JP2000192239A - Sputtering method and sputtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sputtering method capable of inexpensively forming a film with high productivity while both the improvement of the utilizing efficiency of a target and the good film thickness uniformity of the thin film are achieved and to provide a sputtering device. SOLUTION: To both end sides in a moving range st of a magnet 8 in which it is moved parallel along the outside face 3b on the side opposite to the face 3a to be sputtered in a target 3, acceleration-deceleration moving regions with the same width ea are respectively set, and the region other than the acceleration-deceleration moving regions in the moving range st is set to a uniform speed moving region be. The control of its movement is executed in such a manner that, when the magnet 8 enters the acceleration-deceleration moving regions from the uniform speed moving region be, it is moved to the end part in the moving range st while it is decelerated at certain deceleration, directly after the temporary stop at the end part in the moving range st, it is moved toward the opposite direction while it is accelerated within the acceleration-deceleration moving regions at certain acceleration, and, when it enters the uniform speed moving region be, it transfers to uniform speed movement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sputtering method and a sputtering apparatus for depositing a thin film having a uniform thickness on a substrate having a relatively large area.

[0002]

2. Description of the Related Art For example, in manufacturing a large liquid crystal display device, it is necessary to form a thin film on a rectangular flat glass substrate having a relatively large area with a uniform thickness. Generally, a sputtering apparatus having a configuration as shown in FIG. 13 is used.

In this sputtering apparatus, a substrate 2 made of, for example, rectangular flat glass to be formed into a film and a target 3 of a sputtering material are vertically opposed to each other in a vacuum vessel 1 connected to a ground potential. Is provided. The substrate 2 is horizontally supported by a plurality of support pins 6 of a substrate support 5 above the inside of the vacuum vessel 1. On the other hand, the target 3 is arranged such that a surface to be sputtered (upper surface in the figure) 3a and an outer surface (lower surface in the figure) 3b face the inside and outside of the vacuum vessel 1, respectively, and an insulator 7 is interposed therebetween. It is fixed to the vacuum vessel 1 in an electrically insulated state.

A ball screw 1 rotatably driven by a motor 9 is provided outside the target 3 with respect to the vacuum vessel 1.
0 is provided in parallel with the outer surface 3b of the target 3, and the magnet 8 reciprocating linearly moved along the ball screw 10 by forward and reverse rotation of the ball screw 10 moves along the outer surface 3b of the target 3. To move in the longitudinal direction. As a result, magnetic lines of force 13 are generated in the vicinity of the surface of the target surface 3a to be sputtered. A power supply 4 is connected between the target 3 and the vacuum vessel 1. That is, the cathode of the power supply 4 is connected to the target 3, and the anode is connected to the vacuum vessel 1.

For example, when an aluminum film is formed to a uniform thickness on a large-area glass substrate 2 by using the above-mentioned sputtering apparatus, the target 3 and the glass substrate 2 made of aluminum are formed as shown in FIG. Install in such an arrangement. The inside of the vacuum vessel 1 is evacuated from an exhaust port 11 by driving a vacuum pump (not shown) to a high vacuum state, and then an argon gas (discharge gas) is introduced from a gas inlet 12 to a pressure of several mTorr. Gas pressure. In this state, when a high voltage is applied between the vacuum vessel 1 and the target 3 from the power supply 4, plasma 14 is generated at a position near the surface 3 a of the target 3 to be sputtered.

The high-energy positive argon ions in the plasma 14 are incident on the target 3 having a negative potential. As a result, sputter particles and secondary electrons are ejected from the target 3. These secondary electrons collide with argon molecules and ionize gas molecules. The sputtered particles are substances in the target 3 and deposit on the surface of the glass substrate 2 to form a thin film. Here, the secondary electrons cannot travel straight due to the magnetic lines of force 13 and perform helical motion along the magnetic lines of force 13, so that the probability of the secondary electrons colliding with the argon molecules increases. As a result, the plasma density is increased at the location where the lines of magnetic force 13 are generated, and the target 3 is locally consumed by sputtering at a location facing the portion having a high plasma density. Therefore, by moving the magnet 8 in parallel with the target 3 by rotating the motor 9, the plasma 1 is moved.
The reference numeral 4 moves integrally with the lines of magnetic force displaced with the movement of the magnet 8. Thus, the entire target 3 can be effectively used by the movement of the plasma 14, and the aluminum film having excellent film thickness uniformity can be formed on the large-area glass substrate 2 by well controlling the movement of the magnet 8. A film can be formed.

