Device, method and equipment for improving electroplating uniformity in wafer electroplating

Abstract

A device, method, and equipment for improving the electroplating uniformity in wafer electroplating. The device includes an electroplating component and an electroplating rate adjustment component. The electroplating component includes an electroplating head, an electroplating tank, an anode metal and a power supply. The electroplating rate adjustment component includes an auxiliary electrode assembly, a switching device and a control module. The auxiliary electrode assembly consists of auxiliary electrodes, a circuit resistor assembly and a support ring structure. The auxiliary electrode is set on the support ring structure, and when the auxiliary electrode is connected to the circuit resistor assembly, the support ring body can be controlled to lift or rotate, bringing the auxiliary electrode closer to or farther from the wafer notch, thereby adjusting the electroplating rate at the notch.

1 - 16 . (canceled) 
     
     
         17 . A device for improving electroplating uniformity in wafer electroplating, comprising:
 an electroplating component and an electroplating rate adjustment component;   the electroplating component includes an electroplating head, an electroplating tank, an anode metal and a power supply; the electroplating head is used to hold and rotate the wafer; the anode metal is placed in the electroplating tank and submerged in the electroplating solution during electroplating; the positive pole of the power supply is connected to the anode metal, and the negative pole is connected to the electroplating head;   the electroplating rate adjustment component includes an auxiliary electrode assembly, a switching device, and a control module; the auxiliary electrode assembly comprises one or more auxiliary electrodes, which are placed in designated areas within the electroplating tank and are fully or partially submerged in the electroplating solution during electroplating; the auxiliary electrodes are connected to the negative pole of the power supply, and the switching device is placed in the connection path of the auxiliary electrodes;   the control module is used to control one or more parameters of the connection path of the auxiliary electrodes, such as the closing time of the switching device, the interval of electrification, the pulsation frequency, and the duty cycle;   during electroplating, the wafer is rotated by the electroplating head; when the notch of the wafer rotates to approach or slightly move away from the designated area of the auxiliary electrodes, the control module adjusts the opening and closing of the switching device to regulate the electroplating rate around the wafer notch.   
     
     
         18 . The device for improving electroplating uniformity in wafer electroplating according to  claim 17 , wherein:
 the auxiliary electrode assembly further includes a circuit resistor assembly, which is connected in series with the auxiliary electrodes; the circuit resistor assembly comprises one or more resistor units, each of which includes one or more resistors;   when a resistor unit includes multiple resistors, these resistors are connected in series and/or parallel.   
     
     
         19 . The device for improving electroplating uniformity in wafer electroplating according to  claim 17 , wherein:
 the auxiliary electrode assembly further includes a support ring structure, which is placed in the electroplating tank; this structure comprises a support ring body, a support ring control assembly, and a circuit access assembly; the auxiliary electrodes are fixedly connected to the support ring body; the support ring control assembly is used for controlling the support ring body to drive the auxiliary electrodes to raise and lower and/or to rotate the auxiliary electrode in the electroplating tank, bringing the auxiliary electrodes closer to or farther from the wafer notch; the circuit access assembly is connected to the auxiliary electrodes to integrate them into the circuit, controlled by the switching device; the support ring body is made of insulating material.   
     
     
         20 . The device for improving electroplating uniformity in wafer electroplating according to  claim 19 , wherein:
 the support ring control assembly can control the support ring body to move the auxiliary electrodes up and down in the electroplating tank; the support ring control assembly consists of one or more screw-nut structures, which include a screw and a nut; the support ring body is provided with a corresponding number of screw through-holes to allow the screw to pass through; the screw is inserted into the screw through-holes, and the nut is positioned on the lower surface of the support ring body to support it, allowing the support ring body to move up and down along the screw with the nut's support;   the circuit access assembly comprises electroplating adjustment leads connected to the auxiliary electrodes;   during electroplating, the synchronous rotation of the screws controls the up-and-down movement of the support ring body and its auxiliary electrodes, thereby adjusting the distance between the wafer notch and the auxiliary electrodes.   
     
     
         21 . The device for improving electroplating uniformity in wafer electroplating according to  claim 19 , wherein:
 the support ring control assembly can control the support ring body to move the auxiliary electrodes up and down and rotate around the axis in the electroplating tank; the support ring structure is a magnetic levitation support ring, and the support ring control assembly includes multiple permanent magnets embedded in the support ring body and AC coils respectively arranged at the bottom and side walls of the electroplating tank; the permanent magnets are evenly distributed around the center of the support ring body, with adjacent permanent magnets having opposite polarities; the AC coils on the side walls of the electroplating tank correspond to the permanent magnets in the support ring body, controlling the rotation of the support ring body; the AC coils at the bottom of the electroplating tank correspond to the permanent magnets in the support ring body, controlling the vertical movement of the support ring body; the AC coils are connected to the control module, which controls the direction, magnitude, sequence changes, and duration of the current in the AC coils.   
     
