JP2007214215A - Etching device, etching method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an etching device which can sufficiently be worked into an arbitrary shape, and to provide an etching method and a program. <P>SOLUTION: The etching device 10 is provided with an ion gun 11, an XY stage 12, a control unit 13 and a PC15. An etched total amount of each region of a substrate 21 classified in a grid shape is calculated from the distribution of the thickness of the substrate 21 to which previously measured etching is performed. The PC 15 discriminates an etching time in each region so that it reaches an etched total amount. The control unit 13 controls the XY stage 12 and the ion gun 11 based on the etching time discriminated by the PC15. Since a shielding object such as a mask is not arranged between the ion gun 11 and the XY stage 12, the device can sufficiently be worked into the arbitrary shape without interrupting an etching possible region. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an etching apparatus, an etching method, and a program used for manufacturing an electronic component.

  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, after polishing the substrate, measure the thickness distribution of the substrate, or after depositing the electrode film, measure the individual frequency distribution, and pass each area through a mask. For example, Patent Document 1 discloses a method in which variation in thickness of a substrate or an electrode film is reduced by selective etching.
JP 2001-36370 A

  By the way, as disclosed in Patent Document 1, in order to reduce variation in thickness distribution, when etching is performed through a mask, not only the substrate or the thin film but also the mask surface is consumed during the etching. It is essential. In addition, particles generated by the exhaustion of the mask surface cause contamination of the element and cause a defect of the element. Further, since only a part of the etchable region can be etched, there is a problem that the time required to obtain a predetermined etching amount is increased, the manufacturing efficiency is poor, and the cost is increased.

  Therefore, an etching apparatus that does not require consumable parts such as a mask that causes element defects and can be efficiently processed into an arbitrary shape without providing a shielding object between the etching source and the substrate to be etched. There is a need for an etching method and program.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the etching apparatus, the etching method, and program which can be favorably processed into arbitrary shapes.

In order to achieve the above object, an etching apparatus according to the first aspect of the present invention comprises:
An etching source having a predetermined etching distribution;
A stage on which the object to be etched is placed;
A relative position adjusting means for adjusting a relative position between the etching source and the stage;
Based on the distribution of the etching amount of the etching object and the etching distribution of the etching source, the relative position adjusting unit and the etching device are arranged so that the total etching amount at each position of the etching object corresponds to the etching amount. Control means for controlling at least one of the etching source;
It is characterized by comprising.

The etching source irradiates the etching object with a particle beam for etching,
For example, the control unit controls the etching source and the relative position adjusting unit to control the irradiation time of the particle beam from the etching source at each position of the etching target.

The control means includes
Controlling the etching source to continuously irradiate the particle beam;
The relative position adjusting means is controlled to move the etching object with respect to the etching source by pitch feed, and by adjusting a stop time at each pitch position, the etching source from the etching source at each pitch position is adjusted. Control the irradiation time of the particle beam.

  The control means controls, for example, the relative position adjusting means to move the object to be etched at a predetermined pitch with respect to the etching source, and controls the etching source so that the etching source at each pitch position The particle beam irradiation time is controlled.

  The control means controls the moving speed of the etching object by controlling the relative position adjusting means, for example. Thereby, the total amount of etching at each position can be controlled.

  The control means controls, for example, the strength of etching particles generated by the etching source. Thereby, the total amount of etching at each position can be controlled.

  The control means controls the relative position adjustment means so that an integrated value of the intensity of etching particles generated by the etching source at each position of the etching target coincides with the distribution of the amount to be etched. To do.

  The control means, for example, irradiates from the etching source so that the integrated value of the intensity of the etching particles generated by the etching source at each position of the etching target matches the distribution of the etching amount. Control the strength of the particles produced.

  For example, the control unit controls the relative position adjusting unit to scan a predetermined area including the periphery of the etching target area of the etching target with the etching particles.

  For example, the etching distribution is represented by a Gaussian distribution or a trigonometric single waveform.

  You may further arrange | position the thickness measurement part which measures the thickness of the area | region etched by the said etching source.

  Means for obtaining a distribution of the etching amount; an arithmetic means for calculating a control pattern for controlling the etching source and the relative position control means from the distribution of the etching amount and the etching distribution of the etching source; May be further arranged.

In order to achieve the above object, an etching method according to the second aspect of the present invention comprises:
Etching for etching the etching target area by generating etching particles in the etching target area of the etching target by an etching source having a known etching distribution and moving the relative position of the etching source and the etching target. A method,
The etching source and the relative position of the etching source and the etching target are controlled so that the integrated value of the intensity of the etching particles matches the distribution of the etching amount at each position of the etching target area. It is characterized by.

