JP5277390B2 - Etching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an etching device capable of satisfactorily processing a substrate into an arbitrary shape, an etching method, an etching program, and a film forming device. <P>SOLUTION: An etching device 30 is provided with an ion gun 11, an XY stage 12, a control unit 13, and a PC 15. An etching amount of each of regions divided like a grid of a substrate 31 to be etched is calculated in accordance with a distribution of the thickness of the substrate 31 which is preliminarily measured, and the PC 15 determines an etching time in each region so that the region is etched up to the etching amount. In the case of the existence of a region of which the etching time is negative, this region is covered with a shutter 40 to prevent the excessive etching of the region of which the etching time is negative. Thus the substrate 31 is processed into an arbitrary shape. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to an etching equipment utilized in the manufacture of electronic components.

  Conventionally, in the field of manufacturing semiconductors and electronic components, a technique of forming a thin film on a substrate to form a device is generally used. For example, taking a piezoelectric element as an example, an electrode film is formed on a wafer or substrate made of a piezoelectric material, and several tens to several thousands of elements are formed, and then divided into individual elements. Is manufactured.

  The piezoelectric element differs depending on the vibration mode to be used. For example, in a vibration element using thickness-shear vibration, the frequency is determined by the thickness of the substrate and the thickness of the electrode film. Therefore, the frequency accuracy is determined by the accuracy of these thicknesses. Even in the surface acoustic wave device, the frequency accuracy is determined by the accuracy of the thickness of the electrode film. Therefore, in order to obtain a desired frequency accuracy with these elements, it is important to control the thickness of the substrate and the electrode film.

  However, the precision of the polishing technique currently used for the substrate is not sufficient, and a thickness distribution occurs in the substrate. Furthermore, since an electrode film formed by sputter deposition also has a thickness distribution, elements formed on the same substrate have a problem in that frequency characteristics vary.

  Therefore, in order to suppress variations in the thickness within the substrate, there is a configuration in which the total amount to be etched in each region of the substrate is calculated in advance, and the etching time to reach the total amount to be etched is calculated for each region (for example, Patent Documents) 1).

JP 2007-214215 A

  By the way, if the total amount to be etched is calculated in advance and the etching time for each region is calculated as disclosed in Patent Document 1, there is a region where there is no solution of the etching time, that is, the etching time is negative. There is a problem. In such a case, if etching is performed, there is a problem that etching is performed more than necessary in a region where there is no solution. The above-mentioned problem is similarly the same in that an excessively formed region is generated in the film formation.

  For this reason, the etching time that reaches the total amount to be etched is calculated for each area, preventing unnecessary etching in areas where there is no solution, reducing variation in thickness distribution, and processing into any desired shape There is a need for an etching apparatus, an etching method, an etching program, and a film forming apparatus that can perform the above process.

The present invention was made in view of the above circumstances, and an object thereof is to provide an etching equipment capable of satisfactorily processed into any shape.

In order to achieve the above object, the etching apparatus of the present invention comprises:
An etching source for irradiating a particle beam;
A stage on which a plurality of etching objects are placed;
A relative position adjusting means for adjusting a relative position between the etching source and the stage;
Control means for controlling the etching source and the relative position adjusting means,
The etching source has a grid for extracting the particle beam;
The particle beam has a predetermined current density distribution on a surface on which the etching object is placed,
Based on the distribution of the etching amount of the etching object and the current density distribution of the particle beam, the control means is configured so that the total etching amount at each position of the etching object corresponds to the etching amount. When the etching time of the particle beam at each position of the etching object is calculated and there is a position where the etching time is negative in the calculation, the current density distribution when the irradiation range of the particle beam is narrowed again, after performing the calculation of the etching time, the etching time at each position of said etching object, to determine the irradiation range of the particle beam,
The control means changes at least one of the potential of the grid and the discharge voltage so as to narrow the irradiation range of the particle beam around a position where the etching time is negative in calculation, or the etching source The grid is replaced with a different grid by the grid exchanging means provided in the above.

  The grid is divided into divided acceleration grids each formed with a group of holes,
  The hole group formed in the divided acceleration grid and the hole group formed in another divided acceleration grid may have different shapes.

According to the present invention, an etching device that can be satisfactorily processed into an arbitrary shape by preventing excessive etching in a region where the etching time is negative when calculating the etching time to reach the total amount to be etched. it is possible to provide a location.

  An etching apparatus, an etching method, an etching program, and a film forming apparatus according to each embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows the configuration of the etching apparatus 30 according to the first embodiment. FIG. 2 schematically shows a substrate 31 to be etched by the etching apparatus 30 of this embodiment.

  As shown in FIG. 1, the etching apparatus 30 includes an ion gun 11, an XY stage 12, a control unit 13, a vacuum chamber 14, a PC 15, and a shutter 40. The ion gun 11 and the XY stage 12 are installed in a vacuum chamber 14 and are shielded from the atmosphere by the vacuum chamber 14.

  The ion gun 11 is a device that generates an ion beam. Ar, for example, is introduced into the chamber of the ion gun 11, and a DC voltage is applied between the anode and the filament in the chamber to generate a DC hot cathode discharge to generate Ar plasma. Subsequently, Ar positive ions are accelerated by an accelerator and extracted from the extraction hole as an ion beam. The ion gun is not limited to the one using direct current hot cathode discharge, and an RF ion source or a microwave ion source may be used. The current density of the ion beam, that is, the ion density varies depending on the number and shape of the extraction holes. In addition, FIG. 5 shows the current density distribution when these lead holes are used. The current density distribution in FIG. 5 (a) corresponds to the case of using the drawing hole in FIG. 4 (a), FIG. 5 (b) in FIG. 4 (b), and FIG. 5 (c) in FIG. Correspond. The points are actually measured values, and the lines shown in FIGS. 5A and 5B are approximations by Gaussian distribution. In each graph, the ion gun 11 and the substrate 31 to be etched are arranged facing each other, and the distance from the origin when the position facing the center of the ion gun 11 of the substrate 31 is the origin and the irradiated ions. It shows the relationship with the current density of the beam.

