Optical proximity correction

Optical proximity correction (OPC, English, German as: optical proximity correction ) in semiconductor technology, a method for correction or reduction of aberrations of structures in photolithographic processes. It belongs to the group of resolution enhancement techniques ( engl.: resolution enhancement technique, RET).

Description

In the photolithographic imaging of a structure with dimensions in the range and below the wavelength used, as for several years it is the case in microelectronics (eg diffraction ) are mainly wave-optical effects aberrations. The OPC tried these effects, such as line end shortening, edge rounding or widening of adjacent lines, to be compensated by additional structures on the photomask. Correction to these structures can also be used a plurality of stages include:

• Extended line ends (English: end line extensions ) to correct line truncations
• Partially spread lines (English: end line extensions ) to the width correction
• Additional lines on the side (English: subresolution scattering bar ) to the width correction
• T-shaped structures at the line ends (English: hammerheads ) in order to correct rounding of the edges
• Extra or missing rectangular / square areas (English: serifs ) to correct rounding of the edges additional areas at the convex corners
• Negative (lack of) areas of concave corners