JP5657378B2 - Ion beam etching apparatus, method and control apparatus - Google Patents

Description

  The present invention relates to an etching apparatus, an etching method, and a control apparatus for forming a concavo-convex structure in a manufacturing process of a semiconductor device, an electronic device, a magnetic device, a display device, etc., particularly in a processing process of a reading unit in a magnetic head of a hard disk device. .

  In recent years, a hard disk drive, which is a magnetic recording / reproducing device used as an external recording device of an information processing apparatus such as a computer, has been required to have a large capacity and a small size. With this demand, the recording density of magnetic recording is increasing.

  Along with the increase in the density of magnetic recording, magnetoresistive elements (hereinafter referred to as MR) using a giant magnetoresistance (hereinafter referred to as GMR) effect and tunneling magnetoresistance (hereinafter referred to as TMR) effect are used for reproducing recorded information. Yes.

  Conventionally, when forming an MR element, an MR film is formed and then processed by ion beam etching (hereinafter referred to as IBE). In general, IBE processing is performed while rotating the substrate at a constant speed.

  However, this processing method has a problem that a distribution occurs in the etching amount of each element on the substrate and the taper angle after processing due to the divergence of the ion beam and the attenuation of the ion energy. Such variation in element shape may cause operation failure, yield, etc. as the element is miniaturized.

  This will be specifically described with reference to FIG. FIG. 1 shows how IBE is performed on a substrate on which an MR film is formed. Here, the actual ion beam has divergence as shown in FIG. Therefore, since the ion beam diverges as the distance between the grid for extracting the ion beam from the plasma formation space and the substrate increases, the incident amount of the ion beam decreases at a point far from the grid. The energy of the ion beam attenuates as the distance between the grid and the substrate increases. That is, the incident amount and incident energy of the ion beam are increased at a portion close to the grid, and the incident amount and incident energy of the ion beam are decreased at a portion far from the grid. This is schematically shown in the enlarged display portion of FIG. A point X where the distance between the grid and the substrate is close indicates that the amount and energy of the incident ion beam are large, and a point Y where the distance between the grid and the substrate is long indicates that the amount of incident ion beam and energy are small. As a result, there is a difference in the etching amount between the point X and the point Y.

  The distribution of the etching amount within the substrate surface described above can be made uniform by making the average etching amount at each point uniform by performing rotation control of the substrate at a constant speed. However, this method creates a new problem.

  This will be specifically described with reference to FIGS. First, in FIG. 3, the incident amount and energy of the ion beam are larger at the point X that is close to the grid than at the point Y that is far away. This state is schematically shown by using an arrow representing an ion beam. Next, FIG. 4 shows a state where the substrate is rotated 180 degrees and the positional relationship between the grid and the points X and Y is opposite to that in FIG. In this state, the point X is far from the grid, and the incident amount and energy of the ion beam are small, and the point Y is short from the grid, and the incident amount and energy of the ion beam are large. FIG. 5 shows a comparison of the amount of incident ion beam and the incident direction in each of the states of FIGS. A broken arrow indicates an ion beam incident in the state of FIG. 3, and a solid arrow indicates an ion beam incident in the state of FIG. As can be seen from FIG. 5, by controlling the rotation of the substrate at a constant speed, the average ion beam incident amount at each point in the substrate surface can be made uniform, but the ion beam incident amount depends on the ion beam incident direction. The problem of being different arises.

  For this reason, when the IBE is performed while controlling the rotation of the substrate at a constant speed, the etching amount and the taper angle are not uniform even on the surfaces facing the same direction at the point X and the point Y. Such a problem becomes more noticeable as the substrate becomes larger.

  In view of the above-described problems, the present invention reduces the influence of different incident amounts in each incident direction when forming an uneven structure by obliquely irradiating an ion beam in IBE, and improves the characteristics between the fabricated elements. The purpose is to reduce variation.

