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A five-color fluorescence-detection system for eight-channel plastic-microchip electrophoresis was developed. In the eight channels (with effective electrophoretic lengths of 10 cm), single-stranded DNA fragments were separated (with single-base resolution up to 300 bases within 10 min), and seventeen-loci STR genotyping for forensic human identification was successfully demonstrated. In the system, a side-entry laser beam is passed through the eight channels (eight A channels), with alternately arrayed seven sacrificial channels (seven B channels), by a technique called "side-entry laser-beam zigzag irradiation." Laser-induced fluorescence from the eight A channels and Raman-scattered light from the seven B channels are then simultaneously, uniformly, and spectroscopically detected, in the direction perpendicular to the channel array plane, through a transmission grating and a CCD camera. The system is therefore simple and highly sensitive. Because the microchip is fabricated by plastic-injection molding, it is inexpensive and disposable and thus suitable for actual use in various fields.

Although multi-point, multi-color fluorescence-detection systems are widely used in various sciences, they would find wider applications if they are miniaturized. Accordingly, an ultra-small, four-emission-point and four-color fluorescence-detection system was developed. Its size (space between emission points and a detection plane) is 15 × 10 × 12 mm, which is three-orders-of-magnitude smaller than that of a conventional system. Fluorescence from four emission points with an interval of 1 mm on the same plane was respectively collimated by four lenses and split into four color fluxes by four dichroic mirrors. Then, a total of sixteen parallel color fluxes were directly input into an image sensor and simultaneously detected. The emission-point plane and the detection plane (the image-sensor surface) were parallel and separated by a distance of only 12 mm. The developed system was applied to four-capillary array electrophoresis and successfully achieved Sanger DNA sequencing. Moreover, compared with a conventional system, the developed system had equivalent high fluorescence-detection sensitivity (lower detection limit of 17 pM dROX) and 1.6-orders-of-magnitude higher dynamic range (4.3 orders of magnitude).

With a measurement technique called television holographic interferometry, we investigated the internal stress generated at the initial deposition stage in electrolessly deposited Cu films on silicon substrates. In a region of film thickness less than 100 nm, two inflection points, at which the direction of stress was reversed, were observed on the film thickness-stress curve. From crosssectional transmission electron microscopy observation of these films, it was found that the films grew in the Volmer-Weber mode and that the above inflection points related to specific stages observed, such as islands growth, islands coalescence, the formation of continuous film, and grain growth.As thin solid films for practical use in microelectronics become thinner, the adherence of these films at the initial deposition stage has attracted attention. 1-4 Elucidation of the generation mechanism of the intrinsic stress is indispensable for improving the adherence of the films. Stress measurement at the initial deposition stage of various thin films has been suggested in the field of the dry process ͑physical vapor deposition, PVD͒. 5,6 In connection with this, we have already developed an in situ measurement technique for initial internal stress by television holographic interferometry and applied this technique to the wet deposition process ͑plating͒. 7 In this study, we aimed at relating the internal stress of electrolessly deposited Cu films on silicon substrates to the microstructure of the matching films revealed by cross-sectional transmission electron microscopy ͑TEM͒ observation. Figure 1 shows the optical apparatus for TV holographic interferometry. The incident Ar laser beam ͑ = 488 nm͒ is split into two beams, a reference beam to the charge-coupled device ͑CCD͒ camera and an object beam to the plating bath. The end deflection of the substrate is calculated from interference fringes imaged from the phase contrast between the reference beam and the object beam reflected by the reverse side of the substrate. The internal stress in the deposited film is obtained from Stoney's equation Experimentalin which E s is Young's modulus of the substrate, T is the substrate thickness, ␦ is the substrate end deflection, L is the substrate length, D is the film thickness, and s is Poisson's ratio of the substrate. The total energy required for deformation of the substrate is obtained by using the following equationin which G in is the internal strain energy of deposited film proportional to the substrate end deflection ␦. As the substrate for deposition, the test strip with dimensions of 120 mm in length, 7 mm in width, and 0.1 mm in thickness made from a silicon wafer ͓E&M, CZ,͑100͒, E s : 170 GPa, s :0.25͔ was used. Pd films with a thickness of 10 nm serving as a catalytic layer were deposited on Si substrates by electron beam vapor deposition. The plating solution consisted of 0.008 M copper sulfate ͑CuSO 4 ·5H 2 O͒, 0.24 M formaldehyde ͑HCHO, 37%͒, 0.14 M tetrasodium ethylenediaminetetraacetate ͑EDTA-4Na͒ was used for examination...

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