JP4471767B2 - Sputtering apparatus and sputtering method using the same - Google Patents

Description

  The present invention relates to a sputtering apparatus for forming a thin film on a processing surface of a semiconductor wafer (hereinafter referred to as a wafer) and a sputtering method using the same, and in particular, a sputtering apparatus capable of greatly improving the film thickness distribution in the wafer surface and The present invention relates to a sputtering method using the same.

  Various materials and film forming methods are selected for the wafer according to the purpose. Examples of film forming methods include CVD, vacuum vapor deposition, sputtering, etc. Among them, sputtering is frequently used for forming a metal thin film (Ti, Au, Al, Cu, WSi, etc.) on a wafer.

  FIG. 9 is a cross-sectional view showing a configuration of a conventional sputtering apparatus. A conventional sputtering apparatus 91 shown in FIG. 9 includes a vacuum chamber 92 that forms a sputtered film, a target holding portion 94 that is disposed above the vacuum chamber 92 and holds a target 93, and is disposed below the vacuum chamber 92. A pallet 96 on which the wafer 95 is placed is provided. A magnet 97 that generates lines of magnetic force is disposed inside the target holding portion 94, a DC power source 98 is connected, and the pallet 96 is grounded. Further, the vacuum chamber 92 includes a gas supply source 99 for supplying a sputtering gas such as Ar, a gas supply valve 100, a gas supply port 101, a vacuum pump 102 for evacuating the vacuum chamber 92, and gas exhaust. A valve 103 and a gas exhaust port 104 are connected. Further, a pre-sputtering shutter 105 is attached between the target 93 and the wafer 95 until impurities on the surface of the target 93 are removed and discharge is stabilized.

  Next, a sputtering method using the conventional sputtering apparatus 91 will be described. First, the target 93 is fixed to the target holding unit 94, and the wafer 95 is placed on the pallet 96. Next, after the inside of the vacuum chamber 92 is evacuated to high vacuum by the vacuum pump 102 through the gas exhaust valve 103, sputtering gas such as Ar gas is supplied to the vacuum chamber 92 by the gas supply source 99 through the gas supply valve 100. The inside of the vacuum chamber 92 is maintained at a predetermined pressure. Next, a DC voltage is applied to the target holding unit 94 by the DC power source 98 to generate magnetron discharge (plasma). The plasma is converged by the magnetic lines of force of the magnet 97 and collides with the surface of the target 93 to sputter the target 93. After that, while the shutter 105 is left on the wafer 95, the surface of the target 93 is pre-sputtered for a predetermined time to remove impurities such as a natural oxide film, and then the shutter 105 is moved to the direction indicated by the arrow 106 by a driving method such as a motor or air. A sputtered film is formed on the wafer 95 by moving in the direction.

  However, this conventional sputtering apparatus 91 uses a target 93 having a diameter approximately twice that of the wafer 95 in order to make the film thickness distribution of the sputtered film formed on the wafer 95 uniform. This is because more sputtered particles are emitted toward the center of the target 93 due to the emission distribution of the sputtered particles scattered from the target 93 and less as it goes to the outer periphery. For this reason, there is a problem that the sputtering apparatus 91 is enlarged and the apparatus cost and installation area are increased. Further, as the size of the wafer 95 is increased, the uniformity of the film thickness distribution is deteriorated, resulting in variations in characteristics of the products.

  In order to solve this, for example, JP-A-5-86467 discloses another sputtering apparatus. 10A and 10B are a cross-sectional view and a plan view of the shutter showing the configuration of the sputtering apparatus. The same components as those in FIG. 9 described above are denoted by the same reference numerals and description thereof is omitted.

  A sputtering apparatus 111 shown in FIG. 10A includes a shutter 112 between the target 93 and the wafer 95. As shown in FIG. 10B, the shutter 112 is formed with a rectangular slit 114 in a direction perpendicular to the moving direction (arrow 113).

Next, a sputtering method using this sputtering apparatus 111 will be described. The process is the same as that of the above-described sputtering apparatus 91 until preliminary sputtering for removing impurities on the surface of the target 93 for a predetermined time with the shutter 112 placed under the target 93 is performed. After preliminary sputtering, the shutter 112 is moved in the direction of arrow 113 by a driving method such as a motor or air. At this time, sputtered particles scattered from the target 93 are allowed to pass through the slit 114, and further, the moving speed of the shutter 112 is slowed down at the outer peripheral portion of the wafer 95 and fastened at the central portion, thereby forming a uniform film over the entire surface of the wafer 95. A thin film having a thickness can be formed.
JP-A-5-86467 (pages 2 and 3, paragraphs 0002 to 0013, FIGS. 1 and 4)

  However, the sputtering apparatus 111 shown in FIG. 10A has the following problems.