[0007]

By the way, the sputtered particles ejected from the target 3 fly not only in the shortest distance toward the substrate 2 arranged in parallel with the target 3 but also in an oblique direction. Therefore, in order to form a thin film having a uniform thickness on the large-sized glass substrate 2 as described above, a target 3 having a large area capable of containing the glass substrate 2 is used, and the target 3 is reciprocated linearly. The moving range of the magnet 8 is
When the magnet 8 is moved to the leftmost position and the rightmost position of the moving range and stopped, the thickness of the end portion of the substrate 2 is the same as that of the other portions. Must be stationary for the required amount of time before moving in the opposite direction.

However, since the magnet 8 is kept stationary at both ends of the moving range for a certain period of time, as shown in FIG. 14 showing the remaining thickness of each part of the target 3 after use, both ends of the target 3 are magnetized. 8 is still exposed to the plasma 14 when it is in a stationary state, so that it is locally eroded. Therefore, in this sputtering apparatus, since only the both ends of the target 3 are quickly eroded to an unusable state, there is a problem that the utilization efficiency of the target 3 is very low, about 20%. In order to prevent the magnet 8 from being stopped at both ends of the moving range, the target 3 having a sufficiently large length with respect to the substrate 2 is used to move the magnet 8 in the moving direction of the magnet 8 on the substrate 2. In this case, the size of the apparatus is increased by the size of the target 3 and the cost is increased.
The productivity decreases as the moving range becomes larger.

In view of the above, the present invention has been made in view of the above-mentioned problems, and is intended to provide a low-cost and high-productivity film formation while achieving both improvement in target use efficiency and good film thickness uniformity. It is an object of the present invention to provide a sputtering method and a sputtering apparatus that can be used.

[0010]

In order to achieve the above object, the present invention provides a vacuum vessel in which a target made of a sputtering material of the same system as a thin film to be formed and a substrate for film formation are opposed to each other. By applying a voltage between the target and the vacuum vessel in a discharge gas atmosphere in a vacuum state, a plasma is generated near the surface of the target to be sputtered on the target facing the substrate, and the plasma is generated. A magnet is moved in parallel along a surface of the target opposite to the surface to be sputtered while depositing sputter particles emitted from the target by the incidence of ions therein on the surface of the substrate to form a thin film. In this way, the movement of the plasma is controlled by the lines of magnetic force of the magnet, and the sputtering for forming a thin film on the surface of the substrate is performed. In the moving method, an acceleration / deceleration movement area having the same width is set on each end side within the movement range of the magnet, and an area excluding both the acceleration / deceleration movement areas in the movement range is set as a constant velocity movement area, The magnet
When entering the acceleration / deceleration movement area from the constant velocity movement area, move to the end of the movement range while decelerating, and then move while accelerating the acceleration / deceleration movement area in the opposite direction, When the vehicle enters the constant-velocity movement area, the movement is shifted to the constant-velocity movement, and the movement is controlled so as to reciprocate a plurality of times within the movement range.

In this sputtering method, since the magnet is not stopped at both ends of the moving range, both ends of the target are not locally eroded unlike the conventional method, and the utilization efficiency of the target is remarkably improved. Also, the magnet
When the vehicle enters the acceleration / deceleration movement area, the movement is controlled so as to move to the end of the movement range while being decelerated, and to move in the opposite direction while accelerating in the opposite direction until reaching the constant velocity movement area. As a result, the magnet in the acceleration / deceleration movement area is moved in a speed distribution in which the movement speed becomes slower toward the end of the movement range when moving in any direction when reciprocating in the area. Therefore, a thin film having a uniform thickness can be formed over the entire substrate, even though the magnet is not stopped at the end of the moving range for a certain period of time.