In order to solve the above-mentioned problems, the present invention provides a plasma forming means for forming plasma, a plasma forming space in which plasma is formed by the plasma forming means, and ions from the plasma formed in the plasma forming space. An ion beam etching apparatus comprising a grid to be pulled out and a substrate holder for holding a substrate, wherein the substrate holder is rotatable, and an inclination angle with respect to the grid can be changed. A position detecting means for detecting the rotational position of the substrate and a rotation control means for controlling the rotational speed of the substrate, wherein the rotation control means is configured to detect ions when the substrate is diagonally opposite the grid. The grid is on a first direction side parallel to the surface to be processed formed by beam etching and parallel to the substrate surface. When the grid is positioned on the second direction side that is perpendicular to the first direction and parallel to the substrate surface, the second state is the first state. The rotation speed of the substrate in the second state is higher than the rotation speed of the substrate in the second state.
The present invention also includes a plasma forming unit for forming plasma, a plasma forming space in which plasma is formed by the plasma forming unit, a grid for drawing ions from the plasma formed in the plasma forming space, and a substrate. An ion beam etching apparatus comprising a substrate holder for holding the substrate holder, wherein the substrate holder is rotatable and an inclination angle with respect to the grid is changeable, and detects a rotational position of the substrate. And a rotation control means for controlling the rotation stop time of the substrate. The rotation control means is formed by ion beam etching when the substrate is diagonally opposite the grid. A state in which the grid is positioned on a first direction side parallel to the surface to be processed and parallel to the substrate surface. When the state in which the grid is located on the second direction side that is perpendicular to the first direction and parallel to the substrate surface is the second state, the substrate in the first state The rotation stop time is longer than the rotation stop time of the substrate in the second state.
The present invention also includes a plasma forming unit for forming plasma, a plasma forming space in which plasma is formed by the plasma forming unit, a grid for drawing ions from the plasma formed in the plasma forming space, and a substrate. An ion beam etching apparatus comprising a substrate holder for holding the substrate holder, wherein the substrate holder is rotatable and an inclination angle with respect to the grid is changeable, and detects a rotational position of the substrate. And a power control means for controlling the power supplied to the plasma forming means, the power control means by ion beam etching when the substrate is diagonally opposite the grid. The grid is positioned on a first direction side that is parallel to the surface to be formed and parallel to the substrate surface. When the state is the first state and the state in which the grid is positioned on the second direction side that is perpendicular to the first direction and parallel to the substrate surface is the second state, the first state The power supplied to the plasma forming means in the state is made larger than the power supplied to the plasma forming means in the second state.
The present invention also includes a plasma forming unit for forming plasma, a plasma forming space in which plasma is formed by the plasma forming unit, a grid for drawing ions from the plasma formed in the plasma forming space, and a substrate. An ion beam etching apparatus comprising a substrate holder for holding the substrate holder, wherein the substrate holder is rotatable and an inclination angle with respect to the grid is changeable, and detects a rotational position of the substrate. Position detecting means, voltage control means for controlling a beam extraction voltage by controlling a voltage applied to the grid, and the voltage control means, when the substrate is diagonally opposite the grid, The first direction side is parallel to the surface to be processed formed by beam etching and parallel to the substrate surface. When the state where the lid is located is the first state, and the state where the grid is located on the second direction side which is perpendicular to the first direction and parallel to the substrate surface is the second state, The beam extraction voltage in the first state is set larger than the beam extraction voltage in the second state.
The present invention also relates to an ion beam etching method, a substrate placing step of placing a substrate on a substrate holder that is rotatable and tiltable with respect to a grid, and a discharge gas in a plasma forming space. A plasma forming step of introducing and forming plasma by plasma forming means; an ion beam forming step of extracting ions from the plasma formed in the plasma forming space by a grid to form an ion beam; and the substrate and the grid are inclined. A tilting process for tilting the substrate holder so as to face the substrate; and a substrate processing process for processing the substrate by irradiating the ion beam while rotating the substrate. A rotational position detecting step for detecting the rotational position of the substrate, and a rotational position of the substrate detected by the rotational position detecting step. Then, the state in which the grid is located on the first direction side parallel to the surface to be processed formed by ion beam etching and parallel to the substrate surface is defined as a first state, and is perpendicular to the first direction. And when the state where the grid is located on the second direction side parallel to the substrate surface is the second state, the etching amount of the substrate in the first state is the amount of the etching in the second state. And a control step of performing control so as to be larger than the etching amount of the substrate.
The present invention also provides a plasma forming means for forming plasma, a plasma forming space in which plasma is formed by the plasma forming means, a grid for extracting ions from the plasma formed in the plasma forming space, and a rotatable structure And a substrate holder tiltable with respect to the grid, position detecting means for detecting a rotational position of the substrate when the substrate is held on the substrate holder, and rotation of the substrate holder. A control device for controlling an ion beam etching apparatus comprising a rotation control means for controlling, the means for obtaining information on the rotational position from the position detection means, and the substrate being diagonally opposite the grid In the case, the first surface is parallel to the surface to be processed formed by ion beam etching and parallel to the substrate surface. A state where the grid is located on the opposite side is defined as a first state, and a state where the grid is located on a second direction side which is perpendicular to the first direction and parallel to the substrate surface is a second state. And means for generating a control signal for controlling the rotation control means so that the rotation speed of the substrate in the second state is faster than the rotation speed of the substrate in the first state. And means for transmitting the generated control signal to the rotation control means.
The present invention also provides a plasma forming means for forming plasma, a plasma forming space in which plasma is formed by the plasma forming means, a grid for extracting ions from the plasma formed in the plasma forming space, and a rotatable structure And a substrate holder tiltable with respect to the grid, a position detecting means for detecting a rotational position of the substrate when the substrate is held on the substrate holder, and detection by the position detecting means A control device for controlling an ion beam etching apparatus comprising a rotation control means for controlling a rotation stop time of the substrate in accordance with the rotated position, wherein information on the rotational position is acquired from the position detection means. Means to be processed and formed by ion beam etching when the substrate is diagonally opposite the grid The first state is the state where the grid is positioned on the first direction side parallel to the substrate surface and the second direction is perpendicular to the first direction and parallel to the substrate surface. When the state where the grid is located on the direction side of the second state is the second state, the rotation stop time of the substrate in the first state is made longer than the rotation stop time of the substrate in the second state. Means for generating a control signal for controlling the rotation control means;
Means for transmitting the generated control signal to the rotation control means.
The present invention also provides a plasma forming means for forming plasma, a plasma forming space in which plasma is formed by the plasma forming means, a grid for extracting ions from the plasma formed in the plasma forming space, and a rotatable structure And a substrate holder tiltable with respect to the grid, a position detecting means for detecting a rotational position of the substrate when the substrate is held on the substrate holder, and a plasma forming means. A control device for controlling an ion beam etching apparatus comprising power control means for controlling supply power, the means for obtaining information on the rotational position from the position detection means, When facing, parallel to the surface to be processed formed by ion beam etching and parallel to the substrate surface A state where the grid is located on a certain first direction side is a first state, and a state where the grid is located on a second direction side which is perpendicular to the first direction and parallel to the substrate surface. Means for generating a control signal for controlling the power control means so that the supply power in the first state is larger than the supply power in the second state when in the second state; And means for transmitting the generated control signal to the power control means.
Further, the present invention provides a plasma forming means for forming plasma, a plasma forming space in which plasma is formed by the plasma forming means, a grid for extracting ions from the plasma formed in the plasma forming space, and a rotatable structure And a substrate holder tiltable with respect to the grid;
A position detection means for detecting a rotational position of the substrate when the substrate is held on the substrate holder; and a voltage control means for controlling a beam extraction voltage by controlling a voltage applied to the grid. A control device for controlling an ion beam etching apparatus provided with means for obtaining information on the rotational position from the position detection means, and when the substrate is diagonally opposite the grid, A state in which the grid is positioned on a first direction side parallel to the surface to be formed and parallel to the substrate surface is defined as a first state, and is perpendicular to the first direction and the substrate surface When the state where the grid is located on the second direction side parallel to the second state is the second state, the beam extraction voltage in the first state is the second state. And a means for generating a control signal for controlling the voltage control means and a means for transmitting the generated control signal to the voltage control means so as to be larger than the beam extraction voltage in And

  By using the present invention, it is possible to reduce variation in characteristics between manufactured devices as compared to devices processed by conventional IBE.

It is the figure which showed ion beam etching typically. It is a figure which shows typically the divergence of an ion beam. It is the figure which showed typically the distribution in the substrate surface of ion beam incident amount and ion energy. It is the figure which showed typically the distribution in the substrate surface of ion beam incident amount and ion energy. It is the figure which showed typically the relationship between an ion beam incident direction, the incident amount of an ion beam, and ion energy. It is a figure which shows the ion beam etching apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the control apparatus which concerns on one Embodiment of this invention. It is a figure for demonstrating the positional relationship of a grid and a board | substrate and the phase of a board | substrate based on one Embodiment of this invention. It is explanatory drawing which shows the control map of the rotational speed of the substrate holder in the ion beam etching which concerns on one Embodiment of this invention. It is a figure which shows a mode that a board | substrate is processed by the conventional ion beam etching. It is a figure which shows the board | substrate processed by the conventional ion beam etching. It is a figure which shows the board | substrate processed by the conventional ion beam etching. It is a figure which shows the magnetoresistive effect film | membrane as an example of the process target using the ion beam etching which concerns on one Embodiment of this invention. It is a figure which shows a magnetoresistive effect element. (A) is explanatory drawing about the case where a board | substrate (substrate holder) is rotated continuously in the case of controlling the rotational speed of board | substrate rotation based on one Embodiment of this invention, (b) is this invention. It is explanatory drawing about the case where a board | substrate (board | substrate holder) is rotated discontinuously when controlling the rotational speed of board | substrate rotation based on one Embodiment. It is a block diagram which shows the control apparatus which concerns on one Embodiment of this invention. (A) is explanatory drawing about the case where a board | substrate (substrate holder) is rotated continuously in the case of controlling the input electric power to the plasma formation space based on one Embodiment of this invention, (b), It is explanatory drawing about the case where a board | substrate (substrate holder) is rotated discontinuously when controlling the input electric power to the plasma formation space based on one Embodiment of this invention. It is a figure for demonstrating the structure and function of a grid which concern on one Embodiment of this invention. It is a block diagram which shows the control apparatus which concerns on one Embodiment of this invention. (A) is explanatory drawing about the case where a board | substrate (board | substrate holder) is rotated continuously in the case of controlling the applied voltage to a grid based on one Embodiment of this invention, (b) is this invention. It is explanatory drawing about the case where a board | substrate (board | substrate holder) is rotated discontinuously when controlling the voltage applied to a grid based on one Embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments. In the drawings described below, components having the same function are denoted by the same reference numerals, and repeated description thereof may be omitted.