  As described later in detail, in this embodiment, the etching time is calculated by approximating the current density distribution of the ion beam irradiated from the ion gun 11 with a Gaussian distribution and calculating the etching rate. Therefore, it is preferable that the current density distribution can be approximated by a Gaussian distribution as shown in FIG. 5 (a) or (b). For this reason, in this embodiment, it is preferable to use the lead-out hole in which the hole of substantially the same diameter was formed like FIG. 4 (a), (b). Further, as is clear from FIGS. 5A and 5B, when the number of holes is increased, the current density distribution tends to spread sideways. Therefore, the number of holes may be adjusted according to the fineness of etching to be performed. In addition, since the current density distribution can be controlled by adjusting the shape, number, arrangement, discharge current, distance between the etching source and etching target, etc. of the hole, when calculating with a Gaussian distribution, trigonometric function, etc. These conditions may be adjusted in advance so that the distribution can be obtained. Note that the current density distribution does not necessarily have to be represented as a waveform using a Gaussian distribution, a trigonometric function, or the like, and an actual measurement value can also be used. In this case, it is possible to use a lead-out hole in which holes having different diameters are formed as shown in FIG.

  The XY stage 12 includes a stage 12a, a stage control unit including a sequencer, a stage driving unit including a motor, and the like. As shown in FIG. 1, a substrate 31 to be etched is placed on the surface of the mounting table 12a facing the ion gun 11. The stage drive unit of the XY stage 12 is controlled by the stage control unit, and the stage control unit is further controlled by the control unit 13. The stage 12a moves the mounting table 12a in the X-axis and Y-axis directions (horizontal plane in FIG. 1). The movement form of the XY stage 12 may be a pitch feed (a process of repeating an operation of moving a certain distance and temporarily stopping), or a form of continuous movement while changing the constant speed or speed. In this embodiment, since the ion gun 11 as an etching source is fixed, the relative position between the substrate 31 and the ion gun 11 is adjusted by the movement of the XY stage 12.

  As shown in FIG. 1, the shutter 40 is installed between the substrate 31 and the ion gun 11. As shown in FIG. 3A, the shutter 40 includes a shutter unit 41, a shutter drive unit 42, and guide rails 43 and 44. The shutter unit 41 has an area corresponding to one region on the substrate 31 and covers the substrate 31 when performing etching, thereby suppressing excessive etching of the substrate 31. The shutter unit 41 is installed between guide rails 43 and 44 installed side by side in the X-axis direction, and the shutter unit 41 is moved along the guide rails 43 and 44 by a shutter driving unit 42 made of a motor or the like. . The shutter drive unit 42 is controlled by the control unit 13 and is located at a desired location at a desired timing. Further, since the guide rails 43 and 44 are disposed on the substrate 31 at the time of etching as shown in FIG. 3A, the guide rails 43 and 44 are formed with a width that does not hinder the etching. As will be described in detail later, there may be a case where a plurality of shutter parts 41 are installed because a plurality of areas may be covered at the same time. Alternatively, contrary to FIG. 3A, a mask-shaped shutter that exposes an area corresponding to one region on the substrate 31 may be used. Although an example is shown in FIG. 3B, the present invention is not limited to this, and a shape that exposes areas corresponding to a plurality of regions on the substrate 31 may be used. The shutter shown in FIG. 3B may be provided with a moving mechanism (not shown) such as an XY stage that positions the exposed surface in an arbitrary region on the substrate 31.

  When the shutter 41 is installed and etched as in the present embodiment, the surface of the shutter 41 is also consumed by the ion beam. At this time, particles may be generated. However, the shutter 41 is provided only for the entire etching time, and such particles do not cause a problem.

  The control unit 13 includes, for example, a microprocessor and controls the ion gun 11, the XY stage 12, and the shutter 40 in accordance with etching conditions such as an etching time calculated by the PC 15 and conditions for covering the substrate with the shutter. .

  The PC 15 is composed of a personal computer or the like. As will be described later in detail, the PC 15 is based on the thickness distribution of the substrate 31 measured by a measuring device such as FTIR (Fourier transform infrared spectrometer) provided in advance independently of the etching device 30. The distribution of the etching amount required in the etching target region is discriminated. The means for measuring the thickness of the substrate is not limited to FTIR (Fourier Transform Infrared Spectrometer), and for example, the thickness may be measured from the transmittance or reflectance of measurement light. Alternatively, when a piezoelectric element is used for the substrate, the frequency may be measured. Further, the PC 15 calculates the time for performing etching on each region of the substrate 31 from the distribution of the etching amount, the current density distribution (etching distribution) of the etching beam, the moving speed of the XY stage 12, and the like. As a result of the calculation, when there is a region where the etching time is a negative value, the timing and position at which the shutter 40 is disposed between the substrate 31 and the ion beam are calculated. In this embodiment, the PC 15 calculates the etching time with a constant etching distribution. However, the etching time and the etching intensity may be calculated with the etching distribution being variable. It is only necessary to calculate the etching dose and control both the etching time and the etching intensity. Alternatively, the etching strength may be calculated with a constant etching time.

  Next, operation | movement of the etching apparatus 30 which takes the structure mentioned above is demonstrated using figures and numerical formula.

