The fine structure of polyethylene film has been investigated by using a high‐resolution scanning electron microscope equipped with a field emission source. The original film surface of a‐axis‐oriented blown polyethylene film and the surface of a necked region formed by drawing the film in the machine direction were observed. High magnification electron micrographs indicate that the basic unit of internal texture of this film consists of piled‐lamellae units, each pile containing three to ten lamellar crystal sheets. The piled‐lamellae unit acts as one body and does not separate into single lamellae during deformation. Many tie fibrils are formed between adjacent piled‐lamellae units, when the film is drawn in the machine direction. Although little attention has been given to this mechanism, it is important in deformation. This fact seems to be reflected in different shapes of the stress‐strain curves of films drawn the machine direction and perpendicular to it.

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Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

A backscattered electron image is widely used to observe crystalline contrast with a scanning electron microscope (SEM), because the backscattered electron image shows stronger contrast of crystalline orientations than a secondary electron image. In order to observe crystalline contrast from fine crystal grains in a very thin top layer, it is necessary to use low energy electrons in order to minimize penetration depth of the incident electrons in the specimens. However, there are two problems for observation of crystalline contrast with low energy electrons. The first is sensitivity; the sensitivity of a backscattered electron becomes lower as the electron energy is reduced. The second is resolution; a conventional backscattered electron detector is used at a relatively long working distance so that the resolution of the backscattered electron image may not be sufficient for the observation of fine crystal grains.The authors succeeded in solving these two problems by combining the newly developed backscattered electron detector with applying a deceleration mode to the latest FE SEM, in which the incident electrons were decelerated by applying a bias voltage on the specimen stage, and in observing the crystalline contrast in a thin recording layer of DVD-RAM in electron energy below 1kV. JEOL JSM-7500F was used for this observation.The deceleration mode accelerates the backscattered electrons generated from a specimen. The accelerated backscattered electrons are detected efficiently. A newly developed backscattered electron detector is mounted directly on the bottom of the objective lens pole-piece, so that a specimen can be observed at a shorter working distance to improve the resolution at lower electron energy. Fig. 1 shows comparison of backscattered electron images taken at the same landing voltage (1kV) but in the deceleration mode and normal mode. A specimen is gold particles evaporated on a carbon substrate. In the deceleration mode, image contrast is comparatively higher than that in the normal mode. Figure 2 shows a backscattered electron image obtained at 0.8kV. The specimen is the recoding surface of a DVD-RAM. Fine crystal grains with sizes from a few tens nm to 100 nm are observed in the area where no data are recorded. Oval patterns with a size of 0.4 µm x 0.7 µm indicate the amorphous area where data are recorded. CD

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.