An electron beam inspection system based on the projection imaging electron microscope was developed and the proof-of-concept system has been constructed and evaluated. The secondary electrons are projected through the projection imaging optics and imaged onto the image detection system. The projected secondary electron image is amplified by the microchannel plate and converted to an optical image by the fluorescent screen and detected by the 2048 element, eight-tap time delay and integration (TDI) image sensor. The stage is linearly moved in synchronism with the TDI signal output data rate, and then, the secondary electron image is continuously captured. The spatial resolution of around 0.1 μm has been obtained in this experiment. Several images obtained by the TDI imaging mode are also demonstrated.
This paper proposes a new thermally isolated pixel structure, having a twice-bent beam structure and eaves structure, suitable for high-resolution uncooled infrared (IR) focal-plane arrays (FPAs). It also describes the properties of test devices, fabricated to verify the effect of the new pixel structure. Although the pixel size of the test devices is 23.5 µm × 23.5 µm, which represents a smaller area by a factor of about 2.5 than the 37 µm × 37 µm pixel size for the 320 × 240 bolometer-type uncooled IRFPA, previously developed by the authors, the test devices have beams with almost the same length as in the previous IRFPA by utilizing the new beam structure. In addition, the cross-sectional area of the beam is reduced. Accordingly, the thermal conductance of the test devices can be reduced by a factor of about 2.5. The eaves structure, which is adopted to increase the fill factor of pixels, improves the responsivity by a factor of 1.3, which is consistent with our calculations. By utilizing the new thermally isolated pixel structure, the test devices with 23.5 µm pixels enable us to achieve thermal sensitivity equivalent to the previous 37 µm pixels.
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