In the present embodiment, as shown in the flowchart of FIG. 12, after calculating the etching time (step S31), if there is a negative solution in the etching time (step S32; Yes), the shutter is in a region where there is no solution. The time and timing for covering are determined (step S33), and the etching process is performed in the flow of performing the etching process (step S34). Each process is described in detail below.

  First, a substrate 31 to be etched is prepared. The substrate 31 has an area where a plurality of elements can be formed as shown by dotted lines in FIG.

  Next, the thickness distribution of the substrate 31 is measured by, for example, FTIR (Fourier transform infrared spectrometer). Further, a current density distribution of the ion gun 11 as shown in FIGS. 5A and 5B is obtained in advance.

  Subsequently, based on the thickness distribution of the substrate 31 measured by a measuring apparatus or the like, the PC 15 calculates the amount to be etched necessary for each region of the mesh virtually formed on the substrate 31. Further, the PC 15 calculates an etching process control pattern from the etching amount necessary in each region, the current density distribution (etching distribution) of the ion beam, and the like according to the following mathematical formula.

  In order to facilitate understanding, a description will first be given using a one-dimensional model. As shown in FIG. 6, it is assumed that an object to be etched has a configuration in which N square regions having the same side as the pitch p are arranged in a row at a constant pitch p. Note that the pitch p corresponds to the moving pitch between the ion gun 11 and the substrate 31. In this embodiment, the pitch p is set as p = σ / 2 from the standard deviation σ of the current density distribution of the ion gun 11. Note that the setting of the pitch p is not limited to a square shape, and may be set arbitrarily, and may be set to the size of an element to be manufactured.

  The etching apparatus 30 controls the XY stage 12 to sequentially stop the center position of the ion beam of the ion gun 11 at the stop position of each rectangular area to be etched as shown in FIG. Irradiate for hours. The total amount etched when stopped at each position is the total etching amount of each region.

Here, the stop position at the center of the ion beam is set to P. In this embodiment, several beam stop positions are set from the end of each region so that each end region is sufficiently etched. Therefore, as shown in FIG. 6, the beam stop positions are P _i ,..., P ₋₂ , P ₋₁ , P ₀ , P ₁ , P ₂ ..., P _n , ..., P _N , P _{N + 1} . _{N + i} . The stop position P may be set as P ₁ , P ₂ ..., P _n ,..., P _N−1 , P _N so as to be equal to each region of the mesh virtually formed on the substrate. Alternatively, when the total amount of etching required in the end region of the substrate is small, the stop position P is set to P _i , P _{i + 1} , P so that the number is smaller than each region of the mesh virtually formed on the substrate. ..., P _n , ..., P _{N- (i + 1)} , P _N-i . The smaller the range of the stop position P, the more effectively the ion beam can be used. Next, when the etching time at each stop position is T, the etching time at each stop position is T _−i ,..., T ₋₂ , T ₋₁ , T ₀ , T ₁ , T ₂ . _{T n, ..., T n,} T n + 1 ..., represented by _{T n + i.} Further, the etching amount of each region _{E 1, E 2 ..., E} n, ..., and _{E N.} In this embodiment, the moving distance at the time of pitch feeding is constant, and the time for stopping at the stop position of each area is set for each area. Therefore, the etching time T indicates the beam stop time at the stop position P.

  In general, the etching amount E is given by Equation 1 shown below. In Equation 1, T is the etching time by the ion gun 11, and C is a proportional constant determined by the sputtering rate S, the molecular weight M, the Avogadro number NA, the density D, the elementary charge e of electrons, and the like.

  Further, as described above, the current density distribution of the ion beam is known, and this distribution can be approximated by a Gaussian distribution as shown in Equation 2 below. Note that A in Equation 2 is the total area between the curve and the baseline in the Gaussian distribution, and w is twice the standard deviation σ.

Next, as shown in FIG. 7A, when the center of the ion beam is at a certain stop position P _n , the etching rate a ₀ of the region corresponding to the center of the ion beam is set to a ₀ = I _bd · C. . The etching rate _a 1 in the peripheral region at this time stopping position _{P n, a 2, a 3} , ..., a m and _{a -1, a -2, ...,} a -m is from etching center x of Equation 2 By substituting the separation distance pm, the following equation 3 can be obtained.

From the above, when the ion beam is at the stop position _Pn and the irradiation time is _Tn , the etching amount of each region can be expressed by the following Equation 4 for each stop position. Note that when the ion beam is positioned in the stop position P _n, previously obtained in advance the ratio of the etch rate of each area with respect to the etching rate of the stop position P _n, idea to the table as shown in FIG. 11 (a), etching The rate a can be calculated more easily and is preferable. For example, in the example shown in FIG. 11A, the area adjacent to the stop position is 0.8, and the area adjacent to the stop position is 0.6. Therefore, the etching rates a ₁ and a ₂ are respectively a ₁ = 0.8 · a ₀ , a ₂ = 0.6 · a ₀ and a ₀ can be used.

(Formula 4)
...
P _n-2 ; a ₋₂ T _n
P _n-1 ; a _-1 T _n
P _n ; a ₀ T _n
P _{n + 1} ; a ₁ T _n
P _{n + 2} ; a ₂ T _n
...

Further, as shown in FIG. 7B, when the center of the ion beam is at the stop position P _{n + 1} and the irradiation time is T _{n + 1} , the etching amount of each region is expressed by the following formula 5.

(Formula 5)
...
P _n-2 ; a _-3 T _{n + 1}
P _n-1 ; a ₋₂ T _{n + 1}
P _n ; a ₋₁ T _{n + 1}
P _{n + 1} ; a ₀ T _{n + 1}
P _{n + 2} ; a ₁ T _{n + 1}
...