FIG. 6 shows a schematic view of an ion beam etching apparatus according to the present invention.
The ion beam etching apparatus 100 includes a processing space 1 and a plasma formation space 2.
As plasma forming means for forming plasma in the plasma forming space 2, the bell jar 4, the gas introduction part 5, the antenna 6 that generates an induced magnetic field in the bell jar 4, and the discharge for supplying high-frequency power (source power) to the antenna 6 A matching unit 7 and an electromagnetic coil 8 provided between the power supply 12, the discharge power supply 12 and the antenna 6 are installed, and a grid 9 is installed at the boundary with the processing space 1. The high frequency power supplied from the discharge power supply 12 is supplied to the antenna 6, and plasma is formed in the plasma forming space 2 inside the bell jar 4.
An exhaust pump 3 is installed in the processing space 1. Further, there is a substrate holder 10 in the processing space 1, and a substrate 11 is placed thereon. The substrate 11 is fixed by the substrate holder 10. Various fixing means such as electrostatic chucking using an ESC electrode or a clamp chuck can be used as the fixing means for the substrate 11.
The discharge gas is introduced into the plasma formation space 2 from the gas introduction unit 5 through a pipe (not shown), a valve (not shown), and a flow rate regulator (not shown) from a cylinder (not shown) that stores the discharge gas. Is done.
After the plasma is formed in the plasma forming space 2, a voltage is applied to the grid 9 to extract ions in the plasma forming space 2 as a beam. The extracted ion beam is electrically neutralized by the neutralizer 13 and irradiated onto the substrate 11. The substrate holder 10 can change an inclination angle with respect to the ion beam, and has a structure capable of rotating (spinning) the substrate 11 in the in-plane direction.

  The substrate holder 10 is provided with a position sensor 14 as position detecting means, and can detect the rotational position of the substrate 11. In the present embodiment, a rotary encoder is used as the position sensor 14. As the position sensor 14, any configuration may be used as long as it can detect the rotational position of the rotating substrate 11 like the above-described rotary encoder.

  In the present embodiment, the rotational position of the substrate 11 held by the substrate holder 10 is detected by directly detecting the rotational position of the substrate 11 or the substrate holder 10 by a sensor such as the position sensor 14. Any configuration may be used as long as the rotation position can be detected. For example, the rotation position of the substrate 11 may be obtained indirectly, for example, by calculation from the rotation speed or rotation time of the substrate holder 10.

  The substrate 11 is held on the mounting surface of the substrate holder 10 while maintaining a horizontal state. As a material of the substrate 11, for example, a disk-shaped silicon wafer is used, but is not limited thereto.

  Next, with reference to FIG. 7, the control device 20 provided in the ion beam etching apparatus 100 of the present embodiment and controlling the above-described components will be described. FIG. 7 is a block diagram showing a control device in the present embodiment.

  As shown in FIG. 7, the control apparatus 20 of this embodiment is provided with a general computer and various drivers, for example. That is, the control device 20 includes a CPU (not shown) that executes processing operations such as various calculations, controls, and determinations, and a ROM (not shown) that stores various control programs executed by the CPU. . In addition, the control device 20 includes a RAM that temporarily stores data during the processing operation of the CPU, input data, and the like, and a nonvolatile memory such as a flash memory and an SRAM (not shown). In such a configuration, the control device 20 executes ion beam etching in accordance with a predetermined program stored in the ROM or a command from the host device. Various process conditions such as discharge time, discharge power, applied voltage to the grid, process pressure, and rotation of the substrate holder 10 are controlled according to the command. In addition, output values of sensors such as a pressure gauge (not shown) for measuring the pressure in the ion beam etching apparatus 100 and a position sensor 14 as a position detection means for detecting the rotation position of the substrate can be acquired. Control according to the state is also possible.

  Further, the control device 20 includes a holder rotation control unit 21 as a rotation control unit that controls the rotation speed of the substrate 11 according to the rotation position detected by the position sensor 14. The holder rotation control unit 21 includes a target speed calculation unit 21a and a drive signal generation unit 21b. Based on the positional relationship between the rotation position of the substrate 11 and the grid 9, the substrate holder 10 is changed according to the rotation position of the substrate. The function of controlling the rotation speed of the substrate 11 by controlling the rotation of the rotating part. The control device 20 is configured to receive information regarding the rotational position of the substrate 11 from the position sensor 14. When the control device 20 receives the information on the rotational position, the target speed calculation unit 21a determines the position based on the current rotational position value of the substrate 11 output from the position sensor 14 that detects the rotational position of the substrate 11. The target rotational speed at is calculated. The value of the target rotation speed can be calculated, for example, by holding the correspondence relationship between the rotation position of the substrate 11 and the target rotation speed as a map in advance. The drive signal generation unit 21 b generates a drive signal for setting the target rotation speed based on the target rotation speed calculated by the target speed calculation unit 21 a and outputs the drive signal to the rotation drive mechanism 30. The control device 20 is configured to transmit the drive signal generated by the drive signal generation unit 21 b to the rotation drive mechanism 30.

  In the example of FIG. 7, the rotation drive mechanism 30 includes a holder rotation drive unit 31 such as a motor that drives the substrate holder 10, a target value, and an actual value (rotation position or rotation speed) output from the position sensor 14. And a feedback control unit 32 that determines an operation value of the holder rotation driving unit 31 based on the deviation of, and drives the substrate holder 10 by a servo mechanism. However, feedback control is not an essential component of the present invention, and the motor may be either a DC motor or an AC motor. The rotation drive mechanism 30 drives the holder rotation drive unit 31 based on the drive signal received from the control device 20 to rotate the substrate holder 10.

  Next, the operation of the ion beam etching apparatus 100 of this embodiment and the ion beam etching method performed using this apparatus will be described.

  In the ion beam etching method using the ion beam etching apparatus 100 according to the present embodiment, first, the substrate 11 to be processed is placed on the substrate holder 10. The substrate 11 is carried onto the substrate holder 10 in the processing space 1 through a gate valve (not shown) by, for example, a handling robot provided in an adjacent vacuum transfer chamber (not shown).

  Next, a discharge gas such as Ar is introduced into the plasma forming space 2 from the gas introduction part 5. When reactive ion beam etching is performed, alcohol gas, hydrocarbon gas, carbon oxide gas, or the like is introduced into the plasma forming space 2.

  Thereafter, high frequency power is supplied from the discharge power source 12 to discharge in the plasma forming space 2. A voltage is applied to the grid 9 to extract ions from the plasma forming space 2 to form an ion beam. The ion beam extracted by the grid 9 is neutralized by the neutralizer 13 and becomes electrically neutral. The neutralized ion beam is applied to the substrate 11 on the substrate holder 10 to perform ion beam etching.

  During the ion beam etching, the substrate holder 10 is rotated and the substrate 11 is processed. Then, the position sensor 14 detects the rotational position of the substrate 11 in a state where the substrate holder 10 is obliquely opposed to the grid 9 while the substrate holder 10 is rotating. The rotation speed of the substrate 11 is controlled according to the rotation position detected by the position sensor 14 by the control of the holder rotation control unit 21 according to the detected rotation position. In the present invention, the diagonally opposite means a state in which the substrate holder 10 and the grid 9 face each other and the substrate holder 10 is further inclined with respect to the grid 9.

  Hereinafter, the control of the rotation speed of the substrate 11 will be described in more detail. FIG. 8 is a diagram for explaining the positional relationship between the grid 9 and the substrate 11 and the phase of the substrate 11 according to this embodiment. FIG. 9 is an explanatory diagram showing a control map of the rotation speed of the substrate in the ion beam etching method using the apparatus according to the present embodiment when processing the reading unit of the HDD magnetic head.