  In order to make the film thickness distribution of the sputtered film formed on the wafer 95 uniform, the moving speed of the shutter 112 is changed between the outer peripheral part and the central part of the wafer 95, so that the moving speed is controlled continuously or stepwise. A new control mechanism is required, and the cost of the sputtering apparatus 111 increases. In particular, when a plurality of sputtered films are continuously formed using the same apparatus, the sputtered particle emission distribution varies depending on the type and size of the target 93, so that the moving speed of the shutter 112 is changed to the type and size of the target 93. It is necessary to strictly control accordingly.

  In addition, preliminary sputtering is performed with the shutter 112 placed under the target 93, and after removing impurities on the surface of the target 93, film formation is performed while the shutter 112 is moved horizontally. An area is required, and the sputtering apparatus 111 is enlarged.

  Further, a large amount of the sputtered film adhering to the target surface side of the shutter 112 due to the preliminary sputtering is peeled off due to vibration during movement and drops and adheres to the wafer 95, thereby reducing the reliability and yield of the product. In particular, as the number of wafers 95 processed increases, the amount of sputtered film adhering to the surface of the shutter 112 increases, so that film stress occurs and the possibility of film peeling increases more and more.

  The present invention has been conceived to solve the above problems, and without increasing the cost and size of the sputtering apparatus, and further reducing the film thickness distribution on the wafer without reducing the reliability and yield of the product. An object of the present invention is to provide a sputtering apparatus capable of forming a sputtered film having excellent uniformity and a sputtering method using the same.

  To achieve the above object, a sputtering apparatus according to claim 1 of the present invention is a sputtering apparatus in which at least a target, a shutter, and a semiconductor wafer are disposed in a vacuum chamber, and a thin film is formed on the semiconductor wafer. A sputter particle control plate having an opening corresponding to the emission distribution of sputtered particles scattered from the target is disposed between the semiconductor wafer and the semiconductor wafer, while the semiconductor wafer is scanned in parallel with the target. A thin film is formed through the opening of the particle control plate.

  According to a second aspect of the present invention, there is provided the sputtering apparatus according to the first aspect, wherein the opening of the sputtered particle control plate has a smaller opening area at the center than at the outer periphery.

  The sputtering apparatus according to claim 3 is the sputtering apparatus according to claim 2, wherein the plurality of sputtered particle control plates having similar-shaped openings having different sizes have a center and an opening forming direction. It is characterized by being arranged so as to coincide.

  The sputtering apparatus according to claim 4 is the sputtering apparatus according to claim 2, wherein the plurality of sputter particle control plates having openings corresponding to the emission distribution of sputter particles scattered from a plurality of different types of targets, It is arranged.

  The sputtering apparatus according to claim 5 is characterized in that, in the sputtering apparatus according to claim 1, the sputter particle control plate has a hole having a small diameter at a central portion and a hole having a large diameter at an outer peripheral portion. .

  Moreover, the sputtering apparatus according to claim 6 is the sputtering apparatus according to any one of claims 1 to 5, wherein the sputter particle control plate is made of stainless steel, titanium, tungsten, or an alloy thereof. It is characterized by that.

  The sputtering apparatus according to claim 7 is the sputtering apparatus according to any one of claims 1 to 6, wherein a film peeling prevention treatment is performed on a surface side of the sputter particle control plate facing the target. Features.

  The sputtering apparatus according to claim 8 is the sputtering apparatus according to claim 7, wherein the film peeling prevention process is any one of a sandblasting process, a copper spraying process, a laser processing process, and an etching process. .

  The sputtering method according to claim 9 has a step of arranging at least a target, a shutter, and a semiconductor wafer in a vacuum chamber, and an opening corresponding to the emission distribution of sputtered particles between the target and the semiconductor wafer. A step of inserting a sputtered particle control plate; a step of moving the shutter between the target and the semiconductor wafer; and an opening of the sputtered particle control plate while scanning the semiconductor wafer in parallel with the target. Forming a thin film through the substrate.

  A sputtering method according to a tenth aspect is the sputtering method according to the ninth aspect, wherein a plurality of the sputtered particle control plates having similar-shaped openings having different sizes are arranged such that the center and the forming direction of the openings are the same. The sputter particle control plates are arranged so as to coincide with each other, and are switched to the sputter particle control plate having a larger opening in accordance with a decrease in the sputtering rate of the target.

  The sputtering method according to claim 11 is the sputtering method according to claim 9, wherein a plurality of the sputter particle control plates having openings corresponding to the emission distribution of sputter particles scattered from a plurality of different types of targets are arranged. The sputter particle control plate is switched according to the type of the target.

  A sputtering method according to a twelfth aspect is the sputtering method according to the ninth aspect, wherein the sputter particle control plate having a hole having a small diameter at a central portion and a hole having a large diameter at an outer peripheral portion is disposed. A thin film is formed through a small hole and a hole having the large diameter.