In the above invention, a target made of a material containing at least 90 wt% of aluminum is used,
Assuming that the erosion interval of the plasma in the moving direction of the magnet is ep, the width of the substrate in the moving direction of the magnet is sw, and the distance between the substrate and the target is ts, the moving range st of the magnet and the acceleration / deceleration moving area on both ends thereof are defined. Width ae, s
t> sw + ep / 2 + 0.64 ts + 75 mm, 0.29 ts <ae
It is preferable to set each to a value that satisfies the formula of <0.57 ts.

The above two formulas are obtained based on experimental results, and the aluminum content is at least 90 wt%.
In the case of using a target made of the above-described material, the optimum value of the magnet moving range and the width of the acceleration / deceleration moving region at both ends within a range that can satisfy the condition that the film thickness uniformity of the thin film is approximately ± 5% Respectively.

Therefore, while a thin film having a uniform thickness is formed over the entire substrate, the moving range of the magnet and the widths of the acceleration / deceleration moving regions on both ends thereof can be set as small as possible. There is an advantage that can be obtained together with an improvement in productivity.

[0015] The sputtering apparatus of the present invention further comprises a vacuum vessel into which a discharge gas is introduced into a vacuum state;
A substrate for film formation and a target of a sputtering material disposed facing each other inside the vacuum vessel, a power supply for applying a voltage between the target and the vacuum vessel, and outside the vacuum vessel, A magnet moved in parallel along the outer surface of the target opposite to the surface to be sputtered opposite to the substrate, an erosion interval of plasma in a moving direction of the magnet, a width of the substrate in a magnet moving direction and the substrate; Signal output means for outputting, as a control command signal, a movement range of the magnet calculated based on each data of the distance to the target and a width of an acceleration / deceleration movement region set on both sides of a constant speed movement region within the movement range; Controlling the driving source of the magnet based on the control command signal output from the signal output means, and moving the magnet And magnet movement control means for controlling the movement speed, wherein the magnet movement control means moves toward the end of the movement range while decelerating at a constant deceleration within the acceleration / deceleration movement area, Immediately after being paused at the end of the movement range, the movement in the opposite direction is started, and the movement of the magnet is controlled so as to move while accelerating at a constant acceleration until reaching the constant velocity movement area. I have.

In this sputtering apparatus, the sputtering method of the present invention can be embodied with a simple configuration and the same effect as that of the above method can be reliably obtained. The optimum value of the magnet movement range and the width of the acceleration / deceleration movement area on both sides within the range where the required film thickness uniformity can be obtained is automatically calculated, and the calculated data is set in the magnet movement control means. be able to.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic vertical sectional view showing a sputtering apparatus according to an embodiment of the present invention. In FIG. 1, the same or equivalent elements as those in FIG. This sputtering apparatus differs from that shown in FIG. 13 only in the configuration in which magnet movement control means 17 and signal output means 18 are additionally provided. The signal output means 18 outputs the movement range of the magnet 8 calculated based on various conditions described later and the movement speed distribution of the magnet 8 within the movement range to the magnet movement control means 17 as a control command signal. The magnet movement control means 17 controls the rotation speed and the rotation time by varying the power to be supplied to the motor 9 and the power supply time based on the control command signal received from the signal output means 18, thereby controlling the magnet 8 to a required value. Movement control is performed with a required speed distribution within the movement range.

More specifically, the signal output means 18 and the magnet movement control means 17 control the movement of the magnet 8 as follows. That is, the moving range of the magnet 8 is set to an optimum width corresponding to various conditions described later, and acceleration / deceleration moving regions having a predetermined width are set at both ends of the moving range. Then, the magnet 8 is moved at the same speed as in the past in the center constant-velocity movement region other than the acceleration / deceleration movement region in the movement range, and moves into the acceleration / deceleration movement region while decelerating at a constant deceleration. Then, when stopping at the end of the moving range, the U-turn is immediately made in the opposite direction without stopping, and is moved while accelerating at a constant acceleration in the acceleration / deceleration movement area. Movement control is performed so as to shift to constant speed movement at the same speed.

