SCATTEROMETRY MEASUREMENT SYSTEM AND METHOD

• Main Authors: GRUNZWEIG TZAHI, ANDY(ANDREW) HILL, BARRY LOEVSKY
• Format: Patent
• Language: English; Japanese
• Published: 23.05.2019
• Subjects: MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; TESTING

To provide a scatterometry measurement system that comprises an illumination beam having a vertical projection on a target plane comprising both a parallel component and a perpendicular component with respect to a target measurement direction.SOLUTION: A scatterometry measurement system includes: an objective lens that includes a central obscuration; and an illumination source that is configured to irradiate a scatterometry target with a first illumination beam at a first illumination angle and a second illumination beam at a second illumination angle, passing through the objective lens. The scatterometry target has a periodic structure located in at least two layers, and the objective lens is configured to collect at least one diffracted order from the first illumination beam and at least one diffraction order from the second illumination beam. The diffraction order from the first illumination beam and the diffraction order from the second illumination beam have a non-overlapping distribution in a portion of an imaging pupil plane not blocked by the central obscuration.SELECTED DRAWING: Figure 1 【課題】ターゲット測定方向に関して平行な成分と垂直な成分との両方を含むターゲット面上の垂直投影を有する照明ビームを含む、スキャトロメトリ測定システムを提供する。【解決手段】スキャトロメトリ測定システムは、中央オブスキュレーションを含む対物レンズと、スキャトロメトリターゲットを、対物レンズを通過させて第１の照明角の第１の照明ビームと第２の照明角の第２の照明ビームとで照射するように構成された照射源を備える。スキャトロメトリターゲットが少なくとも２層に配置された周期構造を有し、対物レンズが第１の照明ビームからの回折次数と第２の照明ビームからの回折次数とを収集するように構成され、第１の照明ビームからの回折次数と第２の照明ビームからの回折次数が、中央オブスキュレーションによって遮られない結像瞳面の部分においてオーバーラップしない分布を有する。【選択図】図１