  As described above, according to the sputtering apparatus of the present invention and the sputtering method using the same, the sputtered particle control plate is disposed between the target and the shutter or the shutter and the wafer, and is further scattered from the target onto the sputtered particle control plate. Since the opening corresponding to the emission distribution of the sputtered particles is formed, the amount of sputtered particles passing through the opening can be made uniform. Thereby, the film thickness distribution of the sputtered film formed on the wafer can be greatly improved, and the reliability and yield of the product can be improved.

  In addition, a plurality of sputter particle control plates are arranged for one target, and openings of similar shapes having different sizes corresponding to the emission distribution of sputter particles scattered from the target are formed on these sputter particle control plates. When the sputter rate decreases, a sputter particle control plate with a larger opening is used, so the target is consumed due to the long-term operation of the sputter device, and the sputter particle emission distribution and sputter rate change. However, the amount of sputtered particles passing through the opening can be made uniform. Thereby, the film thickness distribution of the sputtered film formed on the wafer can be greatly improved without reducing the film forming speed.

  In addition, sputter particle control plates are individually arranged for different types of targets, and openings corresponding to the emission distribution of sputter particles scattered from the target are formed on these sputter particle control plates. Even when continuous sputtering is performed, the amount of sputtered particles passing through the opening can be made uniform, and the film thickness distribution of the sputtered film formed on the wafer can be greatly improved.

  In addition, since the sputter particle control plate has a small diameter hole in the center and a large diameter hole in the outer peripheral part, the amount of sputter particles passing through the opening can be made more uniform, and the film is formed on the wafer. The film thickness distribution of the sputtered film can be further improved.

  In addition, since the film peeling prevention treatment is applied to the target surface side of the sputtered particle control plate, the adhesion between the sputtered particle control plate and the sputtered film is improved, and as the number of wafers processed increases, Even if the sputtered film is deposited thick, film peeling during film formation can be reliably prevented.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIGS. 1A and 1B are a cross-sectional view and a plan view of a sputtered particle control plate showing the configuration of the sputtering apparatus according to the first embodiment of the present invention.

  A sputtering apparatus 1 of the present embodiment shown in FIG. 1A includes a vacuum chamber 2 for forming a sputtered film, a target holding unit 4 that is disposed above the vacuum chamber 2 and holds a target 3, and a vacuum chamber 2. A pallet 6 is provided which is arranged below the inside and on which the wafer 5 is placed. In addition, a magnet 7 that generates magnetic lines of force is disposed inside the target holding unit 4, a DC power supply 8 is connected, and the pallet 6 is grounded. The vacuum chamber 2 includes a gas supply source 9 for supplying a sputtering gas such as Ar, a gas supply valve 10, a gas supply port 11, a vacuum pump 12 for evacuating the inside of the vacuum chamber 2, and a gas exhaust. A valve 13 and a gas exhaust port 14 are connected. Further, a preliminary sputtering shutter 15 is attached between the target 3 and the wafer 5 until impurities on the surface of the target 3 are removed and discharge is stabilized.

  Further, in the sputtering apparatus 1 of the present embodiment, a sputtered particle control plate 16 for controlling sputtered particles is disposed between the target 3 and the shutter 15. The sputtered particle control plate 16 is made of a material such as stainless steel, and an opening 17 is formed at the center thereof. As shown in FIG. 1B, the opening 17 has a shape corresponding to the emission distribution of sputtered particles scattered from the target 3.

  Next, a method for forming the opening 17 of the sputtered particle control plate 16 will be described with reference to FIGS. First, as shown in FIG. 2A, after forming a square opening 22 with one side being X on the stainless steel plate 21, the stainless steel plate 21 is fixed to the lower part of the target 3 so that the centers thereof are aligned. A sputtered film 24 is formed on the dummy substrate 23 through the opening 22. Next, as shown in FIG. 2B, the sputtered film 24 formed on the dummy substrate 23 is subdivided into a plurality of parts (in the figure, 24a to 24e are divided into five parts), and each of the average film thicknesses t1 to t1. t5 is measured. Next, as shown in FIG. 2C, the opening 22 of the stainless steel plate 21 corresponding to the sputter films 24a to 24e is subdivided into a plurality of parts (in the figure, 22a to 22e are divided into five parts), and the sputter film The area of the opening 22 of the stainless steel plate 21 is corrected based on the average film thicknesses t1 to t5 of 24a to 24e. For example, if the desired film thickness is t, the lateral width X1 = X × (t / t1) of the opening 22a, the lateral width X2 = X × (t / t2) of the opening 22b, and the lateral width X3 = XX of the opening 22c. (T / t3), the horizontal width X4 = X × (t / t4) of the opening 22d, and the horizontal width X5 = X × (t / t5) of the opening 22e. That is, if the average film thicknesses t1 to t5 of the sputtered films 24a to 24e are larger than the desired film thickness t, the lateral widths X1 to X5 of the openings 22a to 22e are decreased, and conversely, if the average film thickness t1 to t5 is smaller than the desired film thickness t. The width X1 to X5 is increased. Finally, as shown in FIG. 2D, if both ends of the corrected openings 22a and 22b, 22b and 22c, 22c and 22d, and 22d and 22e are connected, it corresponds to the emission distribution of the sputtered film (that is, The sputtered particle control plate 16 having the opening 17 is obtained in which the opening area is small in the central portion where the amount of radiation of sputtered particles is large and the opening area is large in the outer peripheral portion where the amount of radiation of sputtered particles is small. The sputtering conditions such as the film formation temperature, the applied voltage, the gas flow rate, and the film formation pressure are preliminarily selected by preliminary examination. 2A to 2D, the case where the sputtered film 24 on the dummy substrate 23 and the opening 22 of the stainless steel plate 21 are subdivided in the horizontal direction has been described. By subdividing, the opening 17 of the sputtered particle control plate 16 corresponding to the emission distribution of the sputtered film may be formed with higher accuracy.

