Method for determining photoetching process window

Abstract

The invention relates to a method for determining a photoetching process window and relates to the semiconductor integrated circuit process. The method is characterized in that firstly, selecting a plurality of types of graphs as graphs for judging an optimal exposure process window, then setting an energy-focal length matrix during exposure of a photoetching machine, exposing wafers, measuring line widths of the graphs of different exposure units, collecting line width sizes of the selected various types of graphs, forming a Poisson curve according to the line width sizes, removing the energy-focal length matrix corresponding to unreasonable angle data, and thereby accurately determining the optimal process window of photoetching. The method is advantaged in that new products are importedquickly, the production capacity is improved, manual judgment is not needed, and errors caused by manual judgment are avoided.

Description

technical field [0001] The invention relates to semiconductor integrated circuit technology, in particular to a method for determining a photolithography process window. Background technique [0002] From the advent of the first transistor, the development of semiconductor technology has been more than 50 years. According to Moore's law, the chip integration level doubles in 18 months, and the device size shrinks by 0.7 times every three years. Today, it still maintains a strong development With the development of integrated circuits from micron to nanoscale, the wavelength of light used in lithography has also changed from 436nm and 365nm in the near ultraviolet (NUV) range to 248nm and 193nm in the deep ultraviolet (DUV) range. At present, most chip manufacturing processes use 248nm and 193nm lithography technologies. As technology nodes advance, the lithography process window becomes smaller and smaller. [0003] Photolithography is one of the core processes in integrat...

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Problems solved by technology

[0004] The judgment of imaging quality is often related to the experience of the engineer. Judging based on personal experience may cause judgment errors, which will affect the exposure quality of the wafer.

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