| Plating apparatus -> Monitor Keywords |
|
|
  Plating apparatusUSPTO Application #: 20070246350Title: Plating apparatus Abstract: A plating apparatus includes a bath configured to reserve a plating solution for plating a substrate and a holder configured to hold the substrate. The bath includes an anode electrode provided inside the bath. The holder includes a cathode electrode for applying a voltage to the substrate. The bath is equipped with first and second discharge portions. The plating apparatus includes a first path, a supply path, a second path and a flow rate control valve. The first path circulates the plating solution, which is discharged from the first discharge portion, to the bath. The supply path supplies the plating solution, which is provided from the first path, into the bath. The second path provides the plating solution, which is discharged from the second discharge portion after flowing on the anode electrode, to the first path. The flow rate control valve controls a flow rate of the plating solution flowing from the second path to the first path. (end of abstract) Agent: Mcginn Intellectual Property Law Group, PLLC - Vienna, VA, US Inventor: Yoichi Togashi USPTO Applicaton #: 20070246350 - Class: 204237000 (USPTO) Related Patent Categories: Chemistry: Electrical And Wave Energy, Apparatus, Electrolytic, Cells With Electrolyte Treatment Means, Recirculation The Patent Description & Claims data below is from USPTO Patent Application 20070246350. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a plating apparatus for use in a plating process for manufacturing semiconductor devices. [0003] 2. Description of the Related Art [0004] Some of conventional plating apparatuses are known as facedown type plating apparatuses. The facedown type plating apparatus adopts a form (referred to as facedown form) of arranging a substrate such as silicon wafer above a plating solution bath and forms a plated layer such as a copper layer on the substrate. In the facedown type plating apparatus, there is provided the plating solution bath having an anode electrode disposed at the bottom thereof and a plating solution filled therein. The substrate is arranged such that the surface thereof, on which plating treatment is executed, faces the solution surface of the plating solution. In the facedown type plating apparatus, the plating treatment is executed by applying voltage between the substrate and the anode electrode in this condition. The facedown form has been increasingly widely used since it is advantageous in, for example, downsizing the plating apparatus. [0005] Hereinafter, a conventional plating apparatus will be described. FIG. 1 shows a configuration of the conventional plating apparatus 101 in a cross sectional view. Referring to FIG. 1, the conventional plating apparatus 101 includes a plating treatment chamber 102, a tank 103, a pump 104, and a constant current power source 105. The tank 103 holds a plating solution flowed out from the plating treatment chamber 102. The pump 104 circulates the plating solution held in the tank to the plating solution chamber 102. The pump 104 circulates the plating solution through the tank 103 and the plating treatment chamber 102. The constant current power source 105 supplies DC current to wafer holders 111 and an anode contact plate 119, which are described later. [0006] Referring to FIG. 1, the plating treatment chamber 102 includes the wafer holders 111 for holding a wafer 107 and a plating treatment chamber inner bath 112 for holding the plating solution. The plating treatment chamber 102 is provided with circulation drains 113, which are connected to the plating treatment chamber inner bath 112 via respective anode chamber drain nozzles 114. The plating treatment chamber inner bath 112 includes the anode contact plate 119, an anode 115, a membrane 117, and a diffuser plate 118. The plating treatment chamber inner bath 112 configures an anode chamber 121 between the anode 115 and the membrane 117. Similarly, the plating treatment chamber inner bath 112 configures a membrane diffuser plate chamber 122 above the membrane 117. [0007] The anode contact plate 119 supplies to the anode 115, a current outputted from the constant current power source 105. The anode 115 acts as a bottom electrode in correspondence with the current supplied via the anode contact plate 119. The membrane 117 filters additive decomposition products contained in the plating solution. The diffuser plate 118 supplies the plating solution to the wafer 107 such that the plating solution flows uniformly to the wafer 107. [0008] As a plating solution supply path, a plating solution supply nozzle 116 is configured which penetrates through the anode contact plate 119, the anode 115, and the membrane 117. Referring to FIG. 1, the plating solution supplied into the membrane diffuser plate chamber 122 passes through the diffuser plate 118 and then is discharged through the circulation drains 113. The plating solution supplied into the anode chamber 121 is discharged from the circulation drains 113 via the anode chamber drain nozzles 114 provided for the anode chamber 121. [0009] Here, as for the conventional plating treatment chamber 102, when the plating treatment is executed on the wafer 107 which is set on the wafer holders 111, the plating solution is supplied from the plating solution supply nozzle 116 at a rate of 61/min. During the plating treatment, a current of 1 to 10 A is supplied to the anode 115 for approximately two to five minutes. [0010] Japanese Laid Open Patent Application (JP-P-2001-316887) discloses a face down type plating apparatus. United States Patent Document (U.S. Pat. No. 6,890,416) discloses another plating apparatus. The another plating apparatus is provided with a pump, anode chamber and membrane diffuser plate chamber. The rotation rate and stroke of the pump is increased to control the flow rates of plating solution flowing to the entire of the anode chamber, membrane diffuser plate chamber and surface of a wafer to be plated. [0011] To form a thick copper (Cu) film by plating the wafer 107 with copper, as described above, it is required to provide