  Next, a sputtering method using the sputtering apparatus 1 of the present embodiment will be described with reference to FIGS. 3 (a) to 3 (c). First, as shown in FIG. 3A, the target 3 is fixed to the target support portion 4, and the wafer 5 is placed on the pallet 6. Next, after the inside of the vacuum chamber 2 is made high vacuum by the vacuum pump 12 through the gas exhaust valve 13, a sputtering gas such as Ar gas is supplied to the vacuum chamber 2 by the gas supply source 9 through the gas supply valve 10. The inside of the vacuum chamber 2 is maintained at a predetermined pressure. Next, a DC voltage is applied to the target holding unit 4 by the DC power source 8 to generate magnetron discharge (plasma). This plasma is converged by the magnetic lines of force of the magnet 7 and collides with the surface of the target 3 to sputter the target 3. Then, while the shutter 15 is placed under the target 3, preliminary sputtering is performed on the surface of the target 3 for a predetermined time to remove impurities such as a natural oxide film. Next, as shown in FIG. 3B, the sputtered particle control plate 16 is moved by a driving method such as a motor or air and is allowed to stand at the lower part of the target 3, and then the shutter 15 is moved from the lower part of the target 3. As described with reference to FIG. 2D, the sputtered particle control plate 16 is area-corrected (the central area is small and the outer peripheral area is large) so as to correspond to the emission distribution of the sputtered particles scattered from the target 3. Opening 17 is formed. Next, as shown in FIG. 3C, the pallet 6 on which the wafer 5 is placed is scanned in the direction of the arrow 31 in parallel with the target 3 at a constant speed. At this time, the amount of sputtered particles scattered from the target 3, having a large central portion and a small peripheral distribution, is controlled by the opening 17 of the sputtered particle control plate 16, and is equal between the central portion and the outer peripheral portion. Thus, a sputtered film having a uniform film thickness is formed on the wafer 5. When the desired film thickness is reached, the shutter 15 is moved again to the lower part of the target 3 to turn off the DC power source 8 and finish the thin film formation.

  When a film was formed on an 8-inch wafer 5 using the sputtering apparatus 1 of this example, the film of the sputtered film was compared with the conventional sputtering apparatus 91 that does not use the sputtered particle control plate 16 shown in FIG. The thickness variation was about ½, and the product characteristics could be greatly stabilized.

  Further, in the sputtering apparatus 1 of the present embodiment, it is not necessary to change the moving speed of the shutter 112 during film formation unlike the conventional sputtering apparatus 111 shown in FIG. The device 1 can be reduced in cost and size. Further, since the shutter 15 and the sputter particle control plate 16 are fixed during the film formation, the probability that the sputtered film adhering to the shutter 15 and the sputter particle control plate 16 will be peeled off by vibration is reduced, and the reliability and yield of the product are improved. Can be improved.

  Next, another embodiment of the present invention will be described with reference to the drawings. 4A is a cross-sectional view showing the configuration of the sputtering apparatus of the second embodiment, and FIGS. 4B to 4D are plan views of the sputtered particle control plate. 4 (a) to 4 (d), the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The sputtering apparatus 41 of this embodiment shown in FIG. 4A includes one target 42 and three sputter particle control plates 43a to 43c. The three sputtered particle control plates 43a to 43c are disposed between the target 42 and the shutter 15, and as shown in FIGS. 4B to 4D, openings corresponding to the emission distribution of sputtered particles scattered from the target 42 are provided. Portions 44a to 44c are formed. These openings 44a to 44c are similar to each other, and assuming that the areas are S1 to S3, the relationship is S1 <S2 <S3.

