Rca Inc.

Heinrich Meier

Hans P Kleinknecht

Michael T Gale

William Edward Ham

A two-dimensional knife edge mask comprised of an array of spaced periodic rectangular opaque regions (e.g., a chrome grating pattern layer deposited on one surface of a slide) separated by transparent different given spacing stripes between adjacent rectangular regions in each of the two orthogonal dimensions thereof, is linearly moved at a fixed velocity across an incident light spot, the direction of movement being oblique to the orthogonal dimensions of the rectangular regions and the distance of movement being sufficient to traverse at least one entire spacing strips in each of the two orthogonal dimensions. A photocell (which may be secured to the other side of the slide) senses the occulted light.

Apparatus for measuring parameters of light spots with a moving

The image transfer process in integrated circuit (IC) processes such as large scale integrated (LSI) device process manufacturing is monitored by optical measurements on a stage-by-stage basis by measuring a monitor specimen or test sample formed with a diffraction grating of a predetermined pattern having a strip width corresponding to the desired line widths of the wafers or masks being monitored. A beam of monochromatic light is scanned over the test sample to generate diffracted beams of various orders. Line width, line depth, line edge profile process errors can be determined by various combinations of the diffracted beams of the zero, first, second, etc., orders. The test sample is scanned to generate a display for data representing the diffracted beams. The parameter data can be stored for later use for quality control, process monitoring, circuit design parameters, and the like. Moreover, gross process errors are visually discernible on the monitor specimen.

Optical measurements of fine line parameters in integrated circuit

Optical monitoring of the lateral dimensions of a pattern disposed on a substrate in the form of a wafer or mask is accomplished by testing for the lateral dimensions of a diffraction grating test pattern disposed adjacent the pattern. A beam of monochromatic light such as from a laser is diffracted by the test pattern and detectors determine the intensity of the diffracted beams. The detectors are disposed in a plane orthogonal to the plane of the test pattern and to the direction of the grating lines. The detectors are selectively spaced from each other according to the periodicity d of the grating and the width of the grating lines a is determined from a relationship of the detected intensities of the beams.

Growing community of inventors

Urdorf, Switzerland

Heinrich Meier