In order to achieve the above object, a program according to the third aspect of the present invention provides:
Etching for etching the etching target area by generating etching particles in the etching target area of the etching target by an etching source having a known etching distribution and moving the relative position of the etching source and the etching target. In order to control the method, at each position of the etching target area, the etching source, the etching source, and the etching target so that the integrated value of the intensity of the etching particles matches the distribution of the etching amount. It is characterized by having a computer perform control of the relative position.

  According to the present invention, it is possible to perform good etching by controlling the irradiation amount of particles irradiated to each position to be etched so as to correspond to the distribution of the etching amount.

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

  FIG. 1 shows a configuration of an etching apparatus 10 according to an embodiment of the present invention. FIG. 2 schematically shows a substrate 21 to be etched by the etching apparatus 10 of the present embodiment.

  As shown in FIG. 1, the etching apparatus 10 includes an ion gun 11, an XY stage 12, a control unit 13, a vacuum chamber 14, and a PC 15. 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 an apparatus that generates an ion beam, that is, ion particles. Ar, for example, is introduced into the chamber of the ion gun 11, and Ar plasma is generated by applying a DC voltage between the anode and the filament in the chamber and causing a DC hot cathode discharge. Subsequently, Ar positive ions are accelerated by an accelerator and extracted from the extraction hole as an ion beam. The current density of the ion beam, that is, the ion density varies depending on the number and shape of the extraction holes.
Moreover, the current density distribution when these lead holes are used is shown in FIGS. The current density distribution in FIG. 4 (a) corresponds to the case of using the lead-out hole in FIG. 3 (a), FIG. 5 (b) in FIG. 3 (b), and FIG. 5 (c) in FIG. Correspond. The points are actually measured values, and the lines shown in FIGS. 4A and 5B are approximations based on a Gaussian distribution.
In each graph, the ion gun 11 and the substrate 21 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 21 is the origin and the irradiated ions. It shows the relationship with the current density of the beam.

  As will be described in detail later, in the present 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. 4A or 5B. For this reason, in this embodiment, it is preferable to use a lead-out hole in which holes having substantially the same diameter are formed as shown in FIGS. 3 (a) and 3 (b). Further, as apparent from FIGS. 4A 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 drawing 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 21 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 21 and the ion gun 11 is adjusted by the movement of the XY stage 12.

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

  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 21 measured by a measuring device such as FTIR (Fourier transform infrared spectrometer) provided in advance independently of the etching device 10. The distribution of the etching amount required in the etching target region is discriminated. Further, the PC 15 calculates the time for performing etching on each region of the substrate 21 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.

  Next, operation | movement of the etching apparatus 10 which takes the structure mentioned above is demonstrated using figures and numerical formulas.

  First, a substrate 21 to be etched is prepared. The substrate 21 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 21 is measured by, for example, FTIR (Fourier transform infrared spectrometer). Further, a current density distribution of the ion gun 11 as shown in FIGS. 4A and 5B is obtained in advance.

  Subsequently, based on the thickness distribution of the substrate 21 measured by a measuring device or the like, the PC 15 calculates the amount to be etched necessary for each region of the mesh virtually formed on the substrate 21. 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. The pitch p corresponds to the movement pitch between the ion gun 11 and the substrate 21. In this embodiment, the pitch p is set to p = 2σ from the standard deviation σ of the current density distribution of the ion gun 11. The pitch p can be set arbitrarily, and can be set to the size of the element to be manufactured.

  The etching apparatus 10 controls the XY stage 12 so that the center position of the ion beam of the ion gun 11 is sequentially stopped at the stop position of each rectangular area to be etched as shown in FIG. Irradiate for a long time. 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 etching beam is set to P. Note that 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} . 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 ..., shown by the _{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. Note that T in Equation 1 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.
(Formula 1)

Further, as described above, the current density distribution of the ion beam 11 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.
(Formula 2)

Next, as shown in FIG. 8A, 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.
(Formula 3)

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. 10 (a), etching The rate a can be calculated more easily and is preferable. For example, in the example shown in FIG. 10A, 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. 8B, 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 Equation 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. 8C, 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 represented 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 21 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}
...
(Formula 8)

  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. 9, the substrate 21 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 21 and the peripheral region of the substrate 21 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 n columns are set to P (n, n). In order to satisfactorily etch the peripheral region of the substrate 21 during the etching, a stop position is provided in a region wider than the substrate 21. Therefore, for example, as shown in FIG.