  Next, a sputtering method using the sputtering apparatus 41 of this embodiment will be described. The process is the same as that of the sputtering apparatus 1 of the first embodiment described above until preliminary sputtering is performed for removing impurities on the surface of the target 42 for a predetermined time while the shutter 15 is placed under the target 42. After the preliminary sputtering, the sputter particle control plates 43a to 43c are moved by a driving method such as a motor or air, and are allowed to stand at the lower part of the target 42, and then the shutter 15 is moved from the lower part of the target 42. Next, the pallet 6 on which the wafer 5 is placed is scanned in parallel with the target 42 at a constant speed. As shown in FIG. 4B, the sputter particle control plate 43a is formed with an opening 44a corresponding to the emission distribution of sputter particles scattered from the target 42. The amount of sputtered particles having a large emission distribution in the outer peripheral portion is controlled by the opening 44a so that the amount of sputtered particles is equal between the central portion and the outer peripheral portion, and the film thickness is uniform on the wafer 5. A sputtered film is formed. When the desired film thickness is reached, the shutter 15 is moved again below the target 42, the DC power supply 8 is turned off, and the thin film formation is completed.

  When a large number of wafers 5 are subjected to film formation, the target 42 is consumed, the emission distribution of sputtered particles is expanded, and the sputtering rate is lowered. The degree of wear of the target 42 is monitored by the integrated power amount to the target 42. When the integrated power meter (not shown) provided in the DC power supply 8 reaches a predetermined integrated power amount, the sputter particle control plate 43a Switch to 43b and continue sputter deposition. In the sputtered particle control plate 43b, as shown in FIG. 4C, an opening 44b corresponding to the emission distribution of sputtered particles scattered from the consumed target 42 is formed. The opening 44b is similar to the opening 44a, and the area S2 of the opening 44b is formed larger than the area S1 of the opening 44a, so that the emission distribution of sputtered particles is broadened and the sputtering rate is reduced. Correspondingly, the amount of sputtering can be adjusted. Thereby, even if the target 42 is consumed, a sputtered film having a uniform film thickness can be continuously formed on the wafer 5 without reducing the film forming speed.

  When the target 42 is further consumed, the sputtered particle control plate 43b is switched to the sputtered particle control plate 43c shown in FIG. 4D, and sputter deposition is continued in the same manner.

  In the present embodiment, the case where the three sputter particle control plates 43a to 43c are used has been described. However, if four or more sputter particle control plates 43a to 43c are provided, the sputter particles can be more precisely responded to changes in the emission distribution and the sputter rate. The product characteristics can be greatly stabilized.

  Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 5A is a sectional view showing the configuration of the sputtering apparatus of the third embodiment, and FIGS. 5B and 5C are plan views of the sputtered particle control plate. 5A to 5C, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The sputtering apparatus 51 of this embodiment shown in FIG. 5A includes two different types of targets 52a and 52b and two sputtered particle control plates 53a and 53b. The two sputter particle control plates 53a and 53b are disposed between the targets 52a and 52b and the shutter 15, and as shown in FIGS. 5B and 5C, the emission distribution of sputter particles scattered from the targets 52a and 52b. Openings 54a and 54b corresponding to are formed. The optimum applied voltage, gas flow rate, and deposition pressure are different depending on the types of the targets 52a and 52b, and the emission distribution of sputtered particles is different, so the shapes of the openings 54a and 54b are also different. The target support portions 4a and 4b are configured to be rotatable by a rotation mechanism 55 and a rotation shaft 56.

  Next, a sputtering method using the sputtering apparatus 51 of the present embodiment will be described. First, preliminary sputtering is performed for a predetermined time by the same method as in the first embodiment, with the shutter 15 placed under the target 52a, to remove impurities on the surface of the target 52a. After the preliminary sputtering, the sputter particle control plate 53a is moved by a driving method such as a motor or air and is allowed to stand at the lower part of the target 52a, and then the shutter 15 is moved from the lower part of the target 52a. Next, the pallet 6 on which the wafer 5 is placed is scanned at a constant speed parallel to the target 52a. As shown in FIG. 5B, the sputter particle control plate 53a is formed with an opening 54a corresponding to the emission distribution of sputter particles scattered from the target 52a. The amount of sputtered particles having a large emission distribution with a small outer peripheral portion is controlled by the opening 54a so that the amount of sputtered particles is equal between the central portion and the outer peripheral portion and has a uniform film thickness on the wafer 5. A sputtered film is formed. When the desired film thickness is reached, the shutter 15 is moved again below the target 52a, the DC power supply 8 is turned off, and the thin film formation is completed.

