A method for reducing corrosion of crystal plate in cuprum chemistry mechanical lapping technics

Abstract

The invention discloses a method for decreasing the corrosion of wafer in the copper chemistry mechanical lapping technology, the method can efficiently clean up lapping liquid adhered on the wafer during the period that the wafer is waiting for transferring from a grinding equipment to a washing unit, thereby achieving the purpose that the lapping liquid is prevented from corroding the wafer Themethod comprises the following steps that: after the wafer is lapped and before the wafer is put back to a grinding head washing and absorption / desorption device, during the period that wafer is waiting for transferring from the grinding equipment to the washing unit, a water spray nozzle of the grinding head washing and absorption / desorption device of the grinding equipment is opened for cleaningup the lapping liquid adhered on the wafer. The opening of the water spray nozzle means the opening of the water spray nozzle of a cleaning cup of the grinding head washing and absorption / desorptiondevice and the water spray nozzle of absorption / desorption platform. In addition, the grinding head can be rotated in a specific speed. A pressure regulating valve is added on a pipeline connected with the water spray valve. The shape of the water spray of the absorption / desorption platform of the grinding head washing and absorption / desorption device is improved to lead the liquid sprayed out tobe a spreading shape.

Description

technical field [0001] The invention relates to a method for reducing wafer corrosion in copper chemical mechanical polishing process. Background technique [0002] At present, due to the increasing integration of integrated circuits, the size of devices is getting smaller and smaller, resulting in thinner metal interconnections and increased heat generation, which affects the performance of devices. Therefore, with aluminum, which was widely used in the past, as the metal material of the interconnection structure of advanced integrated circuits, the disadvantages of aluminum wires are becoming more and more obvious. Compared with aluminum, copper interconnection has many advantages, such as the resistivity of copper is lower than that of aluminum (the resistivity of copper is 1.7μΩ·cm, the resistivity of aluminum is 3.1μΩ·cm), the parasitic of copper interconnection The capacitance is smaller than that of aluminum interconnection, the power consumption of copper interconne...

AI Technical Summary

Problems solved by technology

[0007] Although the cleaning device 2 can clean the grinding liquid etc. remaining on the wafer, for copper chemical mechanical polishing, because copper produces corrosion phenomenon in almost all aqueous solutions, and even when there is a strong oxidizing agent, it will not be the same as aluminum. A passivation layer can be formed on the surface, and the abrasive liquid adhering to the wafer corrodes the copper surface very quickly

[0008] However, in the existing chemical mechanical polishing equipment such as MirraMesa 200mm chemical mechanical polishing equipment, the chemical mechanical polishing device 1 and the cleaning device 2 after grinding are separated, and the grinding head cleaning suction device 3 (HCLU: Head Clean Load and Unload) is required. And manipulator (Robot) to drive the wafer, it takes a certain time for the wafer to be cleaned from the chemical mechanical grinding to the cleaning device 2. During this time, the corrosion of the copper surface by the abrasive liquid adhering to the wafer will cause chip defects

Especially when the manipulator or the cleaning device 2 fails and is interrupted, for example, interrupted for more than 5 minutes, the corrosive effect of the adhered grinding liquid can cause the scrapping of the wafer

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