The positional relationship between the grid 9 and the substrate 11 in this embodiment will be described with reference to FIG. The substrate 11 is placed on a rotatable substrate holder 10 and is tilted so that the substrate holder 10 is diagonally opposite to the grid 9 during ion beam etching. Note that the ion beam etching in the ion beam etching apparatus 100 according to the present embodiment does not always require the substrate 11 and the grid 9 to be in a diagonally-facing positional relationship. Even if it is a part, it is applicable.
As shown in FIG. 8, the rotation phase (rotation angle) θ of the substrate is defined as 90 ° closest to the grid 9 and 270 ° farthest, and clockwise from the position where the rotation angle θ is 90 °. A point rotated 90 ° is defined as 0 °, and a point rotated 90 ° counterclockwise from the 90 ° position is defined as 180 °. For convenience, the starting point of the substrate rotation is set when the notch or orientation flat 15 of the substrate 11 is at a position of 180 °, but is not limited thereto.

  In an example of the ion beam etching method using the apparatus according to the present embodiment, the rotational speed y of the substrate is a sine wave with respect to the rotational phase θ of the substrate, as shown in FIGS. The rotational speed is controlled so that

y = Asin (2 (θ−α)) + B (1)
A = a · B (2)

  That is, the holder rotation control unit 21 as the rotation control means of the present invention calculates the rotation speed as a sine wave function having a cycle twice the rotation angle θ of the substrate 11 based on the above formula (1). Here, A is the amplitude of the rotational speed, and is obtained by multiplying the reference speed B by the variation rate a as shown in the equation (2). α is a phase difference, and the distribution of the etching amount and the taper angle for each ion beam incident angle within the substrate surface can be optimized by changing the fluctuation rate a and the phase difference α. The range of the rotation phase θ of the substrate is 0 ° ≦ θ <360 °.

  In the example of FIG. 9, the substrate rotation speed y with respect to the substrate rotation phase θ when the reference speed B is set to 30 rpm, the variation rate a is 0.3, and the phase difference α is 45 ° is shown. In this case, when the notch or orientation flat 15 of the substrate 11 is at the positions of 0 ° and 180 °, the substrate rotation speed (rotational speed) is the slowest, and when it is at the positions of 90 ° and 270 °, it is the fastest. .

  Conversely, in order to make the substrate rotation speed the fastest when the notch or orientation flat 15 of the substrate 11 is at the positions of 0 ° and 180 °, and the slowest when it is at the positions of 90 ° and 270 °, the phase difference α may be set to −45 ° or 135 °.

  Here, specific actions and effects obtained by changing the rotation speed according to the rotation phase will be described with reference to FIG.

In FIG. 10, reference numeral 40 represents a photoresist, and 41 represents an ion beam etching object. 40 does not need to be a photoresist, and can function as a mask when processed by ion beam etching.
Consider the case where a trapezoidal trench structure is formed by ion beam etching from the state of FIG. First, FIG. 11 shows the shape of an ion beam etching target object after processing under the conditions shown in the comparative example of FIG. As described in the problem related to the present invention, the etching amount depends on the ion beam incident angle and the distribution of the taper angle after processing is caused by the positional relationship between the grid 9 and the substrate 11. Similarly, as described in the problem, this is because the incident amount and energy of the ion beam differ between a point close to the grid 9 and a point far from the grid 9.

Here, as shown in FIG. 12, at a point close to the grid 9, the surface facing the grid is 41a, and the surface facing 41a is 41b. At a distant point, the surface facing the grid 9 is 41d, and the surface facing the 41d is 41c. If rotated by 180 degrees, 41a becomes the position 41d and 41b becomes the position 41c. Therefore, 41a and 41d are equivalent, and 41b is equivalent to 41c. In the present embodiment, the problem described at the beginning is solved by reducing the time during which the faces 9a to 41d and the grid 9 face each other. That is, when 41a-41d and the grid 9 are facing each other, the time during which the 41a-41d and the grid 9 are facing is shortened by increasing the rotation speed of the substrate, and 41a-41d and the grid 9 are facing each other. If not, the time during which the grids 9 are not opposed to each other is lengthened by slowing the rotation speed of the substrate. In a state where 41a to 41d and the grid 9 do not face each other, the amount of ion beam and energy incident on 41a and 41b, 41c and 41d are equal. Further, when 41a to 41d are not opposed to the grid 9, the ion beam incident on 41a to 41d is in a relationship close to parallel to the surfaces of 41a to 41d, so that the ion beam incident amount is equal to the incident angle of the ion beam. The influence on the taper angle due to the dependence is reduced. Further, when 41a to 41d are not opposed to the grid 9, the incident amount and energy of the ion beam incident on each surface of 41a to 41d are averaged and made uniform by rotating the substrate.
In the present invention, on the side surfaces 41a to 41d after processing, the distribution of the etching amount and the taper angle is increased more than usual. That is, the present invention is not applied to a process that requires the same high uniformity in all directions, but the direction of the magnetic head read sensor or the magnetic pole of the magnetic head as shown in the above example. Is most suitably applied to processing of objects having different uniformity.

  The effect of this embodiment is demonstrated more concretely using FIG.12 and FIG.9. In order to improve the uniformity of 41a and 41b in FIG. 12, the time for 41a and 41b and the grid 9 to oppose is shortened. That is, in FIG. 9, the rotation phase at which 41a and the grid 9 face each other is 90 degrees (or 270 degrees), and the rotation phase at which 41b and the grid 9 face each other is 270 degrees (or 90 degrees). Then, the ion beam etching is performed by reducing the rotation speed at the rotation phases 0 degrees and 180 degrees where the grids 41a and 41b do not face each other. Here, for convenience of explanation, the description has been made using the relationship between the processed surfaces 41a and 41b and the grid 9, but the surface as described above is naturally not formed before the ion beam etching is started. Therefore, the rotation speed of the substrate is controlled so as to shorten the time of facing the surface where uniformity is desired on the surface formed by ion beam etching.

  In the example of FIGS. 9 and 12, the processing of the reading unit of the HDD magnetic head has been described as an example, and two surfaces facing each other in one convex portion, such as 41a and 41b, 41c and 41d, have been described as processed surfaces. However, even if there is only one surface to be processed, this embodiment is applicable. That is, as can be seen from FIG. 12, the taper angles are different between 41a and 41d. Here, it is possible to reduce the taper angle distribution as shown in FIG. 12 by performing etching while shortening the time in which 41a and 41d and the grid 9 face each other. Therefore, the essence of the present embodiment is that the time for which the surface to be processed and the grid 9 that are required to be uniform after processing is opposed is shorter than the time for which the other surface is opposed to the grid 9. In the present invention, the “surface to be processed” refers to a surface that is formed by ion beam etching or that is desired to be more uniform among surfaces to be processed. Therefore, in the example of the reading unit of the HDD magnetic head described above, 41a and 41b are referred to as “surfaces to be processed” and are described.

  In the present embodiment, the control map shown in FIG. 9 may be stored in advance in a memory such as a ROM included in the control device 20. Thus, by storing the control map in the memory in advance, when the target speed calculation unit 21a receives information on the rotational position of the substrate 11 from the position sensor 14, it is shown in FIG. 9 stored in the memory. Referring to the control map, the rotation speed corresponding to the current rotation angle θ of the substrate 11 is extracted, the target rotation speed is acquired, and the acquired target rotation speed is output to the drive signal generation unit 21b. Therefore, when the rotation angle θ is 0 degree or 180 degrees and 41a and 41b do not face the grid 9 (hereinafter also referred to as the first state), the rotation speed of the substrate 11 can be controlled to be the slowest and the rotation angle θ is 90. When 41a and 41b such as 270 degrees and 270 degrees face the grid 9 (hereinafter also referred to as a second state), the rotation speed of the substrate 11 can be controlled most quickly.