  Next, the target 52a and the target 52b are rotated by the rotation mechanism 55 and the rotation shaft 56 to change the positions. Then, the shutter 15 is moved to the lower part of the target 52b, a DC voltage is applied to the target holding portion 4b by the DC power source 8 to generate magnetron discharge (plasma), the target 52b is pre-sputtered, and impurities on the surface of the target 52b are removed. Remove. Next, the sputtered particle control plate 53b is moved by a driving method such as a motor or air and is allowed to stand at the lower part of the target 52b, and then the shutter 15 is moved from the lower part of the target 52b. Next, the pallet 6 on which the wafer 5 is placed is scanned at a constant speed parallel to the target 52b. As shown in FIG. 5C, the sputtered particle diffusion plate 53b is formed with the opening 54b corresponding to the emission distribution of sputtered particles scattered from the target 52b. The amount of sputtered particles having a large emission distribution with a small outer peripheral portion is controlled by the opening 54b, and the sputtered particle amount is equal between the central portion and the outer peripheral portion, and has a uniform film thickness on the wafer 5. A sputtered film is formed. When the desired film thickness is reached, the shutter 15 is moved again below the target 52b, the DC power supply 8 is turned off, and the thin film formation is completed.

  According to the sputtering apparatus 51 of this embodiment, two different types of targets 52a and 52b and the corresponding sputtered particle control plates 53a and 53b are individually provided. Different sputtered films can be continuously formed.

  In the present embodiment, the case where the two targets 52a and 52b and the two sputter particle control plates 53a and 53b are used has been described. Therefore, productivity can be further improved.

  Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 6A is a sectional view showing the configuration of the sputtering apparatus of the fourth embodiment, and FIG. 6B is a plan view of the sputtered particle control plate. In FIGS. 6A and 6B, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The sputtering apparatus 61 of the present embodiment shown in FIG. 6A includes one target 62 and one sputter particle control plate 63. The sputtered particle control plate 63 is disposed between the target 62 and the shutter 15, and as shown in FIG. 6B, an opening 64 corresponding to the emission distribution of sputtered particles scattered from the target is formed. The opening 64 includes a first opening region 64a, a second opening region 64b, and a third opening region 64c, and the first to third opening regions 64a to 64c have circular holes 65a to 65c, respectively. Many 65c are formed. Further, assuming that the diameters of the circular holes 65a to 65c are D1, D2, and D3, the relationship is D1 <D2 <D3.

  Next, a sputtering method using the sputtering apparatus 61 of this embodiment will be described. The process is the same as that of the sputtering apparatus 1 of the first embodiment described above until preliminary sputtering is performed for removing impurities on the surface of the target 3 for a predetermined time with the shutter 15 placed under the target 62. After the preliminary sputtering, the sputter particle control plate 63 is moved by a driving method such as a motor or air and is allowed to stand at the lower part of the target 62, and then the shutter 15 is moved from the lower part of the target 62. Next, the pallet 6 on which the wafer 5 is placed is scanned in parallel with the target 62 at a constant speed. As shown in FIG. 6B, the sputter particle control plate 63 is formed with the opening 64 corresponding to the emission distribution of the sputtered particles scattered from the target 62. Therefore, the emission scattered from the center of the target 62 is emitted. A large amount of sputtered particles passes through the first opening region 64a in which a hole 65a having a small diameter D1 is formed, and a small amount of sputtered particles scattered from the outer peripheral portion of the target 62 is a first hole 65c in which a large diameter D3 is formed. It passes through the three opening region 64c. As a result, the amount of sputtered particles passing through the sputtered particle control plate 63 is controlled, and the sputtered particles having a uniform film thickness are formed on the wafer 5 with the same amount of sputtered particles as a whole. When the desired film thickness is reached, the shutter 15 is moved again below the target 62, the DC power supply 8 is turned off, and the thin film formation is completed.

  According to the sputtering apparatus 61 of the present embodiment, in addition to the opening 64 of the sputter particle control plate 63 having a shape corresponding to the emission distribution of the sputtered particles, circular holes 65 a to 65 a having different diameters in the opening 64. Since the opening area of the opening 64 is further finely adjusted by forming a large number of 65c, the amount of sputtered particles scattered from the target 62 can be more uniformly controlled and formed on the wafer 5. The film thickness distribution of the sputtered film can be further improved.

  When the film was formed on the 8-inch wafer 5 by using the sputtering apparatus 61 of this embodiment, the film of the sputtered film was compared with the conventional sputtering apparatus 91 not using the sputtered particle control plate 63 shown in FIG. The thickness variation was about 1/4, and the product characteristics could be further stabilized.