Further, as shown in FIG. 7C, when the center of the ion beam is at the stop position P _n-1 and the irradiation time is T _n−1 , the etching amount of each region is expressed by the following formula 6. It is.

(Formula 6)
...
P _n-2 ; a ₋₁ T _n−1
P _n-1 ; a ₀ T _n-1
P _n ; a ₁ T _n-1
P _{n + 1} ; a ₂ T _n−1
P _{n + 2} ; a ₃ T _n-1
...

Above all stop position _{to (P -i, ..., P -2} , P -1, P 0, P 1, P 2 ..., P n, ..., P N, P N + 1 ..., P N + i) applied to Thus, the total etching amount of each region of the substrate 31 is represented by the following formula 7, which can be further represented by the following formula 8, which is a determinant.

(Formula 7)
...
P _n−2 ; E _n−2 = a _{mT n−m−2} +... + A ₋₁ T _n−1 + a ₋₃ T _{n + 1} +... + A _−m T _{n + m−2
P n-1; E n-} 1 = a m T n-m-1 + ... + a 0 T n-1 + a -2 T n + 1 + ... + a -m T n + m-1
_{P n; E 0 = a m} T n-m + ... + a 1 T n-1 + a -1 T n + 1 + ... + a -m T n + m
P _{n + 1} ; E _{n + 1} = a _m T _{n−m + 1} +... + A ₂ T _n−1 + a ₀ T _{n + 1} +... + A _−m T _{n + m + 1}
P _{n + 2} ; E _{n + 2} = a _m T _{n−m + 2} +... + A ₃ T _n−1 + a ₁ T _{n + 1} +... + A _−m T _{n + m + 2}
...

  Here, as described above, since the etching rate a is given as a constant if the distance from the center of the ion gun 11 is determined, Equations 7 and 8 correspond to the multiple simultaneous linear equations of the etching time T. Therefore, a sufficient approximate solution can be obtained by a known solution method such as Gauss-Jordan elimination method, LU decomposition method, Gauss-Saudel iteration method or the like. In this way, the etching time T at each stop position P can be obtained.

  Next, the above one-dimensional model is applied to two dimensions. First, as shown in FIG. 10, a substrate 31 to be etched is divided into a grid shape and divided into a plurality of square regions each having a pitch p. Next, the stop position of the ion gun 11 on the region of the substrate 31 and the peripheral region of the substrate 31 is set to P, and the stop position of the region of 1 row and 1 column is set to P (1, 1) as in the one-dimensional case. 1 row and 2 columns are set to P (1, 2)... N rows and m columns are set to P (n, m). In this embodiment, a stop position is provided in a region wider than the substrate 31 so that the peripheral region of the substrate 31 can be satisfactorily etched at the time of etching. For example, as shown in FIG. The stop position P may be a region equal to the substrate or may be a region narrower than the substrate. Although it is premised that the total amount of etching required for the region at the edge of the substrate is small, the ion beam can be used more effectively.

Next, the etching rate of each region when the ion gun 11 is at a predetermined stop position is obtained using Equations 2 and 3. In the one-dimensional model, the distance from the beam can be expressed in pm using only the formula 3 and the pitch interval p and the number of pitches m from the stop position. Is the same or the same column as the stop position of the ion gun. Therefore, the etching rate of the region that is not in the same column or the same row as the stop position is obtained by substituting the distance from the stop position (for example, the center distance between the regions) into x in Equation 2. When the center of the ion beam is at the stop position P (n, m), the etching rate of the region corresponding to the center of the ion beam is a _0,0 . At this time, the etching rate of the peripheral area (n + i, m + j) around the stop position P (n, m) is a _{i, j} and is calculated as a table in FIG. FIG. 9 shows the etching irradiation area divided into grids with a pitch p. The pitch p corresponds to the movement pitch between the ion gun 11 and the substrate 31. When the ion gun 11 is at a predetermined stop position P (n, m), the etching rate a _{i, j} (n + i, m + j) of the peripheral region with respect to the etching rate a _0,0 (n, m) at the center of the stop position. It is preferable to calculate the ratio in advance as a table as shown in FIG. 11B because the etching rate of each region can be easily calculated. For example, in the example shown in FIG. 11, the intensity of the area where the ion gun 11 stops is 1, the intensity of the upper and lower areas and the left and right areas adjacent to the stop position is 0.8, and the intensity of each of the upper and lower areas is 0. .6. When this is used, the etching rate of P (n−1, m) adjacent to P (n, m) uses a _0,0 as a _−1,0 = 0.8 · a _0,0. Can be expressed.

  Next, the etching time of each region is set as T, and the same expression as Expression 8 is established. In 1D and 2D, the number of terms only increases, and in the 2D model, there are multiple linear simultaneous equations as in the 1D model. Therefore, a sufficient approximate solution can be obtained by a known solution method such as Gauss-Jordan elimination method, LU decomposition method, Gauss-Saudel iteration method or the like. In this way, the etching time for each region of the substrate 31 can be calculated even with the two-dimensional model.

  In the above-described two-dimensional model, the multi-dimensional simultaneous linear equation has several tens to several thousand dimensions depending on the setting of the region division method, the pitch feed movement distance, etc., but the order is linear, so the PC 15 is configured. It is possible to obtain a sufficiently approximate solution with the processing capability of the personal computer. At this time, as the distribution of the etching source (ion gun 11), a simple even function is easier to calculate, and a distribution represented by a Gaussian distribution or a trigonometric function is preferable.

  In this way, the PC 15 calculates the etching time T at each stop position P (step S31).

