HITACHI HIGH-TECH LAUNCHES WAFER SURFACE INSPECTION SYSTEM LS9300AD

Hitachi High-Tech Corporation announced the launch of the LS9300AD, a new system for inspecting the front and backside of non-patterned wafer surfaces for particles and defects. In addition to the conventional dark-field laser scattering detection of foreign material and defects, the LS9300AD is equipped with a new DIC (Differential Interference Contrast) inspection function that enables detection of irregular defects, even shallow, low-aspect microscopic defects. LS9300AD has the wafer edge grip method and rotating stage currently used in conventional products to enabling front and backside wafer inspection.

With the introduction of LS9300AD, Hitachi High-Tech enables reduced inspection costs and improved yield for semiconductor wafers and semiconductor device manufacturers by providing high-sensitivity and high-throughput detection of low-aspect microscopic defects.

Key New Technologies
In addition to conventional dark-field laser scattering, the LS9300AD has a new DIC optical system that enables both high-sensitivity, high-throughput inspection, and detection of low-aspect microscopic defects.

Built-in DIC Optics
While a dark-field laser irradiates the wafer surface, two beams separated from the DIC laser irradiate two different points on the wafer surface. When there is a difference in height on the wafer surface between the two points irradiated by the DIC laser, the phase contrast of the differential interference signal generated from the difference creates a high-contrast image of wafer surface unevenness. As a result, it is possible to detect the height, area, and position information of low-aspect microscopic defects on the wafer surface, which was difficult to detect using previous techniques.

New DIC-compatible Data Processing System
Along with the DIC optical system, a dark-field laser scattering optical system and a data processing system for defect information obtained through the DIC optical system are installed. This enables simultaneous output of dark-field laser scattering and inspection maps from the DIC optical system, enabling high-sensitivity inspection, even of low-aspect defect data, while maintaining a high inspection speed.

By offering LS9300AD, as well as metrology systems using electron beam technology and our optical wafer inspection systems, Hitachi High-Tech is working to meet customers' needs in processing, measurement, and inspection throughout the semiconductor manufacturing process.