  In addition, the circular holes 65a to 65c formed in the opening 64 of the sputtered particle control plate 63 of the present embodiment show an example of a method for adjusting the opening area, and are limited to this. It is not a thing. For example, as shown in FIG. 7, linear holes 66 a to 66 c may be formed in the opening 64 of the sputtered particle control plate 63. In this case, the opening area can be easily adjusted by setting the line widths W1 to W3 of the linear holes 66a to 66c to W1 <W2 <W3. In the present embodiment, the opening 64 is composed of the three regions of the first to third opening regions 64a to 64c, but may be composed of four or more opening regions. In this way, the opening area can be adjusted more finely, and the amount of sputtered particles emitted can be made even more uniform.

  In addition, since the sputter particle control plates 16, 43a to 43c, 53a, 53b, and 63 are all fixed during the film formation in the sputter devices 1, 41, 51, and 61 of the above-described embodiments, the sputter particles The sputtered film adhering to the control plates 16, 43 a to 43 c, 53 a, 53 b, 63 can be effectively prevented from peeling off and adhering onto the wafer 5 due to vibration. In order to more effectively prevent peeling of the sputtered film with an increase in the thickness of the target surface side 81a of the sputtered particle control plate 81, for example, as shown in FIG. A film peeling prevention process may be performed to provide a minute uneven portion 82. Further, as shown in FIG. 8B, copper may be sprayed on the target surface side 81 a of the sputtered particle control plate 81 to form the uneven portion 84 on the surface of the copper film 83. This improves the adhesion between the sputtered particle control plate 81 and the sputtered film, so that even if the sputtered film is deposited thickly on the sputtered particle control plate 81, it is possible to reliably prevent film peeling during film formation. Reliability and yield can be improved. In addition to this, a minute uneven portion 82 may be formed on the target surface side 81a of the sputtered particle control plate 81 by laser processing, etching, or the like.

  Furthermore, although the stainless steel was used as the sputtered particle control plates 16, 43a to 43c, 53a, 53b, and 63 of the above-described embodiments, any material that has high heat resistance and high mechanical strength may be used. Tungsten and its alloys are preferred.

  The sputter particle control plates 16, 43 a to 43 c, 53 a, 53 b, 63 are arranged between the targets 3, 42, 52 a, 52 b, 62 and the shutter 15, but are arranged between the shutter 15 and the wafer 5. It may be.

  In addition, as a sputtering method, the DC magnetron sputtering method in which the magnet 7 is arranged on the back side of the targets 3, 42, 52a, 52b, 62 and a DC voltage is applied has been described. The present invention can also be applied to methods such as DC bipolar sputtering, RF bipolar sputtering, RF magnetron sputtering, ion beam sputtering, and ECR sputtering. At this time, the targets 3, 42, 52 a, 52 b, and 62 may be disposed below the vacuum chamber 2 and the wafer 5 may be disposed above.

  A sputter particle control plate is disposed between the target and the shutter or the shutter and the wafer, and an opening corresponding to the emission distribution of the sputtered particles scattered from the target is formed on the sputter particle control plate, so that the spatter passing through the opening is formed. The amount of particles can be made uniform. Thereby, the film thickness distribution of the sputtered film formed on the wafer can be greatly improved, and the reliability and yield of the product can be improved.

  In addition, a plurality of sputter particle control plates are arranged for one target, and openings of similar shapes having different sizes corresponding to the emission distribution of sputter particles scattered from the target are formed on these sputter particle control plates. If the sputter rate decreases, by using a sputter particle control plate with a larger opening, the target is consumed due to long-term operation of the sputter device, even if the sputter particle emission distribution and sputter rate change, The amount of sputtered particles passing through the opening can be made uniform. Thereby, the film thickness distribution of the sputtered film formed on the wafer can be greatly improved without reducing the film forming speed.

  In addition, by arranging the sputter particle control plates individually for different types of targets and forming openings corresponding to the sputter particle emission distribution scattered from the targets on these sputter particle control plates, different materials are continuously used. Even when sputtering is performed, the amount of sputtered particles passing through the opening can be made uniform, and the film thickness distribution of the sputtered film formed on the wafer can be greatly improved.

  Further, the sputter particle control plate has a small diameter hole in the central part and a large diameter hole in the outer peripheral part, so that the amount of sputter particles passing through the opening can be made more uniform and deposited on the wafer. The film thickness distribution of the sputtered film can be further greatly improved.

  In addition, by performing a film peeling prevention process on the target surface side of the sputtered particle control plate, the adhesion between the sputtered particle control plate and the sputtered film is improved, and the sputtered film on the sputtered particle control plate increases as the number of wafers processed increases. Even if the film is deposited thickly, film peeling during film formation can be reliably prevented.

