Toshiba Markets New Focus Measurement Tool That Enhances Accuracy of Semiconductor Exposure Systems

7 January, 2004


Measurement errors reduced by a full 90%

Tokyo -- Toshiba Corporation today announced that it would market focus measurement technology that greatly improves the focal measurement performance of semiconductor exposure systems. The technology features an innovative photomask pattern that reduces measurement errors by approximately 90%.

The technology has a Japanese patent and was today awarded a U.S. patent. This extensive patent protection opens the way for Toshiba to promote marketing of a focus-measurement tool based on the technology.

Focus measurement tools measure the focal accuracy of semiconductor exposure systems or steppers, which expose circuit patterns on wafers. Toshiba's new tool is a focus test photomask in which grooves have been cut. Two thirds of the surface area between each groove is shielded with a chrome deposit, forming three distinct areas: the chrome shield, the uncoated glass area, and the grooved area. The latter two are the same width. When a beam of light is shone through the glass, the groove diffracts it, causing phase shift that can be used to measure the accuracy of the exposure on the silicon wafer. Perfect focus produces a straight line, while distortion from the true shows the degree of focal inaccuracy and the direction of the inaccuracy. The measurement error of the new tool is approximately 3 nanometers, by far the lowest recorded: current measurements have a tolerance of approximately 30 nanometers.

Commenting on the new tool. Mr. Shunichi Hiraki, General Manager, Process & Manufacturing Engineering Center of Semiconductor Company at Toshiba Corporation said. “Now that we have secured strong patent protection, we can develop the commercial potential of the focus measurement tool. Use in our facilities has already shown its value, and we expect to meet a positive response from device makers and stepper makers alike. We look forward to growing this new business area.”


Information in the press releases, including product prices and specifications, content of services and contact information, is current on the date of the press announcement,but is subject to change without prior notice.