply step, the neutral particle beam source is irradiated with a neutral particle beam using neon as a raw material from the neutral particle beam source to the workpiece at an incident angle of 0 to 10 ° with respect to the processing surface of the workpiece. And a beam irradiation step. The milling device according to claim 1, wherein
An arrangement step of arranging the workpiece in the processing chamber;
A beam irradiation step of irradiating a neutral particle beam using neon as a raw material from the neutral particle beam source to the workpiece at an incident angle of 0 to 10 ° with respect to a processing surface of the workpiece;
And a radical supply step of supplying radicals from the radical source to the processed surface of the workpiece at an incident angle of 80 to 90 ° with respect to the processed surface of the workpiece after the beam irradiation step. A milling method characterized by

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