Sectional view of the sputtering apparatus of the first embodiment of the present invention and a plan view of the sputtered particle control plate Explanatory drawing of the method of forming the opening of the sputter particle control plate Explanatory drawing of the sputtering method using the sputtering apparatus of 1st Example of this invention Sectional drawing of the sputtering apparatus of 2nd Example of this invention, and top view of a sputtered particle control board Sectional view of sputtering apparatus of third embodiment of the present invention and plan view of sputtered particle control plate Sectional view of sputtering apparatus and plan view of sputtered particle control plate of fourth embodiment of the present invention Plan view of another sputtered particle control plate of the fourth embodiment of the present invention Sectional view of sputtered particle control plate of the present invention Sectional view of conventional sputtering equipment Sectional view of another conventional sputtering apparatus and plan view of a sputter particle control plate

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sputtering apparatus of 1st Example of this invention 2 Vacuum chamber 3 Target 4 Target support part 5 Wafer 6 Pallet 7 Magnet 8 DC power supply 9 Gas supply source 10 Gas supply valve 11 Gas supply port 12 Vacuum pump 13 Gas exhaust valve 14 Gas Exhaust port 15 Shutter 16 Sputtered particle control plate 17 Opening 21 Stainless steel plate 22 Opening 22a to 22e Subdivided opening 23 Dummy substrate 24 Sputtered film 24a to 24e Subdivided sputtered film 31 Arrow 41 The second of the present invention Sputtering Device of Example 42 Target 43a to 43c Sputtered Particle Control Plate 44a to 44c Opening 51 Sputtering Device 52a, 52b Target 53a, 53b Sputtered Particle Control Plate 54a, 54b Opening 55 Rotating Mechanism 56 Axis of rotation DESCRIPTION OF SYMBOLS 1 Sputtering apparatus of 4th Example of this invention 62 Target 63 Sputtered particle control board 64 Opening part 64a 1st opening area 64b 2nd opening area 64c 3rd opening area 65a-65c Circular hole 66a-66c Linear hole 81 Sputtered particle control plate 81a Target surface side 82 Uneven portion 83 Copper film 84 Uneven portion 91 Conventional sputtering apparatus 92 Vacuum chamber 93 Target 94 Target holding portion 95 Wafer 96 Pallet 97 Magnet 98 DC power source 99 Gas supply source 100 Gas supply valve 101 Gas supply port 102 Vacuum pump 103 Gas exhaust valve 104 Gas exhaust port 105 Shutter 106 Arrow 111 Other conventional sputtering apparatus 112 Shutter 113 Arrow 114 Rectangular slit

Claims (9)

Corresponds to the emission distribution of sputtered particles scattered from the target between the target and the semiconductor wafer in a sputtering apparatus in which at least the target, shutter, and semiconductor wafer are placed in the vacuum chamber and a thin film is formed on the semiconductor wafer. and placing the sputtered particle control plate having an aperture, while parallel to scanning the semiconductor wafer with respect to the target, a thin film was formed through the opening of the sputtering particles control plate, the sputter particle control plate As for the opening, the center part has a smaller opening area than the outer peripheral part, and the plurality of sputtered particle control plates having similar-shaped openings having different sizes have the same center and the direction in which the opening is formed. A sputtering apparatus characterized by being arranged so as to overlap each other . The sputtering apparatus according to claim 1 , wherein a plurality of the sputter particle control plates having openings corresponding to emission distributions of sputter particles scattered from a plurality of different types of targets are arranged.   The sputtering apparatus according to claim 1, wherein the sputter particle control plate has a hole having a small diameter at a central portion and a hole having a large diameter at an outer peripheral portion. The sputtering apparatus according to any one of claims 1 to 3 , wherein the sputter particle control plate is made of any one of stainless steel, titanium, tungsten, and alloys thereof. The sputtering apparatus according to any one of claims 1 to 4 , wherein a film peeling prevention process is performed on a surface of the sputtered particle control plate facing the target. 6. The sputtering apparatus according to claim 5, wherein the film peeling prevention process is one of a sand blast process, a copper spray process, a laser processing process, and an etching process. Placing at least a target, a shutter, and a semiconductor wafer in a vacuum chamber; inserting a sputtered particle control plate having an opening corresponding to a sputtered particle emission distribution between the target and the semiconductor wafer; and Moving the shutter from between the target and the semiconductor wafer, and forming a thin film through the opening of the sputtered particle control plate while scanning the semiconductor wafer in parallel with the target. And
A plurality of the sputter particle control plates having openings having similar shapes with different sizes are arranged so that the center and the formation direction of the openings coincide with each other, and according to the decrease in the sputtering rate of the target, Switching to the sputter particle control plate having a larger opening . A plurality of sputter particle control plates having openings corresponding to emission distributions of sputter particles scattered from a plurality of different types of targets are arranged, and the sputter particle control plates are switched according to the type of the target. The sputtering method according to claim 7 . The sputtered particle control plate having a small diameter hole in the central part and a large diameter hole in the outer peripheral part is disposed, and a thin film is formed through the small diameter hole and the large diameter hole. The sputtering method according to claim 7 .

Images