Method for improving CMP (chemical mechanical polishing) process stability of polishing materials on polishing pad

Abstract

The invention relates to the field of manufacture of semiconductors, in particular to a method for improving CMP (chemical mechanical polishing) process stability of polishing materials on a polishing pad. The method for improving CMP process stability of polishing materials on the polishing pad includes that a breather hole is arranged at the tail end of the polishing pad fixedly provided with polishing particles, when the polishing pad is about to be worn out, air leakage is caused on a portion, which is provided with the breather hole, of the polishing pad when the portion passes through an annular air-breathing polishing area of a cabinet, the cabinet is triggered to alarm, accordingly, a service end point of a portion, which is fixedly provided with the particles, of the polishing pad can be detected in real time, a wafer is prevented from being seriously scratched and even scraped due to the fact that the wafer is seriously scratched by a portion, without the polishing particles, of the polishing pad, time and cost for examining a damaged wafer by other equipment are saved, simultaneously, a follow-up wafer is also prevented from being damaged, and the method is simple in process and is controllable in real time.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuits and the manufacture thereof, in particular to a method for improving the stability of a CMP process with fixed abrasives on a grinding pad. Background technique [0002] The fixed abrasive on the polishing pad (Fixed Abrasive web, FA web for short) is to use the fixed abrasive on the polishing pad to realize the Chemical Mechanical Polishing (CMP) process. [0003] figure 1 It is a structural schematic diagram of a CMP process device using traditional FA web in the background technology of the present invention; as figure 1 As shown, in the process of fixing the abrasive on the polishing pad (Fixed Abrasive web, referred to as FA web), the end of the FA web is wound on the supply reel with a transparent film material (transparent), because the FA web has a certain use Length, when each wafer (wafer) is ground, the conveyor belt equipped with rollers at both ends of the FA web wil...

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Problems solved by technology

[0003] figure 1 It is a structural schematic diagram of a CMP process device using traditional FA web in the background technology of the present invention; as figure 1 As shown, in the process of fixing the abrasive on the polishing pad (Fixed Abrasive web, referred to as FA web), the end of the FA web is wound on the supply reel with a transparent film material (transparent), because the FA web has a certain use Length, when each wafer (wafer) is ground, the conveyor belt equipped with rollers at both ends of the FA web will drive the polishing pad to move forward for a certain distance, when the part of the polishing pad fixed with abrasive particles on the FA web is exhausted Finally, due to the operation needs of the machine, the supply reel will still output the end of the polishing pad with transparent film material. Since there are no abrasive particles on the polishing pad at this time, and when the wafer is CMP polished, the CMP machine cannot automatically detect the wafer. The wafer has been ground on an abnormal grinding pad, which will cause a large number of serious scratches (Killer Scratches) on the surface of the wafer, which will eventually lead to the substandard yield rate of the wafer, or even scrap; for example, the US patent (application number: US20000593045) disclose A chemical-mechanical polishing is achieved by fixing abrasives on a polishing pad, but this invention cannot detect the end of use of the FA web in time, so that the wafer is scrapped due to damage caused by grinding on a polishing pad without abrasive particles

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