Method for measuring contact hole

Abstract

The invention discloses a method for measuring a contact hole, and the measuring parameters of the contact hole comprise: an upper port characteristic dimension of the contact hole, a bottom characteristic dimension of the contact hole, the height of the contact hole, a side wall angle of the contact hole and whether etching of the contact hole is complete; in the method, after the contact hole is formed by etching, the contact hole is measured on line by adopting an optical measurement method, and simultaneously each parameter is obtained. The efficiency of measuring the contact hole is improved greatly by adopting the method for measuring the contact hole.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for measuring a contact hole. Background technique [0002] At present, when making a semiconductor integrated circuit, after the semiconductor device layer is formed, it is necessary to make a contact hole (contact) on the semiconductor device layer of the wafer. It plays an important role in the structure composition of semiconductor devices. [0003] Before introducing the etching of the contact hole, first briefly introduce the composition of the semiconductor device layer. Combine below Figure 1a to Figure 1b A schematic diagram of the structure is described. Figure 1a to Figure 1b It is a schematic diagram of a specific structure for forming a semiconductor device with a contact hole. [0004] Such as Figure 1a As shown, a semiconductor substrate 100 is provided, on which an active region and an isolation region of a semiconductor device a...

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Problems solved by technology

[0021] As can be seen from the above, although the existing technology measures the parameters of the contact hole online, which has certain advantages compared to offline measurement, but when measuring the parameters of the contact hole in the prior art, different measurement tools are required, and When testing whether the contact hole is completely etched, it is necessary to perform CMP on the conductive metal in the contact hole before testing. Once it is found that it does not meet the target specification, the filled conductive metal can only be removed and etched again

Not only is the process of measuring contact holes more complicated and time-consuming, but also reduces the production efficiency of the entire integrated circuit

Moreover, the height and sidewall angle of the contact hole cannot be measured in the prior art, and the lack of these data makes it impossible to reflect the situation of the contact hole well

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