  In the present invention, the “surface to be processed” does not indicate all surfaces subjected to ion beam etching or all surfaces formed by ion beam etching, but includes surfaces formed by ion beam etching. Of these, a surface where uniformity and symmetry are particularly desired is pointed out.

  In the present invention, the first direction is a direction parallel to the surface to be processed formed by ion beam etching and parallel to the in-plane direction of the substrate. Furthermore, a direction perpendicular to the first direction and parallel to the substrate surface is defined as a second direction. That is, when the substrate holder 10 is diagonally opposite the grid 9, the state in which the grid 9 is located on the first direction side is the first state, and the state in which the grid 9 is located on the second direction side is the state. The second state is entered.

  As described above, what is important in this embodiment is that the ion beam etching in the first state is dominant over the ion beam etching in the second state, which causes variations in the shapes of 41a and 41b. It is to be. Therefore, as long as the holder rotation control unit 21 controls the rotation of the substrate holder 10 so that the rotation speed of the substrate 11 in the second state is larger than the rotation speed of the substrate 11 in the first state, the first rotation is performed. Etching in the first state can be made more dominant than etching in the second state, and the effects of the present invention can be obtained. In other words, the effect of the present invention can be obtained by making the incident component of the ion beam from the first direction larger than the incident component of the ion beam from the second direction.

  In the above description, the trench structure has been described as the concavo-convex structure formed on the substrate 11, but the present invention is also effective for the formation of other concavo-convex structures, for example, the formation of the main pole of the magnetic head.

Example 1
FIG. 13 is an explanatory diagram showing a magnetoresistive film 50 for forming a TMR element used in a magnetic head for a hard disk drive (HDD). Here, the TMR element is a magnetic effect element (TMR (Tunneling Magnetoresistance) element).

  As shown in FIG. 13, the basic layer configuration of the magnetoresistive film 50 includes a magnetic tunnel junction portion (MTJ portion) having a magnetization fixed layer, a tunnel barrier layer, and a magnetization free layer. For example, the magnetization fixed layer is made of a ferromagnetic material, the tunnel barrier layer is made of a metal oxide (magnesium oxide, alumina, etc.) insulating material, and the magnetization free layer is made of a ferromagnetic material. The magnetoresistive film 50 is formed on the lower electrode formed on the substrate 11.

  The magnetoresistive film 50 is processed by ion beam etching to form a TMR element 51 as shown in FIG. Thereafter, an insulating film 52, a lower metal film 53, a magnetic film 54, and an upper metal film 55 are formed on the sidewall surface by a film forming method such as sputtering. At this time, the taper angle and shape of the sidewall of the TMR element are desirably uniform on both side walls, and the taper angle and shape are uniform and symmetrical between the TMR elements regularly arranged on the entire surface of the substrate surface. Is desirable. Therefore, the uniformity and symmetry of the shape can be improved by using the ion beam etching apparatus and the ion beam etching method of the present embodiment.

(Second Embodiment)
As described above, in the first embodiment, the rotational speed of the substrate holder 10 is different between the first state and the second state while keeping the incident amount of the ion beam from the grid 9 to the substrate 11 constant. However, the rotation method of the substrate holder 10 may be continuous rotation or non-continuous pulse rotation. In the present embodiment, the form of the non-continuous pulse rotation will be described.

  FIG. 15A is an explanatory diagram for controlling the rotation speed of the substrate holder 10 in the case where the substrate holder 10 is continuously rotated according to the first embodiment, and FIG. It is explanatory drawing in the case of controlling the rotation stop time of a substrate rotation about the case where the substrate holder 10 is rotated discontinuously according to the embodiment.

When the substrate holder 10 is continuously rotated, as shown in FIG. 15 (a), the holder rotation control unit 21 rotates the substrate 11 during one rotation (one cycle) according to the equation (1). The drive signal is generated so as to continuously change the rotation speed (angular speed ω) of the substrate 11 so that the rotation speed of the substrate 11 is modulated for two periods. That is, the holder rotation control unit 21 controls the rotation of the substrate holder 10 so that the substrate 11 rotates continuously. In FIG. 15A, f ₀ is the reference dose of the ion beam from the grid 9, and ω ₀ is the reference angular velocity.

On the other hand, when the substrate 11 (substrate holder 10) is rotated discontinuously (clockwise), the holder rotation control unit 21 controls the rotation stop time s as shown in FIG. That is, for example, the holder rotation control unit 21 stops the rotation of the substrate 11 at a predetermined plurality of rotation angles, and the rotation unit of the substrate holder 10 rotates at a constant angular velocity (rotation speed) at other rotation angles. Thus, the rotation of the substrate holder 10 is controlled. By such control, the rotation speed of the substrate 11 is controlled so that the substrate 11 rotates discontinuously. The rotational speed of the rotating part of the substrate holder 10 may be constant as described above or may be changed. Here, the time when the angular velocity is 0 when the rotational speed (angular velocity ω) is taken on the vertical axis and the time t is taken on the horizontal axis is called “rotation stop time s”. That is, the rotation stop time s indicates a time during which the rotation of the substrate holder 10 is stopped when the substrate holder 10 is rotated discontinuously. s ₀ is the reference rotation stop time.

  In the present embodiment, it is essential to shorten the time in which the surfaces 41a and 41b face the grid 9 and lengthen the time in which the surfaces 41a and 41b do not face the grid in the first embodiment. By doing in this way, it becomes possible to improve the uniformity in the substrate surface of the taper angle of 41a and 41b. As described above, in the present embodiment, the first state and the second state appear twice each time the substrate 11 (substrate holder 10) is rotated once. Therefore, the first state and the second state are obtained by modulating the stop time of the substrate 11 (substrate holder 10) sinusoidally two cycles while the substrate 11 (substrate holder 10) rotates once (one cycle). The time of each is changed.

(Third embodiment)
In the first and second embodiments, the form of controlling the rotation speed of the substrate holder 10 has been described. In this embodiment, the power supplied from the discharge power supply 12 to the plasma forming means is controlled to the substrate. The amount of incident ion beam is controlled to improve the uniformity and symmetry of the shape between the surfaces to be processed in the concavo-convex structure. That is, in ion beam etching, the ion beam irradiation amount is related to the plasma density of the plasma formed in the plasma forming space 2, so that the plasma density in the plasma forming space 2 can be changed by changing the power supplied to the plasma forming means. Can be changed. Thereby, the ion beam irradiation amount can be changed in accordance with the angular phase of the substrate 11.

  Also in the present embodiment, as in the first embodiment, when the substrate holder 10 rotates, the etching amount in a state where the grid 9 faces the surface where uniformity is required after processing is relatively reduced. Is a big feature.

  FIG. 16 is a block diagram of the control device 20 according to the present embodiment. In the present embodiment, the control device 20 includes a power control unit 60 as a power control unit that controls the power (power) to the plasma forming unit in accordance with the rotational position detected by the position sensor 14. The power control unit 60 includes a target power calculation unit 60a and an output signal generation unit 60b, and controls the power (power) to the plasma forming unit based on the positional relationship between the rotation position of the substrate 11 and the grid 9. Has the function of

  The control device 20 is configured to receive information regarding the rotational position of the substrate holder 10 from the position sensor 14. When the control device 20 receives the information on the rotational position, the target power calculation unit 60a is configured based on the current rotational position value of the substrate holder 10 input from the position sensor 14 that detects the rotational position of the substrate holder 10. The target power (target power) at the position is calculated. The value of the target power can be calculated, for example, by holding the correspondence between the rotation position of the substrate holder 10 and the target power in advance in a memory or the like provided in the control device 20 as a map. Based on the target power calculated by the target power calculation unit 60 a, the output signal generation unit 60 b generates an output signal for setting the target power and outputs the output signal to the power supply 12. The control device 20 is configured to transmit the output signal generated by the output signal generation unit 60 b to the power supply 12.

