TWI225103B - Sputtering target backplate - Google Patents

Abstract

A sputtering target backplate is used for mounting a sputtering target in a treatment chamber. One face of the backplate is a cooling face for contacting with a cooling liquid for heat dissipation, and the other face of the backplate is a support face for supporting the sputtering target, in which the support face of the backplate at least includes a buffer layer, in which the thermal expansion coefficient of the buffer layer is between the thermal expansion coefficients of the backplate and the sputtering target, thereby reducing the stress from the backplate on the sputtering target caused by thermal variations during the sputtering operation, and effectively preventing the cracking, warpage and delamination of the sputtering target.

Description

1225103 V. Description of the invention (1) [Field of invention]

The present invention relates to a sputtering target backplate, particularly a low expansion coefficient sputtering target such as a ceramic glass backplate. [Prior art] Currently known sputtering target backplanes, such as the Republic of China Publication No. 380278 invention patent, can be combined with a quenching and drying in a deposition chamber. In addition, high-speed production needs to increase the electric power of the magnetron target, resulting in The target generates high heat during sputtering. In order to prevent the sputtering target from overheating during sputtering, a cooling system is usually installed as in the method of the Republic of China Announcement No. 2 9 5 7 7 6 for water cooling. The back of the target backplane is sputtered, so the backplane must be made of a metal with high thermal conductivity, such as copper. However, when such a sputtering target backplane is combined with a ceramic or glass sputtering target, and a thin film is sputter-plated on a semiconductor wafer or an optical disc, the heat generated by high-power sputtering cannot be effectively dissipated. The ceramic sputtering target is derived, and the thermal expansion difference between the copper backing plate and the ceramic sputtering target is comparable, and the temperature change of its operation causes the backing plate to exert a thermal stress on the ceramic sputtering target, thereby causing the sputtering target to break. crack. [Objective and Summary of the Invention] In order to solve the above problems, a first object of the present invention is to provide a back plate with a low expansion coefficient sputtering target, and the back plate includes at least a buffer layer made of a metal with a low thermal expansion coefficient, This allows the back plate to prevent chipping of the sputtering target. A second object of the present invention is to provide a back of a low expansion coefficient sputtering target.

1225103 V. Description of the invention (2) The plate uses a buffer layer made of a metal with a low thermal expansion coefficient on the back plate generally suitable for metal sputtering targets, making the back plate manufactured and practical. _ The third object of the present invention is to provide a sputtering target backing plate, which uses the sputtering administration @ back plate to provide a buffer layer on the supporting surface of the sputtering target, so as to effectively prevent the soil plating target from cracking and warping due to temperature variation. Curling and shedding effect. A fourth object of the present invention is to provide a sputtering target fixing device, which utilizes a money-saving dry backing plate to provide a buffer layer on the support surface of the sputtering target, so as to effectively prevent the sputtering target from cracking and warping during physical vapor deposition. Curvature and shedding effect 0 [Explanation of the invention] According to the sputtering target provided by the present invention, a buffer layer [buffer layer] made of several metals, such as Shao, copper, metal on the outer side to form a cooling coefficient for heat dissipation Such as Hengfan A1 loy426 or Ni-Cr, etc., to make it a dry-bonded support surface, especially the back plate which is generated due to thermal changes during operation. It includes a thermally conductive layer and at least, wherein the thermally conductive layer is made of High thermal conductivity steel, titanium or its alloys, etc. to make its surface, and the buffer layer is formed of low thermal expansion steel [Invar, Kovar], molybdenum, 1 side for low expansion sputter coating can weaken the back plate The force against the sputtering target effectively prevents the sputtering target from cracking. As shown in FIG. 2, the splash ore 14 and at least one buffer layer 13 of the present invention, wherein the buffer layer mainly includes a thermally conductive layer which is smaller than the thickness of the thermally conductive layer 14, and the thickness of the conductive layer [5 mm] is made of metal. Made of, such as aluminum, copper, steel, ..., layer 14 is made of at least one of the high thermal conductivity system Yuan Zhong alloy, etc., 1225103