  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. In the two-dimensional model, such a description can be performed. 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 ion gun 11 is at a predetermined stop position P (n, n), the ratio of the etching rate a (m, m) in the peripheral region to the etching rate a (n, n) at the center of the stop position is previously shown. It is preferable to calculate as a table as shown in 10 (b) because the etching rate of each region can be easily calculated. For example, in the example shown in FIG. 10, 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, n) adjacent to P (n, n) is a as shown by a (n-1, n) = 0.8 · a (n, n). It can be expressed using (n, n).

  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 21 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.
The PC 15 transmits information (control pattern information) that associates each stop position P thus obtained with the etching time T at that position to the control unit 13. The control unit 13 controls the XY stage 12 and the ion gun 11 using the control pattern information, and performs predetermined etching on each region.
Specifically, the control unit 13 i) controls the XY stage 12 to move the substrate 21 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 21 with the ion beam is repeated. The ion beam is continuously irradiated from the start to the end of etching.
As the movement pattern of the XY stage 12, for example, P (−i, −i) shown in the figure moves in order from P (−i, N + i), and then P (−i + 1, N + i) to P (− The operation of moving each column such as moving to 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 21 almost entirely, and the total etching amount (integrated value of the irradiation amount) at each position on the substrate 21 is The relative position between the ion gun 11 and the substrate 21 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 match the etching amount (expected value) of the position. Therefore, the ion beam emitted from the ion gun 11 can be efficiently used for etching, and the processing time can be shortened and the energy efficiency can be increased as compared with the case where a shielding mask is used. Further, since the stop time (that is, irradiation time) T at each position is controlled so that the beam irradiation amount (total etching amount) at each position matches the etching amount (expected value) at that position, the desired etching amount Can be obtained.

The present invention is not limited to the above-described embodiment, and various modifications and applications are possible.
For example, 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 FIGS. 4 to 5, and may be a steeper slope or a gentler slope. A narrow irradiation range or 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-described embodiment, the operation example in which the substrate 21 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 has been described. However, the present invention is not limited to this control pattern. For example, the substrate 21 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 as a whole. An etching amount distribution may be obtained. In this case, for example, when there is an etching center in a predetermined area, the center of the area is assumed to be a stop position, and the time during which the etching center exists in each area is considered as the pitch feed interval of the above-described embodiment. Thus, 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 21 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 by making the moving speed or the time interval of pitch feeding constant.
For example, the control unit 13 i) controls the XY stage 12 to move the substrate 21 to be etched at a predetermined pitch p, and ii) stops the XY stage for a certain time after the pitch feed is completed, The control is repeated such that the substrate 21 is irradiated with the ion beam for a time T corresponding to each stop position.

Further, the movement speed or pitch feed interval (movement distance, stop time) of the XY stage 12 is made constant, and the current density of the ion beam irradiated from the ion gun 11 is controlled in each region, that is, the etching intensity is changed. It is also possible to adopt a configuration to make it.
Also in this case, the intensity of the ion beam emitted from the ion gun 11 is controlled so that the total amount (particle amount) of the ion beam irradiated to each position of the substrate 21 to be etched matches the planned etching amount.

  Note that the moving speed of the relative position between the substrate 21 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 21 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 thickness of the substrate 21 and the thickness of the thin film formed on the substrate 21 are measured using an apparatus provided outside the etching apparatus is described as an example. A measuring instrument may be provided in the apparatus. By providing a measuring instrument in the etching apparatus, the thickness of the substrate or the like can be measured again after the etching process, and the process can be repeated to increase the accuracy. Further, by measuring the thickness simultaneously with the etching process, the accuracy can be improved, and the processing time can be shortened. In addition, the measuring device can be used for calculating the etching amount before the etching process.

  In the above-described embodiment, the case where the control unit 13 controls the stage control unit of the XY stage and the ion gun 11 based on the etching time calculated by the PC 15 is described as an example. The control 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 the above-described embodiment, the ion gun has been described as an example of the etching source. However, the etching source is not limited to this as long as it generates etching particles such as ion particles, an etching source such as plasma, an electron beam, and reactivity. Plasma etching or the like can be used.

  According to the etching method of the embodiment described above, the object to be etched changes in a quasi-continuous shape in which adjacent regions are discontinuous and continuous as a whole. However, it is possible to obtain a desired shape. Further, the planar shape of the substrate is exemplified by the rectangular substrate 21, 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, in the above-described embodiment, the ion gun 11 that is an etching source is fixed and the XY stage 12 on which the substrate 21 is installed is moved to adjust the etching region. The etching source can be moved while being fixed, or both the etching source and the substrate 21 can be moved to move the relative position.