Next, the calculation of the moving range of the magnet 8 and the data of the moving speed distribution within this moving range will be described. FIG. 2 shows a substrate 2, a target 3, a magnet 8, and a plasma 1.
FIG. 4 is a perspective view for explaining a positional relationship between a movement range 4 of a magnet 4 and a magnet 8. In this embodiment, various experiments are performed on a case where an aluminum thin film is formed on the surface of the substrate 2 using a target made of a material containing at least 90 wt% of aluminum, and the moving range of the magnet 8 is determined based on the actual measurement results. A formula for calculating each optimum value of the width of the acceleration / deceleration movement area was obtained.

Prior to the calculation of the control data for obtaining the optimum moving speed distribution, the erosion (concentration point of the plasma 14) interval ep in the moving direction of the magnet 8 and the width sw of the substrate 2 in the moving direction of the magnet 8 shown in FIG. An experiment was conducted in which the distance ts between the substrate 2 and the target 3, the moving range st of the magnet 8, and the width ae of the acceleration / deceleration moving region at both ends in the moving range st were variously changed, and an experiment was performed to form an aluminum thin film. The film thickness uniformity of the aluminum thin film was evaluated. Hereinafter, the results will be described. In addition,
A region other than the acceleration / deceleration movement region set to the predetermined width ae at both ends in the movement range st of the magnet 8 is a constant speed movement region b.
e. Further, the width th and the length ero of the erosion in the direction orthogonal to the moving direction of the magnet 8 in the target 3 are shown.
Is set to be at least larger than the width hw of the substrate 2 in a direction orthogonal to the moving direction of the magnet 8.

[0021] FIG. 3 is a characteristic diagram showing the measured values of the relationship between the movement range st ₅ of the magnet 8 to the width sw of the substrate 2 that satisfies the 5% thickness uniformity ±. The respective characteristic curves of A to E in the figure are (ts = 120, ep = 60), (ts
= 70, ep = 100), (ts = 70, ep = 60), (ts
= 70, ep = 30) and (ts = 40, ep = 60) when measured under the condition (unit: mm). Here, the width ae of the acceleration / deceleration movement area on both ends in the movement range st is set to an optimum value that allows the best film thickness uniformity to be obtained under the respective film formation conditions. The film forming technique by sputtering on a large-area substrate 2 which is an object of the present invention is currently mainly used for forming a wiring film in a large-sized liquid crystal display device. Uniformity is ± 10%. On the other hand, the reason why the film thickness uniformity is set to ± 5% as described above is to find the movement range st of the magnet 8 that can secure a margin in the width ae of the acceleration / deceleration movement area. is there.

[0022] Figure 3, which shows the dependence on the width sw of the substrate 2 in the moving range st ₅ of the magnet 8 that satisfies the thickness uniformity ± 5% as described above, as is clear from FIG. In addition, the characteristic is a substantially straight line having a slope of “1”. That is, the characteristics satisfy the following equation (1).

St ₅ = sw + f (ts, ep) (1) where f (ts, ep) is a function of the distance ts between the substrate 2 and the target 3 and the erosion interval ep, and FIG. FIG. 9 is a characteristic diagram showing the dependence of the function f (ts, ep) on the distance ts between the substrate 2 and the target 3 and the erosion interval ep. F, G, in FIG.
The characteristic curves of H are (ts = 120), (ts = 70),
This is an actually measured value when the film forming conditions are set to (ts = 40). Here, the width ae of the acceleration / deceleration movement area on both ends in the movement range st is set to an optimum value that allows the best film thickness uniformity to be obtained under the respective film formation conditions. As is clear from the figure, the function f (ts, ep) is obtained by adding a constant to half of the erosion interval ep. That is, it is understood that the following equation (2) holds.

F (ts, ep) = ep / 2 + g (ts) (2) where g (ts) is the distance t between the substrate 2 and the target 3
FIG. 5 is a characteristic diagram showing the dependence of the function g (ts) on the distance ts between the substrate 2 and the target 3 in FIG. As is clear from the figure, the functions g (ts) and t
It has been found that the relationship with s shows almost linearity and can be expressed by the following equation (3).