  Next, when there is no negative region in the solution of the etching time T (step S32; No), the etching process is performed based on the calculated time (step S34). There is no solution in the etching time T, that is, the time is negative. If there is a region (which is 0 depending on the calculation method) (step S32; Yes), etching cannot be performed even if the ion gun 11 is actually installed in this region. It means to be etched. Therefore, it is necessary to compensate for this. Here, when a negative region occurs in the solution of the etching time T, the etching time becomes zero if 0 is substituted into the region without the solution and recalculated (assuming the negative etching time is 0). Only the region is excessively etched and the peripheral region is not excessively etched. In this embodiment, the etching time is substantially shortened by covering with a shutter during the etching time.

Specifically, the total etching amount E (x, y) of the region P (x, y) is expressed by the following Equation 9 in a substrate having an N × M region. Here, _{Ex, y} means the total etching amount E (x, y) of the region P (x, y), and _{ai, j} is the center of the ion gun in the region P (xi, yj). The etching rate of the region P (x, y) when it is located means T _{x, y} means the etching time when the center of the ion gun is located in the region P (x, y). The etching rate at each position is as shown in FIG.

(Formula 9)
E _{x, y} = a _{K, L} · T _{xK, yL} + ... + a _0,0 · T _{x, y} + ... + a _{i, j} · T _{xi, yj} + a _{i, j + 1} · T _{xi, yj-1} + ... + a _{-K, -L}・ T _{x + K, y + L}

When the etching time T (x, y) of the region P (x, y) is negative, a _0,0 · T _{x, y} is negative in Equation 9. That is, the a _0,0 · T _x, E excluding _{y x, y} means that you have taken a _0,0 · T _x, absolute value of many of _y, that is, the excessive etching. Therefore, when the ion beam is stopped in the region P (x, y) and the ion gun 11 is located in a region other than P (x, y), the etching of the region P (x, y) is | a _{0. , 0} · T _{x, y} | Therefore, for example, a _{i, j} · T _{xi, yj} having a value close to | a _0,0 · T _{x, y} | is discriminated, and P (x, y) is determined at the timing of etching T _{xi, yj.} The shutter part 41 is arranged on the top. Note that the shutter unit 41 may be covered with two or more regions.

  In the case where 0 is not substituted into a region having no solution and recalculation is not performed, not only the region P (x, y) but also the ion beam 11 is located in the region P (x, y). Similarly, even in the peripheral region irradiated with T, the T (x, y) becomes negative, and therefore, excessive etching is performed by a · T (x, y). Therefore, the same treatment as that for the region P (x, y) is required for the peripheral region. For this reason, a plurality of shutter portions 41 of the shutter 40 may be installed. However, when the excessive etching amount falls within a predetermined allowable range, such a countermeasure is unnecessary.

  The PC 15 associates each stop position P thus obtained with the etching time T at that position (control pattern information), the position information of the area covering the shutter, and the installation time information (shutter information). Is calculated (step S33) and transmitted to the control unit 13. The control unit 13 controls the XY stage 12, the ion gun 11 and the shutter 40 using the control pattern information, and performs predetermined etching on each region (step S34).

  Specifically, the control unit 13 i) controls the XY stage 12 to move the substrate 31 to be etched at a predetermined pitch p, and ii) controls the XY stage 12 after the pitch feed is completed, The control of stopping for the stop time T and irradiating the substrate 31 with the ion beam is repeated. The ion beam is continuously irradiated from the start to the end of etching. In addition, the shutter unit 41 is moved to a predetermined area on the substrate 31 at a predetermined timing.

  Note that the movement pattern of the XY stage 12 is, for example, sequentially moved from P (−i, −i) to P (−i, M + i) shown in FIG. 10 and subsequently from P (−i + 1, M + i). The operation of moving each column such as moving to P (−i + 1, −i) may be performed for all rows. In addition, the direction, order, etc. which perform etching are arbitrary.

  Thus, according to the present embodiment, ions emitted from the ion gun 11 irradiate the substrate 31 almost entirely, and the total etching amount (integrated value of the irradiation amount) at each position on the substrate 31 is the position. The relative position of the ion gun 11 and the substrate 31 and the stop time at each relative position, in other words, the irradiation time of the ion beam from the ion gun 11 are controlled so as to coincide with the etching amount (expected value). At this time, if there is no solution of the irradiation time, it is possible to prevent excessive etching by covering the region with the shutter portion 41 when other regions are etched. Thereby, excessive etching can be prevented and the substrate 31 can be etched into a desired shape.

  In particular, in this embodiment, since the substrate 31 is covered by the shutter unit 41 for a predetermined time, a complicated operation is not necessary, and it can be applied when etching an integrated substrate. In the embodiment shown in FIG. 12, the shutter is operated based on the etching time T once calculated, but the PC 15 may recalculate the etching processing time based on the shutter information. For example, after determining the shielding region and shielding time by the shutter, the etching processing time T may be recalculated. Since there is a region having a large total etching amount necessary around the region where the etching time is not solved, for example, when etching a region having a large total etching amount, the mask shape shown in FIG. A shutter may be arranged. In the case where not only the excessively etched region but also other regions are shielded by the shutter, it is necessary to recalculate the etching processing time.

(Second Embodiment)
An etching apparatus, etching method, and program according to the second embodiment will be described. This embodiment is different from the first embodiment described above in the first embodiment in which a shutter is provided in a region where there is no solution in the etching time to prevent etching more than desired. By replacing the etching target object (for example, a piezoelectric element such as a quartz crystal resonator) installed in a region without any etching with the etching target object installed in a region with a small amount of etching, and performing recalculation, the region without solution It is in the point of eliminating the occurrence of. For this reason, in this embodiment, the object to be etched is not an integral substrate, but includes a plurality of workpieces, and the workpieces can be replaced.

