Method for detecting measurement stability of tester tables

Abstract

The invention proposes a method for detecting measurement stability of tester tables. The method comprises the following steps: providing a control wafer serving as a test wafer and electroplating a semiconductor substrate with a metal layer; depositing an anti-oxidation layer on the metal layer; utilizing a tester table to measure the thickness of the metal layer of the control wafer more than once; and judging whether the measurement stability of the tester table is within an acceptable range according to more than one metal-layer thicknesses obtained through measurement. The method obtainsa standard deviation value by calculating the more than one metal-layer thicknesses obtained through measurement, and can accurately judge whether the measurement stability of the tester table is within the acceptable range according to the obtained standard deviation value. The method has the advantages of simple effective operation and results easy to observe and judge.

Description

technical field [0001] The invention relates to a method for detecting a test machine, and in particular to a method for detecting the measurement stability of a test machine in a semiconductor process. Background technique [0002] In the process used to make copper wire interconnect structures, there may be non-uniformity in the deposition of copper metal and the grinding rate. If not carefully controlled, it will result in uneven thickness or unwanted residue on the surface of the wafer. substance. Varying thickness will affect the resistance, which will lead to the failure of the component or the reduction of the overall performance. Substances remaining inside may cause short circuits between wires, which can also lead to component failure and yield loss. There is a non-destructive way to directly measure the thickness of sub-micron wire array structures in order to control the deposition of copper metal and the removal rate. [0003] This method is the use of micros...

AI Technical Summary

Problems solved by technology

Since the copper metal layer 120 is exposed to the air, when the microsecond ultrasonic laser sonar 150 emits a laser pulse wave and reaches the surface of the copper metal layer 120, the surface of the copper metal layer 120 will be thermally oxidized to form a copper oxide cover, due to the oxidation of different points The degree is not the same, resulting in poor flatness of the copper metal layer 120 surface, forming some uneven areas, especially after more than one measurement over a long period of time, the copper metal layer 120 on the surface of the control sheet is heated more than once and for a long time Exposure to the air, the degree of oxidation suffered by the copper metal layer 120 is relatively serious, and the oxide thickness difference at different points is relatively large. When measuring, the propagation speed of the sound wave in the copper metal layer 120 and its oxide is inconsistent, so the influence The echo time of different points is changed, thus causing inconsistent results of measuring the thickness value of the copper metal layer 120. The thickness value of the metal layer obtained according to this method itself has a large deviation. Please refer to figure 2 , figure 2 Shown is a schematic diagram of the results of the detection and testing machine in the prior art. It can be seen from the figure that after a long time, the obtained measurement results are quite different from each other, so it cannot be used to judge the performance of the microsecond ultrasonic laser sonar test device. Whether the measurement stability is within the acceptable range

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