V. Description of the invention (3) In this embodiment, copper with good heat transfer is preferred, and the buffer sound system is made of a metal with a low thermal expansion coefficient, such as Invar / Kovar, Molybdenum At least one of Alloy4 26 or Nickel-Chromium etc. Among them, _ Hengfan Steel, such as Invar and Kovar metals with low thermal expansion coefficient, forms a cooling surface for cooling device 3 0 with the outside of the sputtering target back plate 10 J j and a pair of sputter targets 20 supporting surfaces 12 are formed on the inner side thereof, and a sputter target 20 is combined on the support surface i 2, wherein the sputter target 20 is made of ceramic or glass. Different shapes of the sputtering target (such as a semiconductor wafer or an optical disc), the sputtering target 20 and its back plate 10 may be circular, rectangular, or square. In addition, the method of combining spattered ore with the backing plate is known as soft soldering (such as the British GB2053 763 patent case), clips [such as the European Union EP0393344 patent case], or hot-press bonding of rough surfaces [such as the Republic of China Announcement No. Patent Case No. 287125] and other methods, will not be repeated here. As shown in FIG. 1, the sputtering target 20 and its back plate 10 are installed in a processing chamber 40, particularly a physical vapor deposition chamber (PVD). A substrate stage 43 is provided at the bottom of the processing chamber 40. The substrate 50 (such as a semiconductor wafer or an optical disc) to be deposited and a heater 44 for heating the substrate 50 are placed, and the processing chamber 40 extracts air from the chamber 40 to a suitable voltage through an air pump 42. The near-vacuum pressure generated by the slurry, and plasma gas, such as argon, is introduced from an air inlet 41. When an RF power source (not labeled) is activated, the induction coil is coupled to the argon in the processing chamber 40 to generate electrons and ions. Plasma, using ion bombardment [Ion Bombard] of the coin mine 20 [connected to negative electricity], and then sputter plating on the substrate 50. Since the operating temperature of the processing chamber 40 is hundreds of degrees and about 70% of the bombardment energy is converted into heat, the sputtering target 20 is disadvantageous in operation.

1225103 V. Description of the invention (4) High temperature, in order to control the sputter target 20, the target back plate 10 is provided with a cooler 31 to provide water-like cooling liquid 32 to and from a row of outlets 33 to take away the heat. Patent No. 295776. Obviously, since the buffer layer 13 and the sputtering target 20 are preferred, a buffer layer 13 capable of withstanding the strain force due to thermal expansion is formed, which causes cracking and warping of the target 20 after multiple plating. In addition, according to the present invention, the materials of the sputtering targets and the different sputtering targets can be made by combining the heat from the back plate and the different sputtering targets, which is simple and practical. The invention can be implemented without departing from the main precision. For example, although the thermal conductivity layer and buffer layer of the thermally conductive dry backing plate have a metal such as key, bit steel, or nickel chromium to prevent the sputtering from drying out. This artist can be used for a variety of changes and repairs. The scope of the application is defined by the application scope at a lower temperature, usually in several devices 30, which is supplied to the sputtering target back plate 1 in a water-cooled manner. The cooling surface 11 of 0, the cooling device 30 may be a conventional case or US Patent No. 5, 03 9, 913 | the thermal expansion coefficient is between the thermal expansion system of the back plate 1 0 main ^ close to the sputtering target 20 The cold shrinking operation between the back plate 10 and the sputtering target 20 will not cause the ceramic to fall off. The back plate 10 does not need to be tailored to the corresponding material in manufacturing. It only needs to use the same money to forge a metal buffer layer that matches the expansion coefficient. It is poor and expensive in other different forms under the gods and characteristics, but it is not competitive with Tao. The same low thermal expansion t Invar > Kovar) 'A 11oy 42 6 can still be used at the same time. The example reveals, but it is not intended to limit the present invention without departing from the spirit and scope of the present invention.

1225103 Brief Description of Drawings Figure 1: A sectional view of the sputtering target back plate of the present invention applied to a processing chamber; and Figure 2: A partial sectional view of the sputtering target back plate of the present invention combined with a sputtering target. [Illustration of drawing number] 10 sputter target back plate

11 Cooling surface 1 2 Supporting surface 1 3 Buffer layer 14 Thermally conductive layer 20 Sputter target 3 0 Cooling device 31 Feeder 32 Cooling liquid 33 Discharge port 4 0 Processing chamber 41 Air inlet 4 2 Pumping pump 4 3 Substrate stage 44 Heater 5 0 substrate

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Claims (1)

1225103 Case No. 89113731_Year Month Date Amendment 6. Scope of patent application The buffer layer is selected from Invar, Kovar, I, Alloy42, chrome alloy 0 ΙΒΒ page 10