  In the example of FIG. 16, the power source 12 is based on the deviation between the power output unit 12 a that supplies power to the plasma forming unit and the actual value (rotation position or rotation speed) output from the target value and the position sensor 14. A feedback control unit 12b that determines an operation value of the power output unit 12a. However, feedback control is not an essential configuration of the present invention.

  Also in this embodiment, as in the first embodiment, the rotation method of the substrate holder may be continuous rotation or non-continuous pulse rotation.

  FIG. 17A is an explanatory diagram of a case where the substrate (substrate holder) is continuously rotated when the power supplied to the plasma forming means is controlled according to the present embodiment, and FIG. It is explanatory drawing about the case where a board | substrate (board | substrate holder) is rotated discontinuously when controlling the electric power supplied to the plasma formation means based on this embodiment.

  In the present embodiment, the power control unit 60 can calculate the discharge power corresponding to the rotation angle θ of the substrate 11 using a double period sine wave function similar to the equation (1). That is, the power control unit 60 generates an output signal so as to modulate the power supplied to the plasma forming unit for two periods while the substrate 11 (substrate holder 10) rotates once (one period). At this time, the power supplied to the plasma forming means may be changed smoothly and continuously, or may be changed stepwise with a width. As shown in FIGS. 15A and 15B, the power control unit 60 maximizes the power (power) supplied when the rotation angle θ = 0 ° and 180 °, which is the first state. As a result, the amount of ion beam incident on the substrate 11 is maximized, and when the rotation angle θ = 90 °, 270 °, which is the second state, the above power is minimized, so that the ion beam on the substrate 11 is reduced. The discharge power source 12 may be controlled so that the incident amount is minimized.

  As described above, in the present embodiment, the power control unit 60 uses the discharge power source so that the power supplied to the plasma forming unit in the first state is larger than the power supplied to the plasma forming unit in the second state. 12 is controlled.

(Fourth embodiment)
In the third embodiment, the method for improving the uniformity of the surface to be processed by controlling the power supplied to the plasma forming unit has been described. In the present embodiment, the surface to be processed is changed by changing the beam extraction voltage. The uniformity of the taper angle is improved. In ion beam etching, after plasma is formed in the plasma forming space 2, ions are extracted from the plasma forming space 2 by a voltage applied to the grid to form a beam. Here, since the energy of the ion beam extracted from the plasma forming space 2 depends on the beam extraction voltage, the uniformity of the processed surface after processing is improved by changing the voltage in accordance with the rotation phase of the substrate.

  FIG. 18 shows an enlarged view of the grid 9 in FIG. The beam extraction voltage in this embodiment will be described with reference to FIG.

The upper side of FIG. 18 is the plasma forming space 2, and the lower side is the processing space 1.
The grid 9 includes a first electrode 70, a second electrode 71, and a third electrode 72 from the plasma formation space 2 side. FIG. 18 shows a state in which ions are extracted from the plasma generated in the plasma formation space 2 by the electrodes to form an ion beam.
A positive voltage is applied to the first electrode 70 by a first electrode power source 73.
A negative voltage is applied to the second electrode 71 by the second electrode power source 74. Since a positive voltage is applied to the first electrode 70, ions are accelerated by a potential difference from the first electrode 70.
The third electrode 72 is also called a ground electrode and is grounded. By controlling the potential difference between the second electrode 71 and the third electrode 72, the ion beam diameter of the ion beam can be controlled within a predetermined numerical range using the electrostatic lens effect.
In the present embodiment, the substrate holder and the third electrode are normally at ground potential. For this reason, the energy of the ion beam is determined by the positive voltage applied to the first electrode. Therefore, in this embodiment, the voltage applied to the first electrode is the beam extraction voltage. Hereinafter, an embodiment in which the beam extraction voltage is changed by changing the voltage applied to the first electrode will be described.

  Also in this embodiment, as in any of the embodiments, when the substrate holder 10 rotates, the etching is performed in a state in which the grid 9 is opposed to the surface required to be uniform among the surfaces formed by ion beam etching. A major feature is to relatively reduce the amount.

  FIG. 19 is a block diagram of the control device 20 according to the present embodiment. In the present embodiment, the control device 20 includes an applied voltage control unit 80 as voltage control means for controlling the voltage (beam extraction voltage) applied to the first electrode 70 in accordance with the rotational position detected by the position sensor 14. . The applied voltage control unit 80 includes a target voltage calculation unit 80 a and an output signal generation unit 80 b, and controls the voltage applied to the first electrode 70 based on the positional relationship between the rotation phase of the substrate 11 and the grid 9. It has the function to do.

  The control device 20 is configured to receive information regarding the rotational position of the substrate holder 10 from the position sensor 14. When the control device 20 receives the information on the rotational position, the target voltage calculation unit 80a is configured based on the current rotational phase value of the substrate holder 10 input from the position sensor 14 that detects the rotational phase of the substrate holder 10. Calculate the target voltage at the position. The value of the target voltage can be calculated, for example, by storing the correspondence between the rotation position of the substrate holder 10 and the target voltage in advance in a memory or the like provided in the control device 20 as a map. Based on the target power calculated by the target voltage calculation unit 80a, the output signal generation unit 80b generates an output signal for setting the target voltage, and outputs the output signal to the first electrode power source 73. The control device 20 is configured to transmit the output signal generated by the output signal generation unit 80 b to the first electrode power source 73.

  In the example of FIG. 19, the first electrode power source 73 includes an applied voltage output unit 73 a that applies a voltage to the first electrode 70, a target value, and an actual value (rotation position or rotation speed) output from the position sensor 14. ) And a feedback control unit 73b that determines an operation value of the applied voltage output unit 73a. However, feedback control is not an essential configuration of the present invention.

  Also in this embodiment, the rotation method of the substrate holder may be continuous rotation as in the first embodiment, or may be non-continuous pulse rotation as in the second embodiment.

  FIG. 20A is an explanatory diagram of a case where the substrate (substrate holder) is continuously rotated when the beam extraction voltage (that is, the voltage applied to the first electrode 70) is controlled according to the present embodiment. FIG. 20B is an explanatory diagram of the case where the substrate (substrate holder) is rotated discontinuously when the voltage applied to the grid 9 is controlled according to the present embodiment.

  In the present embodiment, the applied voltage control unit 80 can calculate the applied voltage according to the rotation angle θ of the substrate 11 using a double-period sine wave function similar to Equation (1). That is, the applied voltage control unit 80 generates an output signal so as to modulate the beam extraction voltage for two cycles while the substrate 11 (substrate holder 10) rotates once (one cycle). At this time, the beam extraction voltage may be changed smoothly and continuously, or may be changed stepwise with a width. For example, as shown in FIG. 20B, the applied voltage control unit 80 maximizes the voltage applied to the first electrode 70 when the rotation angle θ = 0 °, 180 °, which is the first state. In this case, the ion beam energy is maximized, and the first electrode is configured such that the ion beam energy is minimized by minimizing the voltage when the rotation angle θ = 90 °, 270 °, which is the second state. The power source 73 may be controlled.