[0025] g (ts) = 0.64ts + 75mm ...... (3) moving distance st ₅ magnets 8 for satisfying 5% film thickness uniformity ± is equation (2) in Equation (1) and Equation (3 ) Is obtained from Equation (4).

St ₅ = sw + ep / 2 + 0.64 ts + 75 mm (4) Here, if the moving range st of the magnet 8 is set to be larger than the above-mentioned value of st ₅ , the film thickness uniformity of the thin film is better than ± 5%. However, in such a case, the moving range st of the magnet 8 becomes unnecessarily large, and the productivity is reduced.

Next, the setting of the width ae of the acceleration / deceleration movement area will be described. The optimal value of the width ae of the acceleration / deceleration movement area is
From the above description, the distance ts between the substrate 2 and the target 3 is independent of the width sw of the substrate 2 and the erosion interval ep.
It turns out that this is only a function. FIG. 6 shows the distance t between the target 2 and the substrate 2 having the width ae of the acceleration / deceleration movement area.
A characteristic diagram regarding the dependence on s is shown.

The characteristic curves I ₁ and I in this characteristic diagram
_2, the substrate 2 and the target 3 of the optimum value of the width ae of acceleration and deceleration movement area for fixed movement range st magnets st ₅
Shows the dependence on the distance ts between, I ₁ is the erosion distance ep to 60 mm, I ₂ is the case of setting the erosion distance ep to 100 mm. The characteristic curves J ₁ and J ₂ show the dependence of the maximum value of the width ae of the acceleration / deceleration movement region where the film thickness uniformity is within ± 10% on the distance ts between the substrate 2 and the target 3. J ₁ is the erosion distance ep to 60 mm, J ₂ erosion distance ep
Is set to 100 mm. Furthermore, the characteristic curve K
₁ and K ₂ are the distance t between the substrate 2 and the target 3 at the minimum value of the width ae of the acceleration / deceleration movement region where the film thickness uniformity is within ± 10%.
shows the dependence on s, K ₁ is the erosion distance ep to 60 mm, K ₂ is the erosion distance ep 10
This is the case where it is set to 0 mm.

As is apparent from FIG. 2, the optimum value, maximum value and minimum value of the width ae of the acceleration / deceleration moving area hardly depend on the width sw of the substrate 2 or the erosion interval ep.
It can be seen that the function is a function of only the distance ts between the target and the target 3. Here, the maximum value ae of the width ae of the acceleration / deceleration movement area
_{The maximum} and the minimum value ae _min are calculated as ae _max =
It was found that there was a relationship of 0.57 ts, ae _min = 0.29 ts.

From the results of various measurements described above, when the target 3 made of a material containing at least 90 wt% of aluminum is used, the moving range st of the magnet 8 and the width ae of the accelerating / decelerating moving area are expressed by the following equations. It was found that an aluminum thin film having a film thickness uniformity of approximately ± 5% can be formed on the surface of the large-sized substrate 2 by setting the value calculated based on 5) and Expression (6).

St> sw + ep / 2 + 0.64 ts + 75 mm (5) 0.29 ts <ae <0.57 ts (6) Therefore, in the sputtering apparatus of FIG. 1, the erosion interval ep and the width of the substrate 2 in the moving direction of the magnet 8 are represented. s
The optimum value of the movement range st of the magnet 8 and the width a of the acceleration / deceleration movement area calculated by Expressions (5) and (6) based on w and the distance ts between the substrate 2 and the target 3.
When the optimum value of e is input to the signal output means 18, the signal output means 18 outputs a control command signal to the magnet movement control means 17. The magnet movement control means 17 controls the rotation time and the rotation speed of the motor 9 based on the input control command signal to move the magnet 8 within the optimum movement range st, and to move both ends of the magnet 8 within the movement range st. In the acceleration / deceleration movement area set to the optimum width ae on the side, it is moved while decelerating at a constant deceleration, and when it is temporarily stopped at the end of the movement range, the acceleration is accelerated at a constant acceleration. Movement is performed in the deceleration movement area in the opposite direction, and movement control is performed so as to reach a predetermined speed when leaving the acceleration / deceleration movement area.

