Nikon Corporation

Koji Kaise

Toru Fujii

Yuji Imai

Kyoichi Suwa

Yasushi Mizuno

Hiroki Tateno

Toshio Tsukakoshi

Tsunehito Hayashi

An optical property measurement apparatus is equipped with an optical system unit that selectively places an opening section for passing illumination light, a microlens array for measuring wavefront aberration, and a polarization detection system for measuring a polarization state of the illumination light on an optical path of the illumination light. Accordingly an illumination shape and a size of an illumination optical system, wavefront aberration of a projection optical system and a polarization state of the illumination light can be measured together. Therefore, for example, even when exposure is performed with polarized illumination that is a type of modified illumination, highly-accurate exposure can be achieved by adjusting various optical systems based on the measurement results.

Optical property measurement apparatus and optical property measurement method, exposure apparatus and exposure method, and device manufacturing method

The aberration measurement method can determine an aberration from a width of an image of a pattern line on a resist or from a ratio of light quantities upon measuring an amount of the aberration of the image formed by an optical projection system. This method further can measure an amount of a deviation of a position of the image of the pattern on the resist so that it can solve laborious work otherwise required by conventional technology that uses a complicated microscope such as a scanning-type electronic microscope. Moreover, the aberration can be determined by measuring a pitch width of a whole line-and-space pattern containing wedge-shaped lines or lengths of the wedge-shaped lines. This does not require to learn the absolute position of the image because a difference between the amounts of deviation of the positions of the different pattern images so that no such complicated microscope is not required. In addition, as an error of superimposition of the patterns can be corrected by an image of a comparison pattern, no laborious attention is any longer paid to alignment of the patterns, thereby allowing a measurement of the amount of the aberration with an optical projection system or by other means at a high speed and with high precision.

Method for the measurement of aberration of optical projection system

A measuring method comprises a first step to expose by the irradiation of a predetermined energy ray onto the resist layer of a photosensitive board a first mask pattern having at least two linear pattern portions arranged substantially in axial symmetry with respect to a straight line in a predetermined first direction and inclined at a predetermined angle to the straight line in the first direction, a second step to overlap with the first mask pattern image exposed on the resist layer a second mask pattern formed by the linear patterns which extend in a second direction substantially perpendicular to the first direction by relatively driving the second mask pattern in a predetermined amount in the first direction for exposure, and a third step to measure an interval in the second direction between at least two wedge-shaped resist images formed by the overlapped portions of the first mask pattern and the second mask pattern. The difference between the measured value and a predetermined standard value of the interval in the second direction may be obtained to determined a positional deviation.

Measuring method and exposure apparatus

Growing community of inventors

Kumagaya, Japan

Koji Kaise