  FIG. 13 shows a configuration of an etching apparatus 50 according to the second embodiment. FIG. 13 schematically shows an etching object 51 to be etched by the etching apparatus 50 of the present embodiment.

  As shown in FIG. 13, the etching apparatus 50 includes an ion gun 11, an XY stage 12, a control unit 13, a vacuum chamber 14, a PC 15, and a robot arm 53. The ion gun 11, the XY stage 12, and the robot arm 53 are installed in the vacuum chamber 14 and are shielded from the atmosphere by the vacuum chamber 14.

  In the present embodiment, as shown in FIGS. 14A and 14B, a workpiece 51a such as a crystal resonator that is subject to etching has a recess corresponding to the shape of the workpiece 51a. It is installed in the placement part 51c. When further etching is performed, a mask 51b having an opening corresponding to the shape of the workpiece 51a is provided.

  The robot arm 53 is installed in the vacuum chamber 14 and is controlled by the control unit 13. The workpiece 51a shown in FIGS. 14A and 14B is replaced by the robot arm 53. FIG. For example, when the etching time is calculated as in the first embodiment, if a region where the etching time is negative (it is 0 depending on the calculation method) is generated as shown in FIG. 15, the workpiece in this region is processed. 51a is replaced with a workpiece that can be further etched from the calculated etching amount, that is, a workpiece 51a in a region where the etching amount has an allowable range.

Next, the etching process of this embodiment is demonstrated using the flowchart of FIG.
First, as in the first embodiment described above, the total etching amount of each region (each workpiece) is calculated, and the etching time of each region is calculated (step S51).

  When there is no minus in the calculated time (step S52; No), the processing is performed with the calculated etching time (step S58). On the other hand, when there is a negative solution in the calculated etching time (step S52; Yes), the robot arm 53 is driven to replace the workpiece (step S53). At this time, the workpiece to be replaced with the workpiece in the minus region is selected so that the etching amount has an allowable range. If there is a workpiece having an allowable range in etching amount, a workpiece having a wider allowable range is selected. For example, when the area of the stop position P is not sufficiently large with respect to the substrate area, the workpiece placed in the peripheral area of the substrate is less likely to enter the ion beam irradiation range of the ion gun 11 and is etched. In many cases, the tolerance range is wide.

  Next, after the replacement, the etching time is calculated again (step S54). Thereby, when there is no negative solution (step S55; No), the etching process is performed with the calculated etching time (step S58). If there is a negative solution (step S55; Yes) and the recalculation has not been performed a predetermined number of times (step S56; No), the workpiece is replaced again (step S53), and the recalculation is performed. Perform (step S54). When recalculation is performed a predetermined number of times (step S56; Yes), an error is transmitted and the process is stopped.

  In the present embodiment, when the etching time is calculated from the total etching amount and a region without a solution is generated, the workpiece in the region without the solution and the workpiece having an allowable etching amount are replaced. By calculating the etching time again, it is possible to eliminate the generation of a solution-free region. Therefore, even if a negative solution occurs in the etching time, excessive etching can be prevented and the etching target can be processed into an arbitrary shape.

The work piece in the solution-free area has a smaller amount of etching than the work piece in the adjacent area, so the total work amount in the range away from the solution-free area compared to the work piece in the adjacent area. May be replaced with a workpiece in a large area. In addition, after measuring the thickness of the substrate (or the frequency when a crystal resonator is used for the substrate) and calculating the total amount of etching required for each region, the total amount of etching is extremely reduced by the PC 15 compared to the adjacent surrounding region. The etching time may be calculated after detecting a large region or a small region and exchanging a workpiece placed in this region with another region. In this case, the PC 15 detects a workpiece that needs to be replaced from the difference in the total amount of etching between adjacent regions, so that the distribution of the total amount to be etched becomes gentle.
In the second embodiment, the workpieces are automatically replaced, but may be replaced manually.

(Third embodiment)
An etching apparatus, etching method, and program according to the third embodiment will be described. This embodiment is different from the above-described embodiments in that the present embodiment does not provide a shutter, does not replace the etching target, changes the irradiation range of the ion beam itself, and performs recalculation. . For this reason, in this embodiment, the object to be etched may be an integrated substrate, and it may be possible to replace workpieces as in the second embodiment.

  As shown in FIG. 17, the etching apparatus 60 includes an ion gun 61, an XY stage 12, a control unit 13, a vacuum chamber 14, and a PC 15. The ion gun 61 and the XY stage 12 are installed in the vacuum chamber 14 and are shielded from the atmosphere by the vacuum chamber 14.

  The ion gun 61 of the present embodiment is characterized in that, for example, the irradiation range of the ion beam is changed by changing the voltage applied to the grid portion from which the ion beam is extracted or the discharge voltage. For example, the width of the ion beam irradiated from the ion gun 61 is changed to a beam width A and a beam width B as shown in FIG. By changing the beam width in this way, the etching rate ratio changes as shown in FIGS. 19A and 19B. For example, in FIG. 19A corresponding to the beam width A, the ratio of the etching rate in the central region where the ion gun 61 is installed is 1.0, and is 0.8 in the region adjacent to the central region. Further, the etching rate ratio is 0.6 next to the adjacent region, that is, the region diagonally above and below the center region. On the other hand, in FIG. 19B corresponding to the beam width B, the ratio of the etching rate in the central region where the ion gun 61 is installed is 1.0, whereas in the region adjacent to the central region, it is 0.4. In the region diagonally above and below the center region, the value is 0.2.