As a result, since the magnet 8 is not stopped at both ends of the moving range st, both ends of the target 3 are not locally eroded unlike the conventional method, so that the utilization efficiency of the target 3 is significantly improved. I do. Also, the magnet 8
When the vehicle enters the acceleration / deceleration movement area, it is moved to the end of the movement range st while being decelerated from the constant speed at a constant deceleration, and is moved at a constant speed while being accelerated at a constant acceleration immediately after stopping at the end. The movement is controlled so as to reach a predetermined moving speed when reaching the area be. As a result, the magnet 8 in the acceleration / deceleration movement region moves in a speed distribution in which the movement speed becomes slower toward the end of the movement range st when moving in any direction when reciprocating in the region. Therefore, a thin film having a uniform thickness can be formed over the entire substrate 2 even though the magnet 8 is not stopped at the end of the movement range st for a certain period of time. Such effects were confirmed in the examples described below.

[First Embodiment] In FIG. 2, the size of the substrate 2 is 470 mm (width sw in the moving direction of the magnet 8) × 37.
0 mm (width hw in the direction orthogonal to the moving direction). The size of the target 3 is 740 mm (length tw in the moving direction of the magnet 8) × 630 mm (width t in the direction orthogonal to the moving direction).
h) × 17 (thickness t). The distance ts between the substrate 2 and the target 3 is 70 mm. The erosion specified from the dimensions of the magnet 8 has a length ew of 550 mm and an interval ep.
60 mm. Necessary data of these dimensions was input to the calculating means 18. Aluminum having a purity of 99.99 wt% was used as the material of the target 3.

In the above equation (5), sw = 450 mm (While the width sw in the moving direction of the magnet 8 on the substrate 2 is 470 mm, since the film is not generally formed on both ends using a mask, the film is formed. The width of the area is 450 mm), ep = 60 mm,
The calculation is performed by substituting ts = 70 mm, and st> 59
9.8 mm was calculated, and st = 600 mm was set. Also,
The calculated st = 600 mm was substituted into the above equation (6) to perform an operation to calculate 20.3 mm <ae <39.9 mm, and set ae = 30 mm. Also, in this embodiment,
The moving speed of the magnet 8 in the constant speed moving region be of the magnet moving range st is 120 mm / s, the acceleration and the deceleration in the acceleration / deceleration moving region are 240 mm / s ² ,
Was set to 20 KW and the film formation time was set to 90 seconds, and the film was formed by moving the magnet 8 back and forth during the film formation time.

The film thickness of each part of the aluminum thin film formed on the substrate 2 under the above-mentioned film forming conditions was measured, and FIG. 7 shows a film thickness distribution diagram which is an actually measured value. The thickness uniformity of this aluminum thin film was ± 5.0% as set. FIG. 8 shows the shape of the target 3 after use. As is clear from the comparison with FIG. 14, the erosion depths at both ends are almost uniformly increased, and the target 3 is effectively used. At this time, the utilization efficiency of the target 3 was 32%.
The utilization efficiency of Target 3 is significantly improved compared to 20% of 4. This is, as described above, the equations (5) and (6)
This is the result of controlling the movement of the magnet with the optimal movement range st and the width ae of the acceleration / deceleration movement range calculated by the above calculation. The film is formed on the substrate 2 with excellent uniformity of film thickness of ± 5.0%. The utilization efficiency of Target 3 was significantly improved from 20% to 32%.

[Second Embodiment] In this second embodiment,
The sputtering apparatus to be used, the film forming conditions, and the movement control of the magnet 8 are all the same as those in the first embodiment. The difference from the first embodiment is that the target 3 is made of 90 wt% aluminum and 10 wt% zircon. % Of the alloy. At this time, the film thickness of each part of the thin film formed on the substrate 2 was measured, and the film thickness distribution diagram as the measured values was shown in FIG.
Shown in The film thickness uniformity of this thin film was ±
It was 5.1%. FIG. 10 shows target 3 after use.
It can be seen that the erosion depths at both ends of the target 3 are almost uniformly increased and are effectively used. At this time, the utilization efficiency of the target 3 is 31%, which is also significantly improved as compared with the conventional 20%.
This is a result of controlling the movement of the magnet with the optimum movement range st and the width ae of the acceleration / deceleration movement range calculated by the calculations of the equations (5) and (6), as in the first embodiment. In the case where an alloy of zircon and zircon was used as the material of the target 3, the utilization efficiency of the target 3 could be improved while forming a film having excellent film thickness uniformity on the substrate 2.