  As described above, in this embodiment, the voltage application control unit 80 controls the first electrode power source 73 so that the beam extraction voltage in the first state is larger than the beam extraction voltage in the second state. Control the beam extraction voltage.

In this embodiment, the beam extraction voltage is changed by changing the voltage applied to the first electrode. However, the beam extraction voltage may be changed by other methods. For example, the beam extraction voltage may be changed by applying a positive voltage lower than that of the first electrode to the third electrode and changing the voltage applied to the third electrode. Further, the energy applied when the ion beam enters the substrate may be changed by changing the voltage applied to the substrate holder.
In the present embodiment, the grid 9 does not necessarily need to be composed of three electrodes. This is because, as described above, the essence of the present embodiment is to change the energy of the ion beam in accordance with the rotation phase of the substrate.

In the embodiment of the present invention described above, various modifications can be made without departing from the scope of the present invention.

One embodiment of the present invention can be used not only for the exemplified magnetic head for HDD but also for various fields such as HDD magnetic recording medium, magnetic sensor, thin film solar cell, issuing element, piezoelectric element, and semiconductor wiring formation. .
(Other embodiments)
In one embodiment of the present invention, both the form of controlling the rotation speed of the substrate of the first embodiment and the form of controlling the power supplied to the plasma forming means of the third embodiment may be performed. In this case, the control device 20 may be configured so that the control device 20 includes both the holder rotation control unit 21 and the power control unit 60.
In one embodiment of the present invention, the control device 20 may be incorporated in the ion beam etching apparatus as long as it can control the rotation driving mechanism of the substrate holder and the discharge power source provided in the ion beam etching apparatus. It may be provided separately from the ion beam etching apparatus through a local connection such as a LAN or a WAN connection such as the Internet.
There is also a processing method in which a program for operating the configuration of the above-described embodiment so as to realize the function of the above-described embodiment is stored in a storage medium, the program stored in the storage medium is read as a code, and executed on a computer. It is included in the category of the above-mentioned embodiment. That is, a computer-readable storage medium is also included in the scope of the embodiments. In addition to the storage medium storing the computer program, the computer program itself is included in the above-described embodiment.
As such a storage medium, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, and a ROM can be used.
In addition, the processing is not limited to the single program stored in the above-described storage medium, but operates on the OS in cooperation with other software and expansion board functions to execute the operations of the above-described embodiments. This is also included in the category of the embodiment described above.

DESCRIPTION OF SYMBOLS 1 Processing space 2 Plasma formation space 3 Exhaust pump 4 Bell jar 5 Gas introduction part 6 Antenna 7 Matching device 8 Electromagnetic coil 9 Grid 10 Substrate holder 11 Substrate 12 Discharge power supply 13 Neutralizer 14 Position sensor 15 Notch, Orientation flat 20 Control device 21 Holder Rotation controller 21a Target speed calculator 21b Drive signal generator 30 Rotation drive mechanism 31 Holder rotation driver 32 Feedback controller 40 Photoresist 50 Magnetoresistive film 51 Magnetoresistive element 52 Insulating film 53 Lower metal film 54 Magnetic film 55 Upper metal film 70 First electrode 71 Second electrode 72 Third electrode 73 First electrode power source 74 Second electrode power source

Claims (31)

Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
An ion beam etching apparatus comprising a substrate holder for holding a substrate,
The substrate holder is rotatable, and an inclination angle with respect to the grid can be changed,
Position detecting means for detecting the rotational position of the substrate;
A rotation control means for controlling the rotation speed of the substrate,
The rotation control means, when the substrate is diagonally opposite the grid,
The grid is formed on the first direction side parallel to the surface where uniformity and symmetry are desired among the surfaces processed by ion beam etching of the element formed on the substrate and parallel to the substrate surface. When the state where the grid is located on the second direction side perpendicular to the first direction and parallel to the substrate surface is the second state, the first state is the positioned state. An ion beam etching apparatus characterized in that the rotational speed of the substrate in the state 2 is faster than the rotational speed of the substrate in the first state.   The rotation control unit calculates the rotation speed as a sine wave function of a rotation angle of the substrate, and controls the rotation speed of the substrate based on the sine wave function. Ion beam etching equipment.   3. The ion beam etching apparatus according to claim 2, wherein the rotation control unit controls the rotation speed so that a sine wave of the rotation speed travels for two cycles while the substrate rotates once. Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
An ion beam etching apparatus comprising a substrate holder for holding a substrate,
The substrate holder is rotatable, and an inclination angle with respect to the grid can be changed,
Position detecting means for detecting the rotational position of the substrate;
A rotation control means for controlling the rotation stop time of the substrate,
When the substrate is diagonally opposite to the grid, the rotation control means is arranged so that the grid is parallel to the surface to be processed formed by ion beam etching and on the first direction side parallel to the substrate surface. When the state where the grid is located on the second direction side perpendicular to the first direction and parallel to the substrate surface is the second state, the first state is the positioned state. An ion beam etching apparatus characterized in that the rotation stop time of the substrate in the first state is longer than the rotation stop time of the substrate in the second state.   The rotation control means calculates the rotation stop time as a sine wave function of the rotation angle of the substrate, and controls the rotation stop time of the substrate based on the sine wave function. The ion beam etching apparatus as described.   6. The ion beam etching apparatus according to claim 5, wherein the rotation control unit controls the rotation stop time so that a sine wave of the rotation stop time advances for two cycles while the substrate rotates once. . Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
An ion beam etching apparatus comprising a substrate holder for holding a substrate,
The substrate holder is rotatable, and an inclination angle with respect to the grid can be changed,
Position detecting means for detecting the rotational position of the substrate;
Power control means for controlling power supplied to the plasma forming means,
When the substrate is diagonally opposite to the grid, the power control means is arranged so that the grid is parallel to a surface to be processed formed by ion beam etching and on a first direction side parallel to the substrate surface. When the state where the grid is located on the second direction side perpendicular to the first direction and parallel to the substrate surface is the second state, the first state is the positioned state. An ion beam etching apparatus characterized in that the power supplied to the plasma forming means in the first state is larger than the power supplied to the plasma forming means in the second state.   The ion beam etching according to claim 7, wherein the power control unit calculates the supply power as a sine wave function of a rotation angle of the substrate, and controls the supply power based on the sine wave function. apparatus.   9. The ion beam etching apparatus according to claim 8, wherein the power control unit controls the supply power so that a sine wave of the supply power travels for two periods while the substrate rotates once. Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
An ion beam etching apparatus comprising a substrate holder for holding a substrate,
The substrate holder is rotatable, and an inclination angle with respect to the grid can be changed,
Position detecting means for detecting the rotational position of the substrate;
Voltage control means for controlling the beam extraction voltage by controlling the voltage applied to the grid;
The voltage control means, when the substrate is diagonally opposite the grid,
The grid on the first direction side that is parallel to a surface that is desired to be uniform and symmetric among surfaces processed by ion beam etching of elements regularly arranged on the substrate , and parallel to the substrate surface. When the state where the grid is located on the second direction side that is perpendicular to the first direction and parallel to the substrate surface is the second state, An ion beam etching apparatus characterized in that the beam extraction voltage in the first state is larger than the beam extraction voltage in the second state.   The ion according to claim 10, wherein the voltage control means calculates the beam extraction voltage as a sine wave function of the rotation angle of the substrate, and controls the beam extraction voltage based on the sine wave function. Beam etching equipment.   12. The ion beam etching apparatus according to claim 11, wherein the power control unit controls the beam extraction voltage so that a sine wave of the beam extraction voltage travels for two cycles while the substrate rotates once. . An ion beam etching method comprising:
A substrate mounting step of mounting the substrate on a substrate holder that is rotatable and tiltable with respect to the grid;
A plasma forming step of introducing a discharge gas into the plasma forming space and forming plasma by plasma forming means;
An ion beam forming step of drawing ions from the plasma formed in the plasma forming space by a grid to form an ion beam;
An inclining step of inclining the substrate holder so that the substrate and the grid are located diagonally;
A substrate processing step of processing the substrate by irradiating the ion beam while rotating the substrate;
The substrate processing step includes
A rotational position detecting step for detecting the rotational position of the substrate;
Based on the rotational position of the substrate detected by the rotational position detection step,
The grid on the first direction side that is parallel to a surface that is desired to be uniform and symmetric among surfaces processed by ion beam etching of elements regularly arranged on the substrate , and parallel to the substrate surface. When the state where the grid is located on the second direction side that is perpendicular to the first direction and parallel to the substrate surface is the second state, And a control step of controlling the etching amount of the substrate in the first state to be larger than the etching amount of the substrate in the second state. The control step includes a rotation control step for controlling the rotation speed of the substrate,
The rotation control step increases the etching amount of the substrate in the first state by making the rotation speed of the substrate in the second state faster than the rotation speed of the substrate in the first state. The ion beam etching method according to claim 13, wherein the etching amount is larger than an etching amount of the substrate in the second state.   The rotation control step calculates the rotation speed as a sine wave function of the rotation angle of the substrate, and controls the rotation speed of the substrate based on the sine wave function. Ion beam etching method.   16. The ion beam etching method according to claim 15, wherein in the rotation control step, the rotation speed is controlled so that a sine wave of the rotation speed travels for two cycles while the substrate rotates once. The first-stage control step includes a rotation control step for controlling the rotation stop time of the substrate,
The rotation control means sets the rotation stop time of the substrate holder in the first state to be longer than the rotation stop time of the substrate holder in the second state, so that the substrate in the first state The ion beam etching method according to claim 13, wherein an etching amount of the substrate is larger than an etching amount of the substrate in the second state.   The rotation control step calculates the rotation stop time as a sine wave function of the rotation angle of the substrate, and controls the rotation stop time of the substrate based on the sine wave function. The ion beam etching method as described.   19. The ion beam etching method according to claim 18, wherein the rotation control step controls the rotation stop time so that a sine wave of the rotation stop time advances for two cycles while the substrate rotates once. . The first-stage control step includes a power control step for controlling power supplied to the plasma forming means,
The power control step increases the etching power of the substrate in the first state in the second state by making the supplied power in the first state larger than the supplied power in the second state. The ion beam etching method according to claim 13, wherein the etching amount is larger than the etching amount of the substrate.   21. The ion beam etching according to claim 20, wherein the power control step calculates the supply power as a sine wave function of a rotation angle of the substrate, and controls the supply power based on the sine wave function. Method.   22. The ion beam etching method according to claim 21, wherein the power control step controls the supply power so that a sine wave of the supply power travels for two periods while the substrate rotates once. The first-stage control step includes a voltage control step of controlling the beam extraction voltage by controlling the voltage applied to the grid,
The voltage control step increases the etching amount of the substrate in the first state by setting the beam extraction voltage in the first state to be larger than the beam extraction voltage in the second state. The ion beam etching method according to claim 13, wherein the etching amount is larger than the etching amount of the substrate.   24. The ion according to claim 23, wherein the voltage control step calculates the beam extraction voltage as a sine wave function of the rotation angle of the substrate, and controls the beam extraction voltage based on the sine wave function. Beam etching method.   25. The ion beam etching method according to claim 24, wherein in the voltage control step, the beam extraction voltage is controlled such that a sine wave of the beam extraction voltage travels for two cycles while the substrate rotates once. . Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
A substrate holder that is rotatable and tiltable with respect to the grid;
Position detecting means for detecting the rotational position of the substrate when the substrate is held on the substrate holder;
A control device for controlling an ion beam etching apparatus comprising a rotation control means for controlling the rotation of the substrate holder,
Means for obtaining information on the rotational position from the position detection means;
When the substrate is diagonally opposite the grid,
The grid is formed on the first direction side parallel to the surface where uniformity and symmetry are desired among the surfaces processed by ion beam etching of the element formed on the substrate and parallel to the substrate surface. When the state where the grid is located on the second direction side perpendicular to the first direction and parallel to the substrate surface is the second state, the first state is the positioned state. Means for generating a control signal for controlling the rotation control means so that the rotation speed of the substrate in the state of 2 is faster than the rotation speed of the substrate in the first state;
And a control unit for transmitting the generated control signal to the rotation control unit. Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
A substrate holder that is rotatable and tiltable with respect to the grid;
Position detecting means for detecting the rotational position of the substrate when the substrate is held on the substrate holder;
A control device for controlling an ion beam etching apparatus comprising a rotation control means for controlling a rotation stop time of the substrate according to a rotation position detected by the position detection means,
Means for obtaining information on the rotational position from the position detection means;
When the substrate is diagonally opposite to the grid, a state in which the grid is positioned on a first direction side parallel to the processing surface formed by ion beam etching and parallel to the substrate surface is first. When the state in which the grid is located on the second direction side that is perpendicular to the first direction and parallel to the substrate surface is the second state, the substrate in the first state Generating a control signal for controlling the rotation control means such that the rotation stop time of the substrate is longer than the rotation stop time of the substrate in the second state;
And a control unit for transmitting the generated control signal to the rotation control unit. Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
A substrate holder that is rotatable and tiltable with respect to the grid;
Position detecting means for detecting the rotational position of the substrate when the substrate is held on the substrate holder;
A control device for controlling an ion beam etching apparatus comprising power control means for controlling power supplied to the plasma forming means,
Means for obtaining information on the rotational position from the position detection means;
When the substrate is diagonally opposite to the grid, a state in which the grid is positioned on a first direction side parallel to the processing surface formed by ion beam etching and parallel to the substrate surface is first. When the second state is the state where the grid is positioned on the second direction side that is perpendicular to the first direction and parallel to the substrate surface, the supply in the first state Means for generating a control signal for controlling the power control means such that power is larger than the supplied power in the second state;
And a control unit for transmitting the generated control signal to the power control unit. Plasma forming means for forming plasma;
A plasma forming space in which plasma is formed by the plasma forming means;
A grid for extracting ions from the plasma formed in the plasma forming space;
A substrate holder that is rotatable and tiltable with respect to the grid;
Position detecting means for detecting the rotational position of the substrate when the substrate is held on the substrate holder;
A control device for controlling an ion beam etching apparatus comprising voltage control means for controlling a beam extraction voltage by controlling a voltage applied to the grid,
Means for obtaining information on the rotational position from the position detection means;
When the substrate is diagonally opposite the grid,
The grid on the first direction side that is parallel to a surface that is desired to be uniform and symmetric among surfaces processed by ion beam etching of elements regularly arranged on the substrate , and parallel to the substrate surface. When the state where the grid is located on the second direction side that is perpendicular to the first direction and parallel to the substrate surface is the second state, Means for generating a control signal for controlling the voltage control means so that the beam extraction voltage in the first state is larger than the beam extraction voltage in the second state;
And a control unit for transmitting the generated control signal to the voltage control unit.   A computer program causing a computer to function as the control device according to any one of claims 26 to 29. A storage medium storing a computer-readable program, wherein the computer program according to claim 30 is stored.