a current of approximately 10 A for a long period of time. In this case, Cu concentration in the plating solution flowing on the anode 115 may become high. A small flow rate of the plating solution flowing on the anode 115 in this condition may cause deposition of crystals of copper sulfate on the anode 115. The crystals of copper sulfate on the anode 115 increase the electric resistance between the plating solution and the anode 115. This may make it difficult to maintain the current of approximately 10 A for a long period of time, which may in turn result in failure to perform an appropriate plating treatment. [0012] Conventionally, a power supply, which can supply high voltage, has been used as the constant current power source to secure desired current, thereby coping with the problem of the increased resistance. [0013] In formation of the thick Cu film, the flow rate of the plating solution flowing on the anode 115 has been increased by increasing the amount of the plating solution supplied to the plating treatment chamber 102. As described above, when the thicker film is formed by plating, it is required to increased flow rate of the plating solution flowing on the anode 115 (in order to prevent Cu deposition on the anode). [0014] As for the plating apparatus disclosed in United States Patent Document (U.S. Pat. No. 6,890,416), the pump increases the flow rate of the plating solution and thereby enables suppressing the deposition of crystals of copper sulfate on an anode of the plating apparatus. SUMMARY [0015] It has now been discovered that an increased amount of the plating solution to be supplied results in an increased amount of the plating solution flowing to the surface of the membrane 117. Thus, the plating solution flowing on the surface of the wafer 107 flows faster. This may make it difficult to form a plated film with a uniform film thickness over the surface of the wafer 107. Moreover, the increased amount of the plating solution raises the consumption of various components contained in the plating solution, resulting in the increased cost for plating the wafer. [0016] In an aspect of the present invention, a plating apparatus includes a plating treatment bath and a substrate holder. The plating treatment bath is configured to reserve a plating solution for plating a substrate. The substrate holder is provided above the plating treatment bath and configured to hold the substrate such that the substrate can rotate in a horizontal plane. The plating treatment bath includes an anode electrode provided inside the plating treatment bath. The substrate holder includes a cathode electrode for contacting the substrate to apply a voltage to the substrate. The plating apparatus includes a first flow path, a supply path, a second flow path and a flow rate control valve. The first flow path is configured to circulate the plating solution, which is discharged from the plating treatment bath via a first discharge portion, to the plating treatment bath. The supply path is configured to supply the plating solution, which is provided from the first flow path, into the plating treatment bath. The second flow path is configured to provide the plating solution, which is discharged from the plating treatment bath via a second discharge portion after flowing on the anode electrode, to the first flow path. The flow rate control valve is provided between the first flow path and the second flow path. The flow rate control valve is configured to control a flow rate of the plating solution provided from the second flow path to the first flow path. [0017] In this case, the flow rate control valve controls the flow rate of the plating solution flowing along the second flow path such that the deposition of copper sulfate crystals on the anode electrode can be suppressed. Moreover, the flow rate control valve adjusts its valve opening not to increase a flow speed of the plating solution flowing along the substrate surface. [0018] The present invention is effective in optimally controlling only the flow rate of the plating solution flowing to an anode chamber without changing the amount of the plating solution to be supplied. That is, the present invention enables a variable flow rate of the plating solution flowing to the anode chamber while keeping constant the flow rate of the plating solution flowing on a surface of the wafer. The present invention enables a plating treatment for forming plated films of various thickness from thin film thickness to thick film thickness while keeping constant the flow rate of the plating solution flowing on the surface of the wafer. [0019] According to the present invention, when a thin film is plated, a flow rate of the plating solution flowing on the anode electrode can be reduced to smaller flow rate than when a thick film is plated. The reduction in the flow rate of the plating solution can suppress the consumption of additives and also increase in cost. [0020] According to the present invention, a plating treatment can be executed without configuring a constant current power source that can supply high voltage. This permits execution of an appropriate plating treatment without increasing facility-related costs. [0021] According to the present invention, an increase in a flow speed of the plating solution on the wafer surface can be suppressed to thereby provide a plated film of uniform film thickness over the surface of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS Continue reading... Full patent description for Plating apparatus Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Plating apparatus patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Plating apparatus or other areas of interest. ### Previous Patent Application: Barrel plating device Next Patent Application: Device for generating hydrogen for use in internal combustion engines Industry Class: Chemistry: electrical and wave energy ### FreshPatents.com Support Thank you for viewing the Plating apparatus patent info. IP-related news and info Results in 3.59355 seconds Other interesting Feshpatents.com categories: Electronics: Semiconductor , Audio , Illumination , Connectors , Crypto , |
||