[Third Embodiment] In this third embodiment,
As a material of the target 3, a film was formed using an alloy containing 90 wt% of aluminum and 10 wt% of tantalum. The sputtering apparatus to be used, film forming conditions, movement control of the magnet 8, and the like are the same as those in the first and second embodiments. At this time, the film thickness of each part of the thin film formed on the substrate 2 was measured, and FIG. The film thickness uniformity of this thin film was ± 4.8 wt% from the measurement result of FIG.
Met. FIG. 12 shows the shape of the target 3 after use, and it can be seen that the erosion depths at both ends of the target 3 are almost evenly increased and are effectively used. At this time, the utilization efficiency of the target 3 was as excellent as 33%. This is the result of controlling the movement of the magnet with the optimum movement range st and the acceleration / deceleration movement range width ae calculated by the calculations of the equations (5) and (6), as in the first and second embodiments. In addition, even when an alloy of aluminum and tantalum is used as the material of the target 3, a film having excellent film thickness uniformity can be formed on the substrate 2 and the utilization efficiency of the target 3 can be improved. did it.

As is clear from the results of the first to third embodiments, if the target 3 is aluminum or an alloy containing 90 wt% or more of aluminum, the target 3 is calculated by the calculations of the equations (5) and (6). Optimal moving range s
By controlling the movement of the magnet with t and the width ae of the acceleration / deceleration movement range, it is possible to form a film with excellent film thickness uniformity on the substrate 2 and to improve the use efficiency of the target 3. There was found.

[0039]

As described above, according to the sputtering method of the present invention, since the magnet is not stopped at both ends of the moving range, both ends of the target are locally eroded as in the conventional method. And the use efficiency of the target is remarkably improved. Further, acceleration / deceleration movement areas are set at both ends of the magnet movement range, and when the magnet enters the acceleration / deceleration movement area, the magnet is moved to the end of the movement range while decelerating at a constant speed, and then the opposite is performed. Since the movement is controlled so as to reach a predetermined moving speed when reaching the constant-velocity moving region while accelerating in the direction, the magnet in the acceleration / deceleration moving region can be moved in any direction when reciprocating in the region. Even when moving in the direction, the moving speed is slowed down toward the end of the moving range, so that the magnet is not stopped for a certain period of time at the end of the moving range, but over the entire substrate. A thin film having a uniform thickness can be formed.

Further, according to the sputtering apparatus of the present invention, the sputtering method of the present invention can be embodied with a simple structure, and the same effects as those of the above method can be reliably obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a sputtering apparatus according to one embodiment of the present invention.

FIG. 2 is a perspective view showing a positional relationship among a substrate, a target, and a magnet of the sputtering apparatus.

FIG. 3 is a characteristic diagram showing actually measured values of a relationship between a width of a substrate and a moving range of a magnet satisfying a film thickness uniformity of ± 5% in the sputtering apparatus.

FIG. 4 is a graph showing a function f (ts, e
The characteristic diagram which shows the measured value of dependence with respect to the distance and erosion space | interval of a board | substrate and a target of p).

FIG. 5 is a characteristic diagram showing measured values of the dependence of a function g (ts) on the distance ts between the substrate and the target in the above characteristic diagram.

[6] the optimum value of the width of the acceleration and deceleration movement region of the case of fixing the moving range of the magnet st ₅ and the maximum value and the minimum value of the width of the acceleration and deceleration movement area film thickness uniformity is within 10% ± FIG. 4 is a characteristic diagram showing measured values of the dependence of the distance between the substrate and the target.

FIG. 7 is a view showing a film thickness distribution of a thin film on a substrate according to the first embodiment of the present invention.

