All-in-one photomask quality control tool
Photomasks are the original plates used to transfer circuit patterns, so photomask quality greatly impacts final product quality. The DR-8000 is able to measure the line widths, or critical dimensions (CDs), of intricate circuit patterns with high nano-order accuracy and repeatability. In addition to the CD measurement function, the DR-8000 can also be equipped with functions for measuring transmittance and phase shift, both key parameters for intricate circuit patterns, and for observing the aerial image during exposure, which is essential for photomask development and quality assurance.

1. CD measurement with nano-order repeatability
   
   ■CD measurement
   A dedicated UV objective lens specially designed for CD measurement and uniform UV transillumination ensures high resolution and reliability. Consistent and accurate measurements are achieved thanks to a powerful edge determination algorithm and SCREEN’s unique focus system.
   SCREEN has developed a multi-edge CD measurement function that enables measurement of a variety of designs, including line and space (L&S), hole, and resist patterns, as well as mask patterns having complex optical profiles with unique characteristics in the pattern film structure.
   
2. Enables aerial image exposure observation and measurement of transmittance and phase shift, all crucial for photomask development and quality assurance
   
   ■OR function (measurement of aerial images)
   An OR (optical reader) function performs observation and measurement of aerial images when transferring circuit patterns using photomasks. The OR function uses light of the same wavelength as the exposure system and enables setting of the exposure system parameters “NA” and “σ”. The transfer result at the time of exposure is simulated using light without having to use the exposure system. For example, by precisely measuring the intensity and dimensions of the aerial image to assess transfer performance during exposure, it is possible to quantitatively evaluate pattern defects.
   
   ■Phase shift measurement function
   A phase shift mask is a semiconductor miniaturization technology that utilizes a light interference effect. Measuring the amount of phase shift, which is an index of interference, is essential for quality assurance of phase shift masks. The DR-8000 uses SCREEN’s unique double-slit method to measure the phase shift at the exposure wavelength. Combining a unique algorithm with one-shot image acquisition of the double slit interference fringes enables highly accurate phase shift measurements.
   
   ■Transmittance measurement function
   Facilitates measurement of the transmittance of halftone, phase shift, and other masks. Use of an LED light source with exceptionally stable intensity combined with light source intensity correction technology ensures high repeatability (3 σ: 0.1% or less).
   
   ■Review function
   Enables defects to be reviewed at high resolution based on the coordinate data output from the defect detection system. This review can also be performed for photomasks after pellicle attachment.
3. Film thickness measurement function
   We have a wealth of experience in handling substrates other than photomasks. Demos/evaluations using wafers and glass substrates can be provided. Please feel free to contact a SCREEN representative.
   
   ■Lineup
   Photomasks for semiconductors：Compatible with quartz glass and soda lime glass photomasks (4, 5, 6, 7, and 9 inches)
   Photomasks for large panels：Handles large photomask substrates (G6, G8, and G10) with a proven track record for transfer using industrial robots
   
   Special applications
   Wafers (example): 100 to 300 mm in diameter (transparent or opaque)
   Glass substrates (example): 600 x 600 mm