     
         22 . The device for improving electroplating uniformity in wafer electroplating according to  claim 21 , wherein:
 the circuit access assembly of the magnetic levitation support ring includes a conductive rod and a surrounding rail; the conductive rod comprises a connection end and a contact end; the connection end is connected to the auxiliary electrode, while the contact end connects to the surrounding rail; the surrounding rail is arranged around the exterior of the electroplating tank and has at least one groove track; the number of groove tracks corresponds to the number of auxiliary electrodes, and they are insulated from each other;   each groove track contains a conductive metal ring band; the contact end of the conductive rod includes a preloaded spring and a conductive ball; the conductive ball is pressed against the groove track on the surrounding rail by the expansion force of the preloaded spring in its balanced state, forming electrical contact with the metal ring band to conduct current; a fixed wire is connected to the bottom of each metal ring band in the groove track to conduct the current externally; these fixed wires connect to external circuits, allowing each auxiliary electrode to be connected to its respective circuit;   when the auxiliary electrode rotates, the conductive rod is driven by the auxiliary electrode to rotate through the conductive ball on the groove track of the surrounding rail; during rotation, the conductive ball maintains electrical contact with the metal ring band; the current is conducted from the conductive ball to the metal ring band and then through the fixed wire to the external circuit.   
     
     
         23 . The device for improving electroplating uniformity in wafer electroplating according to  claim 22 , wherein:
 the side walls of the groove tracks on the surrounding rail are made of insulating material; when the number of groove tracks on the surrounding rail is greater than one, the metal ring bands in the groove tracks are insulated from each other and staggered vertically; the number of groove tracks is the same as the number of auxiliary electrodes, with each auxiliary electrode corresponding to a specific groove track.   
     
     
         24 . The device for improving electroplating uniformity in wafer electroplating according to  claim 19 , wherein:
 each auxiliary electrode is equipped with an auxiliary electrode lead at one end, which is positioned within the support ring body and extended outside the electroplating tank.   
     
     
         25 . The device for improving electroplating uniformity in wafer electroplating according to  claim 17 , wherein:
 the electroplating rate adjustment component includes one or more switch triggering devices, which are used to transmit signals to the control module for opening or closing the switching device; the switch triggering device comprises a signal recognition structure and a laser signal transceiver; the signal recognition structure reflects the signal emitted by the laser signal transceiver back to it, and the laser signal transceiver receives the reflected signal, sending a signal to the control module to open or close the switching device.   
     
     
         26 . The device for improving electroplating uniformity in wafer electroplating according to  claim 17 , wherein:
 the submerged portion of the auxiliary electrode in the electroplating solution is cylindrical or fan-shaped; the auxiliary electrode is made of copper, or specified metals compatible with the components of the electroplating solution, or copper coated with specified metals on its surface.   
     
     
         27 . The device for improving electroplating uniformity in wafer electroplating according to  claim 17 , wherein:
 the number of electroplating rate adjustment components is one or more; when multiple electroplating rate adjustment components are used, the auxiliary electrodes contained in each are evenly distributed within the electroplating tank.   
     
     
         28 . A method for improving electroplating uniformity in wafer electroplating, using the device for improving electroplating uniformity in wafer electroplating of any of  claims 17 through 27 , comprising the following steps:
 S 10 : define the position of the wafer in the electroplating tank during the electroplating process as the wafer electroplating position; use an electroplating head to hold the wafer to the wafer electroplating position and control the electroplating head to rotate the wafer at the wafer electroplating position;   S 20 : during each rotation cycle of the wafer, when the notch of the wafer is about to approach or slightly move away from the designated area where the auxiliary electrode is located, close the switching device to adjust the electroplating rate around the notch; alternatively, after a certain number of wafer rotation cycles, close the switching device during a rotation cycle when the notch of the wafer is about to approach or slightly move away from the designated area where the auxiliary electrode is located, intermittently adjusting the electroplating rate around the notch.   
     
     
         29 . A method for improving electroplating uniformity in wafer electroplating according to  claim 28 , wherein:
 when the auxiliary electrode is in series with the circuit resistor assembly and the circuit resistor assembly comprises multiple resistors, step S 20  further includes: select the resistor combination of the circuit resistor assembly to adjust the electroplating rate around the wafer notch.   
     
     
         30 . A method for improving electroplating uniformity in wafer electroplating according to  claim 28 , wherein:
 step S 20  further includes: control, via the control module, any combination of the following parameters of the connection path where the auxiliary electrode is located: closure time of the switching device, energization interval, pulsation frequency, duty cycle, and resistance value of the circuit resistor assembly.   
     
     
         31 . A method for improving electroplating uniformity in wafer electroplating according to  claim 28 , wherein:
 when the electroplating rate adjustment assembly includes a support ring structure, step S 20  further includes: during the period when the switching device is closed, control the support ring structure to move up or rotate within the electroplating tank, thereby adjust the proximity of the auxiliary electrode to or away from the wafer notch, further regulate the electroplating rate.   
     
     
         32 . An equipment for improving electroplating uniformity in wafer electroplating, comprising the device for improving electroplating uniformity in wafer electroplating of any of  claims 17 through 27 .