FIG. 8 is a view showing the remaining thickness of each part of the target after use in the example of the embodiment.

FIG. 9 is a view showing a film thickness distribution of a thin film on a substrate according to a second embodiment of the present invention.

FIG. 10 is a diagram showing the remaining thickness of each part of the target after use in the example of the embodiment.

FIG. 11 is a view showing a film thickness distribution of a thin film on a substrate according to a third embodiment of the present invention.

FIG. 12 is a view showing the remaining thickness of each part of the target after use in the example in the embodiment.

FIG. 13 is a schematic longitudinal sectional view showing a conventional sputtering apparatus.

FIG. 14 is a view showing the remaining thickness of each part of the target after use by the sputtering apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Substrate 3 Target 3a Target surface to be sputtered 3b Target outer surface 8 Magnet 9 Motor (drive source) 13 Magnetic field lines 14 Plasma 17 Magnet movement control means 18 Signal output means ep Erosion interval in magnet movement direction sw Magnet movement direction Substrate width ts Distance between substrate and target st Magnet movement range ae Width of acceleration / deceleration movement area be Mag uniform velocity movement area

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Teichi Kimura 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 4K029 AA09 AA24 BA03 BA23 CA05 DC03 DC04 DC12 DC46

Claims (3)

[Claims] 1. A target made of a sputtering material of the same system as a thin film to be formed and a substrate for film formation are opposed to each other in a vacuum container, and the target and the vacuum are placed in a discharge gas atmosphere in a vacuum state. By applying a voltage between the substrate and the target, a plasma is generated near the surface of the surface to be sputtered in the target facing the substrate, and sputtered particles emitted from the target by the incidence of ions in the plasma are generated on the substrate. By moving a magnet in parallel along the surface of the target opposite to the surface to be sputtered while generating a thin film by depositing on the surface of the target, the movement of the plasma is controlled by the lines of magnetic force of the magnet, In a sputtering method for forming a thin film on the surface of the substrate, An acceleration / deceleration movement area having the same width is set, and an area excluding both the acceleration / deceleration movement areas in the movement range is set as a constant velocity movement area, and the magnet is moved from the constant velocity movement area to the acceleration / deceleration. When entering the movement area, move to the end of the movement range while decelerating, then move while accelerating the acceleration / deceleration movement area in the opposite direction, and enter the constant velocity movement area. A sputtering method, wherein the movement is controlled so as to reciprocate a plurality of times within the movement range by shifting to a constant speed movement. 2. A target made of a material containing at least 90 wt% of aluminum is used, where: ep: plasma erosion interval in the magnet moving direction sw: width in the magnet moving direction of the substrate ts: distance between the substrate and the target The width ae of the magnet movement range st and the acceleration / deceleration movement area at both ends of the magnet are set to values that satisfy the following equation: st> sw + ep / 2 + 0.64 ts + 75 mm 0.29 ts <ae <0.57 ts. 2. The sputtering method according to 1. 3. A vacuum vessel into which a discharge gas is introduced into a vacuum state, a film-forming substrate and a target of a sputtering material disposed facing each other inside the vacuum vessel; A power source for applying a voltage between the target and the vacuum container, a magnet which is moved outside of the vacuum container in parallel along an outer surface of the target opposite to the surface to be sputtered facing the substrate, and The erosion interval of the plasma in the moving direction of the magnet, the moving range of the magnet calculated based on the data of the width of the substrate in the moving direction of the substrate and the distance between the substrate and the target, and the uniform velocity moving region within the moving range. A signal output means for outputting the width of the acceleration / deceleration movement area set on both sides as a control command signal, and a control output from the signal output means. A magnet movement control means for controlling a drive range and a movement speed of the magnet by drivingly controlling a drive source of the magnet based on a command signal, wherein the magnet movement control means sets the magnet in the acceleration / deceleration movement area. Within, moving toward the end of the movement range while decelerating at a constant deceleration, immediately after stopping at the end of the movement range, start moving in the opposite direction, and in the constant velocity movement area A sputtering apparatus characterized in that the sputtering apparatus is controlled so as to move while accelerating at a constant acceleration until reaching.