  Moreover, although the substrate 21 such as a semiconductor wafer is illustrated as an etching target, 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.

It is a figure which shows typically the structural example of the etching apparatus which concerns on embodiment of this invention. It is a figure which shows typically the board | substrate etched with the etching apparatus which concerns on embodiment of this invention. 3 (a) to 3 (c) are diagrams showing nozzles of extraction holes of the ion gun. (A) is a figure which shows current density distribution at the time of using the lead-out hole shown to Fig.3 (a). FIG. 5B is a diagram showing a current density distribution when the extraction hole shown in FIG. 3B is used, and FIG. 5C is a diagram when the extraction hole shown in FIG. 3C is used. It is a figure which shows current density distribution. It is a figure which shows a board | substrate when an etching source moves only to a one-dimensional direction and etching is performed. It is a figure which shows the current density distribution in each stop position of an ion gun. (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 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 etching rate ratio when an etching source moves only to a one-dimensional direction, (b) is the ratio of the etching rate when an etching source moves to a two-dimensional direction. It is a figure which shows this table typically.

Explanation of symbols

10 Etching Equipment 11 Ion Gun (Etching Source)
12 XY stage 13 Control unit 14 Vacuum chamber 15 PC
21 Substrate

Claims (14)

An etching source having a predetermined etching distribution;
A stage on which the object to be etched is placed;
A relative position adjusting means for adjusting a relative position between the etching source and the stage;
Based on the distribution of the etching amount of the etching object and the etching distribution of the etching source, the relative position adjusting unit and the etching device are arranged so that the total etching amount at each position of the etching object corresponds to the etching amount. Control means for controlling at least one of the etching source;
An etching apparatus comprising: The etching source irradiates the etching object with a particle beam for etching,
The said control means controls the said etching source and the said relative position adjustment means, and controls the irradiation time of the particle beam from the said etching source in each position of the said etching target object, It is characterized by the above-mentioned. The etching apparatus according to 1. The control means includes
Controlling the etching source to continuously irradiate the particle beam;
Irradiation of the particle beam at each pitch position by controlling the relative position adjusting means to move the etching object with a pitch feed relative to the etching source and adjusting a stop time at each pitch position. The etching apparatus according to claim 2, wherein the time is controlled. The control means includes
Controlling the relative position adjusting means to move the object to be etched at a predetermined pitch with respect to the etching source;
The etching apparatus according to claim 2, wherein the etching source is controlled to control the irradiation time of the particle beam from the etching source at each pitch position.   The etching apparatus according to claim 1, wherein the control unit controls the moving speed of the etching target by controlling the relative position adjusting unit.   The etching apparatus according to claim 1, wherein the control unit controls the strength of etching particles generated by the etching source.   The control means controls the relative position adjustment means so that an integrated value of the intensity of etching particles generated by the etching source at each position of the etching target coincides with the distribution of the amount to be etched. The etching apparatus according to claim 1, wherein   The control means adjusts the strength of the etching particles so that the integrated value of the strength of the etching particles generated by the etching source matches the distribution of the etching amount at each position of the etching target. The etching apparatus according to claim 1, wherein the etching apparatus is controlled.   9. The control unit according to claim 1, wherein the control unit controls the relative position adjusting unit to scan a predetermined area including the periphery of the etching target area of the etching target object with the etching particles. The etching apparatus according to claim 1.   The etching apparatus according to claim 1, wherein the etching distribution is expressed by a Gaussian distribution or a single waveform of a trigonometric function.   11. The etching apparatus according to claim 1, further comprising a thickness measuring unit that measures a thickness of a region to be etched by the etching source. Means for obtaining a distribution of the etching amount;
An arithmetic means for calculating a control pattern for controlling the etching source and the relative position control means from the distribution of the etching amount and the etching distribution of the etching source;
The etching apparatus according to claim 1, further comprising: Etching for etching the etching target area by generating etching particles in the etching target area of the etching target by an etching source having a known etching distribution and moving the relative position of the etching source and the etching target. In the method
The etching source and the relative position of the etching source and the etching target are controlled so that the integrated value of the intensity of the etching particles matches the distribution of the etching amount at each position of the etching target area. Etching method characterized by the above. Etching for etching the etching target area by generating etching particles in the etching target area of the etching target by an etching source having a known etching distribution and moving the relative position of the etching source and the etching target. To control the way
Control of the etching source and the relative position of the etching source and the etching target so that the integrated value of the intensity of the etching particles matches the distribution of the etching amount at each position of the etching target area. ,
A program that causes a computer to execute.

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