Pressure control system for plurality of chambers of CMP (chemical mechanical polishing) head

Abstract

The invention relates to a pressure control system for a plurality of chambers of a CMP (chemical mechanical polishing) head, belonging to the technical field of semiconductor manufacture. The pressure control system is characterized by comprising a pressure source, a control valve group, a pressure sensor, a CPU (central processing unit), digital-to-analog and analog-to-digital conversion circuits and the like. In the control system, pressure control for all chambers at remote ends is realized by control the pressure and the flow of all branches. Each branch in the control valve group consists of a positive pressure channel, a negative pressure and a two-way filter. Each positive pressure channel consists of a pressure reducing valve, a positive pressure air bag, an electric control proportioning valve and a positive and negative pressure switch valve group which are connected with the pressure source in sequence, wherein all the positive pressure channels share the same pressure reducing valve and the same positive pressure air bag. Each negative pressure channel consists of a vacuum switch valve, a vacuum generator, a vacuum air bag, a vacuum pressure adjusting valve and a positive and negative pressure switch valve group which are connected with the pressure source in sequence, wherein all the negative pressure channels share the same vacuum switch valve, the same vacuum generator and the same vacuum air bag. The outputs of the positive and negative switch valve groups are connected with the filters. The pressure sensor transmits acquired pressure of all the chambers to the CPU by the A / D conversion circuits.

Description

technical field [0001] The invention relates to an air pressure control system in semiconductor manufacturing equipment, in particular to a positive pressure and negative pressure control system for a chemical mechanical polishing (CMP) polishing head. Background technique [0002] Currently, CMP is the most effective technique for global planarization of wafers in semiconductor manufacturing processes. In the field of CMP copper polishing, the polishing head clamps the silicon wafer and presses the surface of the copper layer to be polished to the rotating polishing disc. The effective and rapid removal of the copper layer is achieved through the friction of the polishing pad on the polishing disc and the corrosion of the polishing solution. Among them, the polishing head can realize the global dynamic adjustment of the polishing pressure of the silicon wafer by controlling the chamber pressure of each annular area on the back of the silicon wafer. [0003] The internal ch...

AI Technical Summary

Problems solved by technology

However, limited by the structure, the installation position of the sensing unit is often not placed inside the polishing head chamber, but placed at the outlet of the air pressure control system

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