  The negative etching time means that the region is excessively etched when the peripheral region of the region is etched. Therefore, by reducing the beam width in the peripheral region, it is possible to reduce the etching amount received in the region where the negative solution has occurred.

The etching process of this embodiment is demonstrated using the flowchart of FIG.
First, similarly to the first embodiment described above, the total etching amount of each region (each workpiece) is calculated, and the etching time of each region is calculated (step S61).

  When there is no minus in the calculated time (step S62; No), processing is performed with the calculated etching time (step S65). On the other hand, when the calculated etching time has a negative solution (step S62; Yes), the ion beam width is set narrow in the peripheral region of the region where the negative solution has occurred. For example, the etching rate calculated in FIG. 19A is replaced with the rate shown in FIG. 19B (step S63). Next, the etching time is recalculated at an etching rate with a narrow beam width (step S64), and an etching process is performed based on the etching time (step S65).

  As described above, in this embodiment, when a negative solution occurs in the etching time, the beam width of the ion gun during the etching in the peripheral region including the region is narrowed, and recalculation is performed to calculate the etching time again. Etching is performed. Thereby, even if a negative solution occurs in the etching time, excessive etching can be prevented and the etching target can be processed into an arbitrary shape.

  In the example shown in FIG. 17, the ion beam width A and the ion beam width B are obtained by changing the voltage applied to the grid. However, a plurality of ion guns having different ion beam widths may be prepared and processed by replacing the ion guns. . Alternatively, the ion beam width may be changed by providing a mechanism for exchanging the grid or a mechanism capable of opening and closing at least a part of the holes formed in the grid. Alternatively, a shielding grid 115, an acceleration grid 116, and a deceleration grid 117 may be provided as in the ion gun shown in FIG. 21, and the acceleration grid 116 may be divided into divided acceleration grids 116a and 116b. Moreover, a hole group having a different shape may be formed in each of the divided acceleration grids 116a and 116b, and the grid to which a voltage is applied may be switched. For example, an ion beam width A is obtained by applying an acceleration potential to the divided acceleration grid 116a shown in FIG. 22 and a positive potential to the divided acceleration grid 116b, an acceleration potential is applied to the divided acceleration grid 116b, and a positive potential is applied to the divided acceleration grid 116a. For example, the ion beam width B may be obtained by applying. The ion gun shown in FIG. 21 corresponds to FIG. 1 of Japanese Patent Application No. 2008-054137, and the grid potential can be switched by referring to Japanese Patent Application No. 2008-054137. You may refer to the configuration of

The present invention is not limited to the above-described embodiments, and various modifications and applications are possible.
For example, in the first embodiment described above, the integrated substrate 31 has been described as an example. However, the present invention is not limited to this, and can be applied to a case where a plurality of workpieces are etched as in the second embodiment. It is.

  Further, the distribution of the current density (ion density) of the ion beam emitted from the ion gun 11 is not limited to that shown in FIG. 5, and may be a steeper or gentler gradient, and a narrower irradiation range. However, a wider irradiation range may be used. Furthermore, the peak value of the current density may be larger or smaller. However, it is premised on having etching performance.

  In the above embodiment, the operation example is described in which the substrate 31 is moved at a constant pitch by the XY stage 12, and the stop time at each stop position is changed to change the ion beam irradiation time. However, the present invention is not limited to this control pattern. For example, the substrate 31 is moved at a continuous speed v, and the ion gun 11 is controlled and the ion beam irradiation time T is changed for each region as desired. An etching amount distribution may be obtained. In this case, for example, when there is an etching center in a predetermined region, the center of the region is assumed to be a stop position, and the time during which the etching center exists in each region is considered as the pitch feed interval of the above-described embodiment. The etching time by the ion gun can be calculated using the above-described mathematical formula. Further, the ion gun 11 is continuously irradiated from the start to the end of etching, the substrate 31 to be etched is moved at a speed v, and the speed v is changed, so that a desired etching amount distribution is obtained as a whole. May be.

  In the above-described embodiment, the moving distance for moving the XY stage 12 is constant, the stop time is controlled, and the time for irradiating the ion beam from the ion gun 11 is controlled. However, the present invention is not limited to this. It is also possible to adjust the etching time by changing the irradiation time by the ion gun 11 with the speed or pitch feed time interval being constant. For example, the control unit 13 i) controls the XY stage 12 to move the substrate 31 to be etched at a predetermined pitch p, and ii) stops the XY stage for a certain time after the pitch feed is completed, Control is repeated so that the substrate 31 is irradiated with the ion beam for a time T corresponding to each stop position.

  Note that the moving speed of the relative position between the substrate 31 and the XY stage 12, the etching time by the ion gun 11, and the etching intensity are not necessarily constant, and any two of them may be changed. And you may change everything.

  Further, the calculation method of the control pattern by the PC 15 is not limited to the above-described method, and is arbitrary. That is, the etching particles irradiated to each position (each point on the virtual mesh) of the substrate 31 to be etched between the start of the etching process and the end of the entire etching (however, a level that can contribute to the etching) The total amount (time integral value) of the energy) has a moving speed, feed speed, irradiation time, irradiation intensity, and current so that the etching amount (expected value) as a whole matches (almost) the amount to be etched (expected value). What is necessary is just to obtain | require time-sequential patterns, such as a density distribution. And the control part 13 should just perform control according to this control pattern.

In the above-described embodiment, the case where the control unit 13 controls the stage control unit and the ion gun 11 of the XY stage based on the etching time calculated by the PC 15 is described as an example. However, the control of the XY stage 12 and the ion gun 11 is described. The method is not limited to this. For example, the XY stage 12 can be controlled by the control unit 13 without using a stage control unit composed of a sequencer, or the function of the control unit 13 can be given to the PC 15. Further, the movement amount of the XY stage 12 may be fed back to the control unit 13 or the PC 15.
In this embodiment, an ion gun as an etching source is fixed and the substrate is moved by an XY stage. However, the substrate may be fixed and the ion gun may be moved by an XY stage. Alternatively, the substrate may be moved in the X-axis direction and the ion gun may be moved in the Y-axis direction.

  In the above-described embodiment, the ion gun has been described as an example of an etching source. However, the etching source is not limited to this as long as it generates etching particles, and an etching source such as plasma, an electron beam, and reactive plasma etching are used. It is possible.

  According to the etching method of the embodiment described above, the object to be etched is a quasi-continuous shape whose adjacent regions are discontinuous and continuous as a whole. It is also possible to obtain a desired shape. Further, the planar shape of the substrate is exemplified by the rectangular substrate 31, but is not limited thereto, and may be, for example, a circle, an ellipse, or a polygon. Furthermore, as long as the shape changes continuously, it is not limited to a flat plate shape, and may be a curved surface shape.

Further, the substrate 31 such as a semiconductor wafer is illustrated as an etching target, but the etching target is arbitrary, and a semiconductor wafer, a film of an arbitrary material formed on the wafer, a base of an arbitrary material, and a substrate thereon The layer formed is optional.
In the first to third embodiments, an etching source is used, but the present invention can also be applied to film formation such as vapor deposition and sputtering. The total amount of etching in the above embodiment is set to a film forming amount necessary until the target film thickness, and the etching (mass removal) in the above embodiment is formed as a film formation (mass addition). A similar process may be performed to avoid it.

It is a figure which shows typically the structural example of the etching apparatus which concerns on 1st Embodiment. It is a figure which shows typically the board | substrate etched with the etching apparatus which concerns on 1st Embodiment. (A) is a figure explaining a shutter. (B) is a figure which shows the modification of a shutter. 4 (a) to 4 (c) are diagrams showing nozzles of ion gun lead-out holes. (A) is a figure which shows current density distribution at the time of using the extraction | drawer hole shown to Fig.4 (a). (B) is a figure which shows current density distribution at the time of using the lead-out hole shown in FIG.4 (b). (C) is a figure which shows the current density distribution at the time of using the lead-out hole shown in FIG.4 (c). It is a figure which shows a board | substrate when an etching source moves only to a one-dimensional direction and etching is performed. (A) is a figure which shows the current density distribution in the stop position Pn. (B) is a diagram showing a current density distribution at the stop position Pn + 1. (C) is a figure which shows the current density distribution in the stop position Pn-1. It is a figure which shows the current density distribution in each stop position of an ion gun. It is a figure which shows the etching rate a computed as a table. It is a figure which shows a board | substrate when an etching source moves to a two-dimensional direction and etching is performed. (A) is a figure which shows typically the table of the ratio of the etching rate when an etching source moves only to a one-dimensional direction. (B) is a figure which shows typically the table of the ratio of the etching rate at the time of an etching source moving to a two-dimensional direction. It is a flowchart of the etching process of 1st Embodiment. It is a figure which shows typically the structural example of the etching apparatus which concerns on 2nd Embodiment. (A) is a figure which shows typically the etching target object etched with the etching apparatus which concerns on 2nd Embodiment. FIG. 14B is a sectional view taken along line B-B shown in FIG. It is a figure explaining replacement of a processed material. It is a flowchart of the etching process of 2nd Embodiment. It is a figure which shows typically the structural example of the etching apparatus which concerns on 3rd Embodiment. It is a figure which shows a beam width typically. (A) is a figure which shows typically the table of the ratio of the etching rate of beam width A. FIG. (B) is a figure which shows typically the table of the ratio of the etching rate of beam width B. FIG. It is a flowchart of the etching process of 3rd Embodiment. It is a figure which shows an ion gun typically. It is a figure which shows the division | segmentation acceleration grid of the ion gun shown in FIG.

Explanation of symbols

30, 50, 60 Etching device 11, 61 Ion gun (etching source)
12 XY stage 13 Control unit 14 Vacuum chamber 15 PC
31 Substrate 40 Shutter 41 Shutter unit 42 Shutter drive unit 43, 44 Guide rail 51 Etching object

Claims (2)

An etching source for irradiating a particle beam;
A stage on which a plurality of etching objects are placed;
A relative position adjusting means for adjusting a relative position between the etching source and the stage;
Control means for controlling the etching source and the relative position adjusting means,
The etching source has a grid for extracting the particle beam;
The particle beam has a predetermined current density distribution on a surface on which the etching object is placed,
Based on the distribution of the etching amount of the etching object and the current density distribution of the particle beam, the control means is configured so that the total etching amount at each position of the etching object corresponds to the etching amount. When the etching time of the particle beam at each position of the etching object is calculated and there is a position where the etching time is negative in the calculation, the current density distribution when the irradiation range of the particle beam is narrowed again, after performing the calculation of the etching time, the etching time at each position of said etching object, to determine the irradiation range of the particle beam,
The control means changes at least one of the potential of the grid and the discharge voltage so as to narrow the irradiation range of the particle beam around a position where the etching time is negative in calculation, or the etching source An etching apparatus characterized in that the grid is exchanged with a different grid by a grid exchange means provided in the apparatus. The grid is divided into divided acceleration grids each formed with a group of holes,
The etching apparatus according to claim 1, wherein a hole group formed in the divided acceleration grid and a hole group formed in another